WorldWideScience

Sample records for mild steel surface

  1. Characterization of mild steel pre rusted and rust converted surfaces through advanced electrochemical analysis

    International Nuclear Information System (INIS)

    Riaz, F.; Rizvi, Z.H.; Arshad, K.

    2008-01-01

    The present work evaluates the anti corrosive properties of a tannin based rust converter applied on the pre rusted steel coupons as compared with the grit blasted bare metal and pre rusted steel coupons. The mechanism and the corrosion control behaviour of the rust converter are characterized and monitored using EIS technique. The result suggested that when the tannin based rust converter applied on the pre rusted/corroded coupon, the protection properties of the mild steel coupon clearly improved because of the more compact conversion layer being formed on the coupon. It is inferred that the rust converter can be applied on the pre rusted samples as an alternative technique to the surface preparation for protection purpose. (author)

  2. Correlation between Surface Roughness Characteristics in CO2 Laser Cutting of Mild Steel

    Directory of Open Access Journals (Sweden)

    M. Radovanović

    2012-12-01

    Full Text Available CO2 laser oxygen cutting of mild steel is widely used industrial application. Cut surface quality is a very important characteristic of laser cutting that ensures an advantage over other contour cutting processes. In this paper mathematical models for estimating characteristics of surface quality such as average surface roughness and ten-point mean roughness in CO2 laser cutting of mild steel based on laser cutting parameters were developed. Empirical models were developed using artificial neural networks and experimental data collected. Taguchi’s orthogonal array was implemented for experimental plan. From the analysis of the developed mathematical models it was observed that functional dependence between laser cutting parameters, their interactions and surface roughness characteristics is complex and non-linear. It was also observed that there exist region of minimal average surface roughness to ten-point mean roughness ratio. The relationship between average surface roughness and ten-point mean roughness was found to be nonlinear and can be expressed with a second degree polynomial.

  3. Surface protection of mild steel in acidic chloride solution by 5-Nitro-8-Hydroxy Quinoline

    Directory of Open Access Journals (Sweden)

    R. Ganapathi Sundaram

    2018-03-01

    Full Text Available The effect of commercially available quinoline nucleus based pharmaceutically active compound 5-Nitro-8-Hydroxy Quinoline (NHQ against the corrosion of mild steel (MS in 1 M acidic chloride (HCl solution was investigated by chemical (weight loss – WL and electrochemical (Tafel polarization, Linear polarization and Electrochemical impedance spectroscopy techniques. From all the four methods, it is inferred that the percentage of inhibition efficiency increases with increasing the inhibitor concentration from 50 to 300 ppm. The adsorption behavior of inhibitor obeyed through Langmuir isotherm model. Thermodynamic parameters were also calculated and predict that the process of inhibition is a spontaneous reaction. EIS technique exhibits one capacitive loop indicating that, the corrosion reaction is controlled by charge transfer process. Tafel polarization studies revealed that the investigated inhibitor is mixed type and the mode of adsorption is physical in nature. The surface morphologies were examined by FT-IR, SEM and EDX techniques. Theoretical quantum chemical calculations were performed to confirm the ability of NHQ to adsorb onto mild steel surface. Keywords: Acidic chloride solution, MS, NHQ, WL, SEM, FT-IR

  4. Simulation of surface profile formation in oxygen laser cutting of mild steel due to combustion cycles

    Energy Technology Data Exchange (ETDEWEB)

    Ermolaev, G V; Kovalev, O B [Khristianovich Institute of Theoretical and Applied Mechanics, Siberian Branch of Russian Academy of Sciences, Institutskaya Str 4/1, Novosibirsk, 630090 (Russian Federation)

    2009-09-21

    A physicomathematical model of cyclic iron combustion in an oxygen flow during oxygen laser cutting of metal sheets is developed. The combustion front is set into motion by focused laser radiation and a heterogeneous oxidation reaction in oxygen. The burning rate is limited by oxygen supply from the gas phase towards the metal surface, and the interface motion depends on the local temperature. A 3D numerical simulation predicts wavy structures on the metal surface; their linear sizes depend on the scanning speed of the laser beam, the thickness of the produced liquid oxide film and the parameters of the oxygen jet flow. Simulation results help in understanding the mechanism of striation formation during oxygen gas-laser cutting of mild steel and are in qualitative agreement with experimental findings.

  5. Characterisation of rust surfaces formed on mild steel exposed to marine atmospheres using XRD and SEM/Micro-Raman techniques

    International Nuclear Information System (INIS)

    Fuente, D. de la; Alcántara, J.; Chico, B.; Díaz, I.; Jiménez, J.A.; Morcillo, M.

    2016-01-01

    Highlights: • SEM/Micro-Raman is very useful for characterizing rust phases morphologies. • SEM/Micro-Raman enables unequivocal rust phases identification. • γ-FeOOH basically presents two types of morphologies: globular and laminar. • Fe 3 O 4 presents two morphologies: flat patches and black doughnut-type formations. • β-FeOOH presents highly porous morphologies comprised by fine prismatic crystals. - Abstract: The exposure of mild steel to marine atmospheres gives rise to the formation of various corrosion products, mainly lepidocrocite, goethite, magnetite and akaganeite. In this study, Grazing Incidence X-Ray Diffraction, Micro-X-Ray Diffraction and Scanning Electron Microscopy/Micro-Raman are used to characterise rust layer surfaces and to identify the principal component rust phases and their morphology. The main conclusion reached is that lepidocrocite is preferentially located on the outermost surface while magnetite and akaganeite form mostly close to base steel. The Scanning Electron Microscopy/Micro-Raman technique has been very useful for characterising (identifying) the wide variety of morphologies presented by the rust phases.

  6. Synthesis and corrosion inhibition application of NATN on mild steel surface in acidic media complemented with DFT studies

    Directory of Open Access Journals (Sweden)

    Shaimaa B. Al-Baghdadi

    2018-03-01

    Full Text Available The corrosion inhibition effectiveness of thiosemicarbazide compound, namely 3-nitro-5-(2-amino-1,3,4-thiadiazolylnitrobenzene (NATN, on mild steel in 1 M hydrochloric acid media has been investigated by weight loss technique. The results exhibit that the corrosion ratio of mild steel was reduced regarding to adding NATN. The corrosion inhibition rate for the NATN was 92.3% at the highest investigated NATN concentration. From the weight loss results it could be concluded that NATN with sulfur, nitrogen and oxygen atoms has clarified best corrosion inhibition achievement comparing to 3,5-dinitrobenzoic acid. Regarding to theoretical studies, DFT was employee to figured geometrical structure and electronic characteristics on NATN. The investigation have been extensive to the HOMO and LUMO analysis to evaluate the energy gap, Ionization potential, Electron Affinity, Global Hardness, Chemical Potential, Electrophilicity, Electronegativity and Polarizability. Keywords: NATN, Mild steel, Weight loss, Dinitrobenzoic acid

  7. Corrosion inhibition of mild steel by Capsicum annuum fruit paste

    Directory of Open Access Journals (Sweden)

    Chandan M. Reddy

    2016-09-01

    Full Text Available The anti-corrosive property of Capsicum annuum fruit paste (CFP on mild steel was investigated. Weight loss and SEM analysis showed that the aqueous and ethanolic solutions of CFP exhibits excellent corrosion inhibition in 2 M HCl. Contact angle, surface atomic composition and FTIR studies verified the presence of an organic film on the mild steel surface. The FTIR spectra also indicated the formation of active compound-Fe complex. CFP thus shows potential as an inexpensive environment friendly corrosion inhibitor for mild steel.

  8. Synthesis and corrosion inhibition application of NATN on mild steel surface in acidic media complemented with DFT studies

    Science.gov (United States)

    Al-Baghdadi, Shaimaa B.; Hashim, Fanar G.; Salam, Ahmed Q.; Abed, Talib K.; Gaaz, Tayser Sumer; Al-Amiery, Ahmed A.; Kadhum, Abdul Amir H.; Reda, Khalid S.; Ahmed, Wahab K.

    2018-03-01

    The corrosion inhibition effectiveness of thiosemicarbazide compound, namely 3-nitro-5-(2-amino-1,3,4-thiadiazolyl)nitrobenzene (NATN), on mild steel in 1 M hydrochloric acid media has been investigated by weight loss technique. The results exhibit that the corrosion ratio of mild steel was reduced regarding to adding NATN. The corrosion inhibition rate for the NATN was 92.3% at the highest investigated NATN concentration. From the weight loss results it could be concluded that NATN with sulfur, nitrogen and oxygen atoms has clarified best corrosion inhibition achievement comparing to 3,5-dinitrobenzoic acid. Regarding to theoretical studies, DFT was employee to figured geometrical structure and electronic characteristics on NATN. The investigation have been extensive to the HOMO and LUMO analysis to evaluate the energy gap, Ionization potential, Electron Affinity, Global Hardness, Chemical Potential, Electrophilicity, Electronegativity and Polarizability.

  9. Melamine derivatives as effective corrosion inhibitors for mild steel in acidic solution: Chemical, electrochemical, surface and DFT studies

    Science.gov (United States)

    Verma, Chandrabhan; Haque, J.; Ebenso, Eno E.; Quraishi, M. A.

    2018-06-01

    In present study two condensation products of melamine (triazine) and glyoxal namely, 2,2-bis(4,6-diamino-1,3,5-triazin-2-ylamino)acetaldehyde (ME-1) and (N2,N2‧E,N2,N2‧E)-N2,N2‧-(ethane-1,2-diylidene)-bis-(1,3,5-triazine-2,4,6-triamine) (ME-2) are tested as mild steel corrosion inhibitors in acidic solution (1M HCl). The inhibition efficiency of ME-1 and ME-2 increases with increase in their concentrations and maximum values of 91.47% and 94.88% were derived, respectively at 100 mgL-1 (34.20 × 10-5 M) concentration. Adsorption of ME-1 and ME-2 on the surface of metal obeyed the Langmuir adsorption isotherm. Polarization investigation revealed that ME-1 and ME-2 act as mixed type inhibitors with minor cathodic prevalence. The chemical and electrochemical analyses also supported by surface characterization methods where significant smoothness in the surface morphologies was observed in the images of SEM and AFM spectra. Several DFT indices such as EHOMO and ELUMO, ΔE, η, σ, χ, μ and ΔN were derived for both ME-1 and ME-2 molecules and correlated with experimental results. The DFT studies have also been carried out for protonated or cationic form of the inhibitor molecules by considering that in acidic medium the heteroatoms of organic inhibitors easily undergo protonation. The experimental and density functional theory (DFT) studies (neutral and protonated) were in good agreement.

  10. Pulse electrodeposition of self-lubricating Ni–W/PTFE nanocomposite coatings on mild steel surface

    Energy Technology Data Exchange (ETDEWEB)

    Sangeetha, S. [Advanced Nanocomposite Coatings Laboratory, Department of Industrial Chemistry, Alagappa University, Karaikudi 630 003 (India); Kalaignan, G. Paruthimal, E-mail: pkalaignan@yahoo.com [Advanced Nanocomposite Coatings Laboratory, Department of Industrial Chemistry, Alagappa University, Karaikudi 630 003 (India); Anthuvan, J. Tennis [M. Kumarasamy College of Engineering, Karur, Tamil Nadu (India)

    2015-12-30

    Graphical abstract: - Highlights: • PTFE polymer inclusion on Ni–W alloy matrix was electrodeposited by pulse current method. • Tribological properties and electrochemical characterizations of the nanocomposite coatings were analyzed. • The hydrophobic behaviour of Ni–W/PTFE nanocomposite coating was measured. • Ni–W/PTFE nanocomposite coatings have showed superior tribological properties and corrosion resistance relative to that of the Ni–W alloy matrix. - Abstract: Ni–W/PTFE nanocomposite coatings with various contents of PTFE (polytetafluoroethylene) particles were prepared by pulse current (PC) electrodeposition from the Ni–W plating bath containing self lubricant PTFE particles to be co-deposited. Co-deposited PTFE particulates were uniformly distributed in the Ni–W alloy matrix. The coatings were characterized by Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Analysis (EDAX), X-ray Diffractometry (XRD) and Vicker's micro hardness tester. Tafel Polarization and electrochemical Impedance methods were used to evaluate the corrosion resistance behaviour of the nanocomposite coatings in 3.5% NaCl solution. It was found that, the Ni–W/PTFE nanocomposite coating has better corrosion resistance than the Ni–W alloy coating. Surface roughness and friction coefficient of the coated samples were assessed by Mitutoyo Surftest SJ-310 (ISO1997) and Scratch tester TR-101-M4 respectively. The contact angle (CA) of a water droplet on the surface of nanocomposite coating was measured by Optical Contact Goniometry (OCA 35). These results indicated that, the addition of PTFE in the Ni–W alloy matrix has resulted moderate microhardness, smooth surface, less friction coefficient, excellent water repellency and enhanced corrosion resistance of the nanocomposite coatings.

  11. Spectroscopic characterisation of iodine deposits on 18%Cr/8%Ni and mild steel surfaces oxidised in CO2/CH3I gas mixtures

    International Nuclear Information System (INIS)

    Tyler, J.W.

    1987-08-01

    An understanding and quantification of iodine-131 attenuation within the gas circuit of a Commercial Advanced Gas-cooled Reactor is required for reactor safety assessments. To this end it is desirable to identify the chemical state of iodine in the gas phase or when deposited on reactor surfaces. Samples of 18%Cr/8%Ni and mild steel pipe, with iodine deposited on their surfaces following oxidation in CO 2 /CH 3 I gas mixtures, have been characterised in the present work using a variety of different spectroscopic techniques including X-ray photoelectron spectroscopy, scanning electron microscopy, energy dispersive X-ray analysis, scanning Auger microscopy and X-ray diffraction. The chemical nature of the deposited iodine has been determined by X-ray photoelectron spectroscopy to be a metal iodide by correlating I 3d binding energies with those obtained from well characterised standards; the binding energies of the ejected I 3d photoelectrons being sensitive to the chemical environment experienced by the iodine atoms. The distribution of iodine throughout the oxide layers formed on these steels was determined by repeated cycles of argon-ion bombardment and analysis to build up an elemental depth profile whilst at the same time determining the chemical state of the elements present. Differences in oxide composition and morphology are discussed in relation to the deposition behaviour observed on 18%Cr/8%Ni and mild steel and it is suggested that gradual incorporation of the iodine occurs throughout the oxidation/deposition period. (U.K.)

  12. Steel fiber replacement of mild steel in prestressed concrete beams

    Science.gov (United States)

    2010-10-01

    In traditional prestressed concrete beams, longitudinal prestressed tendons serve to resist bending moment and : transverse mild steel bars (or stirrups) are used to carry shear forces. However, traditional prestressed concrete I-beams : exhibit earl...

  13. Steel fiber replacement of mild steel in prestressed concrete beams.

    Science.gov (United States)

    2011-01-01

    In traditional prestressed concrete beams, longitudinal prestressed tendons serve to resist bending moment and transverse mild : steel bars (or stirrups) are used to carry shear forces. However, traditional prestressed concrete I-beams exhibit early-...

  14. Elimination of striation in laser cutting of mild steel

    International Nuclear Information System (INIS)

    Sobih, M; Crouse, P L; Li, L

    2007-01-01

    High-power laser cutting is extensively used in many industrial applications. An important weakness of this process is the formation of striations (regular lines down the cut surface), which affect the quality of the surfaces produced. The elimination of striation formation is of considerable importance, since it could open up a variety of novel high-precision applications. This study presents the results of oxygen-assisted laser cutting of EN43 mild steel sheets, using a high-power fibre laser. Striation-free laser cuts are demonstrated for cutting 1 and 2 mm thick mild steel sheets. The optimal operating windows are presented and a mathematical method is proposed to estimate the critical speed at which striation-free cut can be obtained

  15. Elimination of striation in laser cutting of mild steel

    Energy Technology Data Exchange (ETDEWEB)

    Sobih, M; Crouse, P L; Li, L [Laser Processing Research Centre, School of Mechanical, Aerospace and Civil Engineering, University of Manchester, Sackville Street Building, PO Box 88, Manchester M60 1QD (United Kingdom)

    2007-11-21

    High-power laser cutting is extensively used in many industrial applications. An important weakness of this process is the formation of striations (regular lines down the cut surface), which affect the quality of the surfaces produced. The elimination of striation formation is of considerable importance, since it could open up a variety of novel high-precision applications. This study presents the results of oxygen-assisted laser cutting of EN43 mild steel sheets, using a high-power fibre laser. Striation-free laser cuts are demonstrated for cutting 1 and 2 mm thick mild steel sheets. The optimal operating windows are presented and a mathematical method is proposed to estimate the critical speed at which striation-free cut can be obtaine000.

  16. Recent Natural Corrosion Inhibitors for Mild Steel: An Overview

    Directory of Open Access Journals (Sweden)

    Marko Chigondo

    2016-01-01

    Full Text Available Traditionally, reduction of corrosion has been managed by various methods including cathodic protection, process control, reduction of the metal impurity content, and application of surface treatment techniques, as well as incorporation of suitable alloys. However, the use of corrosion inhibitors has proven to be the easiest and cheapest method for corrosion protection and prevention in acidic media. These inhibitors slow down the corrosion rate and thus prevent monetary losses due to metallic corrosion on industrial vessels, equipment, or surfaces. Inorganic and organic inhibitors are toxic and costly and thus recent focus has been turned to develop environmentally benign methods for corrosion retardation. Many researchers have recently focused on corrosion prevention methods using green inhibitors for mild steel in acidic solutions to mimic industrial processes. This paper provides an overview of types of corrosion, corrosion process, and mainly recent work done on the application of natural plant extracts as corrosion inhibitors for mild steel.

  17. Reliability and performance evaluation of stainless and mild steel ...

    African Journals Online (AJOL)

    Reliability and performance of stainless and mild steel products in methanolic and aqueous sodium chloride media have been investigated. Weight-loss and pre-exposure methods were used. There was a higher rate of weight-loss of mild steels and stainless steels in 1% HCl methanolic solution than in aqueous NaCl ...

  18. Influence of non-edible vegetable based oil as cutting fluid on chip, surface roughness and cutting force during drilling operation of Mild Steel

    Science.gov (United States)

    Susmitha, M.; Sharan, P.; Jyothi, P. N.

    2016-09-01

    Friction between work piece-cutting tool-chip generates heat in the machining zone. The heat generated reduces the tool life, increases surface roughness and decreases the dimensional sensitiveness of work material. This can be overcome by using cutting fluids during machining. They are used to provide lubrication and cooling effects between cutting tool and work piece and cutting tool and chip during machining operation. As a result, important benefits would be achieved such longer tool life, easy chip flow and higher machining quality in the machining processes. Non-edible vegetable oils have received considerable research attention in the last decades owing to their remarkable improved tribological characteristics and due to increasing attention to environmental issues, have driven the lubricant industry toward eco friendly products from renewable sources. In the present work, different non-edible vegetable oils are used as cutting fluid during drilling of Mild steel work piece. Non-edible vegetable oils, used are Karanja oil (Honge), Neem oil and blend of these two oils. The effect of these cutting fluids on chip formation, surface roughness and cutting force are investigated and the results obtained are compared with results obtained with petroleum based cutting fluids and dry conditions.

  19. Factors controlling nitrate cracking of mild steel

    International Nuclear Information System (INIS)

    Donovan, J.A.

    1977-01-01

    Nitrite and hydroxide ions inhibit the growth of nitrate stress corrosion cracks in mild steel. Crack growth measurements showed that sufficient concentrations of nitrite and hydroxide ions can prevent crack growth; however, insufficient concentrations of these ions did not influence the Stage II growth rate or the threshold stress intensity, but extended the initiation time. Stage III growth was discontinuous. Oxide formed in the grain boundaries ahead of the crack tip and oxide dissolution (Stage II) and fracture (Stage III) are the proposed mechanisms of nitrate stress corrosion crack growth

  20. Inhibition of mild steel corrosion using Jatropha Curcas leaf extract

    Directory of Open Access Journals (Sweden)

    OLORUNFEMI MICHAEL AJAYI

    2014-05-01

    Full Text Available Jatropha Curcas leaf was investigated as a green inhibitor on the degradation of mild steel in 4 M HCl and 4 M H2SO4 aqueous solutions using gasometric technique. Mild steel coupons of dimension 2 × 1.5 cm were immersed in test solutions of uninhibited acid and also those with extract concentrations of 4 ml, 6 ml, 8 ml and 10 ml at 30 oC, for up to 30 minutes. The results showed that as the concentration of the extract increases, there was reduction in the corrosion rate. As the extract concentration increased from 4 ml to 10 ml at 30 minutes exposure, the volume of hydrogen gas evolved decreased from 19.1 cm3 to 11.2 cm3 in H2SO4 medium, while it reduced to 5 cm3 from 9 cm3 in HCl medium. Also, the metal surface-phytoconstituent interaction mechanism showed that 6 minutes is the best exposure time for the adsorption of the extract in both acidic media. The Jatropha Curcas leaf extract was adsorbed on the mild steel surface to inhibit corrosion, while the experimental data obtained at 30 minutes exposure in both acidic media were well fitted with the Langmuir adsorption isotherm. Hence, Jatropha Curcas leaf extract is a good and safe inhibitor in both acidic solutions.

  1. The enhancing power of iodide on corrosion prevention of mild steel in the presence of a synthetic-soluble Schiff-base: Electrochemical and surface analyses

    International Nuclear Information System (INIS)

    Lashgari, Mohsen; Arshadi, Mohammad-Reza; Miandari, Somaieh

    2010-01-01

    The inhibitory action of N,N'-1,3-propylen-bis(3-methoxysalicylidenimine) {PMSI} on mild steel corrosion in sulfuric acid medium was investigated through electrochemical methods and evaluations based on infrared spectroscopy and scanning electron micrographs. The studies revealed that the molecule is a good mixed-type inhibitor (mostly anodic), acts as a multi-dentate ligand and repels the corrosive agents by hydrophobic forces. Its adsorption on metal surface has a physicochemical nature and obeys the Langmuir isotherm. At a critical (optimum) concentration, an anomalous inhibitory behavior was observed and interpreted at microscopic level by means of desorption/adsorption process and horizontal ↔vertical hypothesis. The addition of iodide into acid moreover causes a synergistic influence, a substantial enhancement on inhibitory performance. Finally, using isolated inhibitor calculations at B3LYP/6-31G + (d,p) level of theory, the equilibrium geometry of PMSI was determined and the energy required for hindrance avoidance was predicted.

  2. Laser melting treatment of Ni-P surface alloys on mild steel. Influence of initial coating thickness and laser scanning rate

    Directory of Open Access Journals (Sweden)

    García-Alonso, M. C.

    1997-08-01

    Full Text Available Different thickness Ni-P coatings deposited on mild steel are submitted to laser surface melting at different scanning rates. The microstructure of the alloys is characterized by optical and scanning electron microscopy and microprobe analysis. It is shown that both the initial coating thickness and the laser scanning rate have an influence on the shape, extent and size of the different structures resulting from the solidification process. Thus, when the laser scanning rate increases a progressive refinement of the structure takes place that could even totally block the dendritic growth produced during solidification for a high initial coating thickness.

    Recubrimientos de Ni-P, con distinto espesor, depositados sobre un acero microaleado fueron tratados con láser a diferentes velocidades de barrido. La microestructura, tanto del recubrimiento como del acero base, ha sido caracterizada por microscopía óptica y electrónica y por microanálisis. En el proceso de solidificación se han obtenido distintas estructuras que varían en cuanto a la forma, extensión y tamaño dependiendo del espesor inicial de recubrimiento y de la velocidad de barrido del haz láser. A medida que la velocidad del haz aumenta, se produce un refinamiento progresivo de la microestructura dendrítica y, en casos extremos de alto espesor de recubrimiento y velocidades grandes, este crecimiento dendrítico se bloquea.

  3. Corrosion behavior of duplex polyaniline/epoxy coating on mild steel in 3% NaCl

    Directory of Open Access Journals (Sweden)

    Gvozdenović Milica M.

    2005-01-01

    Full Text Available The corrosion behavior and thermal stability of epoxy coatings electrodeposited on mild steel and on mild steel with electrochemically deposited polyaniline (PANI film were investigated by electrochemical impedance spectroscopy (EIS and thermo gravimetric analysis (TGA. The aim of the paper was to present new findings on the corrosion protection of mild steel by a duplex PANI/-epoxy coating in 3% NaCI solution and to determine the effect of thin PANI film on the protective properties of the coating. PANI film was deposited electrochemically on mild steel from an aqueous solution of 0.5 mol dm"3 sodium benzoate and 0.1 mol dm"3 aniline at a constant current density of 1.5 mA cm"2. Non-pigmented epoxy coatings on mild steel and on mild steel with PANI film were obtained by cathodic electrode position at constant voltage and stirring conditions. The resin concentration in the electrode position bath was 10 wt.% solid dispersion in water at pH 5.7. The applied voltage was 250 V, the temperature 26°C and the deposition time 3 min. It was shown that thin PANI film could be used to modify the surface of mild steel prior to epoxy coating deposition, due to the increased corrosion protection of a duplex PANI/epoxy coating comparing to an epoxy coating on mild steel in 3% NaCl solution.

  4. Striation-free fibre laser cutting of mild steel sheets

    Energy Technology Data Exchange (ETDEWEB)

    Sobih, M.; Crouse, P.L.; Li, L. [University of Manchester, Laser Processing Research Centre, School of Mechanical, Aerospace and Civil Engineering, Sackville Street Building, P.O. Box 88, Manchester (United Kingdom)

    2008-01-15

    High-power laser cutting is extensively used in many industrial applications. An important weakness of this process is the formation of striations, i.e. regular lines on the cut surface, which lowers the quality of the surfaces produced. The elimination of striation formation is thus of considerable importance, since it could open a variety of novel high-precision applications. This study presents the initial results of a laser cutting study using a 1 kW single-mode fibre laser, a relative newcomer in the field of laser metal cutting. Striation-free laser cuts are demonstrated when cutting 1 mm thick mild steel sheets. (orig.)

  5. Atmospheric corrosion of mild steel in Oman

    Energy Technology Data Exchange (ETDEWEB)

    Gismelseed, Abbasher, E-mail: abbasher@squ.edu.om; Al-Harthi, S. H.; Elzain, M.; Al-Rawas, A. D.; Yousif, A.; Al-Saadi, S.; Al-Omari, I.; Widatallah, H.; Bouziane, K. [College of Science, Department of Physics (Oman)

    2006-01-15

    A systematic study has been made of the initial corrosion products which form on mild steel capons exposed near the coastal region of Oman and at some industrial areas. The phases and compositions of the products formed at different periods of exposure were examined by using Moessbauer spectroscopy (295 and 78 K) and X-ray diffraction (XRD) techniques. The results show that lepidocorcite and maghemite are early corrosion products and goethite starts to form after 2 months of metal exposure to the atmosphere. Akaganeite is an early corrosion product but it forms in marine environments only, which reflects the role of chlorine effect in the atmosphere. The 12 months coupons showed the presence of goethite, lepidocorcite and maghemite, but no akaganeite being seen in the products of one of the studied areas.

  6. Atmospheric corrosion of mild steel in Oman

    International Nuclear Information System (INIS)

    Gismelseed, Abbasher; Al-Harthi, S. H.; Elzain, M.; Al-Rawas, A. D.; Yousif, A.; Al-Saadi, S.; Al-Omari, I.; Widatallah, H.; Bouziane, K.

    2006-01-01

    A systematic study has been made of the initial corrosion products which form on mild steel capons exposed near the coastal region of Oman and at some industrial areas. The phases and compositions of the products formed at different periods of exposure were examined by using Moessbauer spectroscopy (295 and 78 K) and X-ray diffraction (XRD) techniques. The results show that lepidocorcite and maghemite are early corrosion products and goethite starts to form after 2 months of metal exposure to the atmosphere. Akaganeite is an early corrosion product but it forms in marine environments only, which reflects the role of chlorine effect in the atmosphere. The 12 months coupons showed the presence of goethite, lepidocorcite and maghemite, but no akaganeite being seen in the products of one of the studied areas.

  7. Anticorrosion potential of hydralazine for corrosion of mild steel in ...

    African Journals Online (AJOL)

    Anticorrosion potential of mild steel by Hydralazine as corrosion inhibitor for mild steel in 1M hydrochloric acid was investigated by chemical and electrochemical measurements at 303-333 K temperature. The maximum inhibition efficiency of inhibitor by Weight loss method is around 90%, Tafel polarization method is ...

  8. Mechanical behaviour of Zn-Fe alloy coated mild steel

    International Nuclear Information System (INIS)

    Panagopoulos, C.N.; Georgiou, E.P.; Agathocleous, P.E.; Giannakopoulos, K.I.

    2009-01-01

    Zinc alloy coatings containing various amounts of Fe were deposited by electrodeposition technique on a mild steel substrate. The concentration of Fe in the produced alloy coatings ranged from 0 to 14 wt.%, whereas the thickness of the coatings was about 50 μm. Structural and metallurgical characterization of the produced coatings was performed with the aid of X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) techniques. This study aims in investigating the mechanical behaviour of Zn-Fe coated mild steel specimens, as no research investigation concerning the tensile behaviour of Zn alloy coated ferrous alloys has been reported in the past. The experimental results indicated that the ultimate tensile strength of the Zn-Fe coated mild steel was lower than the bare mild steel. In addition, the ductility of the Zn-Fe coated mild steel was found to decrease significantly with increasing Fe content in the coating.

  9. Tannin bark Melalauca cajuputi powell (gelam) as green corrosion inhibitor of mild steel

    Energy Technology Data Exchange (ETDEWEB)

    Talib, Nur Atiqah Abu; Zakaria, Sarani; Hua, Chia Chin; Othman, Norinsan Kamil [School of Applied Physic, Faculty Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia)

    2014-09-03

    Tannin was extracted from gelam bark and used to produce corrosion inhibitor for mild steel. Tannin was extracted from gelam bark using 70% aqueous acetone for 6 hour. Tannin powder was characterization using fourier transform infrared spectroscopy to analyse chemical component in tannin and Scanning electron microscope (SEM) for tannin physical structure. The tannin effect on the corrosion inhibition of mild steel has been investigated in 1Mol HCl solution for 6 hour followed ASTM. The weight loss method were applied to study the mild steel corrosion behavior in the present and absend of different concentration of tannin (250, 300, 350)ppm. Tannin act good inhibitor as corrosion inhibitor for mild steel in acid medium. Surface morphology of carbon steel with and without inhibitor was investigated by scanning electron microscopy.

  10. Adsorption characteristics of green 5-arylaminomethylene pyrimidine-2,4,6-triones on mild steel surface in acidic medium: Experimental and computational approach

    Science.gov (United States)

    Verma, Chandrabhan; Olasunkanmi, Lukman O.; Ebenso, Eno E.; Quraishi, M. A.

    2018-03-01

    The effect of electron withdrawing nitro (-NO2) and electron releasing hydroxyl (-OH) groups on corrosion inhibition potentials of 5-arylaminomethylenepyrimidine-2,4,6-trione (AMP) had been studied. Four AMPs tagged AMP-1, AMP-2, AMP-3 and AMP-4 were studied for their ability to inhibit mild steel corrosion in 1 M HCl using experimental and theoretical methods. Gravimetric results showed that inhibition efficiency of the studied inhibitors increases with increasing concentration. The results further revealed that that electron withdrawing nitro (-NO2) group decreases the inhibition efficiency of AMP, while electron donating hydroxyl (-OH) group increases the inhibition efficiency of AMP. SEM and AFM studies showed that the studied compounds inhibit mild steel corrosion by adsorbing at the metal/electrolyte interface and their adsorption obeyed the Temkin adsorption isotherm. Potentiodynamic polarization study revealed that studied inhibitors act as mixed type inhibitors with predominant effect on cathodic reaction. The inhibitive strength of the compounds might have direct relationship electron donating ability of the molecules as revealed by quantum chemical parameters. The order of interaction energies derived from Monte Carlo simulations is AMP-4 > AMP-3 > AMP-2 > AMP-1, which is in agreement with the order of inhibition efficiencies obtained from experimental measurements.

  11. Corrosion of mild steel and stainless steel by marine Vibrio sp.

    Digital Repository Service at National Institute of Oceanography (India)

    PrabhaDevi; Wagh, A.B.

    Microbially induced corrosion (MIC) of stainless steel and mild steel coupons exposed to media with and without a bacterial culture Vibrio sp. was studied using Scanning Electron Microscope (SEM). Pitting type of corrosion was noticed which was more...

  12. Development of mild steel exposure chart for neutron radiography application

    International Nuclear Information System (INIS)

    Hafizal Yazid; Rafhayudi Jamro; Hishamuddin Husain; Muhammad Rawi Mohd Zin; Razali Kassim; Abd Aziz Mohamed; Azali Muhammad

    2004-01-01

    A neutron radiography exposure chart for mild steel was developed to facilitate the determination of exposure time when producing neutron radiographs for any given mild steel thickness. A mild steel sample in the form of step wedge (1-10 mm thick) was exposed to thermal neutron using Direct technique. This technique involves exposing x-ray film-Gadolinium converter housed in one film cassette simultaneously to thermal neutron beam. Gadolinium converters with thickness of 0.025 mm and 0.5 mm were used to observe the effect of converter thickness on radiographic density and exposure time. Collected radiographic density data is then calculated based on manufacturer's film characteristic chart and finally exposure chart for mild steel was plotted. This chart could later be used as a guide for estimating exposure time for any given sample thickness providing other conditions are similar (material, film processing, neutron flux, film density and converter thickness). (Author)

  13. Development of new corrosion inhibitor tested on mild steel supported by electrochemical study

    Directory of Open Access Journals (Sweden)

    Hussein Jwad Habeeb

    2018-03-01

    Full Text Available Mild steel is a metal which is commonly used in industrials and manufacturing of equipment for most industries round the world. It is cheaper cost compared with the other metals and its durable, hard and easy-to-wear physical properties make it a major choice in the manufacture of equipment parts. The main problem through the uses of mild steel in industry is its resistance against corrosion, especially in acidic solutions. This case led to raise the cost of maintenance of equipment that used mild steel and as a result increased costs for the company. Organic corrosive inhibitors that also act as green chemicals, 4-hydroxybenzylideneaminomethyl-5-ethyl-1,3,4-thiadiazol have been synthesized. This inhibitor is tested as corrosion inhibitor on a mild steel sample MS in 1 M hydrochloric acid solution (HCl using electrochemical measurements test includes PD (Potentiodynamic, EIS (Electrochemical impedance spectroscopy, OCP (Open circuit potential and EFM (electrochemical frequency modulation. The obtained results indicate that 4-hydroxybenzylideneaminomethyl-5-ethyl-1,3,4-thiadiazol acts as a good corrosion inhibitor for mild steel sample in HCl solution with efficiency above 90%. Changes in the impedance parameters postulated adsorption on the mild steel specimens' surfaces of, which it going to the formation of protective coating layer. It also shows that 4-hydroxybenzylideneaminomethyl-5-ethyl-1,3,4-thiadiazol corrosion inhibitors are effective in helping to reduce and slow down the corrosion process that occurs on mild steel surface in hydrochloric acid solution. Increase of corrosion inhibitor concentration provides a protective layer of mild steel. However, this protective layer becomes weak when the temperature of the solution increases. Keywords: Hydroxybenzylideneaminomethy, Potentiodynamic, Electrochemical frequency modulation, Impedance

  14. Development of new corrosion inhibitor tested on mild steel supported by electrochemical study

    Science.gov (United States)

    Habeeb, Hussein Jwad; Luaibi, Hasan Mohammed; Dakhil, Rifaat Mohammed; Kadhum, Abdul Amir H.; Al-Amiery, Ahmed A.; Gaaz, Tayser Sumer

    2018-03-01

    Mild steel is a metal which is commonly used in industrials and manufacturing of equipment for most industries round the world. It is cheaper cost compared with the other metals and its durable, hard and easy-to-wear physical properties make it a major choice in the manufacture of equipment parts. The main problem through the uses of mild steel in industry is its resistance against corrosion, especially in acidic solutions. This case led to raise the cost of maintenance of equipment that used mild steel and as a result increased costs for the company. Organic corrosive inhibitors that also act as green chemicals, 4-hydroxybenzylideneaminomethyl-5-ethyl-1,3,4-thiadiazol have been synthesized. This inhibitor is tested as corrosion inhibitor on a mild steel sample MS in 1 M hydrochloric acid solution (HCl) using electrochemical measurements test includes PD (Potentiodynamic), EIS (Electrochemical impedance spectroscopy), OCP (Open circuit potential) and EFM (electrochemical frequency modulation). The obtained results indicate that 4-hydroxybenzylideneaminomethyl-5-ethyl-1,3,4-thiadiazol acts as a good corrosion inhibitor for mild steel sample in HCl solution with efficiency above 90%. Changes in the impedance parameters postulated adsorption on the mild steel specimens' surfaces of, which it going to the formation of protective coating layer. It also shows that 4-hydroxybenzylideneaminomethyl-5-ethyl-1,3,4-thiadiazol corrosion inhibitors are effective in helping to reduce and slow down the corrosion process that occurs on mild steel surface in hydrochloric acid solution. Increase of corrosion inhibitor concentration provides a protective layer of mild steel. However, this protective layer becomes weak when the temperature of the solution increases.

  15. Johnson - Cook Strength Models for Mild and DP 590 Steels

    International Nuclear Information System (INIS)

    Vedantam, K.; Brar, N. S.; Bajaj, D.; Hill, S.

    2006-01-01

    Automotive steels, Mild and Dual Phase590 (DP590) are characterized in tension at room temperature, using the quasi-static and split Hopkinson bar techniques at various strain rates ranging from ∼10-3/s to ∼1800/s. Tension stress-strain data for both the steels are analyzed to determine the Johnson-Cook Strength model constants, J-C strength model constants for mild steel are A=217 MPa, B = 234 MPa, n = 0.643 and C = 0.076 and for DP590 steel are A = 430 MPa, B = 824 MPa, n = 0.510 and C = 0.017. Higher value of strain rate sensitivity constant C for mild steel (0.076) compared to DP 590 (0.017) is also reflected in the stress- strain data at various strain rates

  16. Inhibition Effect of Deanol on Mild Steel Corrosion in Dilute ...

    African Journals Online (AJOL)

    NICOLAAS

    2014-06-23

    Jun 23, 2014 ... The influence of deanol on the corrosion behaviour of mild steel in dilute sulphuric acid with sodium ... the formation of a complex precipitate of protective film, which ... silicon carbide abrasive papers of 80, 120, 220, 800 and 1000 grit ...... ions in sulphuric acid on the corrosion behaviour of stainless steel,.

  17. inhibition performance of mild ste thiophene ac rmance of mild steel

    African Journals Online (AJOL)

    userpc

    d Industrial Chemistry, Faculty of Physical Science, Bayero University, Kan. P. M. B. 3011 ..... chemical studies on the inhibition potentials of some ... Efficiency of Thiophene Derivatives on. Mild Steel : A QSAR Model. International. Journal.

  18. Thermochemical surface engineering of steels

    DEFF Research Database (Denmark)

    Thermochemical Surface Engineering of Steels provides a comprehensive scientific overview of the principles and different techniques involved in thermochemical surface engineering, including thermodynamics, kinetics principles, process technologies and techniques for enhanced performance of steels...

  19. Development of Zn50 Brazing Alloy for Joining Mild Steel to Mild Steel (SAE1018

    Directory of Open Access Journals (Sweden)

    S.C. Nwigbo

    2014-09-01

    Full Text Available This work has developed new brazing alloys for joining mild steel to mild steel (SAE1018 at a lower temperature. The alloys blends and error analysis were done by experimental design software (Design Expert 8.0.7.1. Design of experiments was done by Scheffe quadratic mixture method. The liquidus temperatures were predicted by calculation of phase diagrams of the alloying metals. The brazing alloys were produced by gravity technique and melted using silicon carbide graphite crucible. The quality of the brazing alloys was analyzed by optical microscopy (OM, atomic absorption spectroscopy (AAS and fourier transform infrared spectroscopy (FT-IR. Brazed joints were produced by torch method with a commercial flux. Brazing temperatures (liquidus were tracked by a digital infrared/laser pyrometer. Some mechanical properties studied were tensile strength and hardness. Finally, brazed joints produced from the developed brazing alloys were compared to that produced from muntz brass. Six (6 brazing alloys were successfully developed. Zinc and manganese were the main components, to which were added; 3 to 4 %wt silver and 11 to15 %wt modifying element. The microstructure showed a typical eutectic structure with zinc-rich phase distributed uniformly in the matrix with a combination of different sizes of dendrite, rounded blocks of compounds and hypoeutectic structures. AAS results indicated minimal out-gassing of zinc and FT-IR results indicated very low presence of atmospheric gas. The range of brazing temperature for best results was recorded from 690.90 to 735.10 0C. The joints produced from the developed brazing alloys had acceptable strengths with improved stress-strain behaviour compared to muntz brass.

  20. Inhibiting Effect of Nicotinic Acid Hydrazide on Corrosion of Aluminum and Mild Steel in Acidic Medium

    Energy Technology Data Exchange (ETDEWEB)

    Bhat, J. Ishwara [Mangalore Univ., Karnataka (India); Alva, Vijaya D. P. [Shree Devi Institute of Technology, Karnataka (India)

    2014-02-15

    The corrosion behavior of aluminum and mild steel in hydrochloric acid medium was studied using a nicotinic acid hydrazide as inhibitor by potentiodynamic polarization, electrochemical impedance spectroscopy technique and gravimetric methods. The effects of inhibitor concentration and temperature were investigated. The experimental results suggested, nicotinic acid hydrazide is a good corrosion inhibitor for both aluminum and mild steel in hydrochloric acid medium and the inhibition efficiency increased with increase in the inhibitor concentration. The polarization studies revealed that nicotinic acid hydrazide exhibits mixed type of inhibition. The inhibition was assumed to occur via adsorption of the inhibitor molecules on the aluminum and mild steel surface and inhibits corrosion by blocking the reaction sites on the surface of aluminum.

  1. Inhibiting Effect of Nicotinic Acid Hydrazide on Corrosion of Aluminum and Mild Steel in Acidic Medium

    International Nuclear Information System (INIS)

    Bhat, J. Ishwara; Alva, Vijaya D. P.

    2014-01-01

    The corrosion behavior of aluminum and mild steel in hydrochloric acid medium was studied using a nicotinic acid hydrazide as inhibitor by potentiodynamic polarization, electrochemical impedance spectroscopy technique and gravimetric methods. The effects of inhibitor concentration and temperature were investigated. The experimental results suggested, nicotinic acid hydrazide is a good corrosion inhibitor for both aluminum and mild steel in hydrochloric acid medium and the inhibition efficiency increased with increase in the inhibitor concentration. The polarization studies revealed that nicotinic acid hydrazide exhibits mixed type of inhibition. The inhibition was assumed to occur via adsorption of the inhibitor molecules on the aluminum and mild steel surface and inhibits corrosion by blocking the reaction sites on the surface of aluminum

  2. CORROSION INHIBITIVE PROPERTIES OF EXTRACT OF JATROPHA CURCAS LEAVES ON MILD STEEL IN HYDROCHLORIC ACID ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    J. Odusote

    2016-09-01

    Full Text Available Jatropha curcas leaves extract was tested as a green corrosion inhibitor for mild steel in aqueous hydrochloric acid solution using gravimetric and thermometric techniques. The results reveal that the inhibition efficiency vary with concentration of the leaf extract and the time of immersion. Maximum inhibition efficiency was found to be 95.92% in 2M HCl with 0.5 g/l concentration of the extract in gravimetric method, while 87.04% was obtained in thermometric method. The inhibiting effect was attributed to the presence of alkaloids, flavonoids, saponins, tannins and phenol in the extract. The adsorption processes of the Jatropha curcas leaves extract onto the mild steel is consistent with the assumptions of Langmuir isotherm model and also found to be spontaneous. From the results, a physical adsorption mechanism is proposed for the adsorption of Jatropha curcas leaves extract onto mild steel surface.

  3. Ginger extract as green corrosion inhibitor of mild steel in hydrochloric acid solution

    Science.gov (United States)

    Fidrusli, A.; Suryanto; Mahmood, M.

    2018-01-01

    Ginger extract as corrosion inhibitor from natural resources was studied to prevent corrosion of mild steel in acid media. Ginger rhizome was extracted to produce green corrosion inhibitor (G-1) while ginger powder bought at supermarket was also extract to form green corrosion inhibitor (G-2). Effectiveness of inhibitor in preventing corrosion process of mild steel was studied in 1.0 M of hydrochloric acid. The experiment of weight loss method and polarization technique were conducted to measure corrosion rate and inhibition efficiency of mild steel in solution containing 1.0 M of hydrochloric acid with various concentration of inhibitor at room temperature. The results showed that, the rate of corrosion dropped from 8.09 mmpy in solution containing no inhibitor to 0.72 mmpy in solution containing 150g/l inhibitor while inhibition efficiency up to 91% was obtained. The polarization curve in polarization experiments shows that the inhibition efficiency is 86% with high concentration of inhibitor. The adsorption of ginger extract on the surface of mild steel was observed by using optical microscope and the characterization analysis was done by using pH measurement method. When high concentration of green inhibitor in the acid solution is used, the pH at the surface of steel is increasing.

  4. Marine corrosion of mild steel at Lumut, Perak

    Science.gov (United States)

    Ting, Ong Shiou; Potty, Narayanan Sambu; Liew, Mohd. Shahir

    2012-09-01

    The corrosion rate of structural steels in the adverse marine and offshore environments affects the economic interest of offshore structures since the loss of steel may have significant impact on structural safety and performance. With more emphasis to maintain existing structures in service for longer time and hence to defer replacement costs, there is increasing interest in predicting corrosion rate at a given location for a given period of exposure once the protection coating or cathodic protection is lost. The immersion depth, salinity, steel composition and water pollution will be taken into account. Various corrosion allowances are prescribed for structural members by different standards. There are no studies to determine the appropriate corrosion allowance for steel structures in marine environment in Malaysia. The objectives of the research are to determine the nature and rate of corrosion in mm/year for steel structures in marine environment. It also tries to identify whether the corrosion rate is affected by differences in the chemical composition of the steels, and microalgae. Two sets of corrosion coupons of Type 3 Steel consisting of mild steel were fabricated and immersed in seawater using steel frames. The corrosion rate of the coupon in mm/ per year is estimated based on the material weight loss with time in service. The results are compared with recommendations of the code.

  5. An ac impedance study of the corrosion behaviour of mild steel coated with electrochemically synthesized polyoxyphenylenes

    Energy Technology Data Exchange (ETDEWEB)

    Musiani, M.M.; Mengoli, G.; Pagura, C.

    1985-04-01

    Electrochemically synthesized polyoxphenylene coatings on mild steel exposed to NaCl or H2SO4 solutions were investigated by ac impedance measurements. The influence of coating cohesion, adhesion to substrate, and surface pretreatment on the corrosion behaviour of the samples is clarified.

  6. modelling of responses from orthogonal metal cutting of mild steel

    African Journals Online (AJOL)

    user

    technical sciences which are shaped by local operating conditions. ... Three different tool types namely, HSS, tungsten carbide and carbide ... procedure indicated that a tape rule model Fat Max Blade. Armor 35' ... Carbon, C. 0.30 – 0.59% ... Block is Mild Steel x carbide. Runs. Cutting Speed. Feed Rate. Depth of Cut. 1. 250.

  7. Inhibition Effect of Deanol on Mild Steel Corrosion in Dilute ...

    African Journals Online (AJOL)

    The influence of deanol on the corrosion behaviour of mild steel in dilute sulphuric acid with sodium chloride addition was studied by means of mass-loss, potentiodynamic polarization, electrode potential monitoring, scanning electron microscopy and statistical analysis. Results show that deanol performed excellently with ...

  8. Corrosion of mild steel, copper and brass in crude oil / seawater mixture

    Digital Repository Service at National Institute of Oceanography (India)

    PrabhaDevi, S.; Sawant, S.S.; Wagh, A.B.

    Mild steel, copper and brass coupons were introduced in natural seawater containing varying amount of crude oil. Mild steel showed higher rate of corrosion in seawater containing oil and lower corrosion rate in natural as well as artificial seawater...

  9. On the inhibition of mild steel corrosion by 4-amino-5-phenyl-4H-1, 2, 4-trizole-3-thiol

    International Nuclear Information System (INIS)

    Musa, Ahmed Y.; Kadhum, Abdul Amir H.; Mohamad, Abu Bakar; Takriff, Mohd Sobri; Daud, Abdul Razak; Kamarudin, Siti Kartom

    2010-01-01

    The corrosion inhibition of mild steel in a 2.5 M H 2 SO 4 solution by 4-amino-5-phenyl-4H-1, 2, 4-trizole-3-thiol (APTT) was studied at different temperatures, utilising open circuit potential, potentiodynamic and impedance measurements. The results indicate that APTT performed as an excellent mixed-type inhibitor for mild steel corrosion in a 2.5 M H 2 SO 4 solution and that the inhibition efficiencies increased with the inhibitor concentration but decreased proportionally with temperature. The kinetic and thermodynamic parameters for adsorption of APTT on the mild steel surface were calculated. A chemisorption mechanism of APTT molecules on the mild steel surface was proposed based on the thermodynamic adsorption parameters.

  10. Synthesis and characterization of a novel organic corrosion inhibitor for mild steel in 1 M hydrochloric acid

    Directory of Open Access Journals (Sweden)

    Mohammed H. Othman Ahmed

    2018-03-01

    Full Text Available The synthesis and characterization of a novel organic corrosion inhibitor (4-(3-mercapto-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-b][1,2,4,5]tetrazin-6-ylphenol, for mild steel in 1 M hydrochloric acid (HCl has been successfully reported for the first time. The inhibitor evaluated as corrosion inhibitor for mild steel in 1 M of Hydrochloric acid solution using electrochemical impedance spectroscopy (EIS, and electrochemical frequency modulation (EFM measurement techniques. Changes in the impedance parameters suggested an adsorption of the inhibitor onto the mild steel surface, leading to the formation of protective films. The results show that the inhibition efficiencies increased with increasing the concentrations of the inhibitors and decreased with increasing temperature. The maximum inhibition efficiency up to 67% at the maximum concentration 0.5 mM. This shows that those inhibitors are effective in helping to reduce and slowing down the corrosion process that occurs to mild steel with a hydrochloric acid solution by providing an organic inhibitor for the mild steel that can be weakened by increasing the temperature. The adsorption process of the synthesized organic inhibitor depends on its electronic characteristics in addition to steric effects and the nature of metal surface, temperature degree and the varying degrees of surface-site activity. The synthesized inhibitor molecules were absorbed by metal surface and follow Langmuir isotherms. Keywords: Corrosion, Inhibitor, Mild steel, EIS spectroscopy

  11. Corrosion Inhibition of Mild Steel in Seawater using Jatropha Stem

    Directory of Open Access Journals (Sweden)

    Olawale Olamide

    2016-10-01

    Full Text Available The present work investigate the inhibition of Jatropha Stem Extract (JSE in sea water using mild steel coupons of dimension 5 × 5 × 0.5 cm. The cupons were immersed in test solutions of sea water and varied concentrations of extracts of 0.1g/l to 0.9g/l was used. The functional groups of the compounds was analyzed using an FTIR. The results showed that as the concentration of the extract increases, there was a reduction in the corrosion rates. Furthermore, as the extract concentrations increased from 0.1g/l to 0.4g/l at 48hrs exposure time, the weight loss decreased by 14.3% in the medium. However, the Jatropha Stem Extract was absorbed on the substrate surface to inhibit corrosion, the morphology of phases formed from the scanning Electron Microscopy examination confirmed this trend. Hence, JSE is a good and safe inhibitor in sea water solution. The FT-IR results also indicates the presence of active corrosion inhibitor present in the Jatropha Stem.

  12. Melt refining of uranium contaminated copper, nickel, and mild steel

    International Nuclear Information System (INIS)

    Ren Xinwen; Liu Wencang; Zhang Yuan

    1993-01-01

    This paper presents the experiment results on melt refining of uranium contaminated metallic discards such as copper, nickel, and mild steel. Based on recommended processes, uranium contents in ingots shall decrease below 1 ppm; metal recovery is higher than 96%; and slag production is below 5% in weight of the metal to be refined. The uranium in the slag is homogeneously distributed. The slag seems to be hard ceramics, insoluble in water, and can be directly disposed of after proper packaging

  13. Development of nano SiO2 incorporated nano zinc phosphate coatings on mild steel

    International Nuclear Information System (INIS)

    Tamilselvi, M.; Kamaraj, P.; Arthanareeswari, M.; Devikala, S.; Selvi, J. Arockia

    2015-01-01

    Highlights: • Nano SiO 2 incorporated nano zinc phosphate coating on mild steel was developed. • Coatings showed enhanced corrosion resistance. • The nano SiO 2 is adsorbed on mild steel surface and become nucleation sites. • The nano SiO 2 accelerates the phosphating process. - Abstract: This paper reports the development of nano SiO 2 incorporated nano zinc phosphate coatings on mild steel at low temperature for achieving better corrosion protection. A new formulation of phosphating bath at low temperature with nano SiO 2 was attempted to explore the possibilities of development of nano zinc phosphate coatings on mild steel with improved corrosion resistance. The coatings developed were studied by Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDX), X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and Electrochemical measurements. Significant variation in the coating weight, morphology and corrosion resistance was observed as nano SiO 2 concentrations varied from 0.5–4 g/L. The results showed that, the nano SiO 2 in the phosphating solution changed the initial potential of the interface between mild steel substrate and phosphating solution and reduce the activation energy of the phosphating process, increase the nucleation sites and yielded zinc phosphate coatings of higher coating weight, greater surface coverage and enhanced corrosion resistance. Better corrosion resistance was observed for coatings derived from phosphating bath containing 1.5 g/L nano SiO 2 . The new formulation reported in the present study was free from Ni or Mn salts and had very low concentration of sodium nitrite (0.4 g/L) as accelerator

  14. Risk of lung cancer according to mild steel and stainless steel welding

    DEFF Research Database (Denmark)

    Sørensen, Anita Rath; Thulstrup, Ane Marie; Hansen, Johnni

    2007-01-01

    OBJECTIVES: Whether the elevated risk of lung cancer observed among welders is caused by welding emissions or by confounding from smoking or asbestos exposure is still not resolved. This question was addressed in a cohort with a long follow-up and quantified estimates of individual exposure.......06-1.70)]. Among the stainless steel welders, the risk increased significantly with increasing accumulative welding particulate exposure, while no exposure-response relation was found for mild steel welders, even after adjustment for tobacco smoking and asbestos exposure. CONCLUSIONS: The study corroborates...... earlier findings that welders have an increased risk of lung cancer. While exposure-response relations indicate carcinogenic effects related to stainless steel welding, it is still unresolved whether the mild steel welding process carries a carcinogenic risk....

  15. Development of microstructural heterogeneities in the initial stage of mild steel conformation

    International Nuclear Information System (INIS)

    Silva, B.F. da.

    1980-07-01

    After determining the Forming Limit Diagrams (FLD) and discussing some changes in formability of mild aluminum-killed steel sheets, prestrained by various amounts by uniaxial tension and symmetrical biaxial stretching modes, the microstructural heterogeneities developed during uniform deformation, such as, internal and superficial damage, caracterized by inclusions, cracks, pores and surface roughness, were studied experimentally. In addition, the surface roughness behaviour of rimmed mild steel sheets developed during uniform deformation by uniaxial tension and symmetrical biaxial stretching modes, was studied. The results showed that, in the range of uniform deformation, the evolution of superficial damage, mainly the relief of these sheets, seems to be more important than internal damage. These observations could be a possible explanation for the development of localized necks in biaxially stretched sheets. (Author) [pt

  16. Evaluation of Plants and Weeds Extract on the Corrosion Inhibition of Mild Steel in Sulphuric Acid

    Directory of Open Access Journals (Sweden)

    Abida Begum

    2011-01-01

    Full Text Available Experiments were performed in order to determine the inhibitive effects of extracts of plants and weeds namely Parthenium hysterophorus, Dathura stromonium, Azadirachta indica, Helianthus annuus leaves extract for mild steel in sulphuric acid by using weight loss and thermometric technique. Results demonstrated that, all the experimental inhibitors show an adsorption on steel surface according to Langmuir’s isotherm. The inhibition efficiency increased with increase in the concentration of all tested inhibitors to attain a maximum value at 1.0%. Free energy values for adsorption process show that the process is spontaneous. The kinetic treatment of the results shows first order kinetics.

  17. Redemption of asthma pharmaceuticals among stainless steel and mild steel welders

    DEFF Research Database (Denmark)

    Kristiansen, Pernille; Jørgensen, Kristian Tore; Hansen, Johnni

    2015-01-01

    PURPOSE: The purpose was to examine bronchial asthma according to cumulative exposure to fume particulates conferred by stainless steel and mild steel welding through a proxy of redeemed prescribed asthma pharmaceuticals. METHODS: A Danish national company-based historical cohort of 5,303 male ever...... was estimated by combining questionnaire data on welding work with a welding exposure matrix. The estimated exposure accounted for calendar time, welding intermittence, type of steel, welding methods, local exhaustion and welding in confined spaces. Hazard ratios (HRs) with 95 % confidence intervals (CIs) were...... nonsignificant increased rate of redemption of asthma medicine was observed among high-level exposed stainless steel welders in comparison with low-level exposed welders (HR 1.54, 95 % CI 0.76-3.13). This risk increase was driven by an increase risk among non-smoking stainless steel welders (HR 1.46, 95 % CI 1...

  18. Synthesis and characterization of a novel organic corrosion inhibitor for mild steel in 1 M hydrochloric acid

    Science.gov (United States)

    Ahmed, Mohammed H. Othman; Al-Amiery, Ahmed A.; Al-Majedy, Yasmin K.; Kadhum, Abdul Amir H.; Mohamad, Abu Bakar; Gaaz, Tayser Sumer

    2018-03-01

    The synthesis and characterization of a novel organic corrosion inhibitor (4-(3-mercapto-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-b][1,2,4,5]tetrazin-6-yl)phenol), for mild steel in 1 M hydrochloric acid (HCl) has been successfully reported for the first time. The inhibitor evaluated as corrosion inhibitor for mild steel in 1 M of Hydrochloric acid solution using electrochemical impedance spectroscopy (EIS), and electrochemical frequency modulation (EFM) measurement techniques. Changes in the impedance parameters suggested an adsorption of the inhibitor onto the mild steel surface, leading to the formation of protective films. The results show that the inhibition efficiencies increased with increasing the concentrations of the inhibitors and decreased with increasing temperature. The maximum inhibition efficiency up to 67% at the maximum concentration 0.5 mM. This shows that those inhibitors are effective in helping to reduce and slowing down the corrosion process that occurs to mild steel with a hydrochloric acid solution by providing an organic inhibitor for the mild steel that can be weakened by increasing the temperature. The adsorption process of the synthesized organic inhibitor depends on its electronic characteristics in addition to steric effects and the nature of metal surface, temperature degree and the varying degrees of surface-site activity. The synthesized inhibitor molecules were absorbed by metal surface and follow Langmuir isotherms.

  19. Lung cancer mortality in stainless steel and mild steel welders: a nested case-referent study

    DEFF Research Database (Denmark)

    Lauritsen, Jens; Hansen, K S

    1996-01-01

    . Analysis was based on 439 deceased referents and 94 deceased cases. There was a 70% excess of lung cancer associated with "welding exposure ever" (OR +/- 95% C.I.: 1.68, 1.02-2.78). Overall OR for "mild steel (MS) welding ever" was 1.64, 0.99-2.72. The risk estimates for welding exposures showed...... an increasing tendency up to 15 years of exposure. The pattern of stainless steel (SS) welding resembles that of mild steel with an estimated OR of 1.65, 0.88-3.0. The general conclusion is that MS welding as well as SS welding seems to be associated with an increased risk of lung cancer. Further followup...

  20. A comparative study of the corrosion inhibition of mild steel in sulphuric acid by 4,4-dimethyloxazolidine-2-thione

    International Nuclear Information System (INIS)

    Musa, Ahmed Y.; Kadhum, Abdul Amir H.; Mohamad, Abu Bakar; Daud, Abdul Razak; Takriff, Mohd Sobri; Kamarudin, Siti Kartom

    2009-01-01

    The corrosion protection of mild steel in a 2.5 M H 2 SO 4 solution by 4,4-dimethyloxazolidine-2-thione (DMT) was studied at different temperatures by measuring changes in open circuit potential (OCP), potentiodynamic polarisation and electrochemical impedance spectroscopy (EIS). Corrosion current densities calculated from EIS data were comparable to those obtained from polarisation measurements. Results showed that DMT inhibited mild steel corrosion in a 2.5 M H 2 SO 4 solution and indicated that the inhibition efficiencies increased with the concentration of inhibitor, but decreased proportionally with temperature. Polarisation curves showed that DMT is a mixed-type inhibitor. Changes in impedance parameters suggested the adsorption of DMT on the mild steel surface, leading to the formation of protective films. The DMT adsorption on the mild steel surface followed the Langmuir adsorption isotherm. The kinetic and thermodynamic parameters for dissolution and adsorption were investigated. Comprehensive adsorption (physisorption and chemisorption) of the inhibitor molecules on the mild steel surface was suggested based on the thermodynamic adsorption parameters.

  1. The optimization of CNT-PVA nanocomposite for mild steel coating: Effect of CNTs concentration on the corrosion rate of mild steel

    Science.gov (United States)

    Maryam, M.; Ibrahim, N. M. A. A.; Eswar, K. A.; Guliling, M.; Suhaimi, M. H. F.; Khusaimi, Z.; Abdullah, S.; Rusop, M.

    2018-05-01

    Carbon Nanotubes (CNTs) are molecular-scale tubes of graphitic carbon which have outstanding mechanical and magnetic properties with extraordinary strength. It can be said that CNTs can be used in coating application to prevent corrosion and lower the rate of corrosion on steel. However, CNT alone cannot be used for coating purposes. Therefore, by combining it with polymer to produce a nanocomposite thin film, it can be used for nanocoating on mild steel substrate. Polyvinyl alcohol (PVA) was chosen due to its high strength and high modulus polymer fibers and has the possibilities of improving the physicochemical properties of carbon nanotubes. Carbon nanotubes and polyvinyl alcohol (CNT-PVA) nanocomposite were prepared by using sol-gel method and coated as thin film on mild steel substrate by using spin coating. Sol-gel is a convenient technique used for the production of nanocomposite aqueous solution. Five samples were prepared at the different concentration of CNTs-PVA to verify the corrosion rate application. The samples were then characterized by Field Emission Scanning Electron Microscopy (FESEM) and Atomic Force Microscopy (AFM) obtaining the structural properties, surface morphology and topography of samples. Raman spectroscopy was used to determine the microraman spectra of CNTs which showed the quality and purity of samples. Finally, corrosion test was done to measure the corrosion rate of samples at the different concentration of CNTs/PVA nanocomposite.

  2. Studies on the Inhibition of Mild Steel Corrosion by Rauvolfia serpentina in Acid Media

    Science.gov (United States)

    Bothi Raja, P.; Sethuraman, M. G.

    2010-07-01

    Alkaloid extract of Rauvolfia serpentina was tested as corrosion inhibitor for mild steel in 1 M HCl and H2SO4 using weight loss method at three different temperatures, viz., 303, 313, and 323 K, potentiodynamic polarization, electrochemical impedance spectroscopy and scanning electron microscope (SEM) studies. It is evident from the results of this study that R. serpentina effectively inhibits the corrosion in both the acids through adsorption process following Tempkin adsorption isotherm. The protection efficiency increased with increase in inhibitor concentration and temperature. Free energy of adsorption calculated from the temperature studies also revealed the chemisorption. The mixed mode of action exhibited by the inhibitor was confirmed by the polarization studies while SEM analysis substantiated the formation of protective layer over the mild steel surface.

  3. Interaction of Benzimidazoles and Benzotriazole: Its Corrosion Protection Properties on Mild Steel in Hydrochloric Acid

    Science.gov (United States)

    Ramya, K.; Mohan, Revathi; Joseph, Abraham

    2014-11-01

    Synergistic hydrogen-bonded interaction of alkyl benzimidazoles and 1,2,3-benzotrizole and its corrosion protection properties on mild steel in hydrochloric acid at different temperatures have been studied using polarization, EIS, adsorption, surface studies, and computational methods. The extent of synergistic interaction increases with temperature. Quantum chemical approach is used to calculate some electronic properties of the molecules and to ascertain the synergistic interaction, inhibitive effect, and molecular structures. The corrosion inhibition efficiencies and the global chemical reactivity relate to some parameters, such as total energy, E HOMO, E LUMO, and gap energy (Δ E). 1,2,3-Benzotrizole interacts with benzimidazoles derivatives up to a bond length of approximately 1.99 Å. This interaction represents the formation of a hydrogen bond between the 1,2,3-benzotrizole and benzimidazoles. This synergistic interaction of 1,2,3-benzotrizole and benzimidazole derivatives offers extended inhibition efficiency toward mild steel in hydrochloric acid.

  4. Inhibition of mild steel corrosion in acid solution by Pheniramine drug: Experimental and theoretical study

    Energy Technology Data Exchange (ETDEWEB)

    Ahamad, Ishtiaque [Department of Applied Chemistry, Institute of Technology, Banaras Hindu University, Varanasi 221 005 (India); Prasad, Rajendra [Department of Chemistry, SGB Amravati University, Amravati 444 602 (India); Quraishi, M.A., E-mail: maquraishi@rediffmail.co [Department of Applied Chemistry, Institute of Technology, Banaras Hindu University, Varanasi 221 005 (India)

    2010-09-15

    Inhibition of mild steel corrosion in 1 M HCl solution by Pheniramine drug was studied using weight loss, electrochemical impedance spectroscopy, linear polarization resistance, and potentiodynamic polarization measurements. The values of activation energy (E{sub a}) and different thermodynamic parameters such as adsorption equilibrium constant (K{sub ads}), free energy of adsorption ({Delta}G{sub ads}{sup o}), adsorption enthalpy ({Delta}H{sub ads}{sup o}) and adsorption entropy ({Delta}S{sub ads}{sup o}) were calculated and discussed. The adsorption process of studied drug on mild steel surface obeys the Langmuir adsorption isotherm. Potentiodynamic polarization measurements showed that Pheniramine is mixed-type inhibitor. Further, theoretical calculations were carried out and relations between computed parameters and experimental inhibition efficiency were discussed.

  5. Inhibition of mild steel corrosion in acid solution by Pheniramine drug: Experimental and theoretical study

    International Nuclear Information System (INIS)

    Ahamad, Ishtiaque; Prasad, Rajendra; Quraishi, M.A.

    2010-01-01

    Inhibition of mild steel corrosion in 1 M HCl solution by Pheniramine drug was studied using weight loss, electrochemical impedance spectroscopy, linear polarization resistance, and potentiodynamic polarization measurements. The values of activation energy (E a ) and different thermodynamic parameters such as adsorption equilibrium constant (K ads ), free energy of adsorption (ΔG ads o ), adsorption enthalpy (ΔH ads o ) and adsorption entropy (ΔS ads o ) were calculated and discussed. The adsorption process of studied drug on mild steel surface obeys the Langmuir adsorption isotherm. Potentiodynamic polarization measurements showed that Pheniramine is mixed-type inhibitor. Further, theoretical calculations were carried out and relations between computed parameters and experimental inhibition efficiency were discussed.

  6. New hypotheses for hydrogenase implication in the corrosion of mild steel

    Energy Technology Data Exchange (ETDEWEB)

    Mehanna, Maha; Basseguy, Regine; Delia, Marie-Line [Laboratoire de Genie Chimique (LGC) CNRS-INPT, 5 rue Paulin Talabot BP 1301, 31106 Toulouse (France); Girbal, Laurence; Demuez, Marie [Laboratoire d' Ingenierie des Systemes Biologiques et des Procedes (LISBP) CNRS-INSA, 135 Avenue de Rangueil, 31077 Toulouse (France); Bergel, Alain [Laboratoire de Genie Chimique (LGC) CNRS-INPT, 5 rue Paulin Talabot BP 1301, 31106 Toulouse (France)], E-mail: Alain.Bergel@ensiacet.fr

    2008-12-01

    The influence of [Fe]-hydrogenase from Clostridium acetobutylicum was studied on the anaerobic corrosion of mild steel. Two short-circuited mild steel electrodes were exposed to the same solution and hydrogenase was retained on the surface of only one electrode thanks to a dialysis membrane. The galvanic current and the electrode potential were measured as a function of time in order to monitor the difference in electrochemical behaviour induced by the presence of hydrogenase. A sharp potential decrease of around 500 mV was controlled by the deoxygenating phase. When hydrogenase was introduced after complete deoxygenation, significant heterogeneous corrosion was observed under the vivianite deposit on the electrode in contact with hydrogenase, while the other electrode only showed the vivianite deposit, which was analysed by MEB and EDX. The effect of hydrogenase was then confirmed by monitoring the free potential of single coupons exposed or not to the enzyme in a classical cell after complete deoxygenating. In both phosphate and Tris-HCl buffers, the presence of hydrogenase increased the free potential around 60 mV and induced marked general corrosion. It was concluded that [Fe]-hydrogenase acts in the absence of any final electron acceptor by catalysing direct proton reduction on the mild steel surface.

  7. New hypotheses for hydrogenase implication in the corrosion of mild steel

    International Nuclear Information System (INIS)

    Mehanna, Maha; Basseguy, Regine; Delia, Marie-Line; Girbal, Laurence; Demuez, Marie; Bergel, Alain

    2008-01-01

    The influence of [Fe]-hydrogenase from Clostridium acetobutylicum was studied on the anaerobic corrosion of mild steel. Two short-circuited mild steel electrodes were exposed to the same solution and hydrogenase was retained on the surface of only one electrode thanks to a dialysis membrane. The galvanic current and the electrode potential were measured as a function of time in order to monitor the difference in electrochemical behaviour induced by the presence of hydrogenase. A sharp potential decrease of around 500 mV was controlled by the deoxygenating phase. When hydrogenase was introduced after complete deoxygenation, significant heterogeneous corrosion was observed under the vivianite deposit on the electrode in contact with hydrogenase, while the other electrode only showed the vivianite deposit, which was analysed by MEB and EDX. The effect of hydrogenase was then confirmed by monitoring the free potential of single coupons exposed or not to the enzyme in a classical cell after complete deoxygenating. In both phosphate and Tris-HCl buffers, the presence of hydrogenase increased the free potential around 60 mV and induced marked general corrosion. It was concluded that [Fe]-hydrogenase acts in the absence of any final electron acceptor by catalysing direct proton reduction on the mild steel surface

  8. Nano zinc phosphate coatings for enhanced corrosion resistance of mild steel

    International Nuclear Information System (INIS)

    Tamilselvi, M.; Kamaraj, P.; Arthanareeswari, M.; Devikala, S.

    2015-01-01

    Highlights: • Nano zinc phosphate coating on mild steel was developed. • Nano zinc phosphate coatings on mild steel showed enhanced corrosion resistance. • The nano ZnO increases the number of nucleating sites for phosphating. • Faster attainment of steady state during nano zinc phosphating. - Abstract: Nano crystalline zinc phosphate coatings were developed on mild steel surface using nano zinc oxide particles. The chemical composition and morphology of the coatings were analyzed by X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). The particles size of the nano zinc phosphate coating developed was also characterized by TEM analysis. Potentiodynamic polarization and electrochemical impedance studies were carried out in 3.5% NaCl solution. Significant variations in the coating weight, morphology and corrosion resistance were observed as nano ZnO concentrations were varied from 0.25 to 2 g/L in the phosphating baths. The results showed that nano ZnO particles in the phosphating solution yielded phosphate coatings of higher coating weight, greater surface coverage and enhanced corrosion resistance than the normal zinc phosphate coatings (developed using normal ZnO particles in the phosphating baths). Better corrosion resistance was observed for coatings derived from phosphating bath containing 1.5 g/L nano ZnO. The activation effect brought about by the nano ZnO reduces the amount of accelerator (NaNO 2 ) required for phosphating

  9. Synergistic effect of iodide ion addition on the inhibition of mild steel corrosion in 1 M HCl by 3-amino-2-methylbenzylalcohol

    Energy Technology Data Exchange (ETDEWEB)

    Obot, I.B., E-mail: obot@kfupm.edu.sa; Madhankumar, A.

    2016-07-01

    The inhibition of mild steel corrosion in 1 M HCl aqueous solution by 3-amino-2-methylbenzylalcohol (AMBA) was investigated using weight loss, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP) and cyclic voltammametry (CV) techniques. Attenuated total reflectance infrared spectroscopy (ATR-IR), contact angle (CA) and scanning electron microscopy (SEM) measurements were carried out to confirm the adsorption of AMBA on mild steel surface. Computer simulations using density functional theory (DFT) and Monte Carlo methodologies were further employed to provide insights into the mechanism of interaction between the inhibitor and the steel surface. All the results confirmed that AMBA is a good corrosion inhibitor for mild steel in 1 M HCl. The addition of NaI was found to increase the inhibition effect of AMBA on mild steel to a considerable extent. DFT results reveal that the N atom together with the π-systems in the aromatic ring were the active sites for the interaction of AMBA with steel surface. Furthermore, the negative value of the adsorption energy obtained from the Monte Carlo simulation indicates the stability of the adsorbed inhibitor film on the steel surface. - Graphical abstract: EIS spectra and adsorption configuration of AMBA on Fe (110). - Highlights: • 3-amino-2-methylbenzylalcohol inhibit mild steel corrosion in acid medium. • ATR-IR, contact angle, SEM, were used for steel surface characterization. • DFT and Monte Carlo simulations provide atomic and molecular level insights. • The theoretical data clearly support the experimental results obtained.

  10. Effect of hydroxyl group position at imine structure on corrosion inhibition of mild steel in 0.5 m NaCl

    Science.gov (United States)

    Mohd, Yusairie; Dzolin, Syaidah Athirah; Bahron, Hadariah; Halim, Nurul Huda Abdul

    2017-12-01

    Corrosion is inherent for mild steel and it can be retarded through many approaches including electrodeposition of inert inhibitors in the form of organic molecules. Salicylideneaniline (L1) and 4-hydroxybenzalaniline (L2) were electrodeposited on mild steel using cyclic voltammetry (CV) using 0.1 M inhibitor concentration in 0.3 M NaOH. The scanning potential range for coating via CV was set from 0 - 2 V and back to 0 V for five cycles. A yellow film was observed covering the surface of the mild steel. The corrosion behavior of coated and uncoated mild steel was studied using Linear Polarization Resistance (LPR) in 0.5 M NaCl. Both coated mild steel specimens showed better corrosion resistance than the uncoated, with L1 providing a better inhibition protection with the inhibition efficiency of 80.51 %.

  11. Long-term atmospheric corrosion of mild steel

    International Nuclear Information System (INIS)

    Fuente, D. de la; Diaz, I.; Simancas, J.; Chico, B.; Morcillo, M.

    2011-01-01

    Research highlights: → Atmospheric corrosion rate stabilises after the first 4-6 years of exposure. → Great compaction of the rust layers in rural and urban atmospheres. → Corrosion (in rural and urban) deviates from common behaviour of bilogarithmic law. → Typical structures of lepidocrocite, goethite and akaganeite are identified. → Formation of hematite (industrial atmosphere) and ferrihydrite (marine atmosphere). - Abstract: A great deal of information is available on the atmospheric corrosion of mild steel in the short, mid and even long term, but studies of the structure and morphology of corrosion layers are less abundant and generally deal with those formed in just a few years. The present study assesses the structure and morphology of corrosion product layers formed on mild steel after 13 years of exposure in five Spanish atmospheres of different types: rural, urban, industrial and marine (mild and severe). The corrosion layers have been characterised by X-ray diffraction (XRD) and scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS). Long-term corrosion is seen to be more severe in the industrial and marine atmospheres, and less so in the rural and urban atmospheres. In all cases the corrosion rate is seen to decrease with exposure time, stabilising after the first 4-6 years of exposure. The most relevant aspects to be noted are (a) the great compaction of the rust layers formed in the rural and urban atmospheres, (b) the formation of hematite and ferrihydrite phases (not commonly found) in the industrial and marine atmospheres, respectively and (c) identification of the typical morphological structures of lepidocrocite (sandy crystals and flowery plates), goethite (cotton balls structures) and akaganeite (cotton balls structures and cigar-shaped crystals).

  12. Cancer incidence among mild steel and stainless steel welders and other metal workers

    DEFF Research Database (Denmark)

    Hansen, K S; Lauritsen, J M; Skytthe, A

    1996-01-01

    by a postal questionnaire in living cohort members and interviews by proxy for deceased and emigrated subjects. The incidence of lung cancer was increased among workers ever "employed as welders" (SIR = 1.38, 95% C.I. 1.03-1.81). There was a significant excess risk of lung cancer among "mild steel (MS) only...... "stainless steel (SS) only welders" (SIR = 2.38, 95% C.I. 0.77-5.55). In spite of signs of inconsistency in the risk estimation by duration and latency, we find the results support the conclusions of other studies: employment as a welder is associated with an increased lung cancer risk....

  13. Synergistic Effect on Corrosion Inhibition Efficiency of Ginger Affinale Extract in Controlling Corrosion of Mild Steel in Acid Medium

    International Nuclear Information System (INIS)

    Subramanian, Ananth Kumar; Arumugam, Sankar; Mallaiya, Kumaravel; Subramaniam, Rameshkumar

    2013-01-01

    The corrosion inhibition nature of Ginger affinale extract for the corrosion of mild steel in 0.5N H 2 SO 4 was investigated using weight loss, electrochemical impedance and potentiodynamic polarization methods. The results revealed that Ginger affinale extract acts as a good corrosion inhibitor in 0.5N H 2 SO 4 medium. The inhibition efficiency increased with an increase in inhibitor concentration. The inhibition could be attributed to the adsorption of the inhibitor on the steel surface

  14. Inhibition of Mild Steel Corrosion in Hydrochloric Acid Solution by New Coumarin

    Directory of Open Access Journals (Sweden)

    Abdul Amir H. Kadhum

    2014-06-01

    Full Text Available A new coumarin derivative, N,N′-((2E,2′E-2,2′-(1,4-phenylenebis (methanylylidenebis(hydrazinecarbonothioylbis(2-oxo-2H-chromene-3-carboxamide PMBH, was synthesized and its chemical structure was elucidated and confirmed using spectroscopic techniques (Infrared spectroscopy IR, Proton nuclear  magnetic resonance, 1H-NMR and carbon-13 nuclear magnetic resonance 13C-NMR. The corrosion inhibition effect of PMBH on mild steel in 1.0 M HCl was investigated using corrosion potential (ECORR, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS, and electrochemical frequency modulation (EFM measurements. The obtained results indicated that PMBH has promising inhibitive effects on the corrosion of mild steel in 1.0 M HCl across all of the conditions examined. Scanning electron microscopy (SEM was used to investigate the morphology of the mild steel before and after immersion in 1.0 M HCl solution containing 0.5 mM of PMBH. Surface analysis revealed improvement of corrosion resistance in presence of PMBH.

  15. Inhibition of Mild Steel Corrosion in Hydrochloric Acid Solution by New Coumarin

    Science.gov (United States)

    Kadhum, Abdul Amir H.; Mohamad, Abu Bakar; Hammed, Leiqaa A.; Al-Amiery, Ahmed A.; San, Ng Hooi; Musa, Ahmed Y.

    2014-01-01

    A new coumarin derivative, N,N′-((2E,2′E)-2,2′-(1,4-phenylenebis(methanylylidene))bis(hydrazinecarbonothioyl))bis(2-oxo-2H-chromene-3-carboxamide) PMBH, was synthesized and its chemical structure was elucidated and confirmed using spectroscopic techniques (Infrared spectroscopy IR, Proton nuclear magnetic resonance, 1H-NMR and carbon-13 nuclear magnetic resonance 13C-NMR). The corrosion inhibition effect of PMBH on mild steel in 1.0 M HCl was investigated using corrosion potential (ECORR), potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and electrochemical frequency modulation (EFM) measurements. The obtained results indicated that PMBH has promising inhibitive effects on the corrosion of mild steel in 1.0 M HCl across all of the conditions examined. Scanning electron microscopy (SEM) was used to investigate the morphology of the mild steel before and after immersion in 1.0 M HCl solution containing 0.5 mM of PMBH. Surface analysis revealed improvement of corrosion resistance in presence of PMBH. PMID:28788680

  16. Study on tea leaves extract as green corrosion inhibitor of mild steel in hydrochloric acid solution

    Science.gov (United States)

    Hamdan, A. B.; Suryanto; Haider, F. I.

    2018-01-01

    Corrosion inhibitor from extraction of plant has been considered as the most preferable and most chosen technique to prevent corrosion of metal in acidic medium because of the environmental friendly factor. In this study, black tea leaves extraction was tested as corrosion inhibitor for mild steel in 0.1M of hydrochloric acid (HCl) with the absence and presence of corrosion inhibitor. The efficiency and effectiveness of black tea as corrosion inhibitor was tested by using corrosion weight loss measurement experiment was carried out with varies parameters which with different concentration of black tea extract solution. The extraction of black tea solution was done by using aqueous solvent method. The FT-IR result shows that black tea extract containing compounds such as catechin, caffeine and tannins that act as anti-corrosive reagents and responsible to enhance the effectiveness of black tea extract as corrosion inhibitor by forming the hydrophobic thin film through absorption process. As a result of weight loss measurement, it shows that loss in weight of mild steel reduces as the concentration of inhibitor increases. The surface analysis was done on the mild steel samples by using SEM.

  17. Heterogeneous corrosion of mild steel under SRB-biofilm characterised by electrochemical mapping technique

    International Nuclear Information System (INIS)

    Dong Zehua; Shi Wei; Ruan Hongmei; Zhang Guoan

    2011-01-01

    Highlights: → Highly conductive SRB-biofilm can shield the potential differences of mild steel. → Potential maps fail to indicate the localised corrosion of steel under SRB-biofilm. → Galvanic current maps can detect the location of localised corrosion under biofilm. → SRB-biofilm is super-capacitive due to the conductive sulphide micropores. - Abstract: Heterogeneous corrosion of mild steel under sulphate reducing bacteria (SRB)-biofilm was characterised by wire beam electrode (WBE) technique and electrochemical impedance spectrum. The potential/current distributions of the WBE under SRB-biofilm showed that the potential maps could not indicate the localised corrosion of steels beneath biofilm due to the fact that all wire electrodes were short-circuited by the highly conductive sulphide precipitates embedded in SRB-biofilm. Instead, the galvanic current maps may give a good indication. The characteristic of super-capacitance (0.21 F/cm 2 ) of SRB-biofilm was attributed to the huge specific surface area of conductive pore walls inside biofilm.

  18. Chromate coating of zinc-aluminum plating on mild steel

    International Nuclear Information System (INIS)

    Haque, I.; Khan, A.; Nadeem, A.

    2005-01-01

    The chromate coating on zinc-aluminium deposits has been studied. Zinc-aluminium deposition from non-cyanide bath was carried out at current density 3-3.5 A/dm/sup 2/, plating voltage approx. equal to 1.25 V, temperature 18-20 deg. C, for 15 min. The effect of aluminium chloride on the rest potentials of golden, colorless and non-chromated zinc-aluminium alloy deposits was observed. It was found that rest potential was slightly increased with the increase in the concentration of aluminium chloride, only in the case of golden chromating. The rest potential of colorless chromated zinc-aluminium deposits on mild steel were observed to have no correlation with aluminium chloride concentration. The abrasion resistance of colorless chromating was better than golden chromating. (author)

  19. Theoretical description of the influence of neutron irradiation on viscoplastic properties of mild steel

    International Nuclear Information System (INIS)

    Pecherski, R.

    1978-01-01

    The physical bases of plastic deformation of mild steel are described. The influence of neutron irradiation on the change of mechanisms of plastic deformation is discussed in detail. Constitutive equations of viscoplasticity for irradiated mild steel are given. The problem of thickwalled viscoplastic spherical tank irradiated by neutrons is studied. (Z.R.)

  20. Creep rupture of mild steel compact tension test pieces

    International Nuclear Information System (INIS)

    Priddle, E.K.

    1978-10-01

    Creep rupture lives have been determined for compact tension and unnotched tensile test pieces of mild steel at 450 0 C. Three sizes of compact tension specimens were used in which the ratios of reference stress to elastic stress intensity factor were 2.76, 4.78 and 6.6 (msup(-1/2)). The analysis of results in terms of either initial reference stress or stress intensity was unable to reduce the data to a single failure curve. An empirical correlation was found between rupture time and a reference stress/crack length combination where t = 2.46 x 10 20 sub(σref) sup(-8.96) asup(-1.56) (units hours, MPa and metres). This equation has no valid application to materials or specimens other than those from which it was derived. Reported data for 1/2Cr Mo V and 2 1/4Cr Mo steels at 565 0 C were also correlated by this approach. (author)

  1. The effect of organic matter associated with the corrosion products on the corrosion of mild steel in the Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Bhosle, N.B.; Wagh, A.B.

    The corrosion of mild steel immersed at various depths (0-100 m) from three stations of the Arabian Sea was investigated. The corrosion of mild steel decreased with increasing immersion depth. Significant positive relationships were observed between...

  2. Cathodic protection of mild steel and copper in deep waters of the Arabian Sea and Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Sawant, S.S.; Venkat, K.; Wagh, A.B.

    Performance of cathodic protection system to mild steel and copper in deep (> 1000 m) oceanic waters of the Arabian Sea and Bay of Bengal has been assessed using aluminium and mild steel sacrificial anodes. The corrosion rates of unprotected metals...

  3. Evaluation of Corrosion Inhibition of Mild Steel in 1 M Hydrochloric Acid Solution by Mollugo cerviana

    Directory of Open Access Journals (Sweden)

    P. Arockiasamy

    2014-01-01

    Full Text Available The inhibiting effect of methanolic extract of Mollugo cerviana plant on the corrosion of mild steel in 1 M HCl solution has been investigated by different techniques like potentiodynamic polarization, electrochemical impedance spectroscopy, and weight loss methods for five different concentrations of plant extract ranging from 25 to 1000 mg/L. The results indicated that the corrosion inhibition efficiency increased on increasing plant extract concentration till 500 mg/L and decreased on further increasing concentration. The extract was a mixed type inhibitor with the optimum inhibition concentration of 500 mg/L in potentiodynamic polarization. The adsorption of the plant extract on the mild steel surface was found to obey Langmuir adsorption isotherm. Surface analysis was also carried out to find out the surface morphology of the mild steel in the presence and in the absence of the inhibitor to find out its efficiency. The obtained results showed that the Mollugo cerviana extract acts as a good inhibitor for the corrosion of mild steel in 1 M HCl solution.

  4. The inhibition effect of Azure A on mild steel in 1 M HCl. A complete study: Adsorption, temperature, duration and quantum chemical aspects

    International Nuclear Information System (INIS)

    Özkır, Demet; Kayakırılmaz, Kadriye; Bayol, Emel; Gürten, A. Ali; Kandemirli, Fatma

    2012-01-01

    Highlights: ► Azure A molecule is found to be a good inhibitor for mild steel in HCl solution. ► SEM results clearly indicate that a protective film formation occurred on the mild steel surface. ► The long term corrosion tests are cleared that the Azure A has effectively protected the mild steel in HCl solution. ► The quantum chemical measurements were cleared the reactive sites and charges of atoms in the molecule. - Abstract: In this study, inhibition effect of Azure A on mild steel in 1.0 M HCl were evaluated by using electrochemical impedance spectroscopy (EIS), linear polarization resistance (LPR), and potentiodynamic polarization and scanning electron microscope (SEM) methods. These studies were carried out at different concentrations, temperatures and durations. The inhibitor molecules were chemisorbed on electrode surface according to the Langmuir adsorption isotherm. The quantum chemical calculations were employed to give further insight into the inhibition mechanism of Azure A.

  5. Effect of coating mild steel with CNTs on its mechanical properties and corrosion behaviour in acidic medium

    Science.gov (United States)

    Abdulmalik Abdulrahaman, Mahmud; Kamaldeeen Abubakre, Oladiran; Ambali Abdulkareem, Saka; Oladejo Tijani, Jimoh; Aliyu, Ahmed; Afolabi, Ayo Samuel

    2017-03-01

    The study investigated the mechanical properties and corrosion behaviour of mild steel coated with carbon nanotubes at different coating conditions. Multi-walled carbon nanotubes (MWCNTs) were synthesized via the conventional chemical vapour deposition reaction using bimetallic Fe-Ni catalyst supported on kaolin, with acetylene gas as a carbon source. The HRSEM/HRTEM analysis of the purified carbon materials revealed significant reduction in the diameters of the purified MWCNT bundles from 50 nm to 2 nm and was attributed to the ultrasonication assisted dispersion with surfactant (gum arabic) employed in purification process. The network of the dispersed MWCNTs was coated onto the surfaces of mild steel samples, and as the coating temperature and holding time increased, the coating thickness reduced. The mechanical properties (tensile strength, yield strength, hardness value) of the coated steel samples increased with increase in coating temperature and holding time. Comparing the different coating conditions, coated mild steels at the temperature of 950 °C for 90 min holding time exhibited high hardness, yield strength and tensile strength values compared to others. The corrosion current and corrosion rate of the coated mild steel samples decreased with increase in holding time and coating temperature. The lowest corrosion rate was observed on sample coated at 950 °C for 90 min.

  6. Effect of chlorides on the corrosion behaviour of mild steel

    International Nuclear Information System (INIS)

    Harada, Kazuyuki; Shimada, Minoru

    1980-01-01

    In PWR's steam generators, ''denting'' resulted from corrosion of support plate material, carbon steel is an important problem. The role of chlorides in corrosion acceleration of mild steel was studied. Corrosion tests were conducted at temperature from 100 0 C to 280 0 C in deaerated solutions of NaCl and MgCl 2 which are main content of sea water. 1) Solution of MgCl 2 was more corrosive than that of NaCl. The more increased in concentration of each chloride solution, the more corrosive in MgCl 2 soln. but the less corrosive in NaCl soln. 2) The rate of corrosion in the mixed solution of NaCl and MgCl 2 was governed by the concentration of MgCl 2 soln. The corrosion behaviour in sea water was suggested to be not controlled by NaCl but by MgCl 2 . 3) Acidification of MgCl 2 soln. could be evaluated by experiment at 100 0 C, the degree of acidification increased with increasing the concentration. However, the value of pH during corrosion was kept constant by the concentration of dissolved Fe 2+ ions. 4) The corrosion acceleration by MgCl 2 soln. was arised not only from acidification by the solution itself but from continuous supplementation of H + ions with the hydrolysis of dissolved Fe 2+ ions. This autocatalytic corrosion process not exhausting acid was characterized with the corrosion in closed system such as in crevice. In addition to acidification of MgCl 2 soln., the formation of non-protective magnetite film by Mg 2+ ion was estimated to be a reason of accelerated corrosion. (author)

  7. Milled Die Steel Surface Roughness Correlation with Steel Sheet Friction

    DEFF Research Database (Denmark)

    Berglund, J.; Brown, C.A.; Rosén, B.-G.

    2010-01-01

    This work investigates correlations between the surface topography ofmilled steel dies and friction with steel sheet. Several die surfaces were prepared by milling. Friction was measured in bending under tension testing. Linear regression coefficients (R2) between the friction and texture...

  8. Effect of some pyrimidinic Schiff bases on the corrosion of mild steel in hydrochloric acid solution

    International Nuclear Information System (INIS)

    Ashassi-Sorkhabi, H.; Shaabani, B.; Seifzadeh, D.

    2005-01-01

    The efficiency of benzylidene-pyrimidin-2-yl-amine (A) (4-methyl-benzylidene)-pyrimidine-2-yl-amine (B) and (4-chloro-benzylidene)-pyrimidine-2-yl-amine, as corrosion inhibitors for mild steel in 1 M HCl have been determined by weight loss measurements and electrochemical polarization method. The results showed that these inhibitors revealed a good corrosion inhibition even at very low concentrations. Polarization curves indicate that all compounds are mixed type inhibitors. The effect of various parameters such as temperature and inhibitor concentration on the efficiency of the inhibitors has been studied. Activation energies of corrosion reaction in the presence and absence of inhibitors have been calculated. The adsorption of used compounds on the steel surface obeys Langmuir's isotherm. It appears that an efficient inhibition is characterized by a relatively greater decrease in free energy of adsorption. Significant correlations are obtained between inhibition efficiency and quantum chemical parameters using quantitative structure-activity relationship (QSAR) method

  9. Electrochemical studies of novel corrosion inhibitor for mild steel in 1 M hydrochloric acid

    Directory of Open Access Journals (Sweden)

    Ahmed A. Al-Amiery

    2018-06-01

    Full Text Available The electrochemical performance of a novel organic corrosion inhibitor 6-(4-hydroxyphenyl-3-mercapto-7,8-dihydro-[1,2,4]triazolo[4,3-b][1,2,4,5]tetrazine [HT3], for mild steel in 1 M hydrochloric acid is evaluated by potentiodynamic curves. The experimental results show that the investigated inhibitor [HT3], which can effectively retard the corrosion process that occurs to mild steel with a hydrochloric acid solution by providing a protective coating for the mild steel that, can be weakened by increasing the temperature. Furthermore, the inhibition efficiency of [HT3] increased with increasing the concentrations of the inhibitors and decreased with increasing temperature. Keywords: Corrosion, Inhibitor, Mild steel, Potentiodynamic polarization, HT3, NMR, FT-IR

  10. Inhibition Effect of Deanol on Mild Steel Corrosion in Dilute ...

    African Journals Online (AJOL)

    NICOLAAS

    2014-06-23

    Jun 23, 2014 ... allows for extensive use as the material of construction in petro- leum industries .... steel specimens was investigated after mass-loss analysis ..... Ogbuliec, Inhibition of pseudo-anaerobic corrosion of oil pipeline steel in ...

  11. A phase analysis of mild steel corrosion using 57Fe Moessbauer technique

    International Nuclear Information System (INIS)

    Lal, Roshan; Sharma, N.D.; Suman

    2005-01-01

    A phase analysis of corrosion of mild steel was studied by 57 Fe Moessbauer spectroscopy, when the fumes of aqueous hydrochloric acid in the environment of thermal power plant react with various equipment's and machinery parts made from mild steel. The formation of ΥFeOOH was observed. But the presence of some amount of αFeOOH in the super paramagnetic form cannot be ruled out. (author)

  12. Effect of methanol extract of Prosopis juliflora on mild steel corrosion in 1M HCl

    OpenAIRE

    Zulfareen, Nasarullah; Kannan, Kulanthi; Venugopal, Thiruvengadam

    2016-01-01

    The Prosopis juliflora extract was investigated as a corrosion inhibitor for mild steel in 1M HCl using weight loss measurements, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS). The inhibition efficiency of Prosopis juliflora increases with an increase in inhibitor concentration and temperature. Polarization studies revealed that Prosopis juliflora acts as a mixed type inhibitor for mild steel in 1M HCl. AC impedance indicates that the value of charge transfer ...

  13. Indeno-1-one [2,3-b]quinoxaline as an effective inhibitor for the corrosion of mild steel in 0.5 M H2SO4 solution

    International Nuclear Information System (INIS)

    Obot, I.B.; Obi-Egbedi, N.O.

    2010-01-01

    Indeno-1-one [2,3-b] quinoxaline (INQUI), synthesized in our laboratory, was tested as inhibitor for the corrosion of mild steel in 0.5 M H 2 SO 4 using gravimetric method at 30 o C. The inhibitor (INQUI) showed about 81% inhibition efficiency (E (%)) at an optimum concentration of 10 x 10 -6 M. The inhibition efficiency increases with increase in inhibitor concentration but decreases with increase in immersion time. The adsorption of the inhibitor on the mild steel in the acid solution was found to accord with Temkin's adsorption isotherm. The calculated value of the free energy for the adsorption process, ΔG ads , reveals a strong chemisorbed bond between the inhibitor and mild steel surface and a spontaneous adsorption of the inhibitor on the mild steel surface. Density functional theory (DFT) proves that INQUI molecule is adsorbed on the mild steel surface by the most negatively charged nitrogen and oxygen atoms.

  14. A Novel Schiff Base of 3-acetyl-4-hydroxy-6-methyl-(2Hpyran-2-one and 2,2'-(ethylenedioxydiethylamine as Potential Corrosion Inhibitor for Mild Steel in Acidic Medium

    Directory of Open Access Journals (Sweden)

    Jonnie N. Asegbeloyin

    2015-05-01

    Full Text Available The corrosion inhibition activity of a newly synthesized Schiff base (SB from 3-acetyl-4-hydroxy-6-methyl-(2H-pyran-2-one and 2,2'-(ethylenedioxydiethylamine was investigated on the corrosion of mild steel in 1 M HCl solution using potentiodynamic polarization and electrochemical impedance spectroscopic techniques. Ultraviolet-visible (UV-vis and Raman spectroscopic techniques were used to study the chemical interactions between SB and mild steel surface. SB was found to be a relatively good inhibitor of mild steel corrosion in 1 M HCl. The inhibition efficiency increases with increase in concentration of SB. The inhibition activity of SB was ascribed to its adsorption onto mild steel surface, through physisorption and chemisorption, and described by the Langmuir adsorption model. Quantum chemical calculations indicated the presence of atomic sites with potential nucleophilic and electrophilic characteristics with which SB can establish electronic interactions with the charged mild steel surface.

  15. Detection and evaluation of embedded mild steel can material into 18 Cr-oxide dispersion strengthened steel tubes by magnetic Barkhausen emission

    Science.gov (United States)

    Kishore, G. V. K.; Kumar, Anish; Rajkumar, K. V.; Purnachandra Rao, B.; Pramanik, Debabrata; Kapoor, Komal; Jha, Sanjay Kumar

    2017-12-01

    The paper presents a new methodology for detection and evaluation of mild steel (MS) can material embedded into oxide dispersion strengthened (ODS) steel tubes by magnetic Barkhausen emission (MBE) technique. The high frequency MBE measurements (125 Hz sweep frequency and 70-200 kHz analyzing frequency) are found to be very sensitive for detection of presence of MS on the surface of the ODS steel tube. However, due to a shallow depth of information from the high frequency MBE measurements, it cannot be used for evaluation of the thickness of the embedded MS. The low frequency MBE measurements (0.5 Hz sweep frequency and 2-20 kHz analyzing frequency) indicate presence of two MBE RMS voltage peaks corresponding to the MS and the ODS steel. The ratio of the two peaks changes with the thickness of the MS and hence, can be used for measurement of the thickness of the MS layer.

  16. Intergranular attack observed in radiation-enhanced corrosion of mild steel

    International Nuclear Information System (INIS)

    Reda, R.J.; Kelly, J.L.; Harna, S.L.A.

    1988-01-01

    Experiments were conducted to determine the effects of gamma radiation on the corrosion of AISI 1018 mild steel in deaerated brine solutions of various sodium, magnesium, and chloride ion concentrations. Immersed metal specimens were irradiated at an exposure rate of 3 x 10/sup 5/ R/h (0.3 MR/h) for up to 1250 h at a temperature of --25 C. The corrosion rates of the irradiated specimens were found to be roughly a factor of 10 greater than the rates for the non-irradiated specimens. The radiation-enhanced corrosion rate was also found to have increased with the chloride concentration. Electron micrographs revealed that the surface morphology of the specimens exposed to irradiated brines differed greatly from the non-irradiated specimens. The non-irradiated specimens had undergone uniform corrosion, while the irradiated specimens exhibited intergranular corrosion (IGC), a phenomenon not yet observed in mild steel. An explanation for this observation is offered in terms of the relative rates of formation and recombination of radiolytic species

  17. Evaluation of properties and FEM Model of the Friction welded mild Steel-Al6061-Alumina

    Directory of Open Access Journals (Sweden)

    Hazman Seli

    2013-04-01

    Full Text Available Evaluation of mechanical and interfacial properties of friction welded alumina-mild steel rods with the use of Al6061 sheet are presented in this work. SEM, EDX analysis, hardness and bending strength tests were conducted. The bonds were attained through interfacial interlocking and intermetalllic phase formation with average bending strengths in the range of 40 to 200 MPa and insignificant hardness change in the parent alumina and mild steel. A preliminary simulation was made to predict the deformation, stress, strain and temperature distribution during the joining operation using a fully coupled thermo-mechanical FE model. The aluminum alloy metal being rubbed was simulated using a phenomenological Johnson-Cook viscoplasticity material model, which suited for materials subjected to large strains, high strain rates and high temperatures. The highest stress, strain and deformation are found to be within the heat affected zone of the weld close to the periphery rubbing surface region and correspond to the highest temperature profiles observed.

  18. Evaluation of properties and FEM Model of the Friction welded mild Steel-Al6061-Alumina

    Directory of Open Access Journals (Sweden)

    Hazman Seli

    2012-01-01

    Full Text Available Evaluation of mechanical and interfacial properties of friction welded alumina-mild steel rods with the use of Al6061 sheet are presented in this work. SEM, EDX analysis, hardness and bending strength tests were conducted. The bonds were attained through interfacial interlocking and intermetalllic phase formation with average bending strengths in the range of 40 to 200 MPa and insignificant hardness change in the parent alumina and mild steel. A preliminary simulation was made to predict the deformation, stress, strain and temperature distribution during the joining operation using a fully coupled thermo-mechanical FE model. The aluminum alloy metal being rubbed was simulated using a phenomenological Johnson-Cook viscoplasticity material model, which suited for materials subjected to large strains, high strain rates and high temperatures. The highest stress, strain and deformation are found to be within the heat affected zone of the weld close to the periphery rubbing surface region and correspond to the highest temperature profiles observed.

  19. Neutrophilic Iron-Oxidizing Zetaproteobacteria and Mild Steel Corrosion in Nearshore Marine Environments

    Science.gov (United States)

    2011-02-16

    sample harvested at 14 days, and 316L stainless steel controls did not show evidence of corrosion product formation at any of the time points. A...direct or indirect enzymatic reduction or oxidation of corrosion products, formation of biofilms that create corrosive microen- vironments, or...sampler prior to deployment. Cold-finish 1018 mild steel coupons and 3161. stainless steel control coupons (13 by 15 by 3 mm) were polished with a

  20. Isatin derivatives as a non-toxic corrosion inhibitor for mild steel in 20% H2SO4

    International Nuclear Information System (INIS)

    Ansari, K.R.; Quraishi, M.A.; Singh, Ambrish

    2015-01-01

    Highlights: • Mild steel protection in 20% H 2 SO 4 by TZs. • Potentiodynamic polarization curves reveal that the actions of TZs are mixed type but cathodically predominant. • The adsorption of TZs obeys the Langmuir adsorption isotherm. • Examination of surface morphology by SEM and EDX. • Correlation between experimental and quantum chemical results. - Abstract: The corrosion inhibition action of Isatin-β-thiosemicarbzone derivatives namely 1-Benzylidene-5-(2-oxoindoline-3-ylidene) Thiocarbohydrazone (TZ-1) and 1-(4-Methylbenzylidene)-5-(2-oxoindolin-3-ylidene) Thiocarbohydrazone (TZ-2) was studied on mild steel surface in 20% H 2 SO 4 by gravimetric measurements, Electrochemical measurements (EIS and Tafel), SEM, EDX and quantum chemical methods. Potentiodynamic polarization curves reveal that the TZs act as mixed type inhibitors exhibiting predominantly cathodic behavior. The adsorption of TZs obeys the Langmuir adsorption isotherm. The thermodynamic parameters (E a , K ads , ΔG° ads ) were also computed and discussed

  1. Synergistic Effect on Corrosion Inhibition Efficiency of Ginger Affinale Extract in Controlling Corrosion of Mild Steel in Acid Medium

    Energy Technology Data Exchange (ETDEWEB)

    Subramanian, Ananth Kumar; Arumugam, Sankar [Kandaswami Kandar' s College, Namakkal (India); Mallaiya, Kumaravel; Subramaniam, Rameshkumar [PSG College of Technology Peelamedu, Coimbatore (India)

    2013-12-15

    The corrosion inhibition nature of Ginger affinale extract for the corrosion of mild steel in 0.5N H{sub 2}SO{sub 4} was investigated using weight loss, electrochemical impedance and potentiodynamic polarization methods. The results revealed that Ginger affinale extract acts as a good corrosion inhibitor in 0.5N H{sub 2}SO{sub 4} medium. The inhibition efficiency increased with an increase in inhibitor concentration. The inhibition could be attributed to the adsorption of the inhibitor on the steel surface.

  2. Anticorrosive Performance of Zinc Phosphate Coatings on Mild Steel Developed Using Galvanic Coupling

    Directory of Open Access Journals (Sweden)

    M. Arthanareeswari

    2013-01-01

    Full Text Available The anticorrosive performance of zinc phosphate coatings developed by galvanic coupling technique on mild steel substrates using the cathode materials such as titanium (Ti, copper (Cu, brass (BR, nickel (Ni, and stainless steel (SS is elucidated in this study. Thermal and chemical stability tests, immersion test in 3.5% NaCl, ARE salt droplet test, and salt spray test were carried out. The study reveals that the mild steel substrates phosphated under galvanically coupled condition showed better corrosion resistance than the one coated without coupling. The open circuit potential (OCP of phosphated mild steel panels in 3.5% NaCl was found to be a function of phosphate coating weight and porosity of the coating.

  3. Adsorption and corrosion inhibiting effect of riboflavin on Q235 mild steel corrosion in acidic environments

    Energy Technology Data Exchange (ETDEWEB)

    Chidiebere, Maduabuchi A. [Institute of Metal Research, Chinese Academy of Sciences, 62 Wencui Rd, Shenyang 110016 (China); Electrochemistry and Materials Science Research Laboratory, Department of Chemistry, Federal University of Technology Owerri, PMB 1526 Owerri (Nigeria); Oguzie, Emeka E. [Electrochemistry and Materials Science Research Laboratory, Department of Chemistry, Federal University of Technology Owerri, PMB 1526 Owerri (Nigeria); Liu, Li [Institute of Metal Research, Chinese Academy of Sciences, 62 Wencui Rd, Shenyang 110016 (China); Li, Ying, E-mail: liying@imr.ac.cn [Institute of Metal Research, Chinese Academy of Sciences, 62 Wencui Rd, Shenyang 110016 (China); Wang, Fuhui [Institute of Metal Research, Chinese Academy of Sciences, 62 Wencui Rd, Shenyang 110016 (China)

    2015-04-15

    The inhibiting effect of Riboflavin (RF) on Q235 mild steel corrosion in 1 M HCl and 0.5 M H{sub 2}SO{sub 4} at 30 °C temperature was investigated using electrochemical techniques (electrochemical impedance spectroscopy and potentiodynamic polarization). The obtained results revealed that RF inhibited the corrosion reaction in both acidic solutions. Maximum inhibition efficiency values in 1 M HCl and 0.5 M H{sub 2}SO{sub 4} were 83.9% and 71.4%, respectively, obtained for 0.0012 M RF. Polarization data showed RF to be a mixed-type inhibitor, while EIS results revealed that the RF species adsorbed on the metal surface. The adsorption of RF followed Langmuir adsorption isotherm. Atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) studies confirmed the formation of a protective layer adsorbed on the steel surface. Quantum chemical calculations were used to correlate the inhibition ability of RF with its electronic structural parameters. - Highlights: • The inhibitory mechanism was influenced by the nature of acid anions. • RF has reasonable inhibition effect especially in 1 M HCl solution. • Polarization studies showed that RF functioned as a mixed type inhibitor. • Improved surface morphology was observed in the presence of RF.

  4. COMPARATIVE STUDY OF THE INHIBITIVE ACTION BETWEEN THE BITTER ORANGE LEAF EXTRACT AND ITS CHEMICAL CONSTITUENT LINALOOL ON THE MILD STEEL CORROSION IN HCL SOLUTION

    Directory of Open Access Journals (Sweden)

    Ashraf M. Abdel-Gaber

    Full Text Available Bitter orange, Citrus Aurantium (CA, extract and one of its chemical constituents, Linalool, have been evaluated as a corrosion inhibitor for mild steel in 0.5 mol L-1 hydrochloric acid (HCl solution using potentiodynamic polarization, electrochemical impedance, Fourier transform infrared spectroscopy (FTIR, and atomic force spectroscopy (AFM techniques. Functional groups of CA and Linalool were identified by FTIR spectroscopy. The Potentiodynamic polarization and electrochemical impedance studies showed that CA and Linalool act as mixed type inhibitors. The activation parameters showed that the corrosion inhibition takes place by spontaneous physical adsorption on the mild steel surface. Thermodynamic-kinetic model and Flory-Huggins isotherms were used to investigate the adsorption characteristics of CA and Linalool. The surface morphologies of mild steel specimens were studied using AFM, in which the surface roughness of the metal specimens on a micro scale was characterized.

  5. Green approach to corrosion inhibition of mild steel in hydrochloric acid and sulphuric acid solutions by the extract of Murraya koenigii leaves

    Energy Technology Data Exchange (ETDEWEB)

    Quraishi, M.A., E-mail: maquraishi@rediffmail.com [Department of Applied Chemistry, Institute of Technology, Banaras Hindu University, Varanasi 221005 (India); Singh, Ambrish; Singh, Vinod Kumar [Udai Pratap Autonomous College, Varanasi 221002 (India); Yadav, Dileep Kumar; Singh, Ashish Kumar [Department of Applied Chemistry, Institute of Technology, Banaras Hindu University, Varanasi 221005 (India)

    2010-07-01

    The inhibition of the corrosion of mild steel in hydrochloric acid and sulphuric acid solutions by the extract of Murraya koenigii leaves has been studied using weight loss, electrochemical impedance spectroscopy (EIS), linear polarization and potentiodynamic polarization techniques. Inhibition was found to increase with increasing concentration of the leaves extract. The effect of temperature, immersion time and acid concentration on the corrosion behavior of mild steel in 1 M HCl and 0.5 M H{sub 2}SO{sub 4} with addition of extract was also studied. The inhibition was assumed to occur via adsorption of the inhibitor molecules on the metal surface. The adsorption of the extract on the mild steel surface obeys the Langmuir adsorption isotherm. The activation energy as well as other thermodynamic parameters (Q, {Delta}H*, and {Delta}S*) for the inhibition process was calculated. These thermodynamic parameters show strong interaction between inhibitor and mild steel surface. The results obtained show that the extract of the leaves of M. koenigii could serve as an effective inhibitor of the corrosion of mild steel in hydrochloric and sulphuric acid media.

  6. Spontaneous passivation observations during scale formation on mild steel in CO{sub 2} brines

    Energy Technology Data Exchange (ETDEWEB)

    Han Jiabin, E-mail: jhan@lanl.gov [Institute for Corrosion and Multiphase Technology, Department of Chemical and Biomolecular Engineering, Ohio University, 342 West State Street, Athens, OH 45701 (United States); Nesic, Srdjan, E-mail: nesic@ohio.edu [Institute for Corrosion and Multiphase Technology, Department of Chemical and Biomolecular Engineering, Ohio University, 342 West State Street, Athens, OH 45701 (United States); Yang Yang; Brown, Bruce N. [Institute for Corrosion and Multiphase Technology, Department of Chemical and Biomolecular Engineering, Ohio University, 342 West State Street, Athens, OH 45701 (United States)

    2011-06-01

    Highlights: > We observed spontaneous passivation was at pH > 7. A higher open circuit potential was achieved comparing to bare surface or FeCO{sub 3} scaled surface. > Effects of pH, temperature, CO{sub 2}/FeCO{sub 3} on spontaneous passivation were systematically investigated. > TEM analysis determined the structure and chemistry of the passive film is Fe{sub 3}O{sub 4} instead of FeCO{sub 3}. > Root cause of the galvanic mechanism of localized CO{sub 2} corrosion is clarified. - Abstract: Previous study revealed localized corrosion in CO{sub 2} environments was driven by a galvanic cell established between pit surfaces and scaled surrounding area. In order to underpin the understanding of the galvanic mechanism of localized corrosion, the root cause of potential differences between these two surfaces, passivation of mild steel, in CO{sub 2} environments was investigated using transmission electron microscopy technique and electrochemical techniques including potentiodynamic polarization, cyclic polarization and open circuit potential techniques. Potentiodynamic polarization experiments showed that the passivation of the carbon steel surface favorably occurred at pH > 7 and facilitated with the presence of FeCO{sub 3} scale. Cyclic polarization tests showed that polarization rate had an important influence on passivation behavior. At a slower polarization rate, lower passivation potential and current density were observed. Spontaneous passivation was evidenced by a significant increase of corrosion resistance and an open circuit potential without any externally applied current or potential during electrode immersion. This process is affected by pH, temperature, presence of CO{sub 2} and iron carbonate. Nevertheless, iron carbonate film is not the only one responsible for passivation, as demonstrated from depassivation tests where passivity was lost without losing the existing iron carbonate film. Transmission electron microscopy technique was used to determine

  7. Corrosion Protection Of Mild Steel In Sea Water Using Chemical Inhibitor

    Science.gov (United States)

    Araoyinbo, Alaba O.; Salleh, Mohd Arif Anuar Mohd; Zulerwan Jusof, Muhammad

    2018-03-01

    The effect of sodium nitrite as a corrosion inhibitor of mild steel in sea water (i.e ASTM standard prepared sea water and sea water obtained from a local river) was investigated, using the weight loss technique. Different amount of sodium nitrite were prepared (i.e 2 % to 10 %) in the inhibition of the mild steel corrosion in sea water exposed to irradiation condition from sunlight exposure. The cut samples of mild steel were exposed to these corrosive media and the corresponding weight loss subsequently obtained was recorded at intervals of 1 to 4 weeks. It was observed that corrosion rate increases with the time of exposure to the corrosive medium exposed to sunlight and that sodium nitrite that was used at the chemical inhibitor was able to retard the corrosion rate of mild steel if the appropriate concentration is applied. The results obtained from the weight loss analysis shows that the optimum percentage of sodium nitrate in sea water that gives the optimum corrosion inhibition of mild steel is 4 %.

  8. Baphia nitida Leaves Extract as a Green Corrosion Inhibitor for the Corrosion of Mild Steel in Acidic Media

    Directory of Open Access Journals (Sweden)

    V. O. Njoku

    2014-01-01

    Full Text Available The inhibiting effect of Baphia nitida (BN leaves extract on the corrosion of mild steel in 1 M H2SO4 and 2 M HCl was studied at different temperatures using gasometric and weight loss techniques. The results showed that the leaves extract is a good inhibitor for mild steel corrosion in both acid media and better performances were obtained in 2 M HCl solutions. Inhibition efficiency was found to increase with increasing inhibitor concentration and decreasing temperature. The addition of halides to the extract enhanced the inhibition efficiency due to synergistic effect which improved adsorption of cationic species present in the extract and was in the order KCl < KBr < KI suggesting possible role of radii of the halide ions. Thermodynamic parameters determined showed that the adsorption of BN on the metal surface is an exothermic and spontaneous process and that the adsorption was via a physisorption mechanism.

  9. Synthesis, characterization, and corrosion protection properties of poly(N-(methacryloyloxymethyl) benzotriazole-co-methyl methacrylate) on mild steel

    Energy Technology Data Exchange (ETDEWEB)

    Srikanth, A.P. [Department of Applied Sciences and Humanities, MIT Campus, Anna University, Chennai 600044 (India); Lavanya, A. [Department of Chemistry, CEG Campus, Anna University, Chennai 600025 (India); Nanjundan, S. [Department of Chemistry, CEG Campus, Anna University, Chennai 600025 (India); Rajendran, N. [Department of Applied Sciences and Humanities, MIT Campus, Anna University, Chennai 600044 (India)]. E-mail: nrajendran@annauniv.edu

    2006-12-15

    The copolymers from different feed ratios of N-(methacryloyloxymethyl) benzotriazole (MMBT) and methyl methacrylate (MMA) has been synthesised using free radical solution polymerization technique and characterized using FT-IR and {sup 13}C NMR spectroscopy. The thermal stability of the polymers was studied using theremogravimetrtic analysis (TGA). The corrosion behaviors of mild steel specimens dip coated with different composition of copolymers have been evaluated by potentiodynamic polarization and electrochemical impedance spectroscopic (EIS) method. These electrochemical properties were observed in 0.1 M HCl medium. The polarization and impedance measurements showed different corrosion protection efficiency with change in composition of the copolymers. It was found that the corrosion protection properties are owing to the barrier effect of the polymer layer covered on the mild steel surfaces. However, it was observed that the copolymer obtained from 1:1 mole ratio of MMBT and MMA exhibited better protection efficiency than other combinations.

  10. Synthesis, characterization, and corrosion protection properties of poly( N-(methacryloyloxymethyl) benzotriazole- co-methyl methacrylate) on mild steel

    Science.gov (United States)

    Srikanth, A. P.; Lavanya, A.; Nanjundan, S.; Rajendran, N.

    2006-12-01

    The copolymers from different feed ratios of N-(methacryloyloxymethyl) benzotriazole (MMBT) and methyl methacrylate (MMA) has been synthesised using free radical solution polymerization technique and characterized using FT-IR and 13C NMR spectroscopy. The thermal stability of the polymers was studied using theremogravimetrtic analysis (TGA). The corrosion behaviors of mild steel specimens dip coated with different composition of copolymers have been evaluated by potentiodynamic polarization and electrochemical impedance spectroscopic (EIS) method. These electrochemical properties were observed in 0.1 M HCl medium. The polarization and impedance measurements showed different corrosion protection efficiency with change in composition of the copolymers. It was found that the corrosion protection properties are owing to the barrier effect of the polymer layer covered on the mild steel surfaces. However, it was observed that the copolymer obtained from 1:1 mole ratio of MMBT and MMA exhibited better protection efficiency than other combinations.

  11. The inhibition performance of long-chain alkyl-substituted benzimidazole derivatives for corrosion of mild steel in HCl

    International Nuclear Information System (INIS)

    Zhang, Dongqin; Tang, Yongming; Qi, Sijun; Dong, Dawei; Cang, Hui; Lu, Gang

    2016-01-01

    Highlights: • Inhibition performance of long-chain alkyl-substituted benzimidazole. • Benzimidazole segment donating electrons to metal surface. • Non-polar long chain enhancing inhibition by the barrier effect. • Molecular form of DBI more tightly adsorbs on the steel than its protonated form. - Abstract: The corrosion inhibition of a new benzimidazole derivative, 6-(dodecyloxy)-1H-benzo[d]imidazole (DBI), for mild steel in 1 M HCl was investigated in this paper. Computational chemistry was performed to explore the adsorption of DBI on metal surface. Inhibition performance of DBI is attributed to both the direct interaction of benzimidazole segment with iron surface and the barrier effect of the non-polar long chain against aggressive solution. Compared to the protonated form, the molecular form of DBI could more tightly interact with iron surface. These results show that the long-chain alkyl-substituted benzimidazole derivative is of great potential application as corrosion inhibitor.

  12. X-ray photoelectron spectroscopy and electrochemical studies of mild steel FeE500 passivation in concrete simulated water

    Science.gov (United States)

    Miserque, F.; Huet, B.; Azou, G.; Bendjaballah, D.; L'Hostis, V.

    2006-11-01

    In the context of the prediction of the long-term behaviour of reinforced concrete structures involved in the nuclear waste storage, the corrosion mechanisms of steels have to be assessed. When mild steel rebars are embedded in concrete, the chemical environment of the reinforcement is progressively modified, due to the carbonation of the concrete matrix. This modification leads to the variation of iron oxides properties formed at the steel/concrete interface, and the active corrosion can be initiated. The aim of this study is to evaluate the passivation behaviour and to provide insights into the depassivation of mild steel in concrete pore solution. In a young concrete, due to the alkalinity of the interstitial solution, steel reinforcement remains passive. Immersion tests of mild steel substrate in various alkaline solutions (from pH 13 to 10) have been performed. Due to the low thickness of the corrosion layers formed, X-ray photoelectron spectroscopy has been used to characterize them. In the passive domain, the corrosion products are similar for the various solutions. The corrosion layer is composed of a mixture of Fe3+ and Fe2+. A similar approach is used to determine the depassivation mechanism. The effect of various components such as carbonates, sulfates and silicates resulting from the dissolution of minerals of cement during the carbonation process is investigated. In addition to the surface analysis, the evolution of the electrochemical behaviour as function of the solution nature (pH) is evaluated with the help of electrochemical measurements (free corrosion potential, cyclic voltamperometry).

  13. Inhibition properties of self-assembled corrosion inhibitor talloil diethylenetriamine imidazoline for mild steel corrosion in chloride solution saturated with carbon dioxide

    International Nuclear Information System (INIS)

    Jevremović, Ivana; Singer, Marc; Nešić, Srđan; Mišković-Stanković, Vesna

    2013-01-01

    Highlights: •Corrosion inhibitor talloil diethylenetriamine imidazoline effectively protects mild steel from CO 2 corrosion. •Quartz crystal microbalance measurements were used to the investigate kinetics of corrosion inhibitor adsorption. •Adsorption of talloil diethylenetriamine imidazoline can be described by Langmuir adsorption isotherm. -- Abstract: The inhibition effect of talloil diethylenetriamine imidazoline (TOFA/DETA imidazoline) on corrosion of mild steel in chloride solutions saturated with CO 2 was investigated by weight loss measurements (WL) and atomic force microscopy (AFM). Adsorption mechanism and kinetics of self-assembled (TOFA/DETA imidazoline) monolayers formation on gold were studied using the quartz crystal microbalance measurements (QCM). WL and AFM results demonstrated that TOFA/DETA imidazoline can effectively protect mild steel surface from corrosion. QCM measurements shown that the adsorption of TOFA/DETA imidazoline onto gold follows Langmuir adsorption isotherm and further investigation of the adsorption process will be carried out on a corroding metal surface

  14. Correlating electronic structure with corrosion inhibition potentiality of some bis-benzimidazole derivatives for mild steel in hydrochloric acid: Combined experimental and theoretical studies

    International Nuclear Information System (INIS)

    Dutta, Alokdut; Saha, Sourav Kr.; Banerjee, Priyabrata; Sukul, Dipankar

    2015-01-01

    Highlights: • Bis-benzimidazole derivatives as good corrosion inhibitors for mild steel in acid. • Simultaneous both way electron-transfer is expected to occur during adsorption. • Role of molecular conformation on inhibition efficiency is demonstrated. • Good correlation between inhibition efficiency and molecular parameters established. • MD simulation results support experimental observations. - Abstract: Four different bis-benzimidazole (BBI) derivatives, tested as potential corrosion inhibitors for mild steel in 1 M HCl, have revealed good inhibition efficiency for long period of exposure. Inhibitors impart high resistance towards charge transfer across metal–electrolyte interface and behave broadly as mixed type. DFT calculations are used to correlate inhibition potentiality with intrinsic molecular parameters. From the optimized geometry of BBI derivatives, electron distribution in HOMO and LUMO and Fukui indices of each atom, possible modes of interaction of BBI derivatives with mild steel surface have been predicted. Energy corresponding to inhibitor-metal surface interaction is evaluated following molecular dynamics simulation

  15. Corrosion Inhibition and Adsorption Characteristics of Tarivid on Mild Steel in H2SO4

    Directory of Open Access Journals (Sweden)

    N. O. Eddy

    2010-01-01

    Full Text Available The corrosion inhibition and adsorption characteristics of (+/--9-fluoro-2,3-dihydro-3-methyl-10-(4-methyl-1-piperazinyl-7-oxo-7H-pyrido[1,2,3-de]-1,4-benzoxazine-6-carboxylic acid (Tarivid on the corrosion of mild steel has been studied using thermometric and gasometric methods. The study reveals that tarivid inhibits the corrosion of mild steel in H2SO4. The values of inhibition efficiency of tarivid were found to increase as its concentration increased but decreased with increase in temperature. Activation energies of the inhibited corrosion of mild steel ranged from 39.05 to 50.61 kJ/mol. Values of enthalpy change and free energy of adsorption were negative which indicated exothermic and spontaneous adsorption process. Physical adsorption mechanism is proposed from the obtained kinetic and thermodynamic parameters. Langmuir adsorption isotherm model is obeyed from the fit of the experimental data.

  16. Magnetic Non-destructive Testing of Plastically Deformed Mild Steel

    Directory of Open Access Journals (Sweden)

    Jozef Pala

    2004-01-01

    Full Text Available The Barkhausen noise analysis and coercive field measurement have been used as magnetic non-destructive testing methods for plastically deformed high quality carbon steel specimens. The strain dependence of root mean square value and power spectrum of the Barkhausen noise and the coercive field are explained in terms of the dislocation density. The specimens have been subjected to different magnetizing frequencies to show the overlapping nature of the Barkhausen noise. The results are discussed in the context of usage of magnetic non-destructive testing to evaluate the plastic deformation of high quality carbon steel products.

  17. Study of Plant Cordia Dichotoma as Green Corrosion Inhibitor for Mild Steel in Different Acid Media

    Directory of Open Access Journals (Sweden)

    R. Khandelwal

    2011-01-01

    Full Text Available The corrosion inhibition of mild steel using extracts of Cordia dichotoma in different acid media was investigated by mass loss and thermometric methods. The experiments were carried out at 299±0.2 K in presence of different concentrations of dry fruit, leaves and stem extracts of Cordia dichotoma. The results reveal that the alcoholic extracts of Cordia dichotoma is a better corrosion inhibitor than that of toxic chemicals. The fruit extract is more potent than leaves and stem extracts to inhibit the corrosion rate. The study seeks to investigate the possibility of using extracts of Cordia dichotoma as a green corrosion inhibitor for mild steel.

  18. Performance evaluation of Titanium nitride coated tool in turning of mild steel

    Science.gov (United States)

    Srinivas, B.; Pramod Kumar, G.; Cheepu, Muralimohan; Jagadeesh, N.; kumar, K. Ravi; Haribabu, S.

    2018-03-01

    The growth in demand for bio-gradable materials is opened as a venue for using vegetable oils, coconut oils etc., as alternate to the conventional coolants for machining operations. At present in manufacturing industries the demand for surface quality is increasing rapidly along with dimensional accuracy and geometric tolerances. The present study is influence of cutting parameters on the surface roughness during the turning of mild steel with TiN coated carbide tool using groundnut oil and soluble oil as coolants. The results showed vegetable gave closer surface finish compares with soluble oil. Cutting parameters has been optimized with Taguchi technique. In this paper, the main objective is to optimize the cutting parameters and reduce surface roughness analogous to increase the tool life by apply the coating on the carbide inserts. The cost of the coating is more, but economically efficient than changing the tools frequently. The plots were generated and analysed to find the relationship between them which are confirmed by performing a comparison study between the predicted results and theoretical results.

  19. Biocorrosion of mild steel and copper used in cooling tower water and its control.

    Science.gov (United States)

    Li, Xiao Lei; Narenkumar, Jayaraman; Rajasekar, Aruliah; Ting, Yen-Peng

    2018-03-01

    The present study describes the biocorrosion of mild steel (MS1010) and pure copper (Cu) in cooling water environments (both field and lab study). Electrochemical and surface analyses of both metals were carried out to confirm the corrosion susceptibility in the presence of bacteria and inhibitor. Surface analysis of the MS and Cu coupons revealed that biofilm was developed with increasing exposure time in the field study. In the lab study, accumulation of extracellular polymeric substance over the metal surface was noticed and led to the severe pitting type of corrosion on both metal surfaces. Besides, the anti-corrosive study was carried out using the combinations of commercial corrosion inhibitor (S7653-10 ppm) with biocide (F5100-5 ppm), and the results reveal that the corrosion rate of MS and Cu was highly reduced to 0.0281 and 0.0021 mm/year (inhibitor system) than 0.1589 and 0.0177 mm/year (control system). Inhibition efficiency for both metals in the presence of inhibitor with biocide was found as 82 and 88% for MS and Cu, respectively. The present study concluded that MS was very susceptible to biocorrosion, compared to copper metal in cooling water environment. Further, the combination of the both inhibitor and biocide was effectively inhibiting the biocorrosion which was due to its antibacterial and anti-corrosive properties.

  20. Assessment of biological chromium among stainless steel and mild steel welders in relation to welding processes.

    Science.gov (United States)

    Edmé, J L; Shirali, P; Mereau, M; Sobaszek, A; Boulenguez, C; Diebold, F; Haguenoer, J M

    1997-01-01

    Air and biological monitoring were used for assessing external and internal chromium exposure among 116 stainless steel welders (SS welders) using manual metal arc (MMA), metal inert gas (MIG) and tungsten inert gas (TIG) welding processes (MMA: n = 57; MIG: n = 37; TIG: n = 22) and 30 mild steel welders (MS welders) using MMA and MIG welding processes (MMA: n = 14; MIG: n = 16). The levels of atmospheric total chromium were evaluated after personal air monitoring. The mean values for the different groups of SS welders were 201 micrograms/m3 (MMA) and 185 micrograms/m3 (MIG), 52 micrograms/m3 (TIG) and for MS welders 8.1 micrograms/m3 (MMA) and 7.3 micrograms/m3 (MIG). The curve of cumulative frequency distribution from biological monitoring among SS welders showed chromium geometric mean concentrations in whole blood of 3.6 micrograms/l (95th percentile = 19.9), in plasma of 3.3 micrograms/l (95th percentile = 21.0) and in urine samples of 6.2 micrograms/l (95th percentile = 58.0). Among MS welders, mean values in whole blood and plasma were rather more scattered (1.8 micrograms/l, 95th percentile = 9.3 and 1.3 micrograms/l, 95th percentile = 8.4, respectively) and in urine the value was 2.4 micrograms/l (95th percentile = 13.3). The analysis of variance of chromium concentrations in plasma previously showed a metal effect (F = 29.7, P process effect (F = 22.2, P process interaction (F = 1.3, P = 0.25). Concerning urinary chromium concentration, the analysis of variance also showed a metal effect (F = 30, P process effect (F = 72, P process interaction (F = 13.2, P = 0.0004). Throughout the study we noted any significant differences between smokers and non-smokers among welders. Taking in account the relationships between chromium concentrations in whole, plasma or urine and the different welding process. MMA-SS is definitely different from other processes because the biological values are clearly higher. These higher levels are due to the very significant

  1. The heterogeneous electrochemical characteristics of mild steel in the presence of local glucose oxidase-A study by the wire beam electrode method

    International Nuclear Information System (INIS)

    Wang Wei; Lu Yonghong; Zou Yan; Zhang Xia; Wang Jia

    2010-01-01

    The influence of glucose oxidase (GOD) activity on the heterogeneous electrochemistry at artificial biofilm/mild steel interface was first characterized by the wire beam electrode (WBE) method. Potential/current distribution maps show that a cathodic zone can be formed at the GOD capsule site. The cathodic zone is gradually weakened due to the gluconic acid production in seawater. When GOD capsule is confined on rusted WBE surfaces, the formerly formed anodic zone is gradually changed into cathodic zone, in the presence of glucose. The novel device developed in our laboratory demonstrates powerful applications in heterogeneous electrochemistry measurements at the biofilm/mild steel interfaces.

  2. Utilization of ISO 6892:2009 testing standard for determining tensile properties of TM380 mild steel

    CSIR Research Space (South Africa)

    Shoke, L

    2013-04-01

    Full Text Available mild steel. To achieve this objective, we reviewed the ISO 6892:2009 tensile testing standard along with reported good practice guidelines. Tensile tests were conducted on a dog-bone shaped TM380 mild steel specimen with strain gauges attached on either...

  3. Corrosion behavior of mild steel and SS 304L in presence of dissolved nickel under aerated and deaerated conditions

    Directory of Open Access Journals (Sweden)

    Mohd Mobin

    2011-12-01

    Full Text Available In dual purpose water/power co-generation plants, the presence of high concentration of Cu and Ni in the re-circulating brine/condensate as a result of condenser tubes corrosion has been attributed as one of the several causes of corrosion damage of flash chamber materials and water touched parts of the boilers. The present investigation deals with the effect of dissolved nickel in the concentration range of 10 ppb to 100 ppm on the corrosion behavior of mild steel and SS 304L in two aqueous medium namely, distilled water and artificial seawater. The effect of pH, dissolved oxygen and flow condition of aqueous medium on the corrosion behavior was also monitored. The experimental techniques include immersion test and electrochemical tests which include free corrosion potential measurements and potentiodynamic polarization measurements. The corrosion rate of mild steel and SS 304L under different experimental conditions was determined by weight loss method and spectrophotometric determination of iron ion entered into the test solution during the period of immersion. The pH of the test solution was also monitored during the entire period of immersion. The left over nickel ions present in the test solution after completion of immersion was also estimated using Atomic Absorption Spectrophotometer. The surface morphology of the corroded steel surface was also examined using scanning electron microscopy (SEM. The results of the studies show that SS 304L largely remains unaffected in both distilled water and artificial seawater under different experimental conditions. However, the effect of nickel on the corrosion behavior of mild steel is quite pronounced and follows interesting trends.

  4. Inhibition of the corrosion of mild steel by phosphate conversion coatings

    International Nuclear Information System (INIS)

    Ashraf, W.; Khalid, S.; Rashid, A.; Arshad, M.

    1993-01-01

    Phosphating is the treatment of a metal surface to provide a coating of insoluble metal phosphate crystals which strongly adhere to the base material. Such coatings affect the appearance, surface hardness, and electrical conductivity of the metal. Phosphating is major industrial importance in the production of iron and steel surfaces, e.g., in automotive and appliance industries. The present article discusses a novel description of process controlling parameters. The process may be termed as hot phosphate (95-100 deg. C) and it employs the use of low cost chemicals and entirely new accelerator. Effective layer thickness is found to be 0.72 mg/cm /sup 2/ and can withstand moist and mild chemical conditions. The thickness of coating depends upon dipping time and temperature of the working bath. It seems to increase with increasing dipping time but then reaches a maxima. Any more dipping causes stripping and uneven coating layers. In our system most appropriate dipping time was found to be 45 minutes. The stability and completeness of coating was tested by Ferro Test and Tape Pull Test and was found to be satisfactory. The quality control parameters, such as free and total acidity have been controlled for optimum coating thickness and stability. (author)

  5. Effect of Benzamide on the Corrosion Inhibition of Mild Steel in ...

    African Journals Online (AJOL)

    NICOLAAS

    2SO4 was studied at .... The structure and chemistry of benzamide is expected to give .... corrosion inhibition of mild steel in the sulphuric acid strength ... tion and formation of a compact barrier film on the metal elec- .... metal–acid interface.

  6. Inhibitor for the Corrosion of Mild Steel in H 2 SO 4 | Patel | South ...

    African Journals Online (AJOL)

    An extract of Terminalia chebula fruits was investigated as a corrosion inhibitor of mild steel in 0.5 M H2SO4 by means of conventional mass loss, electrochemical polarization, electrochemical impedance spectroscopy and scanning electron microscopy. The mass loss results showed that the extract of Terminalia chebula is ...

  7. Microstructural characterisation of friction stir welding joints of mild steel to Ni-based alloy 625

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, J. [Brazilian Nanotechnology National Laboratory (LNNano), P.O. Box 6192, Campinas, SP (Brazil); University of Campinas (UNICAMP), Campinas, SP (Brazil); Ramirez, A.J., E-mail: ramirezlondono.1@osu.edu [Brazilian Nanotechnology National Laboratory (LNNano), P.O. Box 6192, Campinas, SP (Brazil); University of Campinas (UNICAMP), Campinas, SP (Brazil); Department of Materials Science and Engineering, The Ohio State University — OSU, Columbus, OH 43221 (United States)

    2015-12-15

    In this study, 6-mm-thick mild steel and Ni-based alloy 625 plates were friction stir welded using a tool rotational speed of 300 rpm and a travel speed of 100 mm·min{sup −1}. A microstructural characterisation of the dissimilar butt joint was performed using optical microscopy, scanning and transmission electron microscopy, and energy dispersive X-ray spectroscopy (XEDS). Six different weld zones were found. In the steel, the heat-affected zone (HAZ) was divided into three zones and was composed of ferrite, pearlite colonies with different morphologies, degenerated regions of pearlite and allotriomorphic and Widmanstätten ferrite. The stir zone (SZ) of the steel showed a coarse microstructure consisting of allotriomorphic and Widmanstätten ferrite, degenerate pearlite and MA constituents. In the Ni-based alloy 625, the thermo-mechanically affected zone (TMAZ) showed deformed grains and redistribution of precipitates. In the SZ, the high deformation and temperature produced a recrystallised microstructure, as well as fracture and redistribution of MC precipitates. The M{sub 23}C{sub 6} precipitates, present in the base material, were also redistributed in the stir zone of the Ni-based alloy. TMAZ in the steel and HAZ in the Ni-based alloy could not be identified. The main restorative mechanisms were discontinuous dynamic recrystallisation in the steel, and discontinuous and continuous dynamic recrystallisation in the Ni-based alloy. The interface region between the steel and the Ni-based alloy showed a fcc microstructure with NbC carbides and an average length of 2.0 μm. - Highlights: • Comprehensive microstructural characterisation of dissimilar joints of mild steel to Ni-based alloy • Friction stir welding of joints of mild steel to Ni-based alloy 625 produces sound welds. • The interface region showed deformed and recrystallised fcc grains with NbC carbides and a length of 2.0 μm.

  8. Effect of zinc phosphate chemical conversion coating on corrosion behaviour of mild steel in alkaline medium: protection of rebars in reinforced concrete

    International Nuclear Information System (INIS)

    Simescu, Florica; Idrissi, Hassane

    2008-01-01

    We outline the ability of zinc phosphate coatings, obtained by chemical conversion, to protect mild steel rebars against localized corrosion, generated by chloride ions in alkaline media. The corrosion resistance of coated steel, in comparison with uncoated rebars and coated and uncoated steel rebars embedded in mortar, were evaluated by open-circuit potential, potentiodynamic polarization, cronoamperometry and electrochemical impedance spectroscopy. The coated surfaces were characterized by x-ray diffraction and scanning electron microscopy. First, coated mild steel rebars were studied in an alkaline solution with and without chloride simulating a concrete pore solution. The results showed that the slow dissolution of the coating generates hydroxyapatite Ca 10 (PO 4 ) 6 (OH) 2 . After a long immersion, the coating became dense and provided an effective corrosion resistance compared with the mild steel rebar. Secondly, the coated and uncoated steel rebars embedded in mortar and immersed in chloride solution showed no corrosion or deterioration of the coated steel. Corrosion rate is considerably lowered by this phosphate coating.

  9. Effect of zinc phosphate chemical conversion coating on corrosion behaviour of mild steel in alkaline medium: protection of rebars in reinforced concrete

    Directory of Open Access Journals (Sweden)

    Florica Simescu and Hassane Idrissi

    2008-01-01

    Full Text Available We outline the ability of zinc phosphate coatings, obtained by chemical conversion, to protect mild steel rebars against localized corrosion, generated by chloride ions in alkaline media. The corrosion resistance of coated steel, in comparison with uncoated rebars and coated and uncoated steel rebars embedded in mortar, were evaluated by open-circuit potential, potentiodynamic polarization, cronoamperometry and electrochemical impedance spectroscopy. The coated surfaces were characterized by x-ray diffraction and scanning electron microscopy. First, coated mild steel rebars were studied in an alkaline solution with and without chloride simulating a concrete pore solution. The results showed that the slow dissolution of the coating generates hydroxyapatite Ca10(PO46(OH2. After a long immersion, the coating became dense and provided an effective corrosion resistance compared with the mild steel rebar. Secondly, the coated and uncoated steel rebars embedded in mortar and immersed in chloride solution showed no corrosion or deterioration of the coated steel. Corrosion rate is considerably lowered by this phosphate coating.

  10. Electrodeposition of zinc-doped silane films for corrosion protection of mild steels

    International Nuclear Information System (INIS)

    Wu Liankui; Hu Jiming; Zhang Jianqing

    2012-01-01

    Highlights: ► Metallic zinc is doped into organosilane films by one-step electrodeposition. ► The composite films exhibit the improved corrosion resistance of mild steels. ► Zinc-doping provides additional cathodic protection to the mild steels. - Abstract: Organosilane/zinc composite films are prepared by one-step electrodeposition onto cold-rolled steels for corrosion protection. Electrochemical impedance spectroscopy measurement, bulk solution immersion and wet heat tests all show that the composite films have improved corrosion performance. X-ray photoelectron spectroscopy measurement suggests the successful encapsulation of metallic zinc. The embedding of metallic zinc results in negative shift in open-circuit potential of the film-covered electrodes. Such cathodic protection effect given by the metallic zinc provides the improved corrosion resistance of the composite films.

  11. Study of passive films formed on mild steel in alkaline media by the application of anodic potentials

    Energy Technology Data Exchange (ETDEWEB)

    Freire, L. [Universidade de Vigo, E.T.S.E.I., Campus Universitario, 36310 Vigo (Spain)], E-mail: lorenafp@uvigo.es; Novoa, X.R. [Universidade de Vigo, E.T.S.E.I., Campus Universitario, 36310 Vigo (Spain); Montemor, M.F. [ICEMS - Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Av. Rovisco Pais, 1049 - 001 Lisboa (Portugal); Carmezim, M.J. [ICEMS - Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Av. Rovisco Pais, 1049 - 001 Lisboa (Portugal); EST Setubal, DEM, Instituto Politecnico de Setubal, Campus IPS, 2910 Setubal (Portugal)

    2009-04-15

    In this paper, iron oxide thin layers formed on mild steel substrates in alkaline media by the application of different anodic potentials were studied in order to characterize their morphology, composition and electrochemical behaviour, in particular under conditions of cathodic protection. The surface composition was evaluated by X-Ray Photoelectron Spectroscopy (XPS) and Auger Electron Spectroscopy (AES). The morphology of the surface oxides was studied via Atomic Force Microscopy (AFM). The electrochemical behaviour of the surface oxides was studied using Electrochemical Impedance Spectroscopy (EIS). The results showed that the surface film is composed by Fe{sup 2+}oxides and Fe{sup 3+} oxides and/or hydroxides. The contribution of Fe{sup 2+} species vanishes when the potential of film formation increases in the passive domain. Two distinct phases were differentiated in the outer layers of the surface film, which proves that film growing is topotactic in nature.

  12. Study of passive films formed on mild steel in alkaline media by the application of anodic potentials

    International Nuclear Information System (INIS)

    Freire, L.; Novoa, X.R.; Montemor, M.F.; Carmezim, M.J.

    2009-01-01

    In this paper, iron oxide thin layers formed on mild steel substrates in alkaline media by the application of different anodic potentials were studied in order to characterize their morphology, composition and electrochemical behaviour, in particular under conditions of cathodic protection. The surface composition was evaluated by X-Ray Photoelectron Spectroscopy (XPS) and Auger Electron Spectroscopy (AES). The morphology of the surface oxides was studied via Atomic Force Microscopy (AFM). The electrochemical behaviour of the surface oxides was studied using Electrochemical Impedance Spectroscopy (EIS). The results showed that the surface film is composed by Fe 2+ oxides and Fe 3+ oxides and/or hydroxides. The contribution of Fe 2+ species vanishes when the potential of film formation increases in the passive domain. Two distinct phases were differentiated in the outer layers of the surface film, which proves that film growing is topotactic in nature

  13. The effect of inhibitor sodium nitrate on pitting corrosion of dissimilar material weldment joint of stainless steel AISI 304 and mild steel SS 400

    Energy Technology Data Exchange (ETDEWEB)

    Hilca, B. R., E-mail: bangkithilca@yahoo.com; Triyono, E-mail: triyonomesin@uns.ac.id [Mechanical Engineering Department, Sebelas Maret University, Surakarta 57126 (Indonesia)

    2016-03-29

    This study experimentally evaluated the effect of Sodium Nitrate inhibitor (NaNO{sub 3}) of 0.1%, 0.3%, and 0.5% on NaCl 3.5% toward pitting corrosion of dissimilar metal welding joint between stainless steel AISI 304 and mild steel SS 400. Electrochemical corrosion was tested using potentiodynamic polarization. Further the Scanning Electron Microscope (SEM) conducted to analyze the specimen. Chemical composition analysis used Energy Dispersive X-ray Spectrometry (EDS). The highest efficiency of sodium nitrate for ER 308 attained 63.8% and 64.89%for ER 309L. The specimen surface which observed through SEM showed decrease of pitting corrosion respectively with the addition of sodium nitrate content as inhibitor.

  14. Correlation between the bending strength and the thickness interlayer of alumina-mild steel friction welded at lower rotational speed

    International Nuclear Information System (INIS)

    Mohamad Zaky Noh; Luay Bakir Hussain; Zainal Arifin Ahmad

    2007-01-01

    The joining of ceramic-metal could be done through a few techniques: brazing, diffusion bonding, friction welding etc. However, the mechanism of ceramic-metal joining was still not properly understood. In this study, alumina rod was bonded to mild steel rod via friction welding technique by using Al 1100 sheet as interlayer. The diameter of the rods was 10 mm. Friction pressure of 20 MPa and forging pressure of 40 MPa were used. Rotational speeds were maintained at 900 rpm and friction times of 2 to 20 seconds were applied. The joining strength was determined through four point bending test. The maximum bending strength, 240 MPa was obtained at the friction times of 20 seconds. Under optical microscope and SEM observation, the deformation of the aluminum interface was clearly obtained. Mechanical interlocking and close contact between the alumina aluminum and aluminum-mild steel were observed at magnifications of 3000X. The strength of alumina-steel bonding is much dependent on the wettability of the alumina surface by the molten aluminum and the existing of mechanical interlocking between interlayer and sample materials. (Author)

  15. Study of New Thiazole Based Pyridine Derivatives as Potential Corrosion Inhibitors for Mild Steel: Theoretical and Experimental Approach

    Directory of Open Access Journals (Sweden)

    T. K. Chaitra

    2016-01-01

    Full Text Available Three new thiazole based pyridine derivatives 5-(4-methoxy-phenyl-thiazole-2-carboxylic acid pyridin-2-ylmethylene-hydrazide (2-MTPH, 5-(4-methoxy-phenyl-thiazole-2-carboxylic acid pyridin-3-ylmethylene-hydrazide (3-MTPH, and 5-(4-methoxy-phenyl-thiazole-2-carboxylic acid pyridin-4-ylmethylene-hydrazide (4-MTPH were synthesized and characterized. Corrosion inhibition performance of the prepared compounds on mild steel in 0.5 M HCl was studied using gravimetric, potentiodynamic polarisation, and electrochemical impedance techniques. Inhibition efficiency has direct relation with concentration and inverse relation with temperature. Thermodynamic parameters for dissolution and adsorption process were evaluated. Polarisation study reveals that compounds act as both anodic and cathodic inhibitors with emphasis on the former. Impedance study shows that decrease in charge transfer resistance is responsible for effective protection of steel surface by inhibitors. The film formed on the mild steel was investigated using FTIR, SEM, and EDX spectroscopy. Quantum chemical parameters like EHOMO, ELUMO, ΔE, hardness, softness, and ionisation potential were calculated. Higher value of EHOMO and lower value of ΔE indicate the better inhibition efficiency of the compounds. Lower ionisation potential of inhibitors indicates higher reactivity and lower chemical stability.

  16. Alkanediyl-α, ω-bis (dimethyl cetylammonium bromide gemini surfactants as novel corrosion inhibitors for mild steel in formic acid

    Directory of Open Access Journals (Sweden)

    Mohammad Mobin

    2012-12-01

    Full Text Available Gemini surfactants, butanediyl 1,4-bis(dimethyl cetylammonium bromide, pentanediyl 1,5 - bis (dimethyl cetylammonium bromide and hexanediyl 1,6 - bis (dimethyl cetylammonium bromide from Alkanediyl-α, ω-bis (dimethyl cetylammonium bromide series were synthesized in laboratory and were characterized by using Nuclear Magnetic Resonance (NMR spectroscopy. The surfactants were tested as corrosion inhibitors for mild steel in 20% formic acid. The influence of surfactants on mild steel corrosion inhibition was investigated by measuring the corrosion rate of mild steel in their absence and presence by weight loss measurements, solvent analysis of iron ions into the test solution and potentiodynamic polarization measurements. The surface morphology of the corroded steel samples in presence and absence of surfactants was evaluated by using Scanning Electron Microscopy (SEM. The synthesized gemini surfactants performed as excellent corrosion inhibitor, the inhibition efficiency (IE being in the range of 76.66-97.41%. The IE of surfactants is slightly affected by the spacer length. The IE increased with increase in surfactant concentration and temperature. The adsorption of gemini surfactants on the steel surface was found to obey Langmuir adsorption isotherm. The results of the potentiodynamic polarization studies are consistent with the results of weight loss studies.

  17. Airborne bacteria associated with corrosion of mild steel 1010 and aluminum alloy 1100.

    Science.gov (United States)

    Rajasekar, Aruliah; Xiao, Wang; Sethuraman, Manivannan; Parthipan, Punniyakotti; Elumalai, Punniyakotti

    2017-03-01

    A novel approach to measure the contribution of airborne bacteria on corrosion effects of mild steel (MS) and aluminum alloy (AA) as a function of their exposure period, and the atmospheric chemical composition was investigated at an urban industrial coastal site, Singapore. The 16S rRNA and phylogenetic analyses showed that Firmicutes are the predominant bacteria detected in AA and MS samples. The dominant bacterial groups identified were Bacillaceae, Staphylococcaceae, and Paenibacillaceae. The growth and proliferation of these bacteria could be due to the presence of humidity and chemical pollutants in the atmosphere, leading to corrosion. Weight loss showed stronger corrosion resistance of AA (1.37 mg/cm 2 ) than MS (26.13 mg/cm 2 ) over the exposure period of 150 days. The higher corrosion rate could be a result of simultaneous action of pollutants and bacterial exopolysaccharides on the metal surfaces. This study demonstrates the significant involvement of airborne bacteria on atmospheric corrosion of engineering materials.

  18. Theoretical studies of three triazole derivatives as corrosion inhibitors for mild steel in acidic medium

    International Nuclear Information System (INIS)

    Guo, Lei; Zhu, Shanhong; Zhang, Shengtao; He, Qiao; Li, Weihua

    2014-01-01

    Highlights: • Three triazole derivatives as corrosion inhibitors were theoretically investigated. • Quantum chemical calculations and Monte Carlo simulations were performed. • Quantitative structure activity relationship (QSAR) approach has been used. • Theoretical conclusions are validated by the consistency with experimental findings. - Abstract: Corrosion inhibitive performance of 4-chloro-acetophenone-O-1′-(1′.3′.4′-triazolyl)-metheneoxime (CATM), 4-fluoro-acetophenone-O-1′-(1′.3′.4′-triazolyl)-metheneoxime (FATM), and 3,4-dichloro-acetophenone-O-1′-(1′.3′.4′-triazolyl)-metheneoxime (DATM) during the acidic corrosion of mild steel surface was investigated using density functional theory (DFT). Quantum chemical parameters such as the highest occupied molecular orbital energy (E HOMO ), the lowest unoccupied molecular orbital energy (E LUMO ), energy gap (ΔE), Mulliken charges, hardness (ξ), dipole moment (μ), and the fraction of electrons transferred (ΔN), were calculated. Quantitative structure activity relationship (QSAR) approach has been used, and a composite index of above-mentioned descriptors was performed to characterize the inhibition performance of the studied molecules. Furthermore, Monte Carlo simulation studies were applied to search for the best configurational space of iron/triazole derivative system

  19. Electrolytic plasma processing of steel surfaces

    International Nuclear Information System (INIS)

    Bejar, M.A; Araya, R.N; Baeza, B

    2006-01-01

    The thermo-chemical treatments of steels with plasma is normally carried out in low-pressure ionized gaseous atmospheres. Among the treatments used most often are: nitruration, carburization and boronized. A plasma can also generate at atmospheric pressure. One way to produce it is with an electrochemical cell that works at a relatively high inter-electrode voltage and under conditions of heavy gas generation. This type of plasma is known as electrolytic plasma. This work studies the feasibility of using electrolytic plasma for the surface processing of steels. Two processes were selected: boronized and nitruration., for the hardening of two types of steel: one with low carbon (1020) and one with low alloy (4140). In the case of the nitruration, the 1020 steel was first aluminized. The electrolytes were aqueous solutions of borax for the boronizing and urea for the nitruration. The electrolytic plasmas were classified qualitatively, in relation with their luminosity by low, medium and high intensity. The boronizing was carried out with low intensity plasmas for a period of one hour. The nitruration was performed with plasmas of different intensities and for period of a few minutes to half an hour. The test pieces processed by electrolytic plasma were characterized by micro-hardness tests and X-ray diffraction. The maximum surface hardnesses obtained for the 1020 and 4140 steels were the following: 300 and 700 HV for the boronizing, and 1650 and 1200 HV for the nitruration, respectively. The utilization of an electrolytic plasma permits the surface processing of steels, noticeably increasing their hardness. With this type of plasma some thermo-chemical surface treatments can be done very rapidly as well (CW)

  20. Grit blasting nozzle fabricated from mild tool steel proves satisfactory

    Science.gov (United States)

    Mc Farland, J. E.; Turbitt, B.

    1966-01-01

    Dry blasting with glass beads through a nozzle assembly descales both the outside and inside surfaces of tubes of Inconel 718 used for the distribution of gaseous oxygen. The inside of the nozzle is coated with polyurethane and the deflector with a commercially available liquid urethane rubber.

  1. Protective Behavior of Poly(m-aminophenol) and Polypyrrole Coatings on Mild Steel

    Science.gov (United States)

    Yahaya, Sabrina M.; Harun, M. K.; Rosmamuhamadani, R.; Bonnia, N. N.; Ratim, S.

    2018-01-01

    Electrodeposition of polypyrrole (PPy) and poly (m-aminophenol) (PMAP) films on mild steel (MS) substrate was achieved in 0.3M oxalic acid solution and 0.3M NaOH, water:ethanol (70:30) solvent respectively using cyclic voltammetry technique. The morphology of the films constructed was determined by scanning electron microscope (SEM) while energy dispersive X-Ray analyzer (EDX) was used to establish the presence of organic PMAP and PPy film coating and its compositions. The corrosion performance of MS coated with both polymer films were investigated after 0.5 hours immersed in 0.5M NaCl aqueous solution by using polarization curves. It was found that PPy coating provides anodic protection while PMAP coating provides cathodic protection towards corrosion protection of mild steel substrate.

  2. Electrochemical Study on Newly Synthesized Chlorocurcumin as an Inhibitor for Mild Steel Corrosion in Hydrochloric Acid

    Directory of Open Access Journals (Sweden)

    Ahmed A. Al-Amiery

    2013-11-01

    Full Text Available A new curcumin derivative, i.e., (1E,4Z,6E-5-chloro-1,7-bis(4-hydroxy-3-methoxyphenylhepta-1,4,6-trien-3-one (chlorocurcumin, was prepared starting with the natural compound curcumin. The newly synthesized compound was characterized by elemental analysis and spectral studies (IR, 1H-NMR and 13C-NMR. The corrosion inhibition of mild steel in 1 M HCl by chlorocurcumin has been studied using potentiodynamic polarization (PDP measurements and electrochemical impedance spectroscopy (EIS. The inhibition efficiency increases with the concentration of the inhibitor but decreases with increases in temperature. The potentiodynamic polarization reveals that chlorocurcumin is a mixed-type inhibitor. The kinetic parameters for mild steel corrosion were determined and discussed.

  3. Electrochemical Study on Newly Synthesized Chlorocurcumin as an Inhibitor for Mild Steel Corrosion in Hydrochloric Acid

    Science.gov (United States)

    Al-Amiery, Ahmed A.; Kadhum, Abdul Amir H.; Mohamad, Abu Bakar; Musa, Ahmed Y.; Li, Cheong Jiun

    2013-01-01

    A new curcumin derivative, i.e., (1E,4Z,6E)-5-chloro-1,7-bis(4-hydroxy-3-methoxyphenyl)hepta-1,4,6-trien-3-one (chlorocurcumin), was prepared starting with the natural compound curcumin. The newly synthesized compound was characterized by elemental analysis and spectral studies (IR, 1H-NMR and 13C-NMR). The corrosion inhibition of mild steel in 1 M HCl by chlorocurcumin has been studied using potentiodynamic polarization (PDP) measurements and electrochemical impedance spectroscopy (EIS). The inhibition efficiency increases with the concentration of the inhibitor but decreases with increases in temperature. The potentiodynamic polarization reveals that chlorocurcumin is a mixed-type inhibitor. The kinetic parameters for mild steel corrosion were determined and discussed. PMID:28788402

  4. Laser-oxygen cutting of mild steel: the thermodynamics of the oxidation reaction

    Energy Technology Data Exchange (ETDEWEB)

    Powell, J; Kaplan, A F H [Department of Applied Physics and Mechanical Engineering, Luleaa University of Technology, SE-971 87 Luleaa (Sweden); Petring, D [Fraunhofer-Institute for Laser Technology (ILT), Steinbachstrasse 15, Aachen (Germany); Kumar, R V [Department of Materials Science and Metallurgy, University of Cambridge, Cambridge CB2 3QZ (United Kingdom); Al-Mashikhi, S O; Voisey, K T [Department of Mechanical, Materials and Manufacturing Engineering, Faculty of Engineering, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom)], E-mail: jpowell@laserexp.co.uk

    2009-01-07

    In a considerable proportion of the published work on the subject of laser-oxygen cutting of mild steel, the details of the oxidation reaction are overlooked or confused. For example, it is not uncommon for the oxidized material to be attributed with the physical characteristics of iron rather than iron oxide. Also, the fact that the oxidation reaction cannot take place above a certain temperature limit is usually overlooked. This paper presents, for the first time, an in-depth analysis of the Iron to FeO oxidation reaction in the context of laser-oxygen cutting of mild steel. The paper concludes by presenting a number of guidelines for future theoretical models.

  5. Plasma sprayed coatings on mild steel split moulds for uranium casting

    International Nuclear Information System (INIS)

    Sreekumar, K.P.; Padmanaban, P.V.A.; Venkatramani, N.; Singh, S.P.; Saha, D.P.; Date, V.G.

    2002-01-01

    High velocity high temperature plasma jets are used to deposit metals and ceramics on metallic substrates for oxidation and corrosion protection applications. Plasma sprayed ceramic coatings on metallic substrates are also used to prevent its reaction with molten metals. Metal-alumina duplex coatings on mild steel split moulds have been developed and successfully used for casting of uranium. Techno-economics of the coated moulds against the conventional graphite moulds are a major advantage. Mild steel moulds of 600 mm long and 75 mm in diameter have been plasma spray coated with alumina over a bond coat of molybdenum. In-plant tests showed an increase in number of castings per mould compared to the commonly used graphite moulds. (author)

  6. Laser-oxygen cutting of mild steel: the thermodynamics of the oxidation reaction

    International Nuclear Information System (INIS)

    Powell, J; Kaplan, A F H; Petring, D; Kumar, R V; Al-Mashikhi, S O; Voisey, K T

    2009-01-01

    In a considerable proportion of the published work on the subject of laser-oxygen cutting of mild steel, the details of the oxidation reaction are overlooked or confused. For example, it is not uncommon for the oxidized material to be attributed with the physical characteristics of iron rather than iron oxide. Also, the fact that the oxidation reaction cannot take place above a certain temperature limit is usually overlooked. This paper presents, for the first time, an in-depth analysis of the Iron to FeO oxidation reaction in the context of laser-oxygen cutting of mild steel. The paper concludes by presenting a number of guidelines for future theoretical models.

  7. Influence of Fretting on Flexural Fatigue of 304 Stainless Steel and Mild Steel

    National Research Council Canada - National Science Library

    Bill, Robert

    1978-01-01

    Fretting fatigue experiments conducted on 304 stainless steel using a flexural-fatigue test arrangement with bolted-on fretting pads have demonstrated that fatigue life is reduced by at least a factor...

  8. Corrosion Inhibition of Mild Steel in Hydrochloric Acid by Sodium Lauryl Sulfate (SLS

    Directory of Open Access Journals (Sweden)

    Atul Kumar

    2008-01-01

    Full Text Available Effect of Sodium Lauryl Sulfate (SLS, a surfactant on corrosion of mild steel in 1 M hydrochloric acid was studied using three techniques namely: weight loss, electrochemical polarization and metallurgical research microscopy. Results obtained reveal that SLS is good inhibitor and shows very good corrosion inhibition efficiency (IE. The IE was found to vary with concentration of inhibitor and temperature. The electrochemical polarization result revealed that SLS is anodic in nature.

  9. Corrosion Inhibition of Mild Steel in Hydrochloric Acid by Sodium Lauryl Sulfate (SLS)

    OpenAIRE

    Atul Kumar

    2008-01-01

    Effect of Sodium Lauryl Sulfate (SLS), a surfactant on corrosion of mild steel in 1 M hydrochloric acid was studied using three techniques namely: weight loss, electrochemical polarization and metallurgical research microscopy. Results obtained reveal that SLS is good inhibitor and shows very good corrosion inhibition efficiency (IE). The IE was found to vary with concentration of inhibitor and temperature. The electrochemical polarization result revealed that SLS is anodic in nature.

  10. ELECTROCHEMICAL STUDIES FOR CORROSION INHIBITION OF MILD STEEL BY CHRYSOPHYLLUM ALBIDUM EXTRACT

    OpenAIRE

    Akoma Chigozie S.; Osarolube Eziaku; Abumere O. E.

    2018-01-01

    The corrosion behavior of mild steel in carbonated drinks produced by Nigerian Breweries (Fanta, Sprite and Coke) was studied in the presence and absence of an eco-friendly inhibitor, Chrysophyllum albidum using Potentiodynamic polarization technique at 25 °C. Results showed that Chrysophyllum albidum reduced the current density (icorr), which in turn means that the corrosion rate was reduced significantly. The inhibition efficiency was found to be 93%, 78.6% and 87.5% for Fanta, Sprite and C...

  11. Inhibition of the corrosion of mild steel in hydrochloric acid by isatin ...

    African Journals Online (AJOL)

    The inhibition of corrosion of mild steel in hydrochloric acid by isatin glycine (ING) and isatin (IN) at 30-60 oC and concentrations of 0.0001 M to 0.0005 M was studied via weight loss method. At the highest inhibitor concentration studied ING exhibited inhibition efficiency of 87% while IN exhibited 84% at 60 oC. A chemical ...

  12. Study of Plant Cordia Dichotoma as Green Corrosion Inhibitor for Mild Steel in Different Acid Media

    OpenAIRE

    R. Khandelwal; S. K. Arora; S. P. Mathur

    2011-01-01

    The corrosion inhibition of mild steel using extracts of Cordia dichotoma in different acid media was investigated by mass loss and thermometric methods. The experiments were carried out at 299±0.2 K in presence of different concentrations of dry fruit, leaves and stem extracts of Cordia dichotoma. The results reveal that the alcoholic extracts of Cordia dichotoma is a better corrosion inhibitor than that of toxic chemicals. The fruit extract is more potent than leaves and stem extracts to in...

  13. Influence of alkali, silicate, and sulfate content of carbonated concrete pore solution on mild steel corrosion behavior

    International Nuclear Information System (INIS)

    L'Hostis, V.; Huet, B.; Tricheux, L.; Idrissi, H.

    2010-01-01

    The increase in the rebar corrosion rate due to the concrete carbonation is the major cause of reinforced concrete degradation. The aim of this study was to investigate the corrosion behavior of mild steel rebars in simulated carbonated concrete solution. For this purpose, thermodynamic calculations, electrochemical techniques, gravimetric measurements, and surface analyses were used. Thermodynamic investigations of the nature of the interstitial solution provides an estimation of the influence of sulfate (SO 4 2- ) and alkali (Na + , K + ) content on carbonate alkalinity of the CO 2 /H 2 O open system (pCO 2 =0. 3 mbar). in this system, calcium-silicate hydrates (C-S-H) remain thermodynamically unstable and amorphous silica controls silicate aqueous content at 100 ppm. Electrochemical results highlight a decrease in the corrosion rate with increasing carbonate alkalinity and the introduction of silicate. The introduction of sulfate at fixed carbonate alkalinity shows a dual effect: at high carbonate alkalinity, the corrosion rate is increased whereas at low carbonate alkalinity, corrosion rate is decreased. Those results are supported by surface analysis. Authors conclude that silicate and sulfate release from cement hydrates and fixation of alkali on carbonated hydrates are key parameters to estimate mild steel corrosion in carbonated concrete. (authors)

  14. New Coumarin Derivative as an Eco-Friendly Inhibitor of Corrosion of Mild Steel in Acid Medium

    Directory of Open Access Journals (Sweden)

    Ahmed A. Al-Amiery

    2014-12-01

    Full Text Available The anticorrosion ability of a synthesized coumarin, namely 2-(coumarin-4-yloxyacetohydrazide (EFCI, for mild steel (MS in 1 M hydrochloric acid solution has been studied using a weight loss method. The effect of temperature on the corrosion rate was investigated, and some thermodynamic parameters were calculated. The results indicated that inhibition efficiencies were enhanced with an increase in concentration of inhibitor and decreased with a rise in temperature. The IE value reaches 94.7% at the highest used concentration of the new eco-friendly inhibitor. The adsorption of inhibitor on MS surface was found to obey a Langmuir adsorption isotherm. Scanning electron microscopy (SEM was performed on inhibited and uninhibited mild steel samples to characterize the surface. The Density Function theory (DFT was employed for quantum-chemical calculations such as EHOMO (highest occupied molecular orbital energy, ELUMO (lowest unoccupied molecular orbital energy and μ (dipole moment, and the obtained results were found to be consistent with the experimental findings. The synthesized inhibitor was characterized by Fourier transform infrared (FTIR and nuclear magnetic resonance (NMR spectroscopic studies.

  15. Gaseous surface hardening of martensitic stainless steels

    DEFF Research Database (Denmark)

    Tibollo, Chiara; Villa, Matteo; Christiansen, Thomas L.

    The present work addresses heat and surface treatments of martensitic stainless steel EN 1.4028. Different combinations of heat treatments and surface treatments were performed: conventional austenitisation, cryogenic treatment and in particular high temperature solution nitriding (HTSN) and low...... that cubic lath martensite in conventionally austenitised EN 1.4028 dissolves nitrogen and develops expanded martensite (ferrite) during LTSH. HTSN leads to a microstructure of tetragonal plate martensite and retained austenite. The content of retained austenite can be reduced by a cryo...

  16. Experimental study of the effect of gas nature on plasma arc cutting of mild steel

    International Nuclear Information System (INIS)

    Kavka, T; Mašláni, A; Hrabovský, M; Křenek, P; Stehrer, T; Pauser, H

    2013-01-01

    This paper is devoted to the experimental investigation of arc cutting of mild steel using plasmas generated in gas and liquid media. Due to different chemical compositions, the examined media have different thermophysical properties, which affect the properties of the generated plasma and cutting performance. The experiments are performed on 15 mm mild steel plates using commercial equipment at 60 A to approach real operation conditions in application areas. The studied gases are chosen according to recommendations of the world's leading manufacturers of arc cutting equipment for mild steel. Specific differences between plasma gases are discussed from the point of view of properties of the gas and the generated plasma, amount of removed material, kerf shape and overall energy balance of the cutting process. The paper describes the role of exothermic reaction of iron oxidation for oxygen cutting and explains its neglect for liquid cutting. This paper explains the potential of facilitating the cutting process by modification of the plasma gas chemical composition and flow rate. (paper)

  17. Measurement and analysis of polarization curves of mild steel in sodium carbonate/bicarbonate solution under erosion-corrosion conditions

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Q. [Taiyuan University of Technology, Taiyuan (China). Research Institute of Surface Engineering

    2002-06-01

    The polarization curves of mild steel in de-aerated 0.5 and mol NaHCO{sub 3} + 0.5 mol Na{sub 2}CO{sub 3} solution with and without erodent particles of 300 g/L of 100 {mu}m alumina have been measured using a rotating cylinder electrode (RCE) apparatus over the range of rotation speeds fro 0 to 4,000 r/min. The results show that the mild steel in the de-aerated slurry exhibits classical active/passive polarization behavior. The speed of cylinder rotation has a great effect in the presence of particles on the active dissolution current density. The erosion-corrosion process is severely erosion-dominated for the mild steel. However, the poor corrosion resistance of the mild steel in such turbulent slurries is also significant, especially at lower than 4 m/s. 19 refs., 5 figs.

  18. Numerical simulation of projectile impact on mild steel armour plates using LS-DYNA, Part II: Parametric studies

    OpenAIRE

    Raguraman, M; Deb, A; Gupta, NK; Kharat, DK

    2008-01-01

    In Part I of the current two-part series, a comprehensive simulation-based study of impact of Jacketed projectiles on mild steel armour plates has been presented. Using the modelling procedures developed in Part I, a number of parametric studies have been carried out for the same mild steel plates considered in Part I and reported here in Part II. The current investigation includes determination of ballistic limits of a given target plate for different projectile diameters and impact velociti...

  19. Numerical Simulation of Projectile Impact on Mild Steel Armour Platesusing LS-DYNA, Part II: Parametric Studies

    OpenAIRE

    M. Raguraman; A. Deb; N. K. Gupta; D. K. Kharat

    2008-01-01

    In Part I of the current two-part series, a comprehensive simulation-based study of impact of jacketed projectiles on mild steel armour plates has been presented. Using the modelling procedures developed in Part I, a number of parametric studies have been carried out for the same mild steel plates considered in Part I and reported here in Part II. The current investigation includes determination of ballistic limits of a given target plate for different projectile diameters and impact velociti...

  20. Selection of parameters on laser cutting mild steel plates taking account of some manufacturing purposes

    Science.gov (United States)

    Asano, Hiroshi; Suzuki, Jippei; Kawakami, Hiroshi; Eguchi, Hiroshi

    2003-11-01

    There are large number of processing conditions which can be set for laser-cutting of plate materials, because importance of the objective for the cutting is different from product to product. This study aims to build a system which can set the processing conditions reasonably and efficiently. From plural processing objectives, roughness of cutting surface was taken up from among the required qualities, such as processing speed, circularity of a processed hole, height of dross on the rear side, roughness of cutting surfaces, accuracy of shapes and dimensions, and with of burning, to review the effects of the processing condition on the cutting surface including the drag line gap. In our experiments, a 1 kW CO2 gas laser machine was used to make laser-cutting samples and 389 combinations of samples were used. From the results of the experiments, the range of processing conditions which allow cutting is defined by the energy input per unit area HIA = 4.8 [J/mm2]. The values of roughness of the cutting surface on both front and rear sides of the plates can be reduced if the cutting speed is 1000 mm/min or higher, and they little change at small values if the heat input per unit area is within a range under 20 J/mm2. In a range of thin plate thickness, the drag gap on cutting surfaces can be evaluated by the heat input per unit area. In the case of thicker plate, the greater the duty is, the smaller the drag gap is, if the heat input per units area is kept unchanged. Cutting with small heat input is desirable for better roughness of cutting surface. Cutting with large heat input is required for better drag gap. In the scope of our study, a value 20 J/mm2 of heat input per unit area is recommended for laer-cutting of 0.8 - 4.5 mm thick mild steel plates.

  1. Effect of temperature and heat fluxes on the corrosion's damage nature for mild and stainless steels in neutral chloride solutions

    Energy Technology Data Exchange (ETDEWEB)

    Kaluzhina, S.A. [Voronezh State University, University Sq.1, 394006 Voronezh (Russian Federation); Malygin, A.V. [JSC Voronezhsynthezkauchuk, Leninsky Av. 2, 394014 Voronezh (Russian Federation); Vigdorovitch, V.V. [Derzhavin State University, International St. 33, 392622 Tambov (Russian Federation)

    2004-07-01

    The detail research of the corrosion-electrochemical behavior of two types steels - mild steel (0.1%C) and stainless steel 12FeCr18Ni10Ti in series chloride solutions under elevated temperature and heat flux on interface has been carried out in the present work using the special plant and the complex electrochemical and microscopic methods. The comparative data has shown that the temperature increase is stimulating as the active alloy's corrosion (mild steel), so the passive alloy's corrosion (12FeCr18Ni10Ti).However at the last case the temperature effect is being higher because the thermal de-passivation of the stainless steel which undergoes pit corrosion under t > 50 deg C. The heat-transfer role in the studied systems is ambiguous. The corrosion rate of heat-transferring electrode from mild steel exceeds the thermo-equilibrium with solution electrode's corrosion rate because of intensification of the oxygen reduction cathodic process. The opposite effect has been established for steel 12FeCr18Ni10Ti where the oxygen flux's strengthening from cold solution to the heated surface transfers the alloy to the most stable passive state and increases its resistance to general and local corrosion. The experimental results demonstrates that the thermal condition's influence on the nature and corrosion intensity of the investigated steels is being commensurable by effect's degree with their composition and showing strictly individually. (authors)

  2. Electrochemical synthesis of bilayer coatings of poly(N-methylaniline) and polypyrrole on mild steel and their corrosion protection performances

    Energy Technology Data Exchange (ETDEWEB)

    Zeybek, Buelent [Ankara University, Faculty of Science, Department of Chemistry, Ankara (Turkey); Dumlupinar University, Faculty of Arts and Sciences, Department of Chemistry, Kuetahya (Turkey); Ozcicek Pekmez, Nuran, E-mail: npekmez@hacettepe.edu.t [Hacettepe University, Faculty of Science, Department of Chemistry, Ankara (Turkey); Kilic, Esma [Ankara University, Faculty of Science, Department of Chemistry, Ankara (Turkey)

    2011-10-30

    Highlights: > The bilayers of poly(N-methylaniline) and polypyrrole-dodecylsulfate were synthesized. > These films on mild steel were characterized by cyclic voltammetry, FTIR and FESEM. > DS dopant allows permeation to cations and decreases the ingress of chloride ions. > The PNMA/PPy-DS bilayer coating exhibited the best corrosion resistance in 0.5 M HCl. > The protective properties of polymers was developed by preparing their bilayer coatings. - Abstract: Homopolymer and bilayer coatings of poly(N-methylaniline) (PNMA) and polypyrrole-dodecylsulfate (PPy-DS) have been electropolymerized on a mild steel (MS) surface by the potentiodynamic method in aqueous oxalic acid solutions. In order to include dodecylsulfate ion as dopant in the polypyrrole, sodium dodecylsulfate was also added to the polymerization solution of pyrrole. Characterization of coatings was carried out by the cyclic voltammetry, Fourier transform infrared (FTIR) spectroscopy and field emission scanning electron microscopy (FESEM). Corrosion behavior of the polymer coated MS electrodes was investigated in highly aggressive 0.5 M HCl solution by the Tafel test and electrochemical impedance spectroscopy (EIS) techniques. Corrosion test revealed that among the protective coatings obtained, the PNMA/PPy-DS bilayer exhibited the best corrosion resistance at all immersion times.

  3. Inhibition of mild steel corrosion in acidic medium using synthetic and naturally occurring polymers and synergistic halide additives

    Energy Technology Data Exchange (ETDEWEB)

    Umoren, S.A. [Department of Chemistry, Faculty of Science, University of Uyo, P.M.B 1017 Uyo (Nigeria)], E-mail: saviourumoren@yahoo.com; Ogbobe, O.; Igwe, I.O. [Department of Polymer and Textile Engineering, School of Engineering and Engineering Technology, Federal University of Technology, P.M.B. 1526 Owerri (Nigeria); Ebenso, E.E. [Department of Chemistry and Chemical Technology, National University of Lesotho, P. O. Roma180, Lesotho (South Africa)

    2008-07-15

    The corrosion inhibition of mild steel in H{sub 2}SO{sub 4} in the presence of gum arabic (GA) (naturally occurring polymer) and polyethylene glycol (PEG) (synthetic polymer) was studied using weight loss, hydrogen evolution and thermometric methods at 30-60 deg. C. PEG was found to be a better inhibitor for mild steel corrosion in acidic medium than GA. The effect of addition of halides (KCl, KBr and KI) was also studied. Results obtained showed that inhibition efficiency (I%) increased with increase in GA and PEG concentration, addition of halides and with increase in temperature. Increase in inhibition efficiency (I%) and degree of surface coverage ({theta}) was found to follow the trend Cl{sup -} < Br{sup -} < I{sup -} which indicates that the radii and electronegativity of the halide ions play a significant role in the adsorption process. GA and PEG alone and in combination with halides were found to obey Temkin adsorption isotherm. Phenomenon of chemical adsorption is proposed from the trend of inhibition efficiency with temperature and values {delta}G{sub ads}{sup 0} obtained. The synergism parameter, S{sub I} evaluated is found to be greater than unity indicating that the enhanced inhibition efficiency caused by the addition of halides is only due to synergism.

  4. Fuzzy Logic Approach for the Prediction of Dross Formation in CO2 Laser Cutting of Mild Steel

    Directory of Open Access Journals (Sweden)

    Miloš Madić

    2015-11-01

    Full Text Available Dross free laser cutting is very important in the application of laser cutting technology. This paper focuses on the development of a fuzzy logic model to predict dross formation in CO2 laser oxygen cutting of mild steel. Laser cutting experiment, conducted according to Taguchi’s experimental design using L25 orthogonal array, provided a set of data for the development of a fuzzy rule base. The predicting fuzzy logic model is based on using Mamdani-type inference system. Developed fuzzy logic model considered the cutting speed, laser power and assist gas pressure as inputs. Using this model the effects of the selected laser cutting parameters on the dross formation were investigated. Additionally, 3-D surface plots were generated to study the interaction effects of the laser cutting parameters. The analysis revealed that the cutting speed has the most significant effect, followed by laser power and assist gas pressure. The results indicated that the fuzzy logic modeling approach can be effectively used for the dross formation prediction in CO2 laser cutting of mild steel.

  5. Structural evolution, thermomechanical recrystallization and electrochemical corrosion properties of Ni-Cu-Mg amorphous coating on mild steel fabricated by dual-anode electrolytic processing

    Energy Technology Data Exchange (ETDEWEB)

    Abdulwahab, M., E-mail: mabdulwahab@abu.edu.ng [Department of Chemical, Metallurgical and Materials Engineering, Tshwane University of Technology, Pretoria (South Africa); Department of Metallurgical and Materials Engineering, Ahmadu Bello University, Zaria (Nigeria); Fayomi, O.S.I., E-mail: ojosundayfayomi3@gmail.com [Department of Chemical, Metallurgical and Materials Engineering, Tshwane University of Technology, Pretoria (South Africa); Department of Mechanical Engineering, Covenant University, Ota (Nigeria); Popoola, A.P.I., E-mail: popoolaapi@tut.ac.za [Department of Chemical, Metallurgical and Materials Engineering, Tshwane University of Technology, Pretoria (South Africa)

    2016-07-01

    Highlights: • The surface of the coat containing Ni-Cu-Mg alloy on mild steel have sufficiently enhanced the properties. • Isothermally treated composites demonstrated 45% increase in the micro-hardness and 79.6% corrosion resistance. • The thermal stability of the developed Ni-Cu-Mg thin films on mild steel was excellent. - Abstract: The electrolytic Ni-Cu based alloy coating with admixed interfacial blend of Mg have been successfully prepared on mild steel substrate by dual anode electroplating processes over a range of applied current density and dwell time. The electrocodeposition of Ni-Cu-Mg coating was investigated in the presence of other bath additives. The influence of deposition current on surface morphology, adhesion behavior, preferred crystal orientation, surface topography and electrochemical activity of Ni-Cu-Mg alloy coating on mild steel were systematically examined. The thermal stability of the developed composite materials was examined via isothermal treatment. Scanning electron microscope equipped with EDS, X-ray diffraction, Atomic force microscope, micro-hardness tester and 3 μmetrohm Potentiostat/galvanostat were used to compare untreated and isothermally treated electrocodeposited composite. The induced activity of the Ni-Cu-Mg alloy changed the surface modification and results to crystal precipitation within the structural interface by the formation of Cu{sub ,} Ni{sub 2}Mg{sub 3} phase. The obtained results showed that the introduction of Mg particles in the plating bath generally modified the surface and brings an increase in the hardness and corrosion resistance of Ni-Cu-Mg layers fabricated. Equally, isothermally treated composites demonstrated an improved properties indicating 45% increase in the micro-hardness and 79.6% corrosion resistance which further showed that the developed composite is thermally stable.

  6. Novel benzimidazole derivatives as corrosion inhibitors of mild steel in the acidic media. Part II: Theoretical studies

    International Nuclear Information System (INIS)

    Cao, Ziyi; Tang, Yongming; Cang, Hui; Xu, Jinqiu; Lu, Gang; Jing, Wenheng

    2014-01-01

    Highlights: • Quantum chemical and MD studies of benzimidazole derivatives inhibitors. • Inhibition effectiveness depends on the ability to accept electrons. • Active sites of adsorption are mainly centralized on imidazole rings. • Steric effect results in the non-planar adsorption of BBIA and TBIA. - Abstract: In this paper, the adsorption behavior and inhibition mechanism of 2-aminomethyl benzimidazole (ABI), bis(2-benzimidazolylmethyl) amine (BBIA) and tri-(2-benzimidazolylmethyl) amine (TBIA) on the surface of mild steel were studied by quantum chemical calculations and molecular dynamics (MD) simulations. It was found that the three molecules show the similar ability to donate electrons while the difference in inhibition performance should mainly be attributed to the difference in accepting electrons. MD simulations show that steric effect between the benzimidazole segments significantly affects the adsorptive configurations of the molecules on Fe (1 0 0) surface

  7. COMPLEX SURFACE HARDENING OF STEEL ARTICLES

    Directory of Open Access Journals (Sweden)

    A. V. Kovalchuk

    2014-01-01

    Full Text Available The method of complex surface hardening of steel detailswas designed. The method is a compound of two processes of hardening: chemical heat treatment and physical vapor deposition (PVD of the coating. The result, achieved in this study is much higher, than in other work on this topic and is cumulative. The method designed can be used in mechanical engineering, medicine, energetics and is perspective for military and space technologies.

  8. Organic compounds as corrosion inhibitors for mild steel in acidic media: correlation between inhibition efficiency and chemical structure

    Energy Technology Data Exchange (ETDEWEB)

    Elias, Elizandra C.S.; Chrisman, Erika C.A.N. [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Escola de Quimica

    2009-12-19

    The use of inhibitors for mild steels corrosion control which are in contact with aggressive environment is an accepted practice in acid treatment of oil-wells. Organic compounds have been studied to evaluate their corrosion inhibition potential. Film-forming corrosion inhibitors, commonly used to protect oil-field equipment, can be absorbed on the steel surface to give structurally ordered layers. Therefore, the electrons should act as an important role for this adsorption. Studies reveal that organic compounds show significant inhibition efficiency. For this purpose, their molecules should contain N, O and S heteroatoms in various functional groups, long hydrocarbon linear or branched radical and anion and cation active components. However, most of these compounds are not only expensive but also toxic to living beings. According to the 'Green Chemistry' rules, corrosion inhibitors based on organic compounds should be cheap, with low toxicity and have high inhibition efficiency. In this study, the effects of some organic compounds with different groups such as amide, ether, phenyldiamine, anime and aminophenol on the corrosion behavior of mild steel in acidic media have been investigated. The experimental data were obtained by gravimetric measurements. The results show that these compounds reveal a promising corrosion inhibition where phenyldiamine is the most efficient. The effect of molecular structure on the corrosion inhibition efficiency was investigated by semi-empirical quantum chemical calculations. The electronic properties such as highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO) energy levels, and LUMO-HOMO energy gap orbital density were calculated. The relations between the inhibition efficiency and some quantum parameters are discussed and correlations are proposed. The highest values for the HOMO densities were found in the vicinity nitrogen atom, indicating that it is the most probable adsorption center

  9. Remediation of phosphate-contaminated water by electrocoagulation with aluminium, aluminium alloy and mild steel anodes.

    Science.gov (United States)

    Vasudevan, Subramanyan; Lakshmi, Jothinathan; Jayaraj, Jeganathan; Sozhan, Ganapathy

    2009-05-30

    The present study provides an electrocoagulation process for the remediation of phosphate-contaminated water using aluminium, aluminium alloy and mild steel as the anodes and stainless steel as the cathode. The various parameters like effect of anode materials, effect of pH, concentration of phosphate, current density, temperature and co-existing ions, and so forth, and the adsorption capacity was evaluated using both Freundlich and Langmuir isotherm models. The adsorption of phosphate preferably fitting the Langmuir adsorption isotherm suggests monolayer coverage of adsorbed molecules. The results showed that the maximum removal efficiency of 99% was achieved with aluminium alloy anode at a current density of 0.2 A dm(-2), at a pH of 7.0. The adsorption process follows second-order kinetics.

  10. Study of a Triazole Derivative as Corrosion Inhibitor for Mild Steel in Phosphoric Acid Solution

    Directory of Open Access Journals (Sweden)

    Lin Wang

    2012-01-01

    Full Text Available The corrosion inhibition by a triazole derivative (PAMT on mild steel in phosphoric acid (H3PO4 solution has been investigated by weight loss and polarization methods. The experimental results reveal that the compound has a significant inhibiting effect on the corrosion of steel in H3PO4 solution. It also shows good corrosion inhibition at higher concentration of H3PO4. Potentiodynamic polarization studies have shown that the compound acts as a mixed-type inhibitor retarding the anodic and cathodic corrosion reactions with predominant effect on the cathodic reaction. The values of inhibition efficiency obtained from weight loss and polarization measurements are in good agreement. The adsorption of this compound is found to obey the Langmuir adsorption isotherm. Some kinetic and thermodynamic parameters such as apparent activation energy, frequency factor, and adsorption free energy have been calculated and discussed.

  11. Tribological and wear behavior of yttria stabilized zirconia thermal barrier coatings on mild steel

    International Nuclear Information System (INIS)

    Farooq, M.; Pervez, A.

    2012-01-01

    The perfection of the temperature confrontation of the engine essentials can be obtained by claim of a single ceramic thermal barrier coating (TBC) or several composite layers. Engine elements protected by TBC can work safely in elevated temperature range above 1000 degree C. Continuous endeavor to increase thermal resistance of engine the elements requires, apart from laboratory investigations, also numerical study of the different engine parts. The high temperatures and stress concentrations can act as the local sources of damage initiation and defects propagation in the form of cracks. The current study focuses the development of Yttria stabilized zirconia thermal barrier coating by Thermal spray technique. Mild steel was used as a substrate and the coating was then characterized for tribological analysis followed by the optical analysis of wear tracks and found the TBC behavior more promising then steel. (author)

  12. Adsorption properties and inhibition of mild steel corrosion in hydrochloric solution by some newly synthesized diamine derivatives: Experimental and theoretical investigations

    Energy Technology Data Exchange (ETDEWEB)

    Herrag, L.; Hammouti, B.; Elkadiri, S.; Aouniti, A. [Laboratoire de Chimie Appliquee et Environnement, LCAE-URAC18, Faculte des Sciences, Universite Mohammed Premier, B.P. 717, M-6000 Oujda (Morocco); Jama, C. [Unite Materiaux et Transformations (UMET), Ingenierie des Systemes Polymeres, CNRS UMR 8207, ENSCL, B.P. 90108, F-59652 Villeneuve d' Ascq Cedex (France); Vezin, H. [Laboratoire de Spectrochimie Infrarouge et Raman (LASIR), UMR-CNRS 8516, Universite des Sciences et Technologies de Lille, Batiment C5, F-59655 Villeneuve d' Ascq Cedex (France); Bentiss, F., E-mail: fbentiss@enscl.f [Laboratoire de Chimie de Coordination et d' Analytique (LCCA), Faculte des Sciences, Universite Chouaib Doukkali, B.P. 20, M-24000 El Jadida (Morocco)

    2010-09-15

    New diamine derivatives, namely 2-[{l_brace}2-[bis-(2-hydroxyethyl)amino]ethyl{r_brace}(2-hydroxyethyl)amino]ethanol (DAME) and 2-[{l_brace}2-[bis-(2-hydroxyethyl)amino]ethyl{r_brace}(2-hydroxyethyl)amino]propanol (DAMP) were synthesised and their inhibitive action against the corrosion of mild steel in 1 M HCl solution were investigated at 308 K. The detailed study of DAME is given using gravimetric measurements and polarization curves method. Results show that DAME is a good inhibitor and inhibition efficiency reaches 91.7% at 10{sup -3} M. Tafel polarization study revealed that DAME acts as a mixed-type inhibitor. The inhibitor adsorption process in mild steel/DAME/hydrochloric acid system was studied at different temperatures (308-353 K) by means of weight loss measurements. The adsorption of DAME on steel surface obeyed Langmuir's adsorption isotherm. The kinetic and thermodynamic parameters for mild steel corrosion and inhibitor adsorption, respectively, were determined and discussed. The comparative study of inhibitive performance of the two diamine derivatives revealed that DAME is more effective than DAMP. Quantitative Structure-Activity Relationship (QSAR) approach has been conducted in attempt to correlate the corrosion inhibition properties of these diamine derivatives with their calculated quantum chemical parameters.

  13. Acoustic emission test on a 25mm thick mild steel pressure vessel with inserted defects

    International Nuclear Information System (INIS)

    Bentley, P.G.; Dawson, D.G.; Hanley, D.J.; Kirby, N.

    1976-12-01

    Acoustic emission measurements have been taken on an experimental mild steel vessel with 4 inserted defects ranging in severity up to 90% of through thickness. The vessel was subjected to a series of pressure excursions of increasing magnitude until failure occurred by extension of the largest inserted defect through the vessel wall. No acoustic emission was detected throughout any part of the tests which would indicate the presence of such serious defects or of impending failure. Measurements of acoustic emission from metallurgical specimens are included and the results of post test inspection using conventional NDT and metallographic techniques are reported. (author)

  14. Some aspects of the electrochemical behaviour of mild steel in carbonate/bicarbonate solutions

    International Nuclear Information System (INIS)

    Rangel, C.M.; Leitao, R.A.; Fonseca, I.T.

    1986-01-01

    The electrochemical behaviour of mild steel in aqueous solutions of sodium carbonate/sodium bicarbonate (600 ppm) has been investigated using potentiodynamic polarization. In the pre-passive region three well-defined peaks are observed associated to reduction peaks corresponding to Fe(II) and Fe(III) species. A transpassive anodic peak is also observed being attributed to Fe(VI) species showing, in sweep reversal experiments, an associated reduction peak and an increase in the peak associated to the reduction of Fe(III) species. The characterization of the transpassive peak will be subject of further publication. (author)

  15. Extract of Camellia sinensis as Green Inhibitor for the Corrosion of Mild Steel in Aqueous Solution

    International Nuclear Information System (INIS)

    Fouda, Abd Elaziz S.; Mekkia, Dina; Badr, Abeer H.

    2013-01-01

    Corrosion inhibition of mild steel used in water station in 35 ppm aluminum sulfate and 10 ppm chloride solution by Camellia sinensis leaves extract was studied using weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy techniques at 30 .deg. C. Results show that the inhibition efficiency increases with increasing concentration of the extract and decreases with increasing temperature. Inhibitive effect was afforded by adsorption of the extract's components which was found to accord with Langmuir adsorption isotherm. Inhibition mechanism is deduced from the temperature dependence of the inhibition efficiency and was further corroborated by the values of activation parameters obtained from the experimental data

  16. Extract of Camellia sinensis as Green Inhibitor for the Corrosion of Mild Steel in Aqueous Solution

    Energy Technology Data Exchange (ETDEWEB)

    Fouda, Abd Elaziz S. [El-Mansoura Univ., El-Mansoura (Egypt); Mekkia, Dina; Badr, Abeer H. [Water and wastewater company, Dakahlia (Egypt)

    2013-04-15

    Corrosion inhibition of mild steel used in water station in 35 ppm aluminum sulfate and 10 ppm chloride solution by Camellia sinensis leaves extract was studied using weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy techniques at 30 .deg. C. Results show that the inhibition efficiency increases with increasing concentration of the extract and decreases with increasing temperature. Inhibitive effect was afforded by adsorption of the extract's components which was found to accord with Langmuir adsorption isotherm. Inhibition mechanism is deduced from the temperature dependence of the inhibition efficiency and was further corroborated by the values of activation parameters obtained from the experimental data.

  17. Spall damage of a mild carbon steel: Effects of peak stress, strain rate and pulse duration

    International Nuclear Information System (INIS)

    Li, C.; Li, B.; Huang, J.Y.; Ma, H.H.; Zhu, M.H.; Zhu, J.; Luo, S.N.

    2016-01-01

    We investigate spall damage of a mild carbon steel under high strain-rate loading, regarding the effects of peak stress, strain rate, and pulse duration on spall strength and damage, as well as related microstructure features, using gas gun plate impact, laser velocimetry, and electron backscatter diffraction analysis. Our experiments demonstrate strong dependences of spall strength on peak stress and strain rate, and its weak dependence on pulse duration. We establish numerical relations between damage and peak stress or pulse duration. Brittle and ductile spall fracture modes are observed at different loading conditions. Damage nucleates at grain boundaries and triple junctions, either as transgranular cleavage cracks or voids.

  18. Benzimidazole and its derivatives as corrosion inhibitors for mild steel in 1M HCl solution

    International Nuclear Information System (INIS)

    Aljourani, J.; Raeissi, K.; Golozar, M.A.

    2009-01-01

    In this paper, the inhibition ability of benzimidazole and its derivatives against the corrosion of mild steel in 1M HCl solution was studied. The change of impedance parameters observed by variation of inhibitors concentration within the range of 50-250 ppm was an indication of their adsorption. The thermodynamic adsorption parameters proposed that these inhibitors retard both cathodic and anodic processes through physical adsorption and blocking the active corrosion sites. The adsorption of these compounds obeyed the Langmuir's adsorption isotherm. The inhibition efficiency was increased with inhibitor concentration in the order of 2-mercaptobenzimidazole > 2-methylbenzimidazole > benzimidazole, which is in accordance with the variation of apparent activation energy of corrosion.

  19. Studies on corrosion of mild steel by water using Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Nigam, A.N.; Tripathi, R.P.; Jangid, M.L.

    1987-01-01

    The corrosion of mild steel as a result of interaction with various types of local natural water samples and distilled water is studied with the help of Moessbauer spectroscopy. The data are supplemented with the studies on IR and magnetic properties as and when required. Distilled water and potable water behave in almost similar fashion wherein ferrihydrite and FeOOH are observed to be the precursors of magnetite, the end corrosion product. In case of brakish water, the additional species, viz., FeCl 2 , βFeOOH and an intermediate possibly FeOCl are accounted, and possible mechanisms are suggested. (author)

  20. Spall damage of a mild carbon steel: Effects of peak stress, strain rate and pulse duration

    Energy Technology Data Exchange (ETDEWEB)

    Li, C. [College of Physical Science and Technology, Sichuan University, Chengdu, Sichuan 610064 (China); Key Laboratory of Advanced Technologies of Materials, Ministry of Education, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); The Peac Institute of Multiscale Sciences, Chengdu, Sichuan 610031 (China); Li, B.; Huang, J.Y. [The Peac Institute of Multiscale Sciences, Chengdu, Sichuan 610031 (China); CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Modern Mechanics, University of Science and Technology of China, Hefei, Anhui 230027 (China); Ma, H.H. [CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Modern Mechanics, University of Science and Technology of China, Hefei, Anhui 230027 (China); Zhu, M.H. [Key Laboratory of Advanced Technologies of Materials, Ministry of Education, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Zhu, J., E-mail: zhujun01@163.com [College of Physical Science and Technology, Sichuan University, Chengdu, Sichuan 610064 (China); Luo, S.N., E-mail: sluo@pims.ac.cn [The Peac Institute of Multiscale Sciences, Chengdu, Sichuan 610031 (China); Key Laboratory of Advanced Technologies of Materials, Ministry of Education, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China)

    2016-04-13

    We investigate spall damage of a mild carbon steel under high strain-rate loading, regarding the effects of peak stress, strain rate, and pulse duration on spall strength and damage, as well as related microstructure features, using gas gun plate impact, laser velocimetry, and electron backscatter diffraction analysis. Our experiments demonstrate strong dependences of spall strength on peak stress and strain rate, and its weak dependence on pulse duration. We establish numerical relations between damage and peak stress or pulse duration. Brittle and ductile spall fracture modes are observed at different loading conditions. Damage nucleates at grain boundaries and triple junctions, either as transgranular cleavage cracks or voids.

  1. Green approach to corrosion inhibition of mild steel in two acidic solutions by the extract of Punica granatum peel and main constituents

    Energy Technology Data Exchange (ETDEWEB)

    Behpour, M., E-mail: m.behpour@kashanu.ac.ir [Department of Analytical Chemistry, Faculty of Chemistry, University of Kashan, Kashan, I.R. 87317-51167 (Iran, Islamic Republic of); Ghoreishi, S.M.; Khayatkashani, M. [Department of Analytical Chemistry, Faculty of Chemistry, University of Kashan, Kashan, I.R. 87317-51167 (Iran, Islamic Republic of); Soltani, N. [Department of Chemistry, Payame Noor University (PNU), 19395-4697 Tehran (Iran, Islamic Republic of)

    2012-01-05

    Graphical abstract: Ellagic acid (EA) and tannic acid (TA) were studied as corrosion inhibitors. The electron density HOMO and LUMO of EA and TA were used to explain difference in behavior of them. Highlights: Black-Right-Pointing-Pointer The extract of Punica granatum (PG) and their main constituent (ellagic acid (EA)) are found to be good inhibitors for the corrosion of mild steel in 1 M H{sub 2}SO{sub 4} and 2 M HCl. Black-Right-Pointing-Pointer The electrochemical inhibitive mechanism is explained by potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS) results. Black-Right-Pointing-Pointer The adsorption of ALLOX on mild steel surface was found to accord with the Temkin adsorption isotherm. Black-Right-Pointing-Pointer The effect of temperature on the corrosion behavior of mild steel in 2 M HCl and 1 M H{sub 2}SO{sub 4} without and with the PG extract was studied. - Abstract: The effect of the extract of Punica granatum (PG) and their main constituents involve ellagic acid (EA) and tannic acid (TA), as mild steel corrosion inhibitor in 2 M HCl and 1 M H{sub 2}SO{sub 4} solutions was investigated by weight loss measurements. The results obtained from the weight loss measurements show that the inhibition efficiency of TA even in high concentration is very low. Thus, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) investigations were used for different concentrations of PG and EA and best concentration of TA. Potentiodynamic polarization curves indicated that PG and EA behave as mixed-type inhibitors. EIS measurements show an increase of the transfer resistance with increasing inhibitor concentration. The temperature effect on the corrosion behavior of steel without and with the PG extract was studied. The inhibition action of the extract was discussed in view of Langmuir adsorption isotherm.

  2. Green approach to corrosion inhibition of mild steel in two acidic solutions by the extract of Punica granatum peel and main constituents

    International Nuclear Information System (INIS)

    Behpour, M.; Ghoreishi, S.M.; Khayatkashani, M.; Soltani, N.

    2012-01-01

    Graphical abstract: Ellagic acid (EA) and tannic acid (TA) were studied as corrosion inhibitors. The electron density HOMO and LUMO of EA and TA were used to explain difference in behavior of them. Highlights: ► The extract of Punica granatum (PG) and their main constituent (ellagic acid (EA)) are found to be good inhibitors for the corrosion of mild steel in 1 M H 2 SO 4 and 2 M HCl. ► The electrochemical inhibitive mechanism is explained by potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS) results. ► The adsorption of ALLOX on mild steel surface was found to accord with the Temkin adsorption isotherm. ► The effect of temperature on the corrosion behavior of mild steel in 2 M HCl and 1 M H 2 SO 4 without and with the PG extract was studied. - Abstract: The effect of the extract of Punica granatum (PG) and their main constituents involve ellagic acid (EA) and tannic acid (TA), as mild steel corrosion inhibitor in 2 M HCl and 1 M H 2 SO 4 solutions was investigated by weight loss measurements. The results obtained from the weight loss measurements show that the inhibition efficiency of TA even in high concentration is very low. Thus, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) investigations were used for different concentrations of PG and EA and best concentration of TA. Potentiodynamic polarization curves indicated that PG and EA behave as mixed-type inhibitors. EIS measurements show an increase of the transfer resistance with increasing inhibitor concentration. The temperature effect on the corrosion behavior of steel without and with the PG extract was studied. The inhibition action of the extract was discussed in view of Langmuir adsorption isotherm.

  3. Moessbauer spectroscopic study of rust formed on a weathering steel and a mild steel exposed for a long term in an industrial environment

    International Nuclear Information System (INIS)

    Kamimura, Takayuki; Nasu, Saburo; Tazaki, Takashi; Kuzushita, Kaori; Morimoto, Shotaro

    2002-01-01

    The rusts formed on mild steel (15-year exposure) and weathering steel (32-year exposure) exposed to an industrial environment have been characterized by means of X-ray diffraction technique and 57 Fe Moessbauer spectroscopy. By using an X-ray diffraction method, it is suggested that the rusts formed on both steels consist of the crystalline α-FeOOH, γ-FeOOH and an X-ray amorphous phase, which gives no peak to X-ray diffraction pattern. The amount of the X-ray amorphous phase exceeds 50% of the total amount of the rust. The 57 Fe Moessbauer spectra observed at 10K indicate that the rust contains only α-FeOOH, γ-FeOOH and Fe 3-δ O 4 (γ-Fe 2 O 3 ) for mild steel, and only α-FeOOH and γ-FeOOH for weathering steel. The X-ray amorphous substance in the rust payer formed on mild steel possesses the structures of mainly α-FeOOH showing superparamagnetism owing to its small particle size, and Fe 3-δ O 4 (γ-Fe 2 O 3 ). They are contained both in the inner rust layer and in the outer rust layer. The X-ray amorphous phase in the rust layer formed on weathering steel is mainly α-FeOOH. (author)

  4. Electrochemical measurements for the corrosion inhibition of mild steel in 1 M hydrochloric acid by using an aromatic hydrazide derivative

    Directory of Open Access Journals (Sweden)

    P. Preethi Kumari

    2017-07-01

    Full Text Available The influence of an aromatic hydrazide derivative, 2-(3,4,5-trimethoxybenzylidene hydrazinecarbothioamide (TMBHC as corrosion inhibitor on mild steel in 1 M hydrochloric acid was studied by Tafel polarization and electrochemical impedance spectroscopy (EIS technique. The results showed that the inhibition efficiency (% IE of TMBHC increased with increasing inhibitor concentrations and also with increase in temperatures. TMBHC acted as a mixed type of inhibitor and its adsorption on mild steel surface was found to follow Langmuir’s adsorption isotherm. The evaluation of thermodynamic and activation parameters indicated that the adsorption of TMBHC takes place through chemisorption. The formation of protective film was further confirmed by scanning electron microscopy (SEM.

  5. The water soluble composite poly(vinylpyrrolidone–methylaniline: A new class of corrosion inhibitors of mild steel in hydrochloric acid media

    Directory of Open Access Journals (Sweden)

    R. Karthikaiselvi

    2017-02-01

    Full Text Available In recent years poly methyl aniline has been reported as one of the efficient corrosion inhibitors of mild steel in acidic media. In view of the major limitation of the insolubility of polymethyl aniline PMA, we propose to convert PMA into a water soluble composite using supporting polymer polyvinylpyrrolidone to get higher solubility and corrosion inhibition efficiency. The water soluble composite poly(vinylpyrrolidone-methyl aniline was synthesized by chemical oxidative polymerization and its inhibitive effect on mild steel in 1 M HCl has been investigated using weight loss and electrochemical techniques (potentiodynamic polarization studies and impedance spectroscopy. SEM and EDX analyses are carried out to establish a protective film formation on the metal surface.

  6. Sodium leak and combustion experiment-II report. Evaluation result of damage of mild steel liner

    Energy Technology Data Exchange (ETDEWEB)

    Aoto, K.; Hirakawa, Y.; Kuroda, T. [Power Reactor and Nuclear Fuel Development Corp., Oarai, Ibaraki (Japan). Oarai Engineering Center

    1996-09-01

    Several material analyses on damage of the floor liner made of a mild steel which was in the test cell of the second sodium leak and combustion experiment (Test-2) performed in OEC/PNC on June 7 in 1996 were carried out to clarify the following issues. (1) Difference of the corrosion mechanism of Test-2 liner to that of the first sodium leak and combustion experiment (Test-1) liner. (2) The vital factor which can desides corrosion mechanism and damage location. The following analyses were accomplished. (1) Microstructure observation, (2) EPMA for cross-section of vicinity of corroded area, (3) X-ray diffraction (XRD) for the interface between corrosion product-liner (mild steel). The differences between the corrosion mechanism of Test-1 liner which is seemed to be the same that of `MONJU` liner and that of Test-2 liner is discussed based on the results of these material analyses. As the result, the Na-Fe double oxidization with mechanical/chemical removal of reaction product can be occurred on the Test-1 and `MONJU` liner. On the other hand, a hot-corrosion, that is the molten salt type corrosion is subject to be thinning of the Test-2 liner. All failures of Test-2 liner surround at the halfway up a convex. Considering the above corrosion mechanism, that fact leads that significant damage is occurred at the molten salt level. (author)

  7. Inhibition of Mild Steel Corrosion in Sulfuric Acid Solution by New Schiff Base

    Directory of Open Access Journals (Sweden)

    Ahmed A. Al-Amiery

    2014-01-01

    Full Text Available The efficiency of Schiff base derived from 4-aminoantipyrine, namely 2-(1,5-dimethyl-4-(2-methylbenzylideneamino-2-phenyl-1H-pyrazol-3(2H-ylidene hydrazinecarbothioamide as a corrosion inhibitor on mild steel in 1.0 M H2SO4 was investigated using electrochemical impedance spectroscopy (EIS, potentiodynamic polarization (PD and electrochemical frequently modulation (EFM in addition to the adsorption isotherm, corrosion kinetic parameters and scanning electron microscopy (SEM. The results showed that this inhibitor behaved as a good corrosion inhibitor, even at low concentration, with a mean efficiency of 93% and, also, a reduction of the inhibition efficiency as the solution temperature increases. A polarization technique and EIS were tested for different concentrations and different temperatures to reveal that this compound is adsorbed on the mild steel, therefore blocking the active sites, and the adsorption follows the Langmuir adsorption isotherm model. The excellent inhibition effectiveness of 2-(1,5-dimethyl-4-(2-methylbenzylideneamino-2-phenyl-1H-pyrazol-3(2H-ylidenehydrazinecarbothioamide was also verified by scanning electron microscope (SEM.

  8. Corrosion studies on mild steel in contact with cemented waste forms

    International Nuclear Information System (INIS)

    Platts, N.

    1987-03-01

    The internal corrosion of mild steel drums has been assessed in support of the proposed cementation of low level solid and sludge wastes arising from the Winfrith SGHWR. General corrosion rates are expected to be very low but while oxygen is present pitting, at least in principle, is possible. Passive currents for mild steel in contact with the different cement formulations have therefore been determined, thereby enabling the timescale for residual oxygen within the drums to be assessed. These measurements indicate that for BFS/OPC cement formulations the oxygen will be exhausted within 37 days, though potential monitoring suggests that sulphides present in the cement may reduce this figure. For PFA/OPC cement formulations the passive currents suggest that it would take ca. one year for the oxygen present in a drum to be exhausted. Therefore though pitting should not be a problem with the BFS/OPC cement formulations, further investigation of the extent of pitting that may occur in the PFA/OPC waste form is desirable. (author)

  9. Inhibition of Mild Steel Corrosion in Sulfuric Acid Solution by New Schiff Base

    Science.gov (United States)

    Al-Amiery, Ahmed A.; Kadhum, Abdul Amir H.; Kadihum, Abdulhadi; Mohamad, Abu Bakar; How, Chong K.; Junaedi, Sutiana

    2014-01-01

    The efficiency of Schiff base derived from 4-aminoantipyrine, namely 2-(1,5-dimethyl-4-(2-methylbenzylidene)amino)-2-phenyl-1H-pyrazol-3(2H)-ylidene) hydrazinecarbothioamide as a corrosion inhibitor on mild steel in 1.0 M H2SO4 was investigated using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PD) and electrochemical frequently modulation (EFM) in addition to the adsorption isotherm, corrosion kinetic parameters and scanning electron microscopy (SEM). The results showed that this inhibitor behaved as a good corrosion inhibitor, even at low concentration, with a mean efficiency of 93% and, also, a reduction of the inhibition efficiency as the solution temperature increases. A polarization technique and EIS were tested for different concentrations and different temperatures to reveal that this compound is adsorbed on the mild steel, therefore blocking the active sites, and the adsorption follows the Langmuir adsorption isotherm model. The excellent inhibition effectiveness of 2-(1,5-dimethyl-4-(2-methylbenzylidene)amino)-2-phenyl-1H-pyrazol-3(2H)-ylidene)hydrazinecarbothioamide was also verified by scanning electron microscope (SEM). PMID:28788488

  10. Environmentally assisted fracture of cast and wrought mild steels in brine

    International Nuclear Information System (INIS)

    Pitman, S.G.; Hall, E.E.

    1984-01-01

    Two test methods, slow strain rate (SSR) tests and corrosion fatigue tests, are being used to investigate the susceptibility of wrought and cast mild steels to environmentally assisted fracture. The SSR test provides an assessment of relative cracking susceptibility, and is most useful for comparing the effects of different environments on a given material, and for measuring the relative susceptibility of different materials to environmentally assisted cracking in a given environment. The corrosion fatigue test measures the stress intensity (which is proportional to stress times the square root of crack length) below which an existing flaw or crack will not grow. The test may also prove useful in measuring the stress intensity that provides an acceptable rate of crack growth. The SSR test has been used to investigate the effects of strain rate, temperature, and solution oxygen content on fracture properties of mild steel. The results of currently available corrosion fatigue tests are limited to crack growth rate measurements at one frequency in air and in brine. These measurements will be part of an overall program to evaluate allowable stress intensities, but this evaluation cannot be made until measurements are taken at different frequencies and at lower stress intensities. This report, then discusses the background of SSR testing, experimental procedures, results, and conclusions

  11. Comparison of stainless and mild steel welding fumes in generation of reactive oxygen species

    Directory of Open Access Journals (Sweden)

    Frazer David

    2010-11-01

    Full Text Available Abstract Background Welding fumes consist of a wide range of complex metal oxide particles which can be deposited in all regions of the respiratory tract. The welding aerosol is not homogeneous and is generated mostly from the electrode/wire. Over 390,000 welders were reported in the U.S. in 2008 while over 1 million full-time welders were working worldwide. Many health effects are presently under investigation from exposure to welding fumes. Welding fume pulmonary effects have been associated with bronchitis, metal fume fever, cancer and functional changes in the lung. Our investigation focused on the generation of free radicals and reactive oxygen species from stainless and mild steel welding fumes generated by a gas metal arc robotic welder. An inhalation exposure chamber located at NIOSH was used to collect the welding fume particles. Results Our results show that hydroxyl radicals (.OH were generated from reactions with H2O2 and after exposure to cells. Catalase reduced the generation of .OH from exposed cells indicating the involvement of H2O2. The welding fume suspension also showed the ability to cause lipid peroxidation, effect O2 consumption, induce H2O2 generation in cells, and cause DNA damage. Conclusion Increase in oxidative damage observed in the cellular exposures correlated well with .OH generation in size and type of welding fumes, indicating the influence of metal type and transition state on radical production as well as associated damage. Our results demonstrate that both types of welding fumes are able to generate ROS and ROS-related damage over a range of particle sizes; however, the stainless steel fumes consistently showed a significantly higher reactivity and radical generation capacity. The chemical composition of the steel had a significant impact on the ROS generation capacity with the stainless steel containing Cr and Ni causing more damage than the mild steel. Our results suggest that welding fumes may cause acute

  12. Induction surface hardening of hard coated steels

    Energy Technology Data Exchange (ETDEWEB)

    Pantleon, K.; Kessler, O.; Hoffann, F.; Mayr, P. [Stiftung Inst. fuer Werkstofftechnik, Bremen (Germany)

    1999-11-01

    The properties of hard coatings deposited using CVD processes are usually excellent. However, high deposition temperatures negatively influence the substrate properties, especially in the case of low alloyed steels. Therefore, a subsequent heat treatment is necessary to restore the properties of steel substrates. Here, induction surface hardening is used as a method of heat treatment after the deposition of TiN hard coatings on AISI 4140 (DIN42CrMo4) substrates. The influences of the heat treatment on both the coating and the substrate properties are discussed in relation to the parameters of induction heating. Thereby, the heating time, heating atmosphere and the power input into the coating-substrate compounds are varied. As a result of induction surface hardening, the properties of the substrates are improved without losing good coating properties. High hardness values in the substrate near the interface allow the AISI 4140 substrates to support TiN hard coatings very well. Consequently, higher critical loads are measured in scratch tests after the heat treatment. Also, compressive residual stresses in the substrate are generated. In addition, only a very low distortion appears. (orig.)

  13. Iron cycling at corroding carbon steel surfaces

    Science.gov (United States)

    Lee, Jason S.; McBeth, Joyce M.; Ray, Richard I.; Little, Brenda J.; Emerson, David

    2013-01-01

    Surfaces of carbon steel (CS) exposed to mixed cultures of iron-oxidizing bacteria (FeOB) and dissimilatory iron-reducing bacteria (FeRB) in seawater media under aerobic conditions were rougher than surfaces of CS exposed to pure cultures of either type of microorganism. The roughened surface, demonstrated by profilometry, is an indication of loss of metal from the surface. In the presence of CS, aerobically grown FeOB produced tight, twisted helical stalks encrusted with iron oxides. When CS was exposed anaerobically in the presence of FeRB, some surface oxides were removed. However, when the same FeOB and FeRB were grown together in an aerobic medium, FeOB stalks were less encrusted with iron oxides and appeared less tightly coiled. These observations suggest that iron oxides on the stalks were reduced and solubilized by the FeRB. Roughened surfaces of CS and denuded stalks were replicated with three culture combinations of different species of FeOB and FeRB under three experimental conditions. Measurements of electrochemical polarization resistance established different rates of corrosion of CS in aerobic and anaerobic media, but could not differentiate rate differences between sterile controls and inoculated exposures for a given bulk concentration of dissolved oxygen. Similarly, total iron in the electrolyte could not be used to differentiate treatments. The experiments demonstrate the potential for iron cycling (oxidation and reduction) on corroding CS in aerobic seawater media. PMID:24093730

  14. Characteristics of modified martensitic stainless steel surfaces under tribocorrosion conditions

    International Nuclear Information System (INIS)

    Rozing, Goran; Marusic, Vlatko; Alar, Vesna

    2017-01-01

    Stainless steel samples were tested in the laboratory and under real conditions of tribocorrosion wear. Electrochemical tests were also carried out to verify the corrosion resistance of modified steel surfaces. Metallographic analysis and hardness testing were conducted on stainless steel samples X20Cr13 and X17CrNi16 2. The possibilities of applications of modified surfaces of the selected steels were investigated by testing the samples under real wear conditions. The results have shown that the induction hardened and subsequently nitrided martensitic steels achieved an average wear resistance of up to three orders of magnitude higher as compared to the delivered condition.

  15. Characteristics of modified martensitic stainless steel surfaces under tribocorrosion conditions

    Energy Technology Data Exchange (ETDEWEB)

    Rozing, Goran [Osijek Univ. (Croatia). Chair of Mechanical Engineering; Marusic, Vlatko [Osijek Univ. (Croatia). Dept. of Engineering Materials; Alar, Vesna [Zagreb Univ. (Croatia). Dept. Materials

    2017-04-01

    Stainless steel samples were tested in the laboratory and under real conditions of tribocorrosion wear. Electrochemical tests were also carried out to verify the corrosion resistance of modified steel surfaces. Metallographic analysis and hardness testing were conducted on stainless steel samples X20Cr13 and X17CrNi16 2. The possibilities of applications of modified surfaces of the selected steels were investigated by testing the samples under real wear conditions. The results have shown that the induction hardened and subsequently nitrided martensitic steels achieved an average wear resistance of up to three orders of magnitude higher as compared to the delivered condition.

  16. Profiling mild steel welding processes to reduce fume emissions and costs in the workplace.

    Science.gov (United States)

    Keane, Michael J; Siert, Arlen; Chen, Bean T; Stone, Samuel G

    2014-05-01

    To provide quantitative information to choose the best welding processes for minimizing workplace emissions, nine gas metal arc welding (GMAW) processes for mild steel were assessed for fume generation rates, normalized fume generation rates (milligram fume per gram of electrode consumed), and normalized generation rates for elemental manganese, nickel, and iron. Shielded metal arc welding (SMAW) and flux-cored arc-welding (FCAW) processes were also profiled. The fumes were collected quantitatively in an American Welding Society-type fume chamber and weighed, recovered, homogenized, and analyzed by inductively coupled atomic emission spectroscopy for total metals. The processes included GMAW with short circuit, globular transfer, axial spray, pulsed spray, Surface Tension Transfer™, Regulated Metal Deposition™, and Cold Metal Transfer™ (CMT) modes. Flux-cored welding was gas shielded, and SMAW was a single rod type. Results indicate a wide range of fume emission factors for the process variations studied. Fume emission rates per gram of electrode consumed were highest for SMAW (~13 mg fume g(-1) electrode) and lowest for GMAW processes such as pulsed spray (~1.5mg g(-1)) and CMT (~1mg g(-1)). Manganese emission rates per gram of electrode consumed ranged from 0.45 mg g(-1) (SMAW) to 0.08 mg g(-1) (CMT). Nickel emission rates were generally low and ranged from ~0.09 (GMAW short circuit) to 0.004 mg g(-1) (CMT). Iron emission rates ranged from 3.7 (spray-mode GMAW) to 0.49 mg g(-1) (CMT). The processes studied have significantly different costs, and cost factors are presented based on a case study to allow comparisons between processes in specific cost categories. Costs per linear meter of weld were $31.07 (SMAW), $12.37 (GMAW short circuit), and $10.89 (FCAW). Although no single process is the best for minimizing fume emissions and costs while satisfying the weld requirements, there are several processes that can minimize emissions. This study provides

  17. Experimental Investigation of Friction Coefficient and Wear Rate of Composite Materials Sliding Against Smooth and Rough Mild Steel Counterfaces

    OpenAIRE

    M.A. Chowdhury; D.M. Nuruzzaman; B.K. Roy; S. Samad; R. Sarker; A.H.M. Rezwan

    2013-01-01

    In the present study, friction coefficient and wear rate of gear fiber reinforced plastic (gear fiber) and glass fiber reinforced plastic (glass fiber) sliding against mild steel are investigated experimentally. In order to do so, a pin on disc apparatus is designed and fabricated. Experiments are carried out when smooth or rough mild steel pin slides on gear fiber and glass fiber disc. Experiments are conducted at normal load 10, 15 and 20 N, sliding velocity 1, 1.5 and 2 m/s and relative h...

  18. A Comparative Study of the Inhibitory Effect of the Extracts of Ocimum sanctum, Aegle marmelos, and Solanum trilobatum on the Corrosion of Mild Steel in Hydrochloric Acid Medium

    Directory of Open Access Journals (Sweden)

    M. Shyamala

    2011-01-01

    Full Text Available A comparative study of the inhibitory effect of plant extracts, Ocimum sanctum, Aegle marmelos, and Solanum trilobatum, on the corrosion of mild steel in 1N HCl medium was investigated using weightloss method, electrochemical methods, and hydrogen permeation method. Polarization method indicates plant extracts behave as mixed-type inhibitor. The impedance method reveals that charge-transfer process mainly controls the corrosion of mild steel. On comparison, maximum inhibition efficiency was found in Ocimum sanctum with 99.6% inhibition efficiency at 6.0% v/v concentration of the extract. The plant extracts obey Langmuir adsorption isotherm. The SEM morphology of the adsorbed protective film on the mild steel surface has confirmed the high performance of inhibitive effect of the plant extracts. From hydrogen permeation method, all the plant extracts were able to reduce the permeation current. The reason for the reduced permeation currents in presence of the inhibitors may be attributed to the slow discharge step followed by fast electrolytic desorption step. Results obtained in all three methods were very much in good agreement in the order Ocimum sanctum > Aegle marmelos > Solanum trilobatum.

  19. Inhibition Effects of a Synthesized Novel 4-Aminoantipyrine Derivative on the Corrosion of Mild Steel in Hydrochloric Acid Solution together with Quantum Chemical Studies

    Directory of Open Access Journals (Sweden)

    Abu Bakar Mohamad

    2013-06-01

    Full Text Available 1,5-Dimethyl-4-((2-methylbenzylideneamino-2-phenyl-1H-pyrazol-3(2H-one (DMPO was synthesized to be evaluated as a corrosion inhibitor. The corrosion inhibitory effects of DMPO on mild steel in 1.0 M HCl were investigated using electrochemical impedance spectroscopy (EIS, potentiodynamic polarization, open circuit potential (OCP and electrochemical frequency modulation (EFM. The results showed that DMPO inhibited mild steel corrosion in acid solution and indicated that the inhibition efficiency increased with increasing inhibitor concentration. Changes in the impedance parameters suggested an adsorption of DMPO onto the mild steel surface, leading to the formation of protective films. The novel synthesized corrosion inhibitor was characterized using UV-Vis, FT-IR and NMR spectral analyses. Electronic properties such as highest occupied molecular orbital energy, lowest unoccupied molecular orbital energy (EHOMO and ELUMO, respectively and dipole moment (μ were calculated and discussed. The results showed that the corrosion inhibition efficiency increased with an increase in the EHOMO values but with a decrease in the ELUMO value.

  20. Inhibition Effects of a Synthesized Novel 4-Aminoantipyrine Derivative on the Corrosion of Mild Steel in Hydrochloric Acid Solution together with Quantum Chemical Studies

    Science.gov (United States)

    Junaedi, Sutiana; Al-Amiery, Ahmed A.; Kadihum, Abdulhadi; Kadhum, Abdul Amir H.; Mohamad, Abu Bakar

    2013-01-01

    1,5-Dimethyl-4-((2-methylbenzylidene)amino)-2-phenyl-1H-pyrazol-3(2H)-one (DMPO) was synthesized to be evaluated as a corrosion inhibitor. The corrosion inhibitory effects of DMPO on mild steel in 1.0 M HCl were investigated using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, open circuit potential (OCP) and electrochemical frequency modulation (EFM). The results showed that DMPO inhibited mild steel corrosion in acid solution and indicated that the inhibition efficiency increased with increasing inhibitor concentration. Changes in the impedance parameters suggested an adsorption of DMPO onto the mild steel surface, leading to the formation of protective films. The novel synthesized corrosion inhibitor was characterized using UV-Vis, FT-IR and NMR spectral analyses. Electronic properties such as highest occupied molecular orbital energy, lowest unoccupied molecular orbital energy (EHOMO and ELUMO, respectively) and dipole moment (μ) were calculated and discussed. The results showed that the corrosion inhibition efficiency increased with an increase in the EHOMO values but with a decrease in the ELUMO value. PMID:23736696

  1. Comparative analysis of adsorption and corrosion inhibitive properties of ethanol extract of Dialium Guineense leaves for mild steel in 0.5 M HCl

    Directory of Open Access Journals (Sweden)

    Shola Elijah Adeniji

    2018-05-01

    Full Text Available Adsorption and corrosion inhibitive properties of ethanol extract of Dialium guineense leaves for mild steel in 0.5M HCl was studied using the gravimetric method. The results showed that the ethanol extract of Dialium guineense leaves is a good corrosion inhibitor for mild steel in 0.5 M HCl. The inhibition efficiency was found to increase with increase in the concentration of ethanol extract of Dialium guineense leaves up to the maximum of 92 %, but at the same time it decreased as the temperature was increased. Corrosion inhibition by the extract of Dialium guineense leaves is carried out by adsorption mechanism with the kinetics of corrosion following the pseudo first order reaction with high correlation. Thermodynamic consideration revealed that adsorption of the ethanol extract of Dialium guineense leaves on mild steel surface is an exothermic and spontaneous process that fitted the Langmuir adsorption isotherm. The values of activation energy and Gibb’s free energy were found within the range of limits expected for the mechanism of physical adsorption.

  2. Laser surface texturing of tool steel: textured surfaces quality evaluation

    Science.gov (United States)

    Šugár, Peter; Šugárová, Jana; Frnčík, Martin

    2016-05-01

    In this experimental investigation the laser surface texturing of tool steel of type 90MnCrV8 has been conducted. The 5-axis highly dynamic laser precision machining centre Lasertec 80 Shape equipped with the nano-second pulsed ytterbium fibre laser and CNC system Siemens 840 D was used. The planar and spherical surfaces first prepared by turning have been textured. The regular array of spherical and ellipsoidal dimples with a different dimensions and different surface density has been created. Laser surface texturing has been realized under different combinations of process parameters: pulse frequency, pulse energy and laser beam scanning speed. The morphological characterization of ablated surfaces has been performed using scanning electron microscopy (SEM) technique. The results show limited possibility of ns pulse fibre laser application to generate different surface structures for tribological modification of metallic materials. These structures were obtained by varying the processing conditions between surface ablation, to surface remelting. In all cases the areas of molten material and re-cast layers were observed on the bottom and walls of the dimples. Beside the influence of laser beam parameters on the machined surface quality during laser machining of regular hemispherical and elipsoidal dimple texture on parabolic and hemispherical surfaces has been studied.

  3. Topical rebamipide improves the ocular surface in mild lagophthalmos

    Directory of Open Access Journals (Sweden)

    Itakura M

    2013-07-01

    Full Text Available Mariko Itakura,1 Hirotaka Itakura,1,2 Tomoyuki Kashima,2 Hideo Akiyama,2 Shoji Kishi21Department of Ophthalmology, Maebashi Red Cross Hospital, Maebashi, Japan; 2Department of Ophthalmology, Gunma University, School of Medicine, Maebashi, JapanAbstract: Administration of topical rebamipide improves the ocular surface in dry eye. We consecutively studied seven eyes in seven cases (three males and four females with mild lagophthalmos (three cases after eyelid surgery, two cases of incomplete facial nerve palsy, and two cases of senile ectropion during the treatment of corneal disorders with rebamipide eye drops four times daily for 2 weeks. The fluorescein corneal staining (FCS score, tear film break-up time (TBUT, Schirmer's test, and decimal visual acuity were examined. Ocular symptoms were examined and scored by questioning each patient before and after administration of the drug. In all seven eyes, inferior corneal erosion decreased or disappeared within 2 weeks after administration of topical rebamipide. The FCS score was significantly improved (P < 0.05. The TBUT was significantly extended from 2.9 ± 0.5 seconds to 5.2 ± 0.4 seconds (P < 0.05. The scores of ocular symptoms, such as eye pain, dryness, blurred vision, and foreign body sensations, were significantly improved (P < 0.05.Topical rebamipide was effective for corneal disorders in mild lagophthalmos. This drug may provide a novel approach to treat lagophthalmos.Keywords: dry eye, ectropion, eyelid surgery, facial nerve palsy, lagophthalmos, rebamipide

  4. Inhibiting effects of some oxadiazole derivatives on the corrosion of mild steel in perchloric acid solution

    International Nuclear Information System (INIS)

    Lebrini, Mounim; Bentiss, Fouad; Vezin, Herve; Lagrenee, Michel

    2005-01-01

    The efficiency of 3,5-bis(n-pyridyl)-1,3,4-oxadiazole (n-POX, n = 1, 2, 3), as corrosion inhibitors for mild steel in 1 M perchloric acid (HClO 4 ) have been determined by weight loss measurements and electrochemical studies. The results show that these inhibitors revealed a good corrosion inhibition even at very low concentrations. Comparison of results among those obtained by the studied oxadiazoles shows that 3-POX was the best inhibitor. Polarisation curves indicate that n-pyridyl substituted-1,3,4-oxadiazoles are mixed type inhibitors in 1 M HClO 4 . The adsorption of these inhibitors follows a Langmuir isotherm model. The electronic properties of n-POX, obtained using the AM1 semi-empirical quantum chemical approach, were correlated with their experimental efficiencies using the linear resistance model (LR)

  5. Deposition of Co-Ti alloy on mild steel substrate using laser cladding

    International Nuclear Information System (INIS)

    Alemohammad, Hamidreza; Esmaeili, Shahrzad; Toyserkani, Ehsan

    2007-01-01

    Laser cladding of a Co-Ti alloy on a mild steel substrate is studied. Premixed powders with the composition of 85 wt% cobalt and 15 wt% titanium are pre-placed on the substrate and a moving laser beam at different velocities is used to produce clad layers well bounded to the substrate. Characteristics of the clad are investigated using optical microscopy, X-ray diffraction (XRD), energy dispersive spectroscopy (EDS) and microhardness tests. The results reveal that the intermetallic phase TiCo 3 and β (i.e. fcc) cobalt are formed in the clad layer. The clad layer can also have major dilution from the substrate depending on the laser scanning velocity. It is observed that a finer microstructure is achievable with higher laser velocities whereas higher hardness is achieved using lower velocities. The latter is due to the formation of a larger fraction of TiCo 3 phase

  6. Quantum chemical studies on the corrosion inhibition of some sulphonamides on mild steel in acidic medium

    International Nuclear Information System (INIS)

    Arslan, Taner; Kandemirli, Fatma; Ebenso, Eno E.; Love, Ian; Alemu, Hailemichael

    2009-01-01

    Quantum chemical calculations using the density functional theory (DFT) and some semi-empirical methods were performed on four sulphonamides (sulfaguanidine, sulfamethazine, sulfamethoxazole and sulfadiazine) used as corrosion inhibitors for mild steel in acidic medium to determine the relationship between molecular structure and their inhibition efficiencies. The results of the quantum chemical calculations and experimental %IE were subjected to correlation analysis and indicate that their inhibition effect are closely related to E HOMO , E LUMO , hardness, polarizability, dipole moment and charges. The %IE increased with increase in the E HOMO and decrease in E HOMO - E LUMO . The negative sign of the E HOMO values and other kinetic and thermodynamic parameters indicates that the data obtained support physical adsorption mechanism

  7. Effect of radioactive chromate on the corrosion and polarisation of mild steel in sodium chloride solution

    International Nuclear Information System (INIS)

    Subramanyan, N.; Ramakrishnaiah, K.; Iyer, S.V.; Kapali, V.

    1980-01-01

    Corrosion tests of mild steel in 0.01% sodium chloride containing radioactive chromate and non-radioactive chromate have been carried out. It has been observed that the labelled sodium chromate has a deleterious effect on the inhibitive action of non-radioactive chromate. The effect of radioactive chromate on the potentiostatic polarization of m.s. in sodium chloride solution containing non-radioactive sodium chromate has also been studied. It is observed that both the cathodic and the anodic polarisation of the metal is diminished in the presence of radioactive chromate. The behaviour of the system in the presence of radioactive chromate is attributed both to the action of depolarisers produced by radiolysis of water and to the effect of gamma radiation on the metal. (author)

  8. Deposition of Co-Ti alloy on mild steel substrate using laser cladding

    Energy Technology Data Exchange (ETDEWEB)

    Alemohammad, Hamidreza [University of Waterloo, Department of Mechanical and Mechatronics Engineering, 200 University Avenue West, Waterloo, ON N2L 3G1 (Canada)], E-mail: shalemoh@engmail.uwaterloo.ca; Esmaeili, Shahrzad [University of Waterloo, Department of Mechanical and Mechatronics Engineering, 200 University Avenue West, Waterloo, ON N2L 3G1 (Canada); Toyserkani, Ehsan [University of Waterloo, Department of Mechanical and Mechatronics Engineering, 200 University Avenue West, Waterloo, ON N2L 3G1 (Canada)

    2007-05-15

    Laser cladding of a Co-Ti alloy on a mild steel substrate is studied. Premixed powders with the composition of 85 wt% cobalt and 15 wt% titanium are pre-placed on the substrate and a moving laser beam at different velocities is used to produce clad layers well bounded to the substrate. Characteristics of the clad are investigated using optical microscopy, X-ray diffraction (XRD), energy dispersive spectroscopy (EDS) and microhardness tests. The results reveal that the intermetallic phase TiCo{sub 3} and {beta} (i.e. fcc) cobalt are formed in the clad layer. The clad layer can also have major dilution from the substrate depending on the laser scanning velocity. It is observed that a finer microstructure is achievable with higher laser velocities whereas higher hardness is achieved using lower velocities. The latter is due to the formation of a larger fraction of TiCo{sub 3} phase.

  9. The role of carbon in the breakaway oxidation of mild steel in high pressure carbon dioxide

    International Nuclear Information System (INIS)

    Surman, P.L.; Brown, A.M.

    1974-01-01

    The rate controlling step in the oxidation of iron and mild steel in CO 2 is the diffusion of iron across the inner of two layers of magnetite scale. Cation diffusion is directed towards available oxidant and hence tends to produce fresh oxide in freely available space. The initial oxidation process is thus protective and stress-free. As oxidation proceeds the gaseous reaction product, carbon monoxide, tends to accumulate at the oxide/metal interface. Eventually this leads to simultaneous carbon deposition and oxide formation. This carbon contamination allows oxidant access to oxide crystallite 'jacking points', and hence volume expansion and stressed breakaway corrosion can occur. Experiments designed to simulate the promotion, propagation and healing of breakaway oxidation and to define the conditions for carbon deposition are reported. (author)

  10. Effect of Schiff's Bases as Corrosion Inhibitors on Mild Steel in Sulphuric Acid

    Directory of Open Access Journals (Sweden)

    R. K. Upadhyay

    2007-01-01

    Full Text Available Mass loss and thermometric methods have been used to study the corrosion inhibitory effect of synthesised Schiff's bases viz. N-(furfurilidine – 4- methoxy aniline (SB1, N-(furfurilidine – 4- methylaniline (SB2, N-(salicylidine – 4- methoxy aniline (SB3, N-(cinnamalidine – 4 –methoxy aniline (SB4 and N-(cinnamalidine - 2-methylaniline (SB5 on mild steel in sulphuric acid solutions. Results show that both methods have good agreement with each other and inhibition efficiency depends upon the concentration of inhibitor as well as that of acid. Maximum inhibition efficiency is shown at highest concentration of Schiff's bases at the highest strength of acid.

  11. In situ testing of titanium and mild steel nuclear waste containers at the WIPP site

    International Nuclear Information System (INIS)

    Molecke, M.A.

    1990-01-01

    An overview of the Waste Isolation Pilot Plant (WIPP) in situ tests on the corrosion of titanium and mild steel for high level waste containers is presented. The tests at Sandia have moved out of the laboratory into a test underground facility in order to evaluate the performance of the waste package material. The tests are being performed under both near-reference and accelerated salt repository conditions. Some containers are filled with high level waste glass (non-radioactive); others contain electric heaters. Backfill material is either bentonite/sand or crushed salt. In other tests metals and glasses are exposed directly to brine. The tests are designed to study the corrosion and metallurgy of the canister and overpack materials; the feasibility and performance of backfill materials; and near-field effects such as brine migration

  12. Duplex stainless steel surface bay laser cladding

    International Nuclear Information System (INIS)

    Amigo, V.; Pineda, Y.; Segovia, F.; Vicente, A.

    2004-01-01

    Laser cladding is one of the most promising techniques to restore damaged surfaces and achieve properties similar to those of the base metal. In this work, duplex stainless steels have been cladded by a nickel alloy under different processing conditions. The influence of the beam speed and defocusing variables ha been evaluated in the microstructure both of the cladding and heat affected zone, HAZ. These results have been correlated to mechanical properties by means of microhardness measurements from cladding area to base metal through the interface. This technique has shown to be very appropriate to obtain controlled mechanical properties as they are determined by the solidification microstructure, originated by the transfer of mass and heat in the system. (Author) 21 refs

  13. Surface characterization of adsorbed asphaltene on a stainless steel surface

    International Nuclear Information System (INIS)

    Abdallah, W.A.; Taylor, S.D.

    2007-01-01

    X-ray photoelectron spectroscopy was used to characterize a single layer of adsorbed asphaltene on a metallic surface. The deposits were created by immersing a stainless steel disc into a dilute asphaltene solution with either toluene or dichloromethane as the solvent, although the toluene solution allowed for better control of the adsorbed asphaltene layer and less atmospheric oxygen contamination. The analyses for C 1s, S 2p 3/2 , N 1s and O 1s photoemission peaks indicated that different functional groups are present in the asphaltene layer including carboxylic, pyrrolic, pyridininc, thiophenic and sulfite, with slight differences in their binding energies

  14. The corrosion behavior of mild steel in molten NaNO3-KNO3 salt and its evaluation

    International Nuclear Information System (INIS)

    Tsujino, Bunzo; Oki, Takeo.

    1992-01-01

    The galvanic behavior of mild steel in molten NaNO 3 -KNO 3 salt (equivalent molar fraction) and its evaluation have been investigated by the amount of galvanic current with zero impedance ammeter. The galvanic currents in a galvanic couple consisting of mild steel and platinum so obtained corresponded approximately to the information for dissolution reaction of iron in molten NaNO 3 KNO 3 salt. Further, the galvanic currents proved to be an effective means for evaluating corrosion rate of metals in molten NaNO 3 KNO 3 salt. The effect of NaCl on galvanic behavior of mild steel couple to platinum in molten NaNO 3 -KNO 3 salt did not appear at the NaCl concentration up to 0.05 molar fraction, but the effect appeared as localized corrosion at the NaCl concentration of 0.05 molar fraction or more. The coloration for mild steel due to the oxide film was well controlled by adjusting amount of electricity rather than the temperature. (author)

  15. Surface design methodology – challenge the steel

    International Nuclear Information System (INIS)

    Bergman, M; Rosen, B-G; Eriksson, L; Anderberg, C

    2014-01-01

    The way a product or material is experienced by its user could be different depending on the scenario. It is also well known that different materials and surfaces are used for different purposes. When optimizing materials and surface roughness for a certain something with the intention to improve a product, it is important to obtain not only the physical requirements, but also the user experience and expectations. Laws and requirements of the materials and the surface function, but also the conservative way of thinking about materials and colours characterize the design of medical equipment. The purpose of this paper is to link the technical- and customer requirements of current materials and surface textures in medical environments. By focusing on parts of the theory of Kansei Engineering, improvements of the companys' products are possible. The idea is to find correlations between desired experience or ''feeling'' for a product, -customer requirements, functional requirements, and product geometrical properties -design parameters, to be implemented on new improved products. To be able to find new materials with the same (or better) technical requirements but a higher level of user stimulation, the current material (stainless steel) and its surface (brushed textures) was used as a reference. The usage of focus groups of experts at the manufacturer lead to a selection of twelve possible new materials for investigation in the project. In collaboration with the topical company for this project, three new materials that fulfil the requirements -easy to clean and anti-bacterial came to be in focus for further investigation in regard to a new design of a washer-disinfector for medical equipment using the Kansei based Clean ability approach CAA

  16. Surface design methodology - challenge the steel

    Science.gov (United States)

    Bergman, M.; Rosen, B.-G.; Eriksson, L.; Anderberg, C.

    2014-03-01

    The way a product or material is experienced by its user could be different depending on the scenario. It is also well known that different materials and surfaces are used for different purposes. When optimizing materials and surface roughness for a certain something with the intention to improve a product, it is important to obtain not only the physical requirements, but also the user experience and expectations. Laws and requirements of the materials and the surface function, but also the conservative way of thinking about materials and colours characterize the design of medical equipment. The purpose of this paper is to link the technical- and customer requirements of current materials and surface textures in medical environments. By focusing on parts of the theory of Kansei Engineering, improvements of the companys' products are possible. The idea is to find correlations between desired experience or "feeling" for a product, -customer requirements, functional requirements, and product geometrical properties -design parameters, to be implemented on new improved products. To be able to find new materials with the same (or better) technical requirements but a higher level of user stimulation, the current material (stainless steel) and its surface (brushed textures) was used as a reference. The usage of focus groups of experts at the manufacturer lead to a selection of twelve possible new materials for investigation in the project. In collaboration with the topical company for this project, three new materials that fulfil the requirements -easy to clean and anti-bacterial came to be in focus for further investigation in regard to a new design of a washer-disinfector for medical equipment using the Kansei based Clean ability approach CAA.

  17. Recent characterization of steel by surface analysis methods

    International Nuclear Information System (INIS)

    Suzuki, Shigeru

    1996-01-01

    Surface analysis methods, such as Auger electron spectroscopy, X-ray photoelectron spectroscopy, secondary ion mass spectrometry, glow discharge optical emission spectrometry and so on, have become indispensable to characterize surface and interface of many kinds of steel. Although a number of studies on characterization of steel by these methods have been carried out, several problems still remain in quantification and depth profiling. Nevertheless, the methods have provided essential information on the concentration and chemical state of elements at the surface and interface. Recent results on characterization of oxide layers, coated films, etc. on the surface of steel are reviewed here. (author). 99 refs

  18. Improvement of deposition efficiency and control of hardness for cold-sprayed coatings using high carbon steel/mild steel mixture powder

    International Nuclear Information System (INIS)

    Ogawa, Kazuhiro; Amao, Satoshi; Yokoyama, Nobuyuki; Ootaki, Kousuke

    2011-01-01

    In this study, in order to make high carbon steel coating by cold spray technique, spray conditions such as carrier gas temperature and pressure etc. were investigated. And also, in order to improve deposition efficiency and control coating hardness of cold-sprayed high carbon steel, high carbon and mild steel mixed powder and its mechanical milled powder were developed and were optimized. By using the cold-spray technique, particle deposition of a high carbon steel was successful. Moreover, by applying mixed and mechanical milled powders, the porosity ratio was decreased and deposition efficiency was improved. Furthermore, using these powders, it is possible to control the hardness value. Especially, when using mechanical milled powder, it is very difficult to identify the interface between the coating and the substrate. The bonding between the coating and the substrate is thus considered to be excellent. (author)

  19. Study to produce polymer gel for decontamination on the surface of steel, ceramic, plastic, glass

    International Nuclear Information System (INIS)

    Pham Quynh Luong; Nguyen Van Chinh; Nguyen Thu Trang; Nguyen An Thai; Nguyen Dinh Lam

    2015-01-01

    Strippable polymer coating is one of the methods for effective surface decontamination. A gel solution of a water soluble polymer, preferably polyvinyl alcohol (PVA) and chelating agent is applied to remove radioisotopes of Cs"1"3"7, Sr"8"5, I"1"3"1, P"3"2 and Tc"9"9"m on the surface of stainless steel, mild steel, ceramic, PVC plastic. After cleaning is completed, the gel solution is dried, formed a strong thin film, which is easily peeled off from a contaminated surface and can be disposed of as radioactive solid waste. Decontamination efficient of this gel polymer for radioisotopes have been studied on the surfaces and compared with Decongel 1101. The influence of decontamination agents, activity, film thickness to decontamination factor have been studied. The infrared spectrophotometer has been conducted to study mechanism of the decontamination for this radioisotope. (author)

  20. Cold pressure welding of aluminium-steel blanks: Manufacturing process and electrochemical surface preparation

    Science.gov (United States)

    Schmidt, Hans Christian; Homberg, Werner; Orive, Alejandro Gonzalez; Grundmeier, Guido; Hordych, Illia; Maier, Hans Jürgen

    2018-05-01

    In this study the manufacture of aluminium-steel blanks by cold pressure welding and their preparation for a welding process through electrochemical surface treatment are investigated and discussed. The cold pressure welding process was done with an incremental rolling tool that allows for the partial pressure welding of two blanks along a prepared path. The influence of the surface preparation by electrochemical deposition of bond promoting organosilane-based agents and roughening on a nano-scale is investigated and compared to conventional surface treatments. Coating the surfaces with a thin organosilane-based film incorporating specific functional groups should promote additional bonding between the mating oxide layers; its influence on the total weld strength is studied. Pressure welding requires suitable process strategies, and the current advances in the proposed incremental rolling process for the combination of mild steel and aluminium are presented.

  1. Experimental and quantum chemical simulations on the corrosion inhibition of mild steel by 3-((5-(3,5-dinitrophenyl)-1,3,4-thiadiazol-2-yl)imino)indolin-2-one

    Science.gov (United States)

    Al-Azawi, Khalida F.; Mohammed, Iman Mahdi; Al-Baghdadi, Shaimaa B.; Salman, Taghried A.; Issa, Hamsa A.; Al-Amiery, Ahmed A.; Gaaz, Tayser Sumer; Kadhum, Abdul Amir H.

    2018-06-01

    Iraq has been one of the most extensive oil and natural gas industries in the world. The corrosion of mild steel is costly and insufficiency process. It is responsible for great loss in manufacture and environment. Natural and organic inhibitors have been utilized for a long time to inhibit the corrosion. Selected thiadiazol derivative, namely 3-((5-(3,5-dinitrophenyl)-1,3,4-thiadiazol-2-yl)imino)indolin-2-one (TDIO) was investigated for it inhibitive impacts in 1 M HCl medium on corrosion of mild steel using weight loss and scanning electron microscope techniques. The maximum inhibition efficiency up to 90.7% at the maximum inhibitor concentration 0.5 mM. Surface morphology of results demonstrated that TDIO formed adsorbed film on surface of mild steel in hydrochloric acid solution. Give molecular based clarifications to the inhibitive impacts of the studied. The interactions between mild steel surface and the inhibitor molecules have been undertaken to further corroborate the methodological results.

  2. A Study of Calcareous Deposits on Cathodically Protected Mild Steel in Artificial Seawater

    Directory of Open Access Journals (Sweden)

    Yuanfeng Yang

    2015-03-01

    Full Text Available Calcareous deposits were formed on steel under conditions of cathodic protection in artificial seawater at applied constant current densities ranging from 50 to 400 mA·m−2. The calcareous layers were characterized using a Field Emission Gun Scanning Electron Microscope (FEG SEM in conjunction with Energy Dispersive X-Ray Analysis (EDX, and Electrochemical Impedance Spectroscopy (EIS. At cathodic current densities of 50–100 mA·m−2 where corrosion was still occurring, a clear correlation existed between the iron containing corrosion product and the overlying magnesium hydroxide layer. This revealed that the mapping of magnesium rich areas on a steel surface can be used in the identification of local corrosion sites. At current densities of 150–200 mA·m−2, a layered deposit was shown to occur consisting of an inner magnesium-containing layer and an outer calcium-containing layer. At current densities of 300–400 mA·m−2, intense hydrogen bubbling through macroscopic pores in the deposits gave rise to cracking of the deposited film. Under such conditions deposits do not have a well-defined double layer structure. There is also preferential formation of magnesium-rich compounds near the steel surface at the early stages of polarisation and within the developing pores and cracks of calcareous deposits later on. Based on SEM/EDX investigation of calcareous depositions the impedance model was proposed and used to monitor in situ variations in steel corrosion resistance, and to calculate the thickness of formed deposits using the length of oxygen diffusion paths.

  3. Performance evaluation of NEEM oil and HONGE Oil as cutting fluid in drilling operation of mild steel

    Science.gov (United States)

    Jyothi, P. N.; Susmitha, M.; Sharan, P.

    2017-04-01

    Cutting fluids are used in machining industries for improving tool life, reducing work piece and thermal deformation, improving surface finish and flushing away chips from the cutting zone. Although the application of cutting fluids increases the tool life and Machining efficiency, but it has many major problems related to environmental impacts and health hazards along with recycling & disposal. These problems gave provision for the introduction of mineral, vegetable and animal oils. These oils play an important role in improving various machining properties, including corrosion protection, lubricity, antibacterial protection, even emulsibility and chemical stability. Compared to mineral oils, vegetable oils in general possess high viscosity index, high flash point, high lubricity and low evaporative losses. Vegetable oils can be edible or non-edible oils and Various researchers have proved that edible vegetable oils viz., palm oil, coconut oil, canola oil, soya bean oil can be effectively used as eco-friendly cutting fluid in machining operations. But in present situations harnessing edible oils for lubricants formation restricts the use due to increased demands of growing population worldwide and availability. In the present work, Non-edible vegetable oil like Neem and Honge are been used as cutting fluid for drilling of Mild steel and its effect on cutting temperature, hardness and surface roughness are been investigated. Results obtained are compared with SAE 20W40 (petroleum based cutting fluid)and dry cutting condition.

  4. Galvanic corrosion study of aluminium alloy plates mounted to stainless and mild steel bolts by accelerated exposure test

    OpenAIRE

    MREMA, Emmanuel; ITOH, Yoshito; KANEKO, Akira; HIROHATA, Mikihito

    2016-01-01

    Despite the fact that aluminium alloy members have a proven durability over stainless steel members, their joint fasteners like bolts, nuts and washers are drawn from steel material due to aluminium alloy inferior mechanical properties. Bare contact between aluminium alloy members and stainless steel fasteners results to galvanic corrosion of aluminium alloy members. A corrosion behaviour study was carried out on different aluminium alloy types with different surface treatments mounted to sta...

  5. Characterization of D2 tool steel friction surfaced coatings over low carbon steel

    International Nuclear Information System (INIS)

    Sekharbabu, R.; Rafi, H. Khalid; Rao, K. Prasad

    2013-01-01

    Highlights: • Solid state coating by friction surfacing method. • D2 tool steel is coated over relatively softer low carbon steel. • Defect free interface between tool steel coating and low carbon steel substrate. • D2 coatings exhibited higher hardness and good wear resistance. • Highly refined martensitic microstructure in the coating. - Abstract: In this work D2 tool steel coating is produced over a low carbon steel substrate using friction surfacing process. The process parameters are optimized to get a defect free coating. Microstructural characterization is carried out using optical microscopy, scanning electron microscopy and X-ray diffraction. Infrared thermography is used to measure the thermal profile during friction surfacing of D2 steel. Wear performance of the coating is studied using Pin-on-Disk wear tests. A lower rotational speed of the consumable rod and higher translational speed of the substrate is found to result in thinner coatings. Friction surfaced D2 steel coating showed fine-grained martensitic microstructure compared to the as-received consumable rod which showed predominantly ferrite microstructure. Refinement of carbides in the coating is observed due to the stirring action of the process. The infrared thermography studies showed the peak temperature attained by the D2 coating to be about 1200 °C. The combined effect of martensitic microstructure and refined carbides resulted in higher hardness and wear resistance of the coating

  6. Influence of nitrogen ion implantation on hydrogen permeation in an extra mild steel

    International Nuclear Information System (INIS)

    Brass, A.M.; Chene, J.; Pivin, J.C.

    1989-01-01

    This paper presents the first results on the effect of nitrogen implantation on hydrogen permeation in steels. Nitrogen can modify superficially the steel's chemistry and/or microstructure depending on the fluence and thereby affect the processes of hydrogen diffusion and trapping. The implantations were performed on low carbon steel specimens with different nominal doses (1% to 10% and 33% nitrogen in a superficial layer of approximately 100 to 120 nm). The corresponding microstructures were characterized and permeation tests were conducted at room temperature in a double electrolytic cell. The nitrogen implanted layers on iron affects the electrochemical behaviour of the surface and the permeation in the material. This effect depends on the nitrogen concentration in the layer and on the corresponding microstructure. A continuous Fe 2 N layer acts as an efficient barrier to hydrogen entry and permeation when the layer is located on the entry face of the permeation membrane. This effect is stronger when the implanted layer is on the downstream face of the membrane. The low permeability values are mainly attributed to a lower hydrogen solubility in the implanted layer, whereas hydrogen trapping on defects and nitride precipitates delay hydrogen penetration. (author)

  7. Binary Mixtures of Nonyl Phenol with Alkyl Substituted Anilines as Corrosion Inhibitors for Mild Steel in Acidic Medium

    Directory of Open Access Journals (Sweden)

    H. S. Shukla

    2012-01-01

    Full Text Available The present study deals with the evaluation of the corrosion inhibition effectiveness of the two binary mixtures of nonyl phenol (NPH with 2, 4 dimethyl aniline (DMA and 2 ethyl aniline (EA at different concentration ratios (from 1:7 to 7:1 for mild steel in H2SO4 (pH=1 solution by weight loss and potentiodynamic polarization method. Corrosion inhibition ability of the compounds has been tested at different exposure periods (6 h to 24 h and at different temperatures (303 K to 333 K. The binary mixture of NPH and EA (at 7:1 concentration ratio has afforded maximum inhibition (IE% 93.5% at 6 h exposure period and at room temperature. The adsorption of both the inhibitors is found to accord with Temkin adsorption isotherm. Potentiodynamic polarization study reveals that the tested inhibitors are mixed type inhibitor and preferentially act on cathodic areas. Electrochemical impedance study suggests formation of an inhibition layer by the adsorption of the inhibitors on the metal surface. An adsorption model of the inhibitor molecules on the metal surface has been proposed after immersion test in the inhibited acid showed characteristic shift of N-H and O-H bond frequencies towards lower side compared to that of the respective pure samples which indicated the donation of electron pair through N and O atom of the inhibitor molecule in the surface adsorption phenomena. SEM study has revealed formation of semi globular inhibitor products on the metal surface. The comparisons of the protection efficiencies of these compounds according to their relative electron density on the adsorption centre and projected molecular area of the inhibitor molecules have been made.

  8. The Synergistic Effect of Iodide and Sodium Nitrite on the Corrosion Inhibition of Mild Steel in Bicarbonate–Chloride Solution

    Directory of Open Access Journals (Sweden)

    Gaius Debi Eyu

    2016-10-01

    Full Text Available The effect of potassium iodide (KI and sodium nitrite (NaNO2 inhibitor on the corrosion inhibition of mild steel in chloride bicarbonate solution has been studied using electrochemical techniques. Potentiodynamic polarisation data suggest that, when used in combination, KI and NaNO2 function together to inhibit reactions at both the anode and the cathode, but predominantly anodic. KI/NO2− concentration ratios varied from 2:1 to 2:5; inhibition efficiency was optimized for a ratio of 1:1. The surface morphology and corrosion products were analysed using scanning electron microscopy (SEM and X-ray diffractometry (XRD. The latter shows that the addition of I− to NO2 facilitates the formation of a passivating oxide (γ-Fe2O3 as compared to NO2− alone, decreasing the rate of metal dissolution observed in electrochemical testing. The synergistic effect of KI/NO2− inhibition was enhanced under the dynamic conditions associated with testing in a rotating disc electrode.

  9. Stress Wave Attenuation in Aluminum Alloy and Mild Steel Specimens Under SHPB Tensile Testing

    Science.gov (United States)

    Pothnis, J. R.; Ravikumar, G.; Arya, H.; Yerramalli, Chandra S.; Naik, N. K.

    2018-02-01

    Investigations on the effect of intensity of incident pressure wave applied through the striker bar on the specimen force histories and stress wave attenuation during split Hopkinson pressure bar (SHPB) tensile testing are presented. Details of the tensile SHPB along with Lagrangian x- t diagram of the setup are included. Studies were carried out on aluminum alloy 7075 T651 and IS 2062 mild steel. While testing specimens using the tensile SHPB setup, it was observed that the force calculated from the transmitter bar strain gauge was smaller than the force obtained from the incident bar strain gauge. This mismatch between the forces in the incident bar and the transmitter bar is explained on the basis of stress wave attenuation in the specimens. A methodology to obtain force histories using the strain gauges on the specimen during SHPB tensile testing is also presented. Further, scanning electron microscope images and photomicrographs are given. Correlation between the microstructure and mechanical properties is explained. Further, uncertainty analysis was conducted to ascertain the accuracy of the results.

  10. Evaluation of the inhibitive effect of some plant extracts on the acid corrosion of mild steel

    International Nuclear Information System (INIS)

    Oguzie, Emeka E.

    2008-01-01

    Corrosion inhibition of mild steel in 2 M HCl and 1 M H 2 SO 4 by extracts of selected plants was investigated using a gasometric technique at temperatures of 30 and 60 deg. C. The studied plants materials include leaf extracts Occimum viridis (OV), Telferia occidentalis (TO), Azadirachta indica (AI) and Hibiscus sabdariffa (HS) as well as extracts from the seeds of Garcinia kola (GK). The results indicate that all the extracts inhibited the corrosion process in both acid media by virtue of adsorption and inhibition efficiency improved with concentration. Synergistic effects increased the inhibition efficiency in the presence of halide additives. Inhibition mechanisms were deduced from the temperature dependence of the inhibition efficiency as well as from assessment of kinetic and activation parameters that govern the processes. Comparative analysis of the inhibitor adsorption behaviour in 2 M HCl and 1 M H 2 SO 4 as well as the effects of temperature and halide additives suggest that both protonated and molecular species could be responsible for the inhibiting action of the extracts

  11. Evaluation of the inhibitive effect of some plant extracts on the acid corrosion of mild steel

    Energy Technology Data Exchange (ETDEWEB)

    Oguzie, Emeka E. [Electrochemistry and Materials Science Research Laboratory, Department of Chemistry, Federal University of Technology, PMB 1526, Owerri (Nigeria)], E-mail: oguziemeka@yahoo.com

    2008-11-15

    Corrosion inhibition of mild steel in 2 M HCl and 1 M H{sub 2}SO{sub 4} by extracts of selected plants was investigated using a gasometric technique at temperatures of 30 and 60 deg. C. The studied plants materials include leaf extracts Occimum viridis (OV), Telferia occidentalis (TO), Azadirachta indica (AI) and Hibiscus sabdariffa (HS) as well as extracts from the seeds of Garcinia kola (GK). The results indicate that all the extracts inhibited the corrosion process in both acid media by virtue of adsorption and inhibition efficiency improved with concentration. Synergistic effects increased the inhibition efficiency in the presence of halide additives. Inhibition mechanisms were deduced from the temperature dependence of the inhibition efficiency as well as from assessment of kinetic and activation parameters that govern the processes. Comparative analysis of the inhibitor adsorption behaviour in 2 M HCl and 1 M H{sub 2}SO{sub 4} as well as the effects of temperature and halide additives suggest that both protonated and molecular species could be responsible for the inhibiting action of the extracts.

  12. Fatigue Strength Assessment of Welded Mild Steel Joints Containing Bulk Imperfections

    Directory of Open Access Journals (Sweden)

    Martin Leitner

    2018-04-01

    Full Text Available This work investigates the effect of gas pores, as bulk imperfections, on the fatigue strength of welded mild steel joints. Two test series containing different butt joint geometries and weld process parameters are included in order to achieve two variable types of pore sizes. Based on the √area-parameter by Murakami, the test series can be grouped into imperfections exhibiting √area < 1000 µm and √area > 1000 µm. Fatigue tests at a load stress ratio of R = 0.1 are performed, which act as comparison for the subsequent fatigue estimation. To assess the fatigue resistance, the approaches by Murakami, De Kazinczy, and Mitchell are utilized, which highlight certain differences in the applicability depending on the imperfection size. It is found that, on one hand, Murakami’s approach is well suitable for both small and large gas pores depending on the applied model parameters. On the other hand, the fatigue concepts by De Kazinczy and Mitchell are preferably practicable for large defects with √area > 1000 µm. In addition, the method by Mitchell incorporates the stress concentration factor of the imperfection, which can be numerically computed considering the size, shape, and location of the gas pore, as presented in this paper.

  13. Modelling probabilistic fatigue crack propagation rates for a mild structural steel

    Directory of Open Access Journals (Sweden)

    J.A.F.O. Correia

    2015-01-01

    Full Text Available A class of fatigue crack growth models based on elastic–plastic stress–strain histories at the crack tip region and local strain-life damage models have been proposed in literature. The fatigue crack growth is regarded as a process of continuous crack initializations over successive elementary material blocks, which may be governed by smooth strain-life damage data. Some approaches account for the residual stresses developing at the crack tip in the actual crack driving force assessment, allowing mean stresses and loading sequential effects to be modelled. An extension of the fatigue crack propagation model originally proposed by Noroozi et al. (2005 to derive probabilistic fatigue crack propagation data is proposed, in particular concerning the derivation of probabilistic da/dN-ΔK-R fields. The elastic-plastic stresses at the vicinity of the crack tip, computed using simplified formulae, are compared with the stresses computed using an elasticplastic finite element analyses for specimens considered in the experimental program proposed to derive the fatigue crack propagation data. Using probabilistic strain-life data available for the S355 structural mild steel, probabilistic crack propagation fields are generated, for several stress ratios, and compared with experimental fatigue crack propagation data. A satisfactory agreement between the predicted probabilistic fields and experimental data is observed.

  14. Mathematical modelling of striation formation in oxygen laser cutting of mild steel

    Energy Technology Data Exchange (ETDEWEB)

    Ermolaev, G V; Kovalev, O B; Orishich, A M; Fomin, V M [Institute of Theoretical and Applied Mechanics SB RAS, 4/1 Institutskaya Str., Novosibirsk 630090 (Russian Federation)

    2006-10-07

    A physicomathematical model is proposed for the phenomenon of formation of periodic striations in oxygen laser cutting of mild steel sheets. The mechanism of roughness origination is assumed to be caused by a cyclic reaction of iron-oxygen oxidation. The mathematical description is based on solving the adjoint problems of heat and mass transfer in the liquid phase and in the solid metal with nonlinear moving interfaces between the substances and phase changes. The motion of the boundaries occurs owing to metal melting under the action of focused laser radiation and the heterogeneous chemical reaction of iron oxidation in oxygen. The main feature of iron oxidation is the loss of protective properties of its oxide film due to melting. The general statement of the problem for the nonlinear heat-conduction equation with variable coefficients is formulated by the type of the Stefan problem solved with the use of the difference method with smoothing coefficients at the melting point and the fictitious domain method, which allows obtaining of the solution without explicit identification of the cut boundary and the phase-transition front. Results of numerical simulations of the shape and linear size of roughness as functions of the cutting velocity, purity of oxygen and thickness of the film of the iron oxide being formed are presented.

  15. Inhibition of the corrosion of mild steel in hydrochloric acid by isatin and isatin glycine

    Directory of Open Access Journals (Sweden)

    B.I. Ita

    2006-12-01

    Full Text Available The inhibition of corrosion of mild steel in hydrochloric acid by isatin glycine (ING and isatin (IN at 30-60 oC and concentrations of 0.0001 M to 0.0005 M was studied via weight loss method. At the highest inhibitor concentration studied ING exhibited inhibition efficiency of 87% while IN exhibited 84% at 60 oC. A chemical adsorption mechanism was proposed on the basis of the temperature effect and obtained average activation energy values of 143.9 kJ/mol for ING and 118.5 kJ/mol for IN. The two inhibitors were confirmed to obey the Langmuir adsorption isotherm equation at the concentrations studied. Also a first-order type of mechanism was proposed from the kinetic treatment of the result. The difference in the inhibitory properties of the inhibitors was explained in terms of the difference in their molecular structures and solubility rather than difference in molecular weights alone.

  16. Finite Element Method Based Modeling of Resistance Spot-Welded Mild Steel

    Directory of Open Access Journals (Sweden)

    Miloud Zaoui

    Full Text Available Abstract This paper deals with Finite Element refined and simplified models of a mild steel spot-welded specimen, developed and validated based on quasi-static cross-tensile experimental tests. The first model was constructed with a fine discretization of the metal sheet and the spot weld was defined as a special geometric zone of the specimen. This model provided, in combination with experimental tests, the input data for the development of the second model, which was constructed with respect to the mesh size used in the complete car finite element model. This simplified model was developed with coarse shell elements and a spring-type beam element was used to model the spot weld behavior. The global accuracy of the two models was checked by comparing simulated and experimental load-displacement curves and by studying the specimen deformed shapes and the plastic deformation growth in the metal sheets. The obtained results show that both fine and coarse finite element models permit a good prediction of the experimental tests.

  17. Simulasi dan Studi Eksperimen Defleksi Beam Bright Mild Steel Akibat Variasi Beban Horisontal

    Directory of Open Access Journals (Sweden)

    Dewa Ngakan Ketut Putra Negara

    2012-11-01

    Full Text Available Beam is a structural member whose cross-sectional dimensions are relatively smaller than its length. Beams play significantroles in many engineering applications, including buildings, bridges, automobiles, and airplane structures. Beams arecommonly subjected to transverse loading, which is a type of loading that creates bending in the beam. In designing of amachine component or structure, deflection has an important role to be considered. If deflection occurred exceeds limitallowed, it can affect serious hazard on machine elements or structure due to it can affect of component deviate from its mainfunction. In this research, material to be used was Bright Mild Steel (ASTM 1060, with specimen in the form of portal beam.Physical condition of beam was modeled use of BEAM3 2D. Variation of loads to be applied were W = 100, 150, 200, 250,300, 350, 400, 450, 500, and 550 gr and concentrated in the one of portal in vehorizontal direction. The result of simulationwas verificated by experimental data. Evaluation was carried out by statistical test (t-test. The result of simulation iscategorized to be good if the result of simulation is same with experimental data. The result of research shows thatloading has a significant effect on the deflection. The higher load affect the higher of deflection Modeling use of BEAM3 2Dgave good result of deflection. This is showed from t-test have done, where the result of simulation was same withexperimental data.

  18. Antibacterial effect of silver nanofilm modified stainless steel surface

    Science.gov (United States)

    Fang, F.; Kennedy, J.; Dhillon, M.; Flint, S.

    2015-03-01

    Bacteria can attach to stainless steel surfaces, resulting in the colonization of the surface known as biofilms. The release of bacteria from biofilms can cause contamination of food such as dairy products in manufacturing plants. This study aimed to modify stainless steel surfaces with silver nanofilms and to examine the antibacterial effectiveness of the modified surface. Ion implantation was applied to produce silver nanofilms on stainless steel surfaces. 35 keV Ag ions were implanted with various fluences of 1 × 1015 to 1 × 1017 ions•cm-2 at room temperature. Representative atomic force microscopy characterizations of the modified stainless steel are presented. Rutherford backscattering spectrometry spectra revealed the implanted atoms were located in the near-surface region. Both unmodified and modified stainless steel coupons were then exposed to two types of bacteria, Pseudomonas fluorescens and Streptococcus thermophilus, to determine the effect of the surface modification on bacterial attachment and biofilm development. The silver modified coupon surface fluoresced red over most of the surface area implying that most bacteria on coupon surface were dead. This study indicates that the silver nanofilm fabricated by the ion implantation method is a promising way of reducing the attachment of bacteria and delay biofilm formation.

  19. Low Temperature Surface Carburization of Stainless Steels

    Energy Technology Data Exchange (ETDEWEB)

    Collins, Sunniva R; Heuer, Arthur H; Sikka, Vinod K

    2007-12-07

    Low-temperature colossal supersaturation (LTCSS) is a novel surface hardening method for carburization of austenitic stainless steels (SS) without the precipitation of carbides. The formation of carbides is kinetically suppressed, enabling extremely high or colossal carbon supersaturation. As a result, surface carbon concentrations in excess of 12 at. % are routinely achieved. This treatment increases the surface hardness by a factor of four to five, improving resistance to wear, corrosion, and fatigue, with significant retained ductility. LTCSS is a diffusional surface hardening process that provides a uniform and conformal hardened gradient surface with no risk of delamination or peeling. The treatment retains the austenitic phase and is completely non-magnetic. In addition, because parts are treated at low temperature, they do not distort or change dimensions. During this treatment, carbon diffusion proceeds into the metal at temperatures that constrain substitutional diffusion or mobility between the metal alloy elements. Though immobilized and unable to assemble to form carbides, chromium and similar alloying elements nonetheless draw enormous amounts of carbon into their interstitial spaces. The carbon in the interstitial spaces of the alloy crystals makes the surface harder than ever achieved before by more conventional heat treating or diffusion process. The carbon solid solution manifests a Vickers hardness often exceeding 1000 HV (equivalent to 70 HRC). This project objective was to extend the LTCSS treatment to other austenitic alloys, and to quantify improvements in fatigue, corrosion, and wear resistance. Highlights from the research include the following: • Extension of the applicability of the LTCSS process to a broad range of austenitic and duplex grades of steels • Demonstration of LTCSS ability for a variety of different component shapes and sizes • Detailed microstructural characterization of LTCSS-treated samples of 316L and other alloys

  20. Topographical Anisotropy and Wetting of Ground Stainless Steel Surfaces

    Directory of Open Access Journals (Sweden)

    Cornelia Bellmann

    2012-12-01

    Full Text Available Microscopic and physico-chemical methods were used for a comprehensive surface characterization of different mechanically modified stainless steel surfaces. The surfaces were analyzed using high-resolution confocal microscopy, resulting in detailed information about the topographic properties. In addition, static water contact angle measurements were carried out to characterize the surface heterogeneity of the samples. The effect of morphological anisotropy on water contact angle anisotropy was investigated. The correlation between topography and wetting was studied by means of a model of wetting proposed in the present work, that allows quantifying the air volume of the interface water drop-stainless steel surface.

  1. Surface modification of steels by electrical discharge treatment in electrolyte

    International Nuclear Information System (INIS)

    Krastev, D.; Paunov, V.; Yordanov, B.; Lazarova, V.

    2013-01-01

    Full text: In this work are discussed some experimental data about the influence of applied electrical discharge treatment in electrolyte on the surface structure of steels. The electrical discharge treatment of steel surface in electrolyte gives a modified structure with specific combination of characteristics in result of nonequilibrium transformations. The modification goes by a high energy thermal process in a very small volume on the metallic surface involving melting, vaporisation, activation and alloying in electrical discharges, and after that cooling of this surface with high rate in the electrolyte. The surface layers obtain a different structure in comparison with the metal matrix and are with higher hardness, wear resistance and corrosion resistance. key words: surface modification, electrical discharge treatment in electrolyte, steels

  2. Experimental Investigation of Friction Coefficient and Wear Rate of Composite Materials Sliding Against Smooth and Rough Mild Steel Counterfaces

    Directory of Open Access Journals (Sweden)

    M.A. Chowdhury

    2013-12-01

    Full Text Available In the present study, friction coefficient and wear rate of gear fiber reinforced plastic (gear fiber and glass fiber reinforced plastic (glass fiber sliding against mild steel are investigated experimentally. In order to do so, a pin on disc apparatus is designed and fabricated. Experiments are carried out when smooth or rough mild steel pin slides on gear fiber and glass fiber disc. Experiments are conducted at normal load 10, 15 and 20 N, sliding velocity 1, 1.5 and 2 m/s and relative humidity 70%. Variations of friction coefficient with the duration of rubbing at different normal loads and sliding velocities are investigated. Results show that friction coefficient is influenced by duration of rubbing, normal load and sliding velocity. In general, friction coefficient increases for a certain duration of rubbing and after that it remains constant for the rest of the experimental time. The obtained results reveal that friction coefficient decreases with the increase in normal load for gear fiber and glass fiber mating with smooth or rough mild steel counterface. On the other hand, it is also found that friction coefficient increases with the increase in sliding velocity for both of the tested materials. Moreover, wear rate increases with the increase in normal load and sliding velocity. The magnitudes of friction coefficient and wear rate are different depending on sliding velocity and normal load for both smooth and rough counterface pin materials.

  3. Surface nanocrystallization of stainless steel for reduced biofilm adherence

    International Nuclear Information System (INIS)

    Yu Bin; Li, D Y; Davis, Elisabeth M; Irvin, Randall T; Hodges, Robert S

    2008-01-01

    Stainless steel is one of the most common metallic biomedical materials. For medical applications, its resistance to the adherence of biofilms is of importance to the elimination or minimization of bacterial infections. In this study, we demonstrate the effectiveness of a process combining surface nanocrystallization and thermal oxidation (or a recovery heat treatment in air) for reducing the biofilm's adherence to stainless steel. During this treatment, a target surface was sandblasted and the resultant dislocation cells in the surface layer were turned into nanosized grains by a subsequent recovery treatment in air. This process generated a more protective oxide film that blocked the electron exchange or reduced the surface activity more effectively. As a result, the biofilm's adherence to the treated surface was markedly minimized. A synthetic peptide was utilized as a substitute of biofilms to evaluate the adhesion between a treated steel surface and biofilms using an atomic force microscope (AFM) through measuring the adhesive force between the target surface and a peptide-coated AFM tip. It was shown that the adhesive force decreased with a decrease in the grain size of the steel. The corresponding surface electron work function (EWF) of the steel was also measured, which showed a trend of variation in EWF with the grain size, consistent with corresponding changes in the adhesive force

  4. PENGARUH BESAR ARUS LISTRIK DENGAN MENGGUNAKAN ELEKTRODA SMAW TERHADAP KEKUATAN SAMBUNGAN LAS BUTT JOINT PADA PLAT MILD STEEL

    Directory of Open Access Journals (Sweden)

    Sarjito Jokosisworo

    2012-03-01

    Full Text Available The influence of mechanic disposition, is one of the factor influence ship strength. This influence can be test by mechanical test in welding butt joint. The result test database analysis can be conclude that very helpful to increase safety and quality butt joint. With steel specification C= 0,15%, Si= 0,24%, Mn= 0,88%,P= 0,018%, S= 0,034%. This material give a 90, 110, 125 ampere with SMAW AC electrode diameter 3,2 mm x 350 mm with V root and 600 angle In the fabrication of mild steel products, components or equipment, manufacturers employ welding as the principal joining method. Mild steel are weldable materials, and a welded joint can provide optimum corrosion resistance, strength, and fabrication economy. However, designers should recognize that any metal, including stainless steels, may undergo certain changes during welding. It is necessary, therefore, to exercise a reasonable degree of care during welding to minimize or prevent any deleterious effects that may occur, and to preserve the same degree of corrosion resistance and strength in weld zone that is an intheren part of the base metal

  5. Induction surface hardening of hard coated steels

    DEFF Research Database (Denmark)

    Pantleon, Karen; Kessler, Olaf; Hoffmann, Franz

    1999-01-01

    The deposition of hard coatings with CVD-processes is commonly used to improve the wear resistance e.g. of tool steels in forming. The advantages of CVD are undisputed (high deposition rates with simple equipment, excellent coating properties). Nevertheless, the disadvantage of the CVD-process is......The deposition of hard coatings with CVD-processes is commonly used to improve the wear resistance e.g. of tool steels in forming. The advantages of CVD are undisputed (high deposition rates with simple equipment, excellent coating properties). Nevertheless, the disadvantage of the CVD...

  6. Comparative assessment of the microhardness and plastic degradation mechanism of deposited modulated coatings on mild steel

    Science.gov (United States)

    Fayomi, O. S. I.; Anawe, P. A. L.; Inegbenebor, A. O.; Udoye, N. E.

    2018-05-01

    Zinc based coatings modified with aluminium and tin inclusions were electrodeposited in chloride zinc sulfate electrolytes containing a metallic powder of titanium. It was found that presence of these particulates is suitable to obtain ZnAlSn-Ti composites coating that could help increase the microhardnesss characteristics and wear properties. The hardness and wear properties of the deposited coatings were examined with diamond base micro-hardness tester and CETR reciprocating sliding tester respectively. The structural properties were examined with the help of scanning electron microscope. It was observed that structural coating surface impact on the hardness propagation with increases from 33.4 to 299 kgf mm-2 (HVN40), and shows a considerably higher wear resistance from 2.351g/min to 0.002g/min. It is obvious that plastic deformation of the working steel structure is dependent on protective coating and the concentration of the individual particulate.

  7. Analysis on Flexural Strength of A36 Mild Steel by Design of Experiment (DOE)

    Science.gov (United States)

    Nurulhuda, A.; Hafizzal, Y.; Izzuddin, MZM; Sulawati, MRN; Rafidah, A.; Suhaila, Y.; Fauziah, AR

    2017-08-01

    Nowadays demand for high quality and reliable components and materials are increasing so flexural tests have become vital test method in both the research and manufacturing process and development to explain in details about the material’s ability to withstand deformation under load. Recently, there are lack research studies on the effect of thickness, welding type and joint design on the flexural condition by DOE approach method. Therefore, this research will come out with the flexural strength of mild steel since it is not well documented. By using Design of Experiment (DOE), a full factorial design with two replications has been used to study the effects of important parameters which are welding type, thickness and joint design. The measurement of output response is identified as flexural strength value. Randomize experiments was conducted based on table generated via Minitab software. A normal probability test was carried out using Anderson Darling Test and show that the P-value is <0.005. Thus, the data is not normal since there is significance different between the actual data with the ideal data. Referring to the ANOVA, only factor joint design is significant since the P-value is less than 0.05. From the main plot and interaction plot, the recommended setting for each of parameters were suggested as high level for welding type, high level for thickness and low level for joint design. The prediction model was developed thru regression in order to measure effect of output response for any changes on parameters setting. In the future, the experiments can be enhanced using Taguchi methods in order to do verification of result.

  8. Tool steel quality and surface finishing of plastic molds

    Directory of Open Access Journals (Sweden)

    Rafael Agnelli Mesquita

    2010-01-01

    Full Text Available Plastic industry is today in a constant growth, demanding several products from other segments, which includes the plastic molds, mainly used in the injection molding process. Considering all the requirements of plastic molds, the surface finishing is of special interest, as the injected plastic part is able to reproduce any details (and also defects from the mold surface. Therefore, several aspects on mold finishing are important, mainly related to manufacturing conditions - machining, grinding, polishing and texturing, and also related to the tool steel quality, in relation to microstructure homogeneity and non-metallic inclusions (cleanliness. The present paper is then focused on this interrelationship between steel quality and manufacturing process, which are both related to the final quality of plastic mold surfaces. Examples are discussed in terms of surface finishing of plastic molds and the properties or the microstructure of mold steels.

  9. Inhibitory action of quaternary ammonium bromide on mild steel and synergistic effect with other halide ions in 0.5 M H2SO4

    Directory of Open Access Journals (Sweden)

    A. Khamis

    2014-11-01

    Full Text Available The corrosion inhibition of mild steel in 0.5 M H2SO4 solution has been investigated using electrochemical methods, X-ray diffraction (XRD and scanning electron microscope (SEM. The adsorption and inhibition action of acid corrosion of mild steel using cetyltrimethylammonium bromide (CTABr and different halides (NaCl, NaBr and NaI has shown synergetic effect. The results showed that the protection efficiency (P% has high values at considerable high concentration of CTABr. However, in the presence of the different halides, the P increases dramatically at low concentration of CTABr. Physisorption was proposed from the the values of ΔGads0. The synergism parameter (Sθ is found to be greater than unity indicating that the enhanced P% caused by the addition of the halides to the CTABr is due to a co-operative adsorption of both species. Corrosion products phases and surface morphology were studied using X-ray diffraction (XRD and scanning electron microscopy (SEM, respectively.

  10. Morphology evaluation of ZrO2 dip coating on mild steel and its corrosion performance in NaOH solution

    Science.gov (United States)

    Anwar, M. A.; Kurniawan, T.; Asmara, Y. P.; Harun, W. S. W.; Oumar, A. N.; Nandyanto, A. B. D.

    2017-10-01

    In this work, the morphology of ZrO2 thin film from dip coating process on mild steel has been investigated. Mild steel was dip-coated on solution made of zirconium butoxide as a precursor, ethanol as solvent, acetylacetone as chelating agent and water for hydrolysis. Number of dipping was adjusted at 3, 5 and 7 times. The dipped sample then annealed at 350°C for two hours by adjusting the heating rate at 1°C/min respectively. The optical microscope showed that micro-cracks were observed on the surface of the coating with its concentration reduced as dipping sequence increased. The XRD result showed that annealing process can produce polycrystalline tetragonal-ZrO2. Meanwhile, SEM image showed that the thicknesses of the ZrO2 coatings were in between 400-600 nm. The corrosion resistance of uncoated and coated substrates was studied by polarization test through potentio-dynamic polarization curve at 1mV/s immersed in with 3.5% NaCl. The coating efficiency was improved as the number of layer dip coated increased, which showed improvement in corrosion protection.

  11. A liquid aluminum corrosion resistance surface on steel substrate

    International Nuclear Information System (INIS)

    Wang Deqing; Shi Ziyuan; Zou Longjiang

    2003-01-01

    The process of hot dipping pure aluminum on a steel substrate followed by oxidation was studied to form a surface layer of aluminum oxide resistant to the corrosion of aluminum melt. The thickness of the pure aluminum layer on the steel substrate is reduced with the increase in temperature and time in initial aluminizing, and the thickness of the aluminum layer does not increase with time at given temperature when identical temperature and complete wetting occur between liquid aluminum and the substrate surface. The thickness of the Fe-Al intermetallic layer on the steel base is increased with increasing bath temperature and time. Based on the experimental data and the mathematics model developed by the study, a maximum exists in the thickness of the Fe-Al intermetallic at certain dipping temperature. X-ray diffraction (XRD) and energy dispersive X-ray (EDX) analysis reveals that the top portion of the steel substrate is composed of a thin layer of α-Al 2 O 3 , followed by a thinner layer of FeAl 3 , and then a much thicker one of Fe 2 Al 5 on the steel base side. In addition, there is a carbon enrichment zone in diffusion front. The aluminum oxide surface formed on the steel substrate is in perfect condition after corrosion test in liquid aluminum at 750 deg. C for 240 h, showing extremely good resistance to aluminum melt corrosion

  12. Elucidation of the Corrosion Inhibition of Mild Steel in 1.0 M HCl by Catechin Monomers from Commercial Green Tea Extracts

    Science.gov (United States)

    Nofrizal, S.; Rahim, Afidah A.; Saad, Bahruddin; Bothi Raja, P.; Shah, Affaizza M.; Yahya, S.

    2012-04-01

    The inhibitive action of commercial green tea extracts on mild steel (MS) in a 1.0 M hydrochloric acid solution was investigated by weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS). A high-performance liquid chromatographic (HPLC) analysis showed conclusively that of the eight catechin monomers and caffeine found in the original extracts, only four components were responsible for the inhibition of MS. The decreasing adsorption capacity of monomers on MS is related to the stereochemistry of molecules and the number of phenolic groups, and it is as follows: epigallocatechin gallate > epicatechin gallate > epigallocatechin > epicatechin. Adsorption of green tea extract constituent was found to follow Langmuir adsorption isotherm and the calculated Gibb's free energy values indicated the physisorption of inhibitor over MS surface. Physisorption was supported well by the potential zero charge (PZC) and molecular surface energy-level calculations.

  13. ABOUT RATIONING MAXIMUM ALLOWABLE DEFECT DEPTH ON THE SURFACE OF STEEL BILLETS IN PRODUCTION OF HOT-ROLLED STEEL

    Directory of Open Access Journals (Sweden)

    PARUSOV E. V.

    2017-01-01

    Full Text Available Formulation of the problem. Significant influence on the quality of rolled steel have various defects on its surface, which in its turn inherited from surface defects of billet and possible damage to the surface of rolled steel in the rolling mill line. One of the criteria for assessing the quality indicators of rolled steel is rationing of surface defects [1; 2; 3; 6; 7]. Current status of the issue. Analyzing the different requirements of regulations to the surface quality of the rolled high-carbon steels, we can conclude that the maximum allowable depth of defects on the surface of billet should be in the range of 2.0...5.0 mm (depending on the section of the billet, method of its production and further the destination Purpose. Develop a methodology for calculating the maximum allowable depth of defects on the steel billet surface depending on the requirements placed on the surface quality of hot-rolled steel. Results. A simplified method of calculation, allowing at the rated depth of defects on the surface of the hot-rolled steel to make operatively calculation of the maximum allowable depth of surface defects of steel billets before heating the metal in the heat deformation was developed. The findings shows that the maximum allowable depth of surface defects is reduced with increasing diameter rolled steel, reducing the initial section steel billet and degrees of oxidation of the metal in the heating furnace.

  14. INHIBITION EFFECT OF FLAVONOID EXTRACT OF Euphorbia Guyoniana ON THE CORROSION OF MILD STEEL IN H2SO4 MEDIUM

    OpenAIRE

    S. Chihi; N. Gherraf; B. Alabed; S. Hameurlain

    2009-01-01

    The influence of flavonoids extracts of three parts of Euphorbia Guyoniana towards the corrosion of type API 5L X52 steel in 15% H2SO4 has been evaluated by weight loss method and polarization technique. The results showed that extracts are a good inhibitors for API 5L X52 steel in this medium. The corrosion inhibition efficiency increases on increasing plant extracts concentration. The inhibition is attributed to the adsorption of the surface of the metal. Potentiodynamic polarization result...

  15. Effects of surface treatments on microstructure in stainless steel

    International Nuclear Information System (INIS)

    Mabuchi, Yasuhiro; Tamako, Hiroaki; Kaneda, Junya; Yamashita, Norimichi; Miyakawa, Masahiko

    2009-01-01

    It is revealed that Stress Corrosion Cracking (SCC) on the surface of the L-grade stainless steels in Nuclear Power Plants is caused by heavily cold work of the materials. The microstructure, hardness and residual stress on the surface of the material are factors for SCC initiation. There are surface treatment methods that is effective reduction on SCC such as Flap Wheel (FW) polishing, Clean N Strip (CNS) polishing, Water Jet Peening (WJP) and Shot Peening (SP). In this paper, the characteristics of the surface cold worked layer of the L-grade stainless steels conducted by above-mentioned surface treatments are analyzed, and effects of the surface treatments on the surface layer are discussed. (author)

  16. Study of yttrium 4-nitrocinnamate to promote surface interactions with AS1020 steel

    Science.gov (United States)

    Hien, P. V.; Vu, N. S. H.; Thu, V. T. H.; Somers, A.; Nam, N. D.

    2017-08-01

    Yttrium 4-nitrocinnamate (Y(4-NO2Cin)3) was added to an aqueous chloride solution and studied as a possible corrosion inhibition system. Electrochemical techniques and surface analysis have been powerful tools to better understand the corrosion and inhibition processes of mild steel in 0.01 M NaCl solution. A combination of scanning electron microscopy (SEM), atomic force microscopy (AFM), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), Potentiodynamic polarization (PD), electrochemical impedance spectroscopy (EIS) and wire beam electrode (WBE) techniques was found to be useful in the characterization of this system. The result indicated that Y(4-NO2Cin)3 is able to effectively inhibit corrosion at a low concentration of 0.45 mM. Surface analysis clearly shows that the surface of steel coupons exposed to Y(4-NO2Cin)3 solution remained uniform and smooth, whereas the surface of steel coupons exposed to solution without inhibitor addition was severely corroded. The results suggest that Y(4-NO2Cin)3 behaves as a mixed inhibitor and mitigates corrosion by promoting random distribution of minor anodes. These are attributed to the formation of metal species bonding to the 4-nitrocinnamate component and hydrolysis of the Y(4-NO2Cin)3 to form oxide/hydroxides as a protective film layer.

  17. Factors influencing the surface quality of polished tool steels

    International Nuclear Information System (INIS)

    Rebeggiani, S; Rosén, B-G

    2014-01-01

    Today’s demands on surface quality of moulds for injection moulding of plastic components involve no/low defect contents and roughness levels in the nm-range for high gloss applications. Material properties as well as operating conditions influence the mould finish, and thus the final surface of moulded products. This paper focuses on how particle content and different polishing strategies influence final surface qualities of moulds. Visual estimations of polished tool steel samples were combined with non-contact 3D-surface texture analysis in order to correlate traditional assessments to more quantitative methods, and to be able to analyse the surfaces at nanometre-level. It was found that steels with a lower proportion of particles, like carbides and oxides, gave rise to smoother polished surfaces. In a comparative study of polishers from different polishing shops, it was found that while different surface preparation strategies can lead to similar final roughness, similar preparation techniques can produce high-quality surfaces from different steel grades. However, the non-contact 3D-surface texture analysis showed that not all smooth polished surfaces have desirable functional topographies for injection moulding of glossy plastic components. (paper)

  18. Investigation on the Effect of Green Inhibitors for Corrosion Protection of Mild Steel in 1 M NaOH Solution

    Directory of Open Access Journals (Sweden)

    Premjith Jayakumar Ramakrishnan

    2014-01-01

    Full Text Available Alkaline corrosion is one of the main issues faced by the industries. The main chemicals abundantly used in industries are NaOH, H3PO4, HCl, and H2SO4. Corrosion control of metals has technical, economical, environmental, and aesthetical importance. The use of inhibitors is one of the best options to protect metals and alloys against corrosion. The corrosion protection of mild steel in 1 M NaOH solution by mix of Henna/Zeolite powder was studied at different temperatures by weight loss technique. Adsorption, activation, and statistical studies were addressed in this work. Adsorption studies showed that inhibitor adsorbed on metal surface according to Langmuir isotherm. Surface studies were performed by using UV-spectra and SEM. The adsorption of inhibitor on the steel surface was found to obey Langmuir’s adsorption isotherm. The inhibition efficiency increased with increasing concentration of the inhibitor in NaOH medium. Inhibition mechanism is deduced from the concentration and temperature dependence of the inhibition efficiency, Langmuir’s adsorption isotherm, SEM, and UV spectroscopic results.

  19. Evaluation of stabilization of steel surface corrosion by paints

    Directory of Open Access Journals (Sweden)

    Aleš Dvořák

    2005-01-01

    Full Text Available This article deals with laboratory experiments focused on protective and stabilizing effects of paints designed to protect rusted steel surfaces. Two well-known paints (the Hammerite No.1 Rustbeater synthetic paint and the Antirezin water-soluble paint have been evaluated. The standardized tests according to ČSN have been used for the evaluation. Stabilization of rusted steel surface hasn’t been demonstrated during the tests. The SEM test method that covers micro-analysis of elements has been used for the evaluation as well.

  20. Compact cross-sections of mild and high-strength steel hollow-section beams

    NARCIS (Netherlands)

    Pavlovic, M.; Veljkovic, M.

    2017-01-01

    The Eurocode 3 rules for the high-strength steel (HSS: fy > 460 MPa) limit the analysis of beams to elastic global analysis and grades up to S700. In order to fully exploit the potential to design lightweight and sustainable steel structures, plastic analysis and the use of higher

  1. Adsorption properties and inhibition of mild steel corrosion in sulphuric acid solution by ketoconazole: Experimental and theoretical investigation

    Energy Technology Data Exchange (ETDEWEB)

    Obot, I.B. [Department of Chemistry, Faculty of Science, University of Uyo, P.M.B. 1017, Uyo, Akwa Ibom State (Nigeria)], E-mail: proffoime@yahoo.com; Obi-Egbedi, N.O. [Department of Chemistry, University of Ibadan, Ibadan (Nigeria)

    2010-01-15

    Ketoconazole (KCZ) has been evaluated as a corrosion inhibitor for mild steel in aerated 0.1 M H{sub 2}SO{sub 4} by gravimetric method. The effect of KCZ on the corrosion rate was determined at various temperatures and concentrations. The inhibition efficiency increases with increase in inhibitor concentration but decrease with rise in temperature. Adsorption followed the Langmuir isotherm with negative values of {delta}G{sub ads}{sup 0}, suggesting a stable and a spontaneous inhibition process. Quantum chemical approach was further used to calculate some electronic properties of the molecule in order to ascertain any correlation between the inhibitive effect and molecular structure of ketoconazole.

  2. Inhibitive effect of a naturally-occurring substance, tobacco, on the dissolution of mild steel in hydrochloric acid

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, K; Srivastava, P

    1980-12-01

    A number of naturally-occurring substances has been found to be effective inhibitors for the dissolution of mild steel in hydrochloric acid. The alkaloids nicotine and papaverine, contained in natural products such as tobacco leaves and black pepper, have proved themselves as excellent inhibitors. Considering the low cost of tobacco leaves, detailed studies were made with these, and they have been found to form an effective inhibitor under all practical conditions. Adsorption studies based on weight-loss measurements showed that adsorption of inhibitor obeys Freundlich's adsorption isoth

  3. Dynamic behaviour of TM380 mild steel and Ti6Al4V alloy subjected to blast loading

    CSIR Research Space (South Africa)

    Shoke, Lerato

    2016-10-01

    Full Text Available and Base Metals Development Network Conference 2016, 19-20 October 2016, KwaZulu Natal, Maharani Hotel Dynamic behaviour of TM380 mild steel and Ti6Al4V alloy subjected to blast loading L. Shoke,1* K. Mutombo2, I.M. Snyman1 and T. Sono1 1... Landwards Sciences, Defence Peace Safety and Security (DPSS), 2 Material Sciences and Manufacturing (MSM), Council for Scientific and Industrial Research (CSIR), Pretoria, South Africa Lshoke@csir.co.za Abstract This paper deals...

  4. Characterization of the corrosion products formed on mild steel in acidic medium with N-octadecylpyridinium bromide as corrosion inhibitor

    Energy Technology Data Exchange (ETDEWEB)

    Nava, N., E-mail: tnava@imp.mx; Likhanova, N. V. [Direccion de Investigacion y Posgrado, Instituto Mexicano del Petroleo (Mexico); Olivares-Xometl, O. [Benemerita Universidad Autonoma de Puebla, Facultad de Ingenieria Quimica (Mexico); Flores, E. A. [Direccion de Investigacion y Posgrado, Instituto Mexicano del Petroleo (Mexico); Lijanova, I. V. [CIITEC, Instituto Politecnico Nacional (Mexico)

    2011-11-15

    The characterization of the corrosion products formed on mild steel SAE 1018 after 2 months exposure in aqueous sulfuric acid with and without corrosion inhibitor N-octadecylpyridinium bromide has been carried out by means of transmission {sup 57}Fe Moessbauer spectroscopy and X-ray powder diffraction (XRD). The major constituent of the rust formed in this environment without corrosion inhibitor is goethite ({alpha}-FeOOH). The samples with N-octadecylpyridinium bromide contain rozenite and large amounts of melanterite in the corrosion layers.

  5. PITTING CORROSION OF STAINLESS STEEL AT THE VARIOUS SURFACE TREATMENT

    Directory of Open Access Journals (Sweden)

    Viera Zatkalíková

    2011-09-01

    Full Text Available The stainless steel surface treatment is very important with regard to its pitting corrosion susceptibility. An effect of various types surfacing on pitting corrosion resistance of AISI 304stainless steel is investigated in this work. The samples of the tested material are turned, blasted, peened, grinded and a half of them are pickled to achieve higher purity of surfaces and better quality of passive film. Eight types of different finished surfaces are tested by electrochemical and immersion tests to determine corrosion behaviour in conditions where pitting is evoked by controlled potential and second by solution with high redox potential. By this way the effect of mechanical and chemical surface treatment on the resistance to pitting corrosion, character, size and shape of pits are compared in the conditions of different mechanisms of corrosion process.

  6. In situ synthesis, electrochemical and quantum chemical analysis of an amino acid-derived ionic liquid inhibitor for corrosion protection of mild steel in 1M HCl solution

    International Nuclear Information System (INIS)

    Kowsari, E.; Arman, S.Y.; Shahini, M.H.; Zandi, H.; Ehsani, A.; Naderi, R.; PourghasemiHanza, A.; Mehdipour, M.

    2016-01-01

    Highlights: • Electrochemical analysis of effectiveness of an amino acid-derived ionic liquid inhibitor. • Quantum chemical analysis of effectiveness of an amino acid-derived ionic liquid inhibitor. • Finding correlation between electrochemical analysis and quantum chemical analysis. - Abstract: In this study, an amino acid-derived ionic liquid inhibitor, namely tetra-n-butyl ammonium methioninate, was synthesized and the role this inhibitor for corrosion protection of mild steel exposed to 1.0 M HCl was investigated using electrochemical, quantum and surface analysis. By taking advantage of potentiodynamic polarization, the inhibitory action of tetra-n-butyl ammonium methioninate was found to be mainly mixed-type with dominant anodic inhibition. The effectiveness of the inhibitor was also indicated using electrochemical impedance spectroscopy (EIS). Moreover, to provide further insight into the mechanism of inhibition, electrochemical noise (EN) and quantum chemical calculations of the inhibitor were performed.

  7. New Stainless Steel Alloys for Low Temperature Surface Hardening?

    DEFF Research Database (Denmark)

    Christiansen, Thomas Lundin; Dahl, Kristian Vinter; Somers, Marcel A. J.

    2015-01-01

    The present contribution showcases the possibility for developing new surface hardenable stainless steels containing strong nitride/carbide forming elements (SNCFE). Nitriding of the commercial alloys, austenitic A286, and ferritic AISI 409 illustrates the beneficial effect of having SNCFE presen...

  8. Micro-Bulges Investigation on Laser Modified Tool Steel Surface

    Directory of Open Access Journals (Sweden)

    Fauzun Fazliana

    2017-01-01

    Full Text Available This paper presents micro-bulges investigation on laser modified tool steel. The aim of this study is to understand the effect of laser irradiance and interaction time on surface morphology configuration. An Nd:YAG laser system with TEM00 pulse processing mode was used to modify the samples. Metallographic study shows samples were analyzed for focal position effect on melted pool size, angle of peaks geometry and laser modified layer depth. Surface morphology were analyzed for surface roughness. Laser modified layer shows depth ranged between 42.22 and 420.12 μm. Angle of peak bulge was found to be increase with increasing peak power. The maximum roughness, Ra, achieved in modified H13 was 21.10 μm. These findings are significant to enhance surface properties of laser modified steel and cast iron for dies and high wear resistance applications.

  9. Kinetics of atmospheric corrosion of mild steel, zinc, galvanized iron and aluminium at 10 exposure stations in India

    International Nuclear Information System (INIS)

    Natesan, M.; Venkatachari, G.; Palaniswamy, N.

    2006-01-01

    As a part of updating Corrosion Map of India project, atmospheric corrosion behaviour of commercially available engineering materials such as mild steel, galvanized iron, zinc and aluminium metals was studied in marine, industrial, urban, and rural environments by weight loss method at 10 exposure stations in India over a period of 5 years. The results of these studies demonstrated that galvanized iron, zinc and aluminium metals were several times more durable than mild steel. Compared to galvanized iron and zinc, aluminium provided superior protection in industrial and marine environment except at Mormugao Port Trust (MPT). It also offered much better resistance to corrosion in rural environments. At certain places, galvanized iron proved to be more durable than aluminium. The results obeyed well with the empirical kinetics equation of the form C = Kt n , where K and C are the corrosion losses in μm after 1 and 't' years of the exposure, respectively, and 'n' is a constant. Based on 'n' values, the corrosion mechanisms of these metals are predicted. The corrosion products formed on the metal samples in Chennai marine atmosphere were identified by X-ray diffraction analysis

  10. Effect of Dissolved Oxygen and Immersion Time on the Corrosion Behaviour of Mild Steel in Bicarbonate/Chloride Solution

    Directory of Open Access Journals (Sweden)

    Gaius Debi Eyu

    2016-09-01

    Full Text Available The electrochemical behavior of mild steel in bicarbonate solution at different dissolved oxygen (DO concentrations and immersion times has been studied under dynamic conditions using electrochemical techniques. The results show that both DO and immersion times influence the morphology of the corrosion products. In comparative tests, the corrosion rate was systematically found to be lower in solutions with lower DO, lower HCO3− concentrations and longer immersion time. The SEM analyses reveal that the iron dissolution rate was more severe in solutions containing higher DO. The decrease in corrosion rate can be attributed to the formation of a passive layer containing mainly α -FeO (OH and ( γ -Fe2O3/Fe3O4 as confirmed by the X-ray diffractometry (XRD and X-ray photoelectron spectroscopy (XPS. Passivation of mild steel is evident in electrochemical test at ≈ −600 mVSCE at pH ≥ 8 in dearated ( ≤ 0.8 ppm DO chloride bicarbonate solution under dynamic conditions.

  11. Experimental and quantum chemical studies on two triazole derivatives as corrosion inhibitors for mild steel in acid media

    Energy Technology Data Exchange (ETDEWEB)

    Li, W.; Tian, H.; Hou, B. [Key Laboratory of Corrosion Science, Shandong, Institute of Oceanology, Chinese Academy of Sciences, Qingdao (China); Hu, L.; Tao, Z. [College of Chemistry and Chemical Engineering, Chongqing University, Chongqing (China)

    2011-11-15

    Two triazole derivatives [1-phenyl-2-(5-(1,2,4) triazol-1-ylmethyl-(1,3,4) oxadizaol-2-ylsulphanyl)-ethanone (PTOE) and 2-(4-tert-butyl-benzylsulphanyl)-5-(1,2,4) triazol-1-ylmethyl-(1,3,4) oxadiazole (TBTO)] were synthesized as new corrosion inhibitors for the corrosion of mild steel in 1 M hydrochloric acid solutions. The inhibiting efficiency of the different inhibitors was evaluated by means of weight loss and electrochemical techniques such as electrochemical impedance spectroscopy (EIS) and polarization curves. The electrochemical investigation results indicate that these compounds act as mixed-type inhibitors retarding the anodic and cathodic corrosion reactions and do not change the mechanism of either hydrogen evolution reaction or mild steel dissolution. The studied compounds followed the Langmuir adsorption isotherm, and the thermodynamic parameters were determined and discussed. The effect of molecular structure on the inhibition efficiency has been investigated with ab initio calculations. The electronic properties such as highest occupied molecular orbital (HOMO) energy level, lowest unoccupied molecular orbital (LUMO) energy level, dipole moment ({mu}) and molecular orbital densities were calculated. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. Chromium surface alloying of structural steels during laser treatment

    International Nuclear Information System (INIS)

    Kurov, I.E.; Nagornykh, S.N.; Sivukhin, G.A.; Solenov, S.V.

    1987-01-01

    Results of matrix alloying from the surface layer and creation of considerably increased chromium concentration in the depth which permits to increase the efficiency of laser treatment of steels (12Kh18N10T and 38KhN3M) in the process of their further mechanical polishing, are presented. The treatment was realized by continuous CO 2 -laser at different power densities and scanning rates are presented. A model describing the creation of anomalous distributions of the alloying element in steels is plotted

  13. Innovative Approaches To Improving The Bond Between Concrete and Steel Surfaces

    National Research Council Canada - National Science Library

    Day, Donna C; Carrasquillo, Mariangelica; Weiss, Jr., Charles A; Sykes, Melvin C; Baugher, Jr., Earl H; Malone, Philip G

    2006-01-01

    A reactive silicate layer fused onto the surface of reinforcing steel provides a coupling layer that allows a very strong bond to develop between hydrating Portland cement paste and the surface of the steel...

  14. Active corrosion protection performance of an epoxy coating applied on the mild steel modified with an eco-friendly sol-gel film impregnated with green corrosion inhibitor loaded nanocontainers

    Science.gov (United States)

    Izadi, M.; Shahrabi, T.; Ramezanzadeh, B.

    2018-05-01

    In this study the corrosion resistance, active protection, and cathodic disbonding performance of an epoxy coating were improved through surface modification of steel by a hybrid sol-gel system filled with green corrosion inhibitors loaded nanocontainer as intermediate layer on mild steel substrate. The green inhibitor loaded nanocontainers (GIN) were used to induce active inhibition performance in the protective coating system. The corrosion protection performance of the coated panels was investigated by electrochemical impedance spectroscopy (EIS), salt spray, and cathodic disbonding tests. It was observed that the corrosion inhibition performance of the coated mild steel panels was significantly improved by utilization of active multilayer coating system. The inhibitor release from nanocontainers at the epoxy-silane film/steel interface resulted in the anodic and cathodic reactions restriction, leading to the lower coating delamination from the substrate and corrosion products progress. Also, the active inhibition performance of the coating system was approved by electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), and energy dispersive X-ray (EDS) analysis on the panels with artificial defects. The inhibitive agents were released to the scratch region and blocked the active sites on the metal surface.

  15. INHIBITION EFFECT OF FLAVONOID EXTRACT OF Euphorbia Guyoniana ON THE CORROSION OF MILD STEEL IN H2SO4 MEDIUM

    Directory of Open Access Journals (Sweden)

    S. Chihi

    2009-08-01

    Full Text Available The influence of flavonoids extracts of three parts of Euphorbia Guyoniana towards the corrosion of type API 5L X52 steel in 15% H2SO4 has been evaluated by weight loss method and polarization technique. The results showed that extracts are a good inhibitors for API 5L X52 steel in this medium. The corrosion inhibition efficiency increases on increasing plant extracts concentration. The inhibition is attributed to the adsorption of the surface of the metal. Potentiodynamic polarization results revealed that the studied inhibitors behave as a mixed type.

  16. Surface interactions of cesium and boric acid with stainless steel

    International Nuclear Information System (INIS)

    Grossman-Canfield, N.

    1995-08-01

    In this report, the effects of cesium hydroxide and boric acid on oxidized stainless steel surfaces at high temperatures and near one atmosphere of pressure are investigated. This is the first experimental investigation of this chemical system. The experimental investigations were performed using a mass spectrometer and a mass electrobalance. Surfaces from the different experiments were examined using a scanning electron microscope to identify the presence of deposited species, and electron spectroscopy for chemical analysis to identify the species deposited on the surface. A better understanding of the equilibrium thermodynamics, the kinetics of the steam-accelerated volatilizations, and the release kinetics are gained by these experiments. The release rate is characterized by bulk vaporization/gas-phase mass transfer data. The analysis couples vaporization, deposition, and desorption of the compounds formed by cesium hydroxide and boric acid under conditions similar to what is expected during certain nuclear reactor accidents. This study shows that cesium deposits on an oxidized stainless steel surface at temperatures between 1000 and 1200 Kelvin. Cesium also deposits on stainless steel surfaces coated with boric oxide in the same temperature ranges. The mechanism for cesium deposition onto the oxide layer was found to involve the chemical reaction between cesium and chromate. Some revaporization in the cesium hydroxide-boric acid system was observed. It has been found that under the conditions given, boric acid will react with cesium hydroxide to form cesium metaborate. A model is proposed for this chemical reaction

  17. Comprehensive surface treatment of high-speed steel tool

    Science.gov (United States)

    Fedorov, Sergey V.; Aleshin, Sergey V.; Swe, Min Htet; Abdirova, Raushan D.; Kapitanov, Alexey V.; Egorov, Sergey B.

    2018-03-01

    One of the promising directions of hardening of high-speed steel tool is the creation on their surface of the layered structures with the gradient of physic-chemical properties between the wear-resistant coatings to the base material. Among the methods of such surface modification, a special process takes place based on the use of pulsed high-intensity charged particle beams. The high speed of heating and cooling allows structural-phase transformations in the surface layer, which cannot be realized in a stationary mode. The treatment was conducted in a RITM-SP unit, which constitutes a combination of a source of low-energy high-current electron beams "RITM" and two magnetron spraying systems on a single vacuum chamber. The unit enables deposition of films on the surface of the desired product and subsequent liquid-phase mixing of materials of the film and the substrate by an intense pulse electron beam. The article discusses features of the structure of the subsurface layer of high-speed steel M2, modified by surface alloying of a low-energy high-current electron beam, and its effect on the wear resistance of the tool when dry cutting hard to machine Nickel alloy. A significant decrease of intensity of wear of high-speed steel with combined treatment happens due to the displacement of the zone of wear and decrease the radius of rounding of the cutting edge because of changes in conditions of interaction with the material being treated.

  18. Application of a cosmetic additive as an eco-friendly inhibitor for mild steel corrosion in HCl solution.

    Science.gov (United States)

    Liao, Liu Li; Mo, Shi; Lei, Jing Lei; Luo, Hong Qun; Li, Nian Bing

    2016-07-15

    The use of the cosmetic ingredient cocamidopropylamine oxide (CAO) to inhibit the corrosion of steel in 0.5mol/LHCl is investigated. Electrochemical and weight loss methods were used to evaluate the inhibiting effect of CAO and the influences of inhibitor concentration and temperature were determined. It was found that CAO acted as a mix-type inhibitor and was adsorbed chemically onto the steel in HCl solution, and the maximum inhibition efficiency was found at critical micelle concentration (CMC) of CAO in tested corrosive media. Moreover, it was speculated that relationships of the two adsorption sites of the inhibitor and steel surface were different. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Comparative analysis of adsorption and corrosion inhibitive properties of ethanol extract of Dialium Guineense leaves for mild steel in 0.5 M HCl

    OpenAIRE

    Shola Elijah Adeniji; Bamigbola Abiola Akindehinde

    2018-01-01

    Adsorption and corrosion inhibitive properties of ethanol extract of Dialium guineense leaves for mild steel in 0.5M HCl was studied using the gravimetric method. The results showed that the ethanol extract of Dialium guineense leaves is a good corrosion inhibitor for mild steel in 0.5 M HCl. The inhibition efficiency was found to increase with increase in the concentration of ethanol extract of Dialium guineense leaves up to the maximum of 92 %, but at the same time it decreased as the tempe...

  20. Effect of Surface Treatment on the Surface Characteristics of AISI 316L Stainless Steel

    Science.gov (United States)

    Trigwell, Steve; Selvaduray, Guna

    2005-01-01

    The ability of 316L stainless steel to maintain biocompatibility, which is dependent upon the surface characteristics, is critical to its effectiveness as an implant material. The surfaces of mechanically polished (MP), electropolished (EP) and plasma treated 316L stainless steel coupons were characterized by X-ray Photoelectron Spectroscopy (XPS) and Auger Electron Spectroscopy (AES) for chemical composition, Atomic Force Microscopy for surface roughness, and contact angle measurements for critical surface tension. All surfaces had a Ni concentration that was significantly lower than the bulk concentration of -43%. The Cr content of the surface was increased significantly by electropolishing. The surface roughness was also improved significantly by electropolishing. Plasma treatment had the reverse effect - the surface Cr content was decreased. It was also found that the Cr and Fe in the surface exist in both the oxide and hydroxide states, with the ratios varying according to surface treatment.

  1. Impact of heat treatment on HSS cutting tool (ASTM A600) and its behaviour during machining of mild steel (ASTM A36)

    Science.gov (United States)

    Afolalu, S. A.; Abioye, O. P.; Salawu, E. Y.; Okokpujie, I. P.; Abioye, A. A.; Omotosho, O. A.; Ajayi., O. O.

    2018-04-01

    Carburization is one the best heat treatment that responded well to hardening with Palm Kernel Shell giving the best hardness value. This work studied the influence of carburization on HSStool(ASTM A600) and its behaviour during machining of mild steel (ASTM A36). Composition of the samples (12 pieces of 180 × 12 × 12 mm) HSS tools were checked using UV-VIS spectrometer and the tools were carburized with PKS at holding temperatures and time of 800, 850, 900, 950 °C and 60,90 120 minutes using muffle furnance. The micro structural analysis, surface and core hardnessof the treated samples gave better results than the untreated samples when checked withsoft driven and optical microscope. It wasalso observed that increase in the feed rate and depth for length of cut of 50 mm significantly reduces the wear progression and thereby gave best machining time at maximum carburizing temperature and time(950 °C / 120 minutes) when it was used to cut mild steelon the lathe machine.

  2. Adsorption and Corrosion Inhibition Studies of Some Selected Dyes as Corrosion Inhibitors for Mild Steel in Acidic Medium: Gravimetric, Electrochemical, Quantum Chemical Studies and Synergistic Effect with Iodide Ions

    Directory of Open Access Journals (Sweden)

    Thabo Peme

    2015-09-01

    Full Text Available The corrosion inhibition properties of some organic dyes, namely Sunset Yellow (SS, Amaranth (AM, Allura Red (AR, Tartrazine (TZ and Fast Green (FG, for mild steel corrosion in 0.5 M HCl solution, were investigated using gravimetric, potentiodynamic polarization techniques and quantum chemical calculations. The results showed that the studied dyes are good corrosion inhibitors with enhanced inhibition efficiencies. The inhibition efficiency of all the studied dyes increases with increase in concentration, and decreases with increase in temperature. The results showed that the inhibition efficiency of the dyes increases in the presence of KI due to synergistic interactions of the dye molecules with iodide (I− ions. Potentiodynamic polarization results revealed that the studied dyes are mixed-type inhibitors both in the absence and presence of KI. The adsorption of the studied dyes on mild steel surface, with and without KI, obeys the Langmuir adsorption isotherm and involves physical adsorption mechanism. Quantum chemical calculations revealed that the most likely sites in the dye molecules for interactions with mild steel are the S, O, and N heteroatoms.

  3. Adsorption and Corrosion Inhibition Studies of Some Selected Dyes as Corrosion Inhibitors for Mild Steel in Acidic Medium: Gravimetric, Electrochemical, Quantum Chemical Studies and Synergistic Effect with Iodide Ions.

    Science.gov (United States)

    Peme, Thabo; Olasunkanmi, Lukman O; Bahadur, Indra; Adekunle, Abolanle S; Kabanda, Mwadham M; Ebenso, Eno E

    2015-09-02

    The corrosion inhibition properties of some organic dyes, namely Sunset Yellow (SS), Amaranth (AM), Allura Red (AR), Tartrazine (TZ) and Fast Green (FG), for mild steel corrosion in 0.5 M HCl solution, were investigated using gravimetric, potentiodynamic polarization techniques and quantum chemical calculations. The results showed that the studied dyes are good corrosion inhibitors with enhanced inhibition efficiencies. The inhibition efficiency of all the studied dyes increases with increase in concentration, and decreases with increase in temperature. The results showed that the inhibition efficiency of the dyes increases in the presence of KI due to synergistic interactions of the dye molecules with iodide (I(-)) ions. Potentiodynamic polarization results revealed that the studied dyes are mixed-type inhibitors both in the absence and presence of KI. The adsorption of the studied dyes on mild steel surface, with and without KI, obeys the Langmuir adsorption isotherm and involves physical adsorption mechanism. Quantum chemical calculations revealed that the most likely sites in the dye molecules for interactions with mild steel are the S, O, and N heteroatoms.

  4. Mechanical properties of dynamic diffusion bonded joints in a mild alloy steel

    International Nuclear Information System (INIS)

    Gomez de Salazar, J. M.; Urena, A.; Menendez, M.

    2001-01-01

    Mechanical properties in Dynamic Diffusion Bonded (DDB) in a A.S.T.M. 1045 steel (=.45%C) joints were studied. The thermomechanical cycle added to the process, favours both the initial deformation stage and probably the diffusion mechanisms which participate in bond formation. (Author) 11 refs

  5. Corrosion properties of chromia based eco-friendly coatings on mild steel

    Czech Academy of Sciences Publication Activity Database

    Brožek, Vlastimil; Pokorný, P.; Bouška, P.; Stoulil, J.; Mastný, L.

    2016-01-01

    Roč. 55, č. 4 (2016), s. 675-678 ISSN 0543-5846 Institutional support: RVO:61389021 Keywords : Ceramic * steel coating * corrosion * plasma spraying Subject RIV: JG - Metallurgy Impact factor: 0.959, year: 2014 http://hrcak.srce.hr/157395

  6. Atomic diffusion in laser surface modified AISI H13 steel

    Science.gov (United States)

    Aqida, S. N.; Brabazon, D.; Naher, S.

    2013-07-01

    This paper presents a laser surface modification process of AISI H13 steel using 0.09 and 0.4 mm of laser spot sizes with an aim to increase surface hardness and investigate elements diffusion in laser modified surface. A Rofin DC-015 diffusion-cooled CO2 slab laser was used to process AISI H13 steel samples. Samples of 10 mm diameter were sectioned to 100 mm length in order to process a predefined circumferential area. The parameters selected for examination were laser peak power, pulse repetition frequency (PRF), and overlap percentage. The hardness properties were tested at 981 mN force. Metallographic study and energy dispersive X-ray spectroscopy (EDXS) were performed to observe presence of elements and their distribution in the sample surface. Maximum hardness achieved in the modified surface was 1017 HV0.1. Change of elements composition in the modified layer region was detected in the laser modified samples. Diffusion possibly occurred for C, Cr, Cu, Ni, and S elements. The potential found for increase in surface hardness represents an important method to sustain tooling life. The EDXS findings signify understanding of processing parameters effect on the modified surface composition.

  7. Laser grooving of surface cracks on hot work tool steel

    Directory of Open Access Journals (Sweden)

    D. Klobčar

    2011-10-01

    Full Text Available The paper presents the analysis of laser grooving of 1.2343 tool steel hardened to 46 HRC. The effect of laser power and grooving speed on groove shape (i.e. depth and width, the material removal rate and the purity of produced groove as a measure of groove quality was investigated and analyzed using response surface methodology. Optimal parameters of laser grooving were found, which enables pure grooves suitable for laser welding.

  8. Iodine susceptibility of pseudomonads grown attached to stainless steel surfaces

    Science.gov (United States)

    Pyle, B. H.; McFeters, G. A.

    1990-01-01

    Pseudomonads were adapted to grow in phosphate-buffered water and on stainless steel surfaces to study the iodine sensitivity of attached and planktonic cells. Cultures adapted to low nutrient growth were incubated at room temperature in a circulating reactor system with stainless steel coupons to allow biofilm formation on the metal surfaces. In some experiments, the reactor was partially emptied and refilled with buffer at each sampling time to simulate a "fill-and-draw" water system. Biofilms of attached bacteria, resuspended biofilm bacteria, and reactor suspension, were exposed to 1 mg l-1 iodine for 2 min. Attached bacterial populations which established on coupons within 3 to 5 days displayed a significant increase in resistance to iodine. Increased resistance was also observed for resuspended cells from the biofilm and planktonic bacteria in the system suspension. Generally, intact biofilms and resuspended biofilm cells were most resistant, followed by planktonic bacteria and phosphate buffer cultures. Thus, biofilm formation on stainless steel surfaces within water systems can result in significantly increased disinfection resistance of commonly-occurring water-borne bacteria that may enhance their ability to colonise water treatment and distribution systems.

  9. Enhancement of the Inhibitor Efficiency of Atropine Methochloride in Corrosion Control of Mild Steel in Sulphuric Acid

    Directory of Open Access Journals (Sweden)

    Abida Begum

    2008-01-01

    Full Text Available The inhibition efficiency and synergistic behaviour of 10-4 M Atropine methochloride was carried out using mass loss and polarisation methods in the presence of (i metal ions, Ni2+ and Cu2+ between 10-2 M to 10-6 M concentrations, (ii different concentrations of metal ions and 10-3 M I-, 10-3 M Cl- and 10-3 M Br- solutions and (iii different metal ions, 10-3M I- and at three different temperatures. The analysis reveals that the inhibition efficiency of Atropine methochloride was maximum at 10-2 M in 5 hours of immersion period. Halides decreased the corrosion rate of mild steel in Sulphuric acid. The decrease is maximum with 10-3 M I-. As the temperature increased from 298K to 308K, the inhibition efficiency gradually decreased. The inhibitor was found to be effective up to 303K

  10. USING A DOE AND EIS TO EVALUATE THE SYNERGISTIC EFFECTS OF LOW TOXICITY INHIBITORS FOR MILD STEEL

    Directory of Open Access Journals (Sweden)

    G. V. Bueno

    2015-03-01

    Full Text Available Abstract Inhibitors are widely used to prevent corrosion in cooling-water systems, and their protective performance can be enhanced by combination. The aim of this paper is to identify possible synergistic effects between four low toxicity substances used as corrosion inhibitors for mild steel in industrial cooling-water systems. Electrochemical measurements were obtained following a design of experiments (DOE where the independent variables were the inhibitors concentrations and the response variable the charge transfer resistance estimated from impedance diagrams. Potentiodynamic polarization curves show that all of them act as anodic corrosion inhibitors. Among the tested formulations, only the interaction between sodium molybdate and sodium tungstate showed statistically significant effects, indicating that they can perform better when used together. The results of this work show the importance of using a statistical tool when designing inhibitor mixtures.

  11. Systematic corrosion investigation of various Cu-Sn alloys electrodeposited on mild steel in acidic solution: Dependence of alloy composition

    Energy Technology Data Exchange (ETDEWEB)

    Suerme, Yavuz, E-mail: ysurme@nigde.edu.t [Department of Chemistry, Faculty of Science and Art, Nigde University, 51200 Nigde (Turkey); Guerten, A. Ali [Department of Chemistry, Faculty of Science and Art, Osmaniye Korkut Ata University, 80000 Osmaniye (Turkey); Bayol, Emel; Ersoy, Ersay [Department of Chemistry, Faculty of Science and Art, Nigde University, 51200 Nigde (Turkey)

    2009-10-19

    Copper-tin alloy films were galvanostatically electrodeposited on the mild steel (MS) by combining the different amount of Cu and Sn electrolytes at a constant temperature (55 deg. C) and pH (3.5). Alloy films were characterized by using the energy dispersive X-ray analysis (EDX), scanning electron microscopy (SEM), X-ray diffraction (XRD) and micrographing techniques. Corrosion behaviours were evaluated with electrochemical impedance spectrometry (EIS) and electrochemical polarization measurements. Time gradient of electrolysis process was adjusted to obtain same thickness of investigated alloys on MS. The systematic corrosion investigation of various Cu{sub x}-Sn{sub 100-x} (x = 0-100) alloy depositions on MS substrate were carried out in 0.1 M sulphuric acid medium. Results indicate that the corrosion resistance of the alloy coatings depended on the alloy composition, and the corrosion resistance increased at Cu-Sn alloy deposits in proportion to Sn ratio.

  12. Desensitization of stainless steels by laser surface heat-treatment

    Energy Technology Data Exchange (ETDEWEB)

    Nakao, Yoshikuni; Nishimoto, Kazutoshi

    1987-11-01

    Laser heating was applied for the desensitization heat-treatment of the surface layer in the sensitized HAZ of Type 304 stainless steel. The degree of sensitization was examined by EPR technique and the 10 % oxalic acid electrolytic etch test. The CO/sub 2/ laser with maximum power of 1.5 kW was used for heat-treatment. Time-Temperature-Desensitization diagram (TTDS diagram) for sensitized Type 304 stainless steels were developed by calculation assuming the chromium diffusion control for desensitization which might occur when the chromium depleted zone was healed up due to dissolution of chromium carbide and chromium diffusion from the matrix being heated at the solution annealing temperatures. TTDS diagrams calculated agree fairly well with ones determined by corrosion tests. Laser irradiation conditions (e.g., Laser power, beam diameter and traveling velocity) required for desensitization of sensitized Type 304 stainless steels were calculated using additivity rule from the TTDS diagram calculated and theoretical thermal curve of laser heating derived from the heat conduction theory. After laser beam irradiated under an optimum condition predicted by calculation, the sensitized HAZ of Type 304 stainless steel restored complete resistance to intergranular corrosion.

  13. A brief review on the atmospheric corrosion of mild steel in Iran

    Directory of Open Access Journals (Sweden)

    E. Shafiei

    2014-12-01

    Full Text Available This paper presents a review on the atmospheric corrosion of steel, at three sites, in Iran. Corrosion rate values, time of wetness, and the level of pollutants, namely of SO2 and chlorides were determined for the first year of exposure in order to establish the aggressiveness of the atmospheres. The results obeyed well with the empirical kinetics equation of the form C = Ktn.

  14. Study of yttrium 4-nitrocinnamate to promote surface interactions with AS1020 steel

    Energy Technology Data Exchange (ETDEWEB)

    Hien, P.V. [Department of Chemical Engineering, Bach Khoa University, VNU-HCM, 268 Ly Thuong Kiet Street, District 10, Ho Chi Minh City (Viet Nam); Vu, N.S.H.; Thu, V.T.H. [Faculty of Physics and Engineering Physics, University of Science, 227 Nguyen Van Cu Street, District 5, Ho Chi Minh City (Viet Nam); Somers, A. [Institute for Frontier Materials, Deakin University, Geelong, Victoria 3220 (Australia); Nam, N.D., E-mail: namnd@pvu.edu.vn [PetroVietnam University, 762 Cach Mang Thang Tam Street, Long Toan Ward, Ba Ria City, Ba Ria—Vung Tau Province (Viet Nam)

    2017-08-01

    Highlights: • Yttrium 4-nitrocinnamate is a new corrosion inhibitor alternative to chromate technologies. • The inhibition performance is increased with increase of the inhibitor concentration. • Yttrium 4-nitrocinnamate mitigates corrosion by promoting random distribution of minor anodes. • Yttrium 4-nitrocinnamate is a good candidate for substitution of chromate inhibitors. - Abstract: Yttrium 4-nitrocinnamate (Y(4-NO{sub 2}Cin){sub 3}) was added to an aqueous chloride solution and studied as a possible corrosion inhibition system. Electrochemical techniques and surface analysis have been powerful tools to better understand the corrosion and inhibition processes of mild steel in 0.01 M NaCl solution. A combination of scanning electron microscopy (SEM), atomic force microscopy (AFM), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), Potentiodynamic polarization (PD), electrochemical impedance spectroscopy (EIS) and wire beam electrode (WBE) techniques was found to be useful in the characterization of this system. The result indicated that Y(4-NO{sub 2}Cin){sub 3} is able to effectively inhibit corrosion at a low concentration of 0.45 mM. Surface analysis clearly shows that the surface of steel coupons exposed to Y(4-NO{sub 2}Cin){sub 3} solution remained uniform and smooth, whereas the surface of steel coupons exposed to solution without inhibitor addition was severely corroded. The results suggest that Y(4-NO{sub 2}Cin){sub 3} behaves as a mixed inhibitor and mitigates corrosion by promoting random distribution of minor anodes. These are attributed to the formation of metal species bonding to the 4-nitrocinnamate component and hydrolysis of the Y(4-NO{sub 2}Cin){sub 3} to form oxide/hydroxides as a protective film layer.

  15. Characterization of a Laser Surface-Treated Martensitic Stainless Steel

    OpenAIRE

    S.R. Al-Sayed; A.A. Hussein; A.A. Nofal; S.I. Hassab Elnaby; H. Elgazzar

    2017-01-01

    Laser surface treatment was carried out on AISI 416 machinable martensitic stainless steel containing 0.225 wt.% sulfur. Nd:YAG laser with a 2.2-KW continuous wave was used. The aim was to compare the physical and chemical properties achieved by this type of selective surface treatment with those achieved by the conventional treatment. Laser power of different values (700 and 1000 W) with four corresponding different laser scanning speeds (0.5, 1, 2, and 3 m?min?1) was adopted to reach the op...

  16. Surface characterization and wear behaviour of laser surface melted AISI 316L stainless steel

    CSIR Research Space (South Africa)

    Kumar, A

    2010-01-01

    Full Text Available The present study concerns an in depth investigation of the influence of laser surface melting of AISI 316L stainless steel using Ar and N2 as shrouding atmosphere. Laser surface melting has been carried out using a 5 kW continuous wave (CW) fibre...

  17. Influence of microstructure on stress corrosion cracking of mild steel in synthetic caustic-nitrate nuclear waste solution

    International Nuclear Information System (INIS)

    Sarafian, P.G.

    1975-12-01

    The influence of alloy microstructure on stress corrosion cracking of mild steel in caustic-nitrate synthetic nuclear waste solutions was studied. An evaluation was made of the effect of heat treatment on a representative material (ASTM A 516 Grade 70) used in the construction of high activity radioactive waste storage tanks at Savannah River Plant. Several different microstructures were tested for susceptibility to stress corrosion cracking. Precracked fracture specimens loaded in either constant load or constant crack opening displacement were exposed to a variety of caustic-nitrate and nitrate solutions. Results were correlated with the mechanical and corrosion properties of the microstructures. Crack velocity and crack arrest stress intensity were found to be related to the yield strength of the steel microstructures. Fractographic evidence indicated pH depletion and corrosive crack tip chemistry conditions even in highly caustic solutions. Experimental results were compatible with crack growth by a strain-assisted anodic dissolution mechanism; however, hydrogen embrittlement also was considered possible

  18. Detection of localized and general corrosion of mild steel in simulated defense nuclear waste solutions using electrochemical noise analysis

    International Nuclear Information System (INIS)

    Edgemon, G.L.; Ohl, P.C.; Bell, G.E.C.; Wilson, D.F.

    1995-12-01

    Underground waste tanks fabricated from mild steel store more than 60 million gallons of radioactive waste from 50 years of weapons production. Leaks are suspected in a significant number of tanks. The probable modes of corrosion failures are reported to be localized corrosion (e.g. nitrate stress corrosion cracking and pitting). The use of electrochemical noise (EN) for the monitoring and detection of localized corrosion processes has received considerable attention and application over the last several years. Proof of principle laboratory tests were conducted to verify the capability of EN evaluation to detect localized corrosion and to compare the predictions of general corrosion obtained from EN with those derived from other sources. Simple, pre-fabricated flat and U-bend specimens of steel alloys A516-Grade 60 (UNS K02100) and A537-CL 1 (UNS K02400) were immersed in temperature controlled simulated waste solutions. The simulated waste solution was either 5M NaNO 3 with 0.3M NaOH at 90 C or 11M NaNO 3 with 0.15M NaOH at 95 C. The electrochemical noise activity from the specimens was monitored and recorded for periods ranging between 140 and 240 hours. At the end of each test period, the specimens were metallographically examined to correlated EN data with corrosion damage

  19. Modelling and Optimization of Corrosion Inhibition of Mild Steel in Phosphoric Acid by Red Pomegranate Peels Aqueous Extract

    Directory of Open Access Journals (Sweden)

    Khalid Hamid Rashid

    2011-11-01

    Full Text Available Taguchi experimental design (TED is applied to find the optimum effectiveness of aqueous Red Pomegranate Peel (RPP extract as a green inhibitor for the corrosion of mild steel in 2M H3PO4 solution. The Taguchi methodology has been used to study the effects of changing, temperature, RPP concentration and contact period, at three levels. Weight-loss measurements were designed by construction a L9 orthogonal arrangement of experiments. Results of the efficiencies of inhibition were embraced for the signal to noise proportion & investigation of variance (ANOVA. The results were further processed with a MINITAB-17 software package to find the optimal conditions for inhibitor usage. Second order polynomial model was used for experimental data fitting. Optimum conditions for achieving the maximum corrosion inhibition efficiency are obtained from optimizing the above model and are found as follow: 39.66 °C temperature of acidic media, 38.29 ml/L inhibitor concentration and 2.95 h contact period. Results demonstrated that rate of corrosion was increased with temperature increasing & decreasing inhibitor concentration. It was concluded that the Taguchi design was adequately useful in the optimization of operating parameters and that RPP sufficiently inhibited the corrosion of steel at the range of variables studied.

  20. Wetting of polymer melts on coated and uncoated steel surfaces

    Science.gov (United States)

    Vera, Julie; Contraires, Elise; Brulez, Anne-Catherine; Larochette, Mathieu; Valette, Stéphane; Benayoun, Stéphane

    2017-07-01

    A comparative study of the wetting of three different commercial polymer melts on various coated and uncoated steel surfaces is described in this report. The wettability of steel and coatings (three different titanium nitride coatings, TiN, TiNOx, TiNOy, a chromium coating, CrN, and a diamond-like carbon coating, DLC) used for mold in polymer processing is determined at different temperatures between 25 °C and 120 °C. Contact angle measurements of melted polypropylene (PP), Acrylonitrile Butadiene Styrene (ABS) and Polycarbonate (PC) on steel and on the different coatings were performed to investigate the wetting behavior under closer-to-processing conditions. Recommendations for good measurement conditions were proposed. Moreover, the surface free energy of each melt polymer was determined. The works of adhesion between all polymers and all substrates were established. Among all tested polymers, the lowest value of the works of adhesion is calculated for ABS and for PC thereafter, and the highest value is calculated for PP. These results will be particularly important for such applications as determining the extent to which these polymers can contribute to the replication quality in injection molding.

  1. Surface martensitization of Carbon steel using Arc Plasma Sintering

    Science.gov (United States)

    Wahyudi, Haris; Dimyati, Arbi; Sebayang, Darwin

    2018-03-01

    In this paper new technology of surface structure modification of steel by short plasma exposure in Arc Plasma Sintering (APS) device is presented. APS is an apparatus working based on plasma generated by DC pulsed current originally used for synthesizing materials via sintering and melting. Plasma exposure in APS was applied into the specimens for 1 and 3 seconds which generate temperature approximately about 1300-1500°C. The SUP9, pearlitic carbon steel samples were used. The hardness, hardening depth and microstructure of the specimens have been investigated by Vickers micro hardness test and Scanning Electron Microscopy (SEM) supported by Energy Dispersive X-Ray Spectroscopy (EDX). The results have showed that the mechanical property was significantly improved due to the formation of single martensitic structures as identified by SEM. The hardness of treated surface evaluated by Vickers hardness test showed significant improvement nearly three time from 190 VHN before to 524 VHN after treatment. Furthermore, EDX confirmed that the formation of martensite layer occurred without altering its composition. The APS also produced uniform hardened layer up to 250 μm. The experiment has demonstrated that arc plasma process was successfully improved the mechanical properties of steel in relatively very short time.

  2. Investigation of Corrosion and Cathodic Protection in Reinforced Concrete. II : Properties of Steel Surface Layers

    NARCIS (Netherlands)

    Koleva, D.A.; De Wit, J.H.W.; Van Breugel, K.; Lodhi, Z.F.; Ye, G.

    2007-01-01

    The present study explores the formation of corrosion products on the steel surface (using as-received low carbon construction steel) in reinforced concrete in conditions of corrosion and subsequent transformation of these layers in conditions of cathodic protection (CP).

  3. Surface protection of austenitic steels by carbon nanotube coatings

    Science.gov (United States)

    MacLucas, T.; Schütz, S.; Suarez, S.; Mücklich, F.

    2018-03-01

    In the present study, surface protection properties of multiwall carbon nanotubes (CNTs) deposited on polished austenitic stainless steel are evaluated. Electrophoretic deposition is used as a coating technique. Contact angle measurements reveal hydrophilic as well as hydrophobic wetting characteristics of the carbon nanotube coating depending on the additive used for the deposition. Tribological properties of carbon nanotube coatings on steel substrate are determined with a ball-on-disc tribometer. Effective lubrication can be achieved by adding magnesium nitrate as an additive due to the formation of a holding layer detaining CNTs in the contact area. Furthermore, wear track analysis reveals minimal wear on the coated substrate as well as carbon residues providing lubrication. Energy dispersive x-ray spectroscopy is used to qualitatively analyse the elemental composition of the coating and the underlying substrate. The results explain the observed wetting characteristics of each coating. Finally, merely minimal oxidation is detected on the CNT-coated substrate as opposed to the uncoated sample.

  4. Effect of Surface Modification on Corrosion Resistance of Uncoated and DLC Coated Stainless Steel Surface

    Science.gov (United States)

    Scendo, Mieczyslaw; Staszewska-Samson, Katarzyna

    2017-08-01

    Corrosion resistance of 4H13 stainless steel (EN-X46Cr13) surface uncoated and coated with an amorphous hydrogenated carbon (a-C:H) film [diamond-like carbon (DLC)] in acidic chloride solution was investigated. The DLC films were deposited on steel surface by a plasma deposition, direct current discharge (PDCD) method. The Fourier transform infrared (FTIR) was used to determine the chemical groups existing on DLC films. The surface of the specimens was observed by a scanning electron microscope (SEM). The tribological properties of the both materials were examined using a ball-on disk tribometer. The microhardness (HV) of diamond-like carbon film increased over five times in relation to the 4H13 stainless steel without of DLC coating. Oxidation kinetic parameters were determined by gravimetric and electrochemical methods. The high value of polarization resistance indicates that the DLC film on substrate was characterized by low electrical conductivity. The corrosion rate of 4H13 stainless steel with of DLC film decreased about eight times in relation to uncoated surface of 4H13 stainless steel.

  5. Studies on plant extracts as corrosion inhibitors for mild steel in air saturated water

    International Nuclear Information System (INIS)

    Mohamad Daud; Abdul Razak Daud; Zainal Abidin Sidi

    1988-01-01

    The effectiveness in inhibiting corrosion by garlic, soya bean, and tobacco extracts and their combinations in air saturated water at ambient temperature were studied by using electrochemical corrosion test. The range of inhibitor concentration studied was from 0.1 to 1.0 g/l. The variations of corrosion potential and corrosion current density was recorded and the results showed that the extracts have inhibitive properties in the corrosion of mild stee. The effectiveness of the inhibitors is in the following order: extract mixture > tobacco > garlic > soya bean extracts. (author)

  6. Laser surface modification of stainless steels for cavitation erosion resistance

    Science.gov (United States)

    Kwok, Chi Tat

    1999-12-01

    Austenitic stainless steel UNS S31603 (Fe -17.6Cr -11.2Ni -2.5Mo -1.4Mn -0.4Si -0.03C) has higher pitting corrosion resistance but lower cavitation erosion resistance than that of UNS S30400. This is because of its lower tendency for strain induced martensitic transformation and higher stacking fault energy as compared with those of UNS S30400. In order to improve its cavitation erosion resistance, surface modification of S31603 was performed by laser surface melting and laser surface alloying using a 2-kW CW Nd-YAG laser and a 3-kW CW CO2 laser. For laser surface melting, austenitic stainless steel UNS S30400, super duplex stainless steel UNS S32760 and martensitic stainless steel UNS S42000 were also investigated for comparison purpose. For laser surface alloying, alloying materials including various elements (Co, Cr, Ni, Mo, Mn, Si & C), alloys (AlSiFe & NiCrSiB), ceramics (Si3N 4, SiC, Cr3C2, TiC, CrB & Cr2O 3) and alloys-ceramics (Co-WC, Ni-WC, Ni-Al2O3, Ni-Cr2C3) were used to modify the surface of S31603. The alloyed surface was achieved first by flame spraying or pre-placing of the alloy powder on the S31603 surface and then followed by laser surface remelting. The cavitation erosion characteristics of laser surface modified specimens in 3.5% NaCl solution at 23°C were studied by means of a 20-kHz ultrasonic vibrator at a peak-to-peak amplitude of 30 mum. In addition, their pitting corrosion behaviour was evaluated by electrochemical techniques. The microstructures, compositions, phase changes and damage mechanisms under cavitation erosion were investigated by optical microscopy, SEM, EDAX and X-ray diffractometry. Mechanical properties such as microhardness profile were also examined. The cavitation erosion resistance Re (reciprocal of the mean depth of penetration rate) of laser surface melted S31603 was found to be improved by 22% and was attributed to the existence of tensile residual stress. Improvement on the Re of S42000 was found to be 8.5 times

  7. Low temperature surface hardening of stainless steel; the role of plastic deformation

    DEFF Research Database (Denmark)

    Bottoli, Federico; Jespersen, Freja Nygaard; Hattel, Jesper Henri

    2016-01-01

    : - plastic deformation of metastable austenitic stainless steels leads to the development of strain-induced martensite, which compromises the uniformity and the homogeneity of the expanded austenite zone. - during low temperature surface engineering composition and stress profiles develop. On numerical......Thermochemical surface engineering by nitriding of austenitic stainless steel transforms the surface zone into expanded austenite, which improves the wear resistance of the stainless steel while preserving the stainless behavior. As a consequence of the thermochemical surface engineering, huge...

  8. Corrosion properties of chromia based eco - friendly coatings on mild steel

    Directory of Open Access Journals (Sweden)

    V. Brozek

    2016-10-01

    Full Text Available Ceramic nanocrystalline coatings of chromium oxide (III on steel S235JRH-1.0038 (EN 10025-1 were prepared using the liquid precursor plasma spraying (LPPS method from ammonia dichromate (VI. Their structure and anti – corrosion properties were compared to the standard chromium oxide (III coating prepared by thermal spraying. The newly prepared coatings had very high adhesion and minimal porosity. Anticorrosion properties were characterized by the means of the electrochemical impedance spectroscopy (EIS, measuring the charge transfer resistance Rct and capacitance of electrical double layer CPEdl in the 0,5 mol/l NaCl. Coatings of Cr2 O3 prepared by the LPPS method showed unambiguously improved anti - corrosion properties.

  9. Task-specific ionic liquid as a new green inhibitor of mild steel corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Kowsari, E., E-mail: kowsarie@aut.ac.ir [Department of Chemistry, Amirkabir University of Technology, No. 424, Hafez Avenue, 1591634311 Tehran (Iran, Islamic Republic of); Payami, M. [Department of Chemistry, Amirkabir University of Technology, No. 424, Hafez Avenue, 1591634311 Tehran (Iran, Islamic Republic of); Amini, R.; Ramezanzadeh, B. [Department of Surface Coating and Corrosion, Institute for Color Science and Technology (ICST), PO 16765-654 Tehran (Iran, Islamic Republic of); Javanbakht, M. [Department of Chemistry, Amirkabir University of Technology, No. 424, Hafez Avenue, 1591634311 Tehran (Iran, Islamic Republic of)

    2014-01-15

    The corrosion inhibition effects of an imidazolium-based task specific ionic liquid (TSIL) were investigated on a low carbon steel in 1 M HCl solution. Samples were exposed to 1 M HCl solution without and with different concentrations of TSIL. Weight loss measurements, potentiodynamic polarization test, electrochemical impedance spectroscopy (EIS), scanning electron microscope (SEM), atomic force microscope (AFM) and contact angle measurements were utilized to investigate the inhibition effects of TSIL. The results obtained from the polarization studies revealed that both the anodic and cathodic branches slopes affected in the presence of TSIL. It was shown that TSIL behaved as a mixed type inhibitor with a dominant effect on the anodic reaction rate depression. It was shown that the increase in polarization resistance and the decrease in corrosion current density were more pronounced using 100 mg/L of TSIL after 2 h immersion time. It was also shown that the adsorption of TSIL followed a Langmuir adsorption isotherm.

  10. Corrosion inhibition of mild steel in 1 M HCl solution by henna extract: A comparative study of the inhibition by henna and its constituents (Lawsone, Gallic acid, α-D-Glucose and Tannic acid)

    International Nuclear Information System (INIS)

    Ostovari, A.; Hoseinieh, S.M.; Peikari, M.; Shadizadeh, S.R.; Hashemi, S.J.

    2009-01-01

    The inhibitive action of henna extract (Lawsonia inermis) and its main constituents (lawsone, gallic acid, α-D-Glucose and tannic acid) on corrosion of mild steel in 1 M HCl solution was investigated through electrochemical techniques and surface analysis (SEM/EDS). Polarization measurements indicate that all the examined compounds act as a mixed inhibitor and inhibition efficiency increases with inhibitor concentration. Maximum inhibition efficiency (92.06%) is obtained at 1.2 g/l henna extract. Inhibition efficiency increases in the order: lawsone > henna extract > gallic acid > α-D-Glucose > tannic acid. Also, inhibition mechanism and thermodynamic parameters are discussed.

  11. Corrosion inhibition of mild steel in 1 M HCl solution by henna extract: A comparative study of the inhibition by henna and its constituents (Lawsone, Gallic acid, {alpha}-D-Glucose and Tannic acid)

    Energy Technology Data Exchange (ETDEWEB)

    Ostovari, A. [Technical Inspection Engineering Department, Petroleum University of Technology, Abadan (Iran, Islamic Republic of)], E-mail: A.Ostovari@gmail.com; Hoseinieh, S.M.; Peikari, M. [Technical Inspection Engineering Department, Petroleum University of Technology, Abadan (Iran, Islamic Republic of); Shadizadeh, S.R. [Petroleum Engineering Department, Petroleum University of Technology, Abadan (Iran, Islamic Republic of); Hashemi, S.J. [Technical Inspection Engineering Department, Petroleum University of Technology, Abadan (Iran, Islamic Republic of)

    2009-09-15

    The inhibitive action of henna extract (Lawsonia inermis) and its main constituents (lawsone, gallic acid, {alpha}-D-Glucose and tannic acid) on corrosion of mild steel in 1 M HCl solution was investigated through electrochemical techniques and surface analysis (SEM/EDS). Polarization measurements indicate that all the examined compounds act as a mixed inhibitor and inhibition efficiency increases with inhibitor concentration. Maximum inhibition efficiency (92.06%) is obtained at 1.2 g/l henna extract. Inhibition efficiency increases in the order: lawsone > henna extract > gallic acid > {alpha}-D-Glucose > tannic acid. Also, inhibition mechanism and thermodynamic parameters are discussed.

  12. Low-waste electrochemical decontamination of stainless-steel surface

    International Nuclear Information System (INIS)

    Babain, V.A.; Smirnov, I.V.; Shadrin, A.Yu.; Firsin, N.G.; Zakharchuk, G.A.; Pavlov, A.B.; Shilov, V.V.

    2002-01-01

    An electrochemical decontamination method using a formic acid-based recycling electrolyte was proposed to remove firmly fixed contaminants from stainless-steel surfaces. The following provisions make for minimisation of the amounts of waste: (i) use of specially designed electrodes with vacuum removal of spent electrolyte; (ii) inter-cycle removal of radionuclides from the electrolyte by using an inorganic sorbent; (iii) periodic regeneration of the spent electrolyte. the dissolved metals (Fe, Cr, Ni) being transformed into acidic phosphates; (iv) solidification of residues arising from the regeneration of the electrolyte and spent sorbent into iron-phosphate ceramics. The technology and equipment developed were used for decontamination of a plutonium glove-box. The level of surface contamination was reduced 100-fold in two decontamination cycles. The depth of metal skimming was 1.5 μ for the ceiling and walls and 4.5 μ for the table top. Each square meter of stainless-steel surface provides about 100 g of solid radioactive waste in the form of iron-phosphate ceramic blocks

  13. Effect of steel surface conditions on reinforcing steel corrosion in concrete exposed to marine environments

    Directory of Open Access Journals (Sweden)

    Anzola, E.

    2005-09-01

    Full Text Available Laboratory methods and experimental tests were deployed in the present study to evaluate corrosion in reinforced concrete exposed to marine environments. Reinforcing steel exhibiting two different surface conditions prior to embedment in concrete were studied, one the one hand to assess the electrochemical behaviour of the bars during exposure of the concrete specimens to a simulated marine environment, and on the other to determine the strength of the steel/concrete bond. The reinforced concrete specimens prepared were adapted as required for electrochemical potential and corrosion rate testing. A total of 56 7x15-cm cylindrical specimens containing 3/8" steel rods anchored at a depth of 11.5 cm were made to evaluate the steel / concrete bond and exposed to a natural marine environment for 28 or 190 days prior to testing. All the specimens were made with ready-mixed concrete. It may be concluded from the results of the corrosion tests on reinforcing steel with different surface conditions that the oxide initially covering the bars was dissolved and the steel passivated by the alkalinity in the concrete. The chief finding of the bonding study was that the layer of oxide formed in pre-embedment steel deterioration contributed to establishing a better bond.

    En el contexto de esta investigación, se tomaron en consideración métodos y ensayos experimentales de laboratorio, que permiten hacer una evaluación de la corrosión del hormigón armado expuesto en ambientes marinos. Por una parte se evaluó el comportamiento electroquímico de dos condiciones de estados superficiales del acero embebido en el hormigón, exponiéndolo en un ambiente marino simulado y, por otra parte, se estudió la adherencia entre el acero y el hormigón, con los mismos estados superficiales usados para la evaluación electroquímica. Las probetas se fabricaron de hormigón con acero de refuerzo en su interior, adecuándolas para realizar los ensayos de potenciales

  14. On the surface topography of ultrashort laser pulse treated steel surfaces

    NARCIS (Netherlands)

    Obona, J. Vincenc; Ocelik, V.; Skolski, J. Z. P.; Mitko, V. S.; Romer, G. R. B. E.; in't Veld, A. J. Huis; De Hosson, J. Th M.; Römer, G.R.B.E.; Huis in’t Veld, A.J.

    2011-01-01

    This paper concentrates on observations of the surface topography by scanning electron microscopy (SEM) on alloyed and stainless steels samples treated by ultrashort laser pulses with duration of 210 fs and 6.7 ps. Globular-like and jet-like objects were found depending on the various levels of the

  15. On the surface topography of ultrashort laser pulse treated steel surface

    NARCIS (Netherlands)

    Vincenc Obona, J.; Ocelik, V.; Skolski, J.Z.P.; Mitko, V.S.; Mitko, S.; Römer, Gerardus Richardus, Bernardus, Engelina; Huis in 't Veld, Bert; de Hosson, J.Th.M.

    2011-01-01

    This paper concentrates on observations of the surface topography by scanning electron microscopy (SEM) on alloyed and stainless steels samples treated by ultrashort laser pulses with duration of 210 fs and 6.7 ps. Globular-like and jet-like objects were found depending on the various levels of the

  16. Inhibition of nitrate stress corrosion cracking of mild steel in nuclear process wastes

    International Nuclear Information System (INIS)

    Donovan, J.A.

    1975-01-01

    The concentration of hydroxide and nitrite ions necessary to prevent crack growth in A-285-B steel exposed to waste solutions was determined by the systematic testing of solutions within the ranges of hydroxide, nitrate, and nitrite concentrations found in waste tanks. The relative susceptibility to SCC was assumed to be dependent on the concentrations of nitrate, nitrite, and hydroxyl ions; the other components were assumed to have little effect on cracking. All of the tests were done at 97 0 C, with specimens loaded initially to an effective stress intensity of 45 ksi √in. Both the temperature of exposure and the initial stress intensity create conditions more severe than would normally be found in the waste tanks. All specimens were exposed for a minimum of 1000 hours. Results showed that the aggressiveness of the solutions increased with increasing nitrate ion concentration. For example, cracks grew in 5M NO 3 - + 0.3M NO 2 - , but not in 1.5M NO 3 - + 0.3M NO 2 - . Also, the solutions causing crack growth within the range of compositions found in the waste tank were concentrated in the high nitrate--low nitrite, hydroxyl ion region. Most of the results were obtained with solutions containing 5M NO 3 - and various amounts of nitrite and hydroxyl ion concentrations. (U.S.)

  17. Surface finishing and levelling of thermomechanically hardened rolled steel

    International Nuclear Information System (INIS)

    Grosval'd, V.G.; Bashchenko, A.P.; Grishkov, A.I.; Gutnik, M.V.; Kanevskij, B.L.; Nikozov, A.I.; Sedov, N.D.; Prosin, K.A.; Safonov, L.I.

    1975-01-01

    The finishing of high-strength merchant shapes from alloy steel was tried out under industrial conditions with the equipment of metallurgical plants. After thermomechanical hardening in the production line of the rolling mill, 30KhGSN2A and 40Kh1NVA steel rounds 32 and 31 mm in diameter were straightened on a two-roller straightening machine designed by the All-Union Scientific Research Institute for Metallurgical Machinery (VNII Metmash). This made possible subsequent turning and grinding of the rods. The conditions of straightening, turning and grinding have been worked so as to obtain thermomechanically strengthened and ground rolled products approximating the gauged and ground metal in shape geometry and surface finish. It is shown that the labour-consuming operation of turning can be eliminated by reducing the machining pass of the rolled product, and this lowers the labour required for the finishing operations by 75%. After grinding with 40- and 25-grain abrasive wheels, high strength rolled shapes were obtained with a diameter of 30-0.20 mm and a surface finish of class 6-5 satisfying the technical specifications. (author)

  18. The #betta# irradiation-enhanced corrosion of stainless and mild steels by water in the presence of air, argon and hydrogen

    International Nuclear Information System (INIS)

    Burns, W.G.; Marsh, W.R.; Walters, W.S.

    1983-01-01

    When air-saturated pure water was #betta#-irradiated in the presence of air to high doses in sealed stainless steel containers hydrogen and oxygen were formed. The amounts were less than one tenth of the maximum possible for continuous aqueous radiolysis but the increase in oxygen appearing as gas was less than that equivalent to the hydrogen formed from the water present, indicating that metallic corrosion had occurred. In the absence of radiation no change in gas composition was observed. When the air in solution and in the gas space was replaced by argon or by hydrogen, radiolysis and corrosion were virtually suppressed. When the container was made of mild steel or strips of mild steel were initially introduced into a sealed stainless steel container containing air and water, oxygen was consumed on irradiation, and hydrogen was formed, together with a suspended brown oxide. In the absence of radiation oxygen was consumed and hydrogen was formed but both at a lower rate than in the presence of radiation. In this case, unlike the case of stainless steel, the formation of hydrogen was not prevented by replacing the air present with argon. The results are discussed. (author)

  19. Effect of machining on the deformability of steel in surface-active medium at lower temperatures

    International Nuclear Information System (INIS)

    Gusti, E.Ya.; Babej, Yu.I.

    1977-01-01

    The effect of some machining methods of carbon steel, chromium steel, and chromium nickel steel, and that of low temperatures on the principle characteristics of formability during impact bending in air and a surface-active environment have been studied. The temperature decrease from the ambient to -80 deg is shown to reduce steel formability as evaluated by deflection (f) and to increase the forming force. The variation of these characteristics with lowering temperature, however, is greatly affected by machining process conditions. The FRHT (Friction-Hardening Treatment) on the white layer assures minimum ductility losses, and increases steel strength at low temperatures both in air and in the surface-active environment

  20. The oxidation of mild steel in high pressure CO2. Paper presented to the Nuclear Engineering Society on Tuesday, 15 November 1977

    International Nuclear Information System (INIS)

    Gleave, C.

    1977-01-01

    The mechanisms of oxidation of mild steels in high pressure carbon dioxide is elucidated. Rimming steel was oxidized sequentially in C 160 2, at 4.1 MPa and 500 0 C. C 180 2 was used as a tracer gas. The distribution of the 18 0 in the oxide scales could be determined by nuclear micro-analytical techniques in order to determine the oxide growth in both protective and breakaway oxide scales. The examination of the data from weight gains and both nuclear and metallurgical techniques is described and discussed. Several conclusions are drawn to explain the mechanism of the corrosion. (U.K.)

  1. Multiaxial Cycle Deformation and Low-Cycle Fatigue Behavior of Mild Carbon Steel and Related Welded-Metal Specimen

    Directory of Open Access Journals (Sweden)

    Weilian Qu

    2017-01-01

    Full Text Available The low-cycle fatigue experiments of mild carbon Q235B steel and its related welded-metal specimens are performed under uniaxial, in-phase, and 90° out-of-phase loading conditions. Significant additional cyclic hardening for 90° out-of-phase loading conditions is observed for both base metal and its related weldment. Besides, welding process produces extra additional hardening under the same loading conditions compared with the base metal. Multiaxial low-cycle fatigue strength under 90° out-of-phase loading conditions is significantly reduced for both base-metal and welded-metal specimens. The weldment has lower fatigue life than the base metal under the given loading conditions, and the fatigue life reduction of weldment increases with the increasing strain amplitude. The KBM, FS, and MKBM critical plane parameters are evaluated for the fatigue data obtained. The FS and MKBM parameters are found to show better correlation with fatigue lives for both base-metal and welded-metal specimens.

  2. Molecular dynamic and quantum chemical calculations for phthalazine derivatives as corrosion inhibitors of mild steel in 1 M HCl

    Energy Technology Data Exchange (ETDEWEB)

    Musa, Ahmed Y., E-mail: AMUSA6@UWO.CA [Department of Chemistry, University of Western Ontario, 1151 Richmond Street, London, Ontario, N6A 5B7 (Canada); Department of Chemical and Process Engineering, Universiti Kebangsaan Malaysia, Bangi, 43600 Selangor (Malaysia); Jalgham, Ramzi T.T.; Mohamad, Abu Bakar [Department of Chemical and Process Engineering, Universiti Kebangsaan Malaysia, Bangi, 43600 Selangor (Malaysia)

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer The inhibition of three phthalazine derivatives was studied. Black-Right-Pointing-Pointer The inhibition efficiency increased in the following order: PTD < PT < PTO. Black-Right-Pointing-Pointer The adsorption energies were calculated using molecular dynamics simulations. Black-Right-Pointing-Pointer Quantum chemical parameters were calculated using the AM1, MNDO and PM3 methods. Black-Right-Pointing-Pointer The adsorption of phthalazine derivatives obeys the Langmuir adsorption isotherm. - Abstract: The abilities of phthalazine derivatives, including phthalazine (PT), phthalazone (PTO) and phthalhydrazide (PTD), to inhibit the corrosion of mild steel in 1 M HCl at 30 Degree-Sign C were studied using electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization measurements. Theoretical calculations were performed to investigate the electronic structures of the PT derivatives. Our results showed that the inhibition efficiencies of these derivatives improved with increases in concentration. The data also showed that PTD < PT < PTO in terms of the inhibiting efficiency. Theoretical calculations also revealed that PTO is expected to be the best inhibitor among the studied phthalazine derivatives.

  3. Characterization of a Laser Surface-Treated Martensitic Stainless Steel

    Directory of Open Access Journals (Sweden)

    S.R. Al-Sayed

    2017-05-01

    Full Text Available Laser surface treatment was carried out on AISI 416 machinable martensitic stainless steel containing 0.225 wt.% sulfur. Nd:YAG laser with a 2.2-KW continuous wave was used. The aim was to compare the physical and chemical properties achieved by this type of selective surface treatment with those achieved by the conventional treatment. Laser power of different values (700 and 1000 W with four corresponding different laser scanning speeds (0.5, 1, 2, and 3 m•min−1 was adopted to reach the optimum conditions for impact toughness, wear, and corrosion resistance for laser heat treated (LHT samples. The 0 °C impact energy of LHT samples indicated higher values compared to the conventionally heat treated (CHT samples. This was accompanied by the formation of a hard surface layer and a soft interior base metal. Microhardness was studied to determine the variation of hardness values with respect to the depth under the treated surface. The wear resistance at the surface was enhanced considerably. Microstructure examination was characterized using optical and scanning electron microscopes. The corrosion behavior of the LHT samples was also studied and its correlation with the microstructures was determined. The corrosion data was obtained in 3.5% NaCl solution at room temperature by means of a potentiodynamic polarization technique.

  4. Characterization of a Laser Surface-Treated Martensitic Stainless Steel.

    Science.gov (United States)

    Al-Sayed, S R; Hussein, A A; Nofal, A A; Hassab Elnaby, S I; Elgazzar, H

    2017-05-29

    Laser surface treatment was carried out on AISI 416 machinable martensitic stainless steel containing 0.225 wt.% sulfur. Nd:YAG laser with a 2.2-KW continuous wave was used. The aim was to compare the physical and chemical properties achieved by this type of selective surface treatment with those achieved by the conventional treatment. Laser power of different values (700 and 1000 W) with four corresponding different laser scanning speeds (0.5, 1, 2, and 3 m•min-1) was adopted to reach the optimum conditions for impact toughness, wear, and corrosion resistance for laser heat treated (LHT) samples. The 0 °C impact energy of LHT samples indicated higher values compared to the conventionally heat treated (CHT) samples. This was accompanied by the formation of a hard surface layer and a soft interior base metal. Microhardness was studied to determine the variation of hardness values with respect to the depth under the treated surface. The wear resistance at the surface was enhanced considerably. Microstructure examination was characterized using optical and scanning electron microscopes. The corrosion behavior of the LHT samples was also studied and its correlation with the microstructures was determined. The corrosion data was obtained in 3.5% NaCl solution at room temperature by means of a potentiodynamic polarization technique.

  5. Corrosion inhibition of mild steel in acidic media using newly synthesized heterocyclic organic molecules: Correlation between inhibition efficiency and chemical structure

    Energy Technology Data Exchange (ETDEWEB)

    Ouici, H. B., E-mail: ouici.houari@yahoo.fr; Guendouzi, A., E-mail: guendouzzi@yahoo.fr [Departement of Chimistry, Faculty of Sciences, University of Saïda (Algeria); Benali, O. [Department of Biology, Faculty of Science, University of Saida (Algeria)

    2015-03-30

    The corrosion inhibition of mild steel in 5% HCl solutions by some new synthesized organic compounds namely 3-(2-methoxyphenyl) 5-mercapto-1. 2. 4-triazole (2-MMT), 3-(3-methoxyphenyl) 5-mercapto-1. 2. 4-triazole (3-MMT) and 3-(2-hydroxyphenyl) 5-mercapto-1. 2. 4-triazole (2-HMT) was investigated using weight loss and potentiostatic polarization techniques. These measurements reveal that the inhibition efficiency obtained by these compounds increased by increasing their concentration. The inhibition efficiency follows the order 2-MMT >3-MMT >2-HMT. Polarization studies show that these compounds are of the mixed type but dominantly act as a cathodic inhibitors for mild steel in 5% HCl solutions. These inhibitors function through adsorption following Langmuir isotherm. Activation energy and Gibbs free energy for adsorption of inhibitors are calculated. Molecular modeling has been conducted to correlate the corrosion inhibition properties with the calculated quantum chemical parameters.

  6. Designing Pulse Laser Surface Modification of H13 Steel Using Response Surface Method

    Science.gov (United States)

    Aqida, S. N.; Brabazon, D.; Naher, S.

    2011-01-01

    This paper presents a design of experiment (DOE) for laser surface modification process of AISI H13 tool steel in achieving the maximum hardness and minimum surface roughness at a range of modified layer depth. A Rofin DC-015 diffusion-cooled CO2 slab laser was used to process AISI H13 tool steel samples. Samples of 10 mm diameter were sectioned to 100 mm length in order to process a predefined circumferential area. The parameters selected for examination were laser peak power, overlap percentage and pulse repetition frequency (PRF). The response surface method with Box-Behnken design approach in Design Expert 7 software was used to design the H13 laser surface modification process. Metallographic study and image analysis were done to measure the modified layer depth. The modified surface roughness was measured using two-dimensional surface profilometer. The correlation of the three laser processing parameters and the modified surface properties was specified by plotting three-dimensional graph. The hardness properties were tested at 981 mN force. From metallographic study, the laser modified surface depth was between 37 μm and 150 μm. The average surface roughness recorded from the 2D profilometry was at a minimum value of 1.8 μm. The maximum hardness achieved was between 728 and 905 HV0.1. These findings are significant to modern development of hard coatings for wear resistant applications.

  7. Corrosion Study of Mild Steel in Aqueous Sulfuric Acid Solution Using 4-Methyl-4H-1,2,4-Triazole-3-Thiol and 2-Mercaptonicotinic Acid—An Experimental and Theoretical Study

    Directory of Open Access Journals (Sweden)

    Valbonë V. Mehmeti

    2017-08-01

    Full Text Available The corrosion behavior of mild steel in 0.1 M aqueous sulfuric acid medium has been studied using weight loss, potentiodynamic polarization measurements, quantum chemical calculations, and molecular dynamic simulations in the presence and absence of 4-methyl-4H-1,2,4-triazole-3-thiol and 2-mercaptonicotinic acid. Potentiodynamic measurements indicate that these compounds mostly act as mixed inhibitors due to their adsorption on the mild steel surface. The goal of the study was to use theoretical calculations to better understand the inhibition. Monte Carlo simulation was used to calculate the adsorption behavior of the studied molecules onto Fe (1 1 1 and Fe2O3 (1 1 1 surface. The molecules were also studied with the density functional theory (DFT, using the B3LYP functional in order to determine the relationship between the molecular structure and the corrosion inhibition behavior. More accurate adsorption energies between the studied molecules and iron or iron oxide were calculated by using DFT with periodic boundary conditions. The calculated theoretical parameters gave important assistance into the understanding the corrosion inhibition mechanism expressed by the molecules and are in full agreement with the experimental results.

  8. Inhibiting mild steel corrosion from sulfate-reducing bacteria using antimicrobial-producing biofilms in Three-Mile-Island process water.

    Science.gov (United States)

    Zuo, R; Ornek, D; Syrett, B C; Green, R M; Hsu, C-H; Mansfeld, F B; Wood, T K

    2004-04-01

    Biofilms were used to produce gramicidin S (a cyclic decapeptide) to inhibit corrosion-causing, sulfate-reducing bacteria (SRB). In laboratory studies these biofilms protected mild steel 1010 continuously from corrosion in the aggressive, cooling service water of the AmerGen Three-Mile-Island (TMI) nuclear plant, which was augmented with reference SRB. The growth of both reference SRB (Gram-positive Desulfosporosinus orientis and Gram-negative Desulfovibrio vulgaris) was shown to be inhibited by supernatants of the gramicidin-S-producing bacteria as well as by purified gramicidin S. Electrochemical impedance spectroscopy and mass loss measurements showed that the protective biofilms decreased the corrosion rate of mild steel by 2- to 10-fold when challenged with the natural SRB of the TMI process water supplemented with D. orientis or D. vulgaris. The relative corrosion inhibition efficiency was 50-90% in continuous reactors, compared to a biofilm control which did not produce the antimicrobial gramicidin S. Scanning electron microscope and reactor images also revealed that SRB attack was thwarted by protective biofilms that secrete gramicidin S. A consortium of beneficial bacteria (GGPST consortium, producing gramicidin S and other antimicrobials) also protected the mild steel.

  9. Experimental and theoretical investigations on the inhibition of mild steel corrosion in the ground water medium using newly synthesised bipodal and tripodal imidazole derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Gopi, D., E-mail: dhanaraj_gopi@yahoo.com [Department of Chemistry, Periyar University, Salem 636 011, Tamilnadu (India); Centre for Nanoscience and Nanotechnology, Periyar University, Salem 636 011, Tamilnadu (India); Sherif, El-Sayed M. [Center of Excellence for Research in Engineering Materials (CEREM), Advanced Manufacturing Institute, King Saud University, P.O. Box 800, Al-Riyadh 11421 (Saudi Arabia); Electrochemistry and Corrosion Laboratory, Department of Physical Chemistry, National Research Centre (NRC), Dokki, 12622 Cairo (Egypt); Surendiran, M. [Department of Chemistry, Periyar University, Salem 636 011, Tamilnadu (India); Jothi, M.; Kumaradhas, P. [Department of Physics, Periyar University, Salem 636 011, Tamilnadu (India); Kavitha, L. [Department of Physics, School of Basic and Applied Sciences, Central University of Tamilnadu, Thiruvarur 610 101, Tamilnadu (India)

    2014-10-15

    Two new imidazole derivatives, namely 1,4-bis(N-imidazolylmethyl)-2-5-dimethoxybenzene (BIDM) and 1,3,5-tris(N-imidazolylmethyl)-2,4,6-trimethoxybenzene (TITM), were synthesised and their effects on the inhibition of mild steel corrosion in ground water medium are reported. The study was carried out using gravimetric and electrochemical techniques in order to determine the corrosion inhibition efficiencies of the bipodal and tripodal structured imidazoles. Further, the quantum chemical calculations using density functional theory (DFT) gave a profound insight into the inhibitory action mechanism of BIDM and TITM and their calculation parameters, such as E{sub HOMO}, E{sub LUMO} and ΔE were in good agreement with the results of the experimental studies. BIDM and TITM exhibited lowest corrosion current densities of circa 7.5 μA cm{sup −2} and 4.1 μAcm{sup −2} at the optimum concentrations of 0.67 and 0.49 mM, respectively. All measurements thus confirmed that both BIDM and TITM behaved as good inhibitors for mild steel corrosion in ground water medium. - Highlights: • Synthesis of new imidazole derivatives-BIDM(bipodal) and TITM(tripodal) inhibitors. • Gravimetric analysis to investigate mild steel corrosion inhibition in ground water. • Electrochemical characterizations to substantiate results of weight loss method. • Quantum studies to analyse the chemical behavior, structure and substituent effect.

  10. Experimental and theoretical investigations on the inhibition of mild steel corrosion in the ground water medium using newly synthesised bipodal and tripodal imidazole derivatives

    International Nuclear Information System (INIS)

    Gopi, D.; Sherif, El-Sayed M.; Surendiran, M.; Jothi, M.; Kumaradhas, P.; Kavitha, L.

    2014-01-01

    Two new imidazole derivatives, namely 1,4-bis(N-imidazolylmethyl)-2-5-dimethoxybenzene (BIDM) and 1,3,5-tris(N-imidazolylmethyl)-2,4,6-trimethoxybenzene (TITM), were synthesised and their effects on the inhibition of mild steel corrosion in ground water medium are reported. The study was carried out using gravimetric and electrochemical techniques in order to determine the corrosion inhibition efficiencies of the bipodal and tripodal structured imidazoles. Further, the quantum chemical calculations using density functional theory (DFT) gave a profound insight into the inhibitory action mechanism of BIDM and TITM and their calculation parameters, such as E HOMO , E LUMO and ΔE were in good agreement with the results of the experimental studies. BIDM and TITM exhibited lowest corrosion current densities of circa 7.5 μA cm −2 and 4.1 μAcm −2 at the optimum concentrations of 0.67 and 0.49 mM, respectively. All measurements thus confirmed that both BIDM and TITM behaved as good inhibitors for mild steel corrosion in ground water medium. - Highlights: • Synthesis of new imidazole derivatives-BIDM(bipodal) and TITM(tripodal) inhibitors. • Gravimetric analysis to investigate mild steel corrosion inhibition in ground water. • Electrochemical characterizations to substantiate results of weight loss method. • Quantum studies to analyse the chemical behavior, structure and substituent effect

  11. Biofilm formation by Listeria monocytogenes on stainless steel surface and biotransfer potential

    OpenAIRE

    Oliveira,Maíra Maciel Mattos de; Brugnera,Danilo Florisvaldo; Alves,Eduardo; Piccoli,Roberta Hilsdorf

    2010-01-01

    An experimental model was proposed to study biofilm formation by Listeria monocytogenes ATCC 19117 on AISI 304 (#4) stainless steel surface and biotransfer potential during this process. In this model, biofilm formation was conducted on the surface of stainless steel coupons, set on a stainless steel base with 4 divisions, each one supporting 21 coupons. Trypic Soy Broth was used as bacterial growth substrate, with incubation at 37 ?C and stirring of 50 rpm. The number of adhered cells was de...

  12. Laser surface modification of boronickelized medium carbon steel

    Science.gov (United States)

    Bartkowska, Aneta; Pertek, Aleksandra; Kulka, Michał; Klimek, Leszek

    2015-11-01

    A two-step process was applied to produce the multicomponent boride layers. Boronickelizing consisted of nickel plating and diffusion boriding. Two different methods of heat treatment of boronickelized C45 steel were used: a typical through-hardening, and a laser surface modification with remelting. Microstructure and some mechanical properties of these layers were examined. Microstructural characterization was studied using optical microscope, Scanning Electron Microscope, energy-dispersive X-ray microanalysis, Electron Back-Scatter Diffraction and X-ray diffraction. The laser modification improved wear resistance, cohesion as well as low-cycle fatigue of the boronickelized layer. Compressive stresses, occurring after laser remelting, could be the reason for the advantageous mechanical behavior of the layer.

  13. Special Advanced Studies for Pollution Prevention. Delivery Order 0017: Sol-Gel Surface Preparation for Carbon Steel and Stainless Steel Bonding

    National Research Council Canada - National Science Library

    Zheng, Haixing

    1997-01-01

    The objective of this program is to study the feasibility of using sol-gel active alumina coatings for the surface preparation of carbon steel and stainless steel for adhesive bonding, and to optimize...

  14. EIS and adjunct electrical modeling for material selection by evaluating two mild steels for use in super-alkaline mineral processing

    DEFF Research Database (Denmark)

    Bakhtiyari, Leila; Moghimi, Fereshteh; Mansouri, Seyed Soheil

    2012-01-01

    The production of metal concentrates during mineral processing of ferrous and non-ferrous metals involves a variety of highly corrosive chemicals which deteriorate common mild steel as the material of choice in the construction of such lines, through rapid propagation of localized pitting...... in susceptible parts, often in sensitive areas. This requires unscheduled maintenance and plant shut down. In order to test the corrosion resistance of different available materials as replacement materials, polarization and electrochemical impedance spectroscopy (EIS) tests were carried out. The EIS numerical...... software-enhanced polarization resistance, and reduced capacitance added to much diminished current densities, verified the acceptable performance of CK45 compared with high priced stainless steel substitutes with comparable operational life. Therefore, CK45 can be a suitable alternative in steel...

  15. Low temperature gaseous surface hardening of stainless steel

    DEFF Research Database (Denmark)

    Christiansen, Thomas; Somers, Marcel A. J.

    2010-01-01

    The present contribution gives an overview of some of the technological aspects of low temperature thermochemical treatment of stainless steel. Examples of low temperature gaseous nitriding, carburising and nitrocarburising of stainless steel are presented and discussed. In particular......, the morphology, microstructure and characteristics of so-called expanite “layers” on stainless steel are addressed....

  16. Multilayered Zn-Ni alloy coatings for better corrosion protection of mild steel

    Directory of Open Access Journals (Sweden)

    Sadananda Rashmi

    2017-06-01

    Full Text Available A simple aqueous electrolyte for the deposition of anti-corrosive Zn-Ni alloy coatings was optimized using conventional Hull cell method. The corrosion protection value of the electrodeposited coatings at a current density (c.d. range of 2.0–5.0 A dm−2 has been testified in 5 wt% NaCl solution, as representative corrosion medium. The electrochemical behavior of the coatings towards corrosion was related to its surface topography, elemental composition and phase structure using scanning electron microscopy (SEM, energy dispersive spectroscopy (EDS and X-ray diffraction (XRD analyses, respectively. Among the monolithic coatings developed at different c.d.’s, the coating obtained at 3.0 A dm−2 was found to be the best with least corrosion current (icorr value. Further, the corrosion protection efficacy of the monolayer coatings were improved to many folds through multilayer coating approach, by modulating the cyclic cathode current densities (CCCD’s. The composition modulated multilayer (CMM Zn-Ni alloy coating with 60 layers, developed from the combination of CCCD’s 3.0 and 5.0 A dm−2 was found to be the best with 3 fold enhancement in corrosion protection efficiency. The formation of multilayer coatings was confirmed using cross-sectional SEM, and the experimental results are discussed with tables and figures.

  17. Strategic surface topographies for enhanced lubrication in sheet forming of stainless steel

    DEFF Research Database (Denmark)

    Nilsson, Morten Sixten; Olsson, David Dam; Petrushina, Irina

    2010-01-01

    Strategic stainless steel surfaces have been developed for which the tribological properties are significantly improved for sheet-metal forming compared with the as-received surfaces. The improvements have been achieved by modification of the surface to promote Micro-Plasto Hydrodynamic Lubrication....... The technique, which has been developed, is based on an electrochemical treatment changing the topography of the stainless steel surface. Comparative testing of the new surface topographies in ironing and deep drawing of stainless steel sheet shows significant improvements and possibilities of replacing...

  18. Dual Electrolytic Plasma Processing for Steel Surface Cleaning and Passivation

    Science.gov (United States)

    Yang, L.; Zhang, P.; Shi, J.; Liang, J.; Tian, W. B.; Zhang, Y. M.; Sun, Z. M.

    2017-10-01

    To remove the rust on rebars and passivate the fresh surfaces, electrodes reversing electrolytic plasma processing (EPP) was proposed and conducted in a 10 wt.% Na2CO3 aqueous solution. The morphology and the composition of the surface were investigated by SEM and XPS. Experimental results show that the rust on the surface was removed effectively by cathode EPP, and a passive film containing Cr2O3 was achieved by the succeeding anode EPP treatment, by a simple operation of reversing the bias. The corrosion resistance was evaluated in a 3.5 wt.% NaCl aqueous solution using an electrochemical workstation. In comparison, the corrosion resistance was improved by the succeeding anode EPP treatment, which is evidenced by a positive shift of the open-circuit potential, an increase in the electrochemical impedance representing the inner layer by 76.8% and the decrease in the corrosion current density by 49.6%. This is an effective and environment-friendly technique to clean and passivate rebars and similar steel materials.

  19. Influence of surface roughness of stainless steel on microbial adhesion and corrosion resistance

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel; Bagge-Ravn, Dorthe; Kold, John

    2003-01-01

    Abstract The aim of this study was to evaluate if hygienic characteristics of stainless steel used in the food industry could be improved by smoothing surface roughness from an Ra of 0.9 to 0.01 ƒÝm. The adherence of Pseudomonas sp., Listeria monocytogenes and Candida lipolytica to stainless steel...... was not affected by surface roughness (Ra) ranging from grit 4000 polished stainless steel (Ra steel (Ra 0.9). Neither adhesion of Ps. aeruginosa nor its removal by an alkaline commercial cleaner in a flow system was affected by surface roughness. Pitting corrosion resistance...... was evaluated in a commercial disinfectant and in 1 M NaCl. Electropolished and grit 4000 polished steel proved more corrosion resistant as opposed to grit 80 and 120 polished surfaces. In conclusion, the surface finish did not influence bacterial attachment, colonisation, or removal, but is an important...

  20. Exposure to respirable dust and manganese and prevalence of airways symptoms, among Swedish mild steel welders in the manufacturing industry.

    Science.gov (United States)

    Hedmer, Maria; Karlsson, Jan-Eric; Andersson, Ulla; Jacobsson, Helene; Nielsen, Jörn; Tinnerberg, Håkan

    2014-08-01

    Welding fume consists of metal fumes, e.g., manganese (Mn) and gases, e.g., ozone. Particles in the respirable dust (RD) size range dominate. Exposure to welding fume could cause short- and long-term respiratory effects. The prevalence of work-related symptoms among mild steel welders was studied, and the occupational exposure to welding fumes was quantified by repeated measurements of RD, respirable Mn, and ozone. Also the variance components were studied. A questionnaire concerning airway symptoms and occupational history was answered by 79% of a cohort of 484 welders. A group of welders (N = 108) were selected and surveyed by personal exposure measurements of RD and ozone three times during 1 year. The welders had a high frequency of work-related symptoms, e.g., stuffy nose (33%), ocular symptoms (28%), and dry cough (24%). The geometric mean exposure to RD and respirable Mn was 1.3 mg/m(3) (min-max 0.1-38.3 mg/m(3)) and 0.08 mg/m(3) (min-max <0.01-2.13 mg/m(3)), respectively. More than 50% of the Mn concentrations exceeded the Swedish occupational exposure limit (OEL). Mainly, low concentrations of ozone were measured, but 2% of the samples exceeded the OEL. Of the total variance for RD, 30 and 33% can be attributed to within-worker variability and between-company variability, respectively. Welders had a high prevalence of work-related symptom from the airways and eyes. The welders' exposure to Mn was unacceptably high. To reduce the exposure further, control measures in the welding workshops are needed. Correct use of general mechanical ventilation and local exhaust ventilation can, for example, efficiently reduce the exposure.

  1. Nanostructure Formations and Improvement in Corrosion Resistance of Steels by Means of Pulsed Electron Beam Surface Treatment

    Directory of Open Access Journals (Sweden)

    K. M. Zhang

    2013-01-01

    Full Text Available The corrosion of steels has long been the topic for materials scientists. It is established that surface treatment is an efficient way to improve the corrosion resistance of steels without changing the bulk properties and with low costs. In the present paper, different kinds of surface treatment techniques for steels are briefly reviewed. In particular, the surface modification involving nanostructure formations of steels by using a low energy high pulsed electron beam (LEHCPEB treatment is lightened in the case of an AISI 316L stainless steel and D2 steel. The overall results demonstrate the high potential of the LEHCPEB technique for improving the corrosion performance of steels.

  2. Physical and chemical characterization of surfaces of nitrogen implanted steels

    International Nuclear Information System (INIS)

    Moncoffre, N.

    1986-01-01

    The studied steels are of industrial type (42CD4, 100C6, Z200C13). Very often, the low carbon steel XCO6 has been used as a reference material. The aim of the research is to understand and to explain the mechanisms of wear resistance to improvement. A good characterization of the implanted layer is thus necessary. It implies to establish the distribution profiles of the implanted ions to identify the chemical and structural state of the phases created during implantation as a function of various implantation parameters (dose, temperature). Temperature is the particularly parameter. Its influence is put in evidence both during implantation and during annealings under vacuum. Nitrogen distribution profiles are performed thanks to the non destructive 15 N(p,αγ) 12 C nuclear reaction. The chemical state of the Fe-N phases formed by implantation is determined using first Electron Conversion Moessbauer Spectroscopy and secondly, as a complement, using grazing angle X ray diffraction. The detected compounds are ε-nitrides, ε-carbonitrides, (N) - martensite and α-Fe 16 N 2 whose evolution is carefully followed versus temperature. The diffraction technique reveals a texture of the implanted layer. This preferentiel orientation is found to be temperature dependent but dose independent. The carbon presence at the surface is studied as a function of implantation conditions (vacuum, temperature, dose). Carbon profiling is obtained using α backscattering ( 12 C(α,α') reaction at 5,7 MeV). Thus is achieved a complete characterization of the implanted zone whose evolution as a function of implantation parameters (especially temperature) is correlated with tribological results [fr

  3. A Field Study on the Respiratory Deposition of the Nano-Sized Fraction of Mild and Stainless Steel Welding Fume Metals.

    Science.gov (United States)

    Cena, L G; Chisholm, W P; Keane, M J; Chen, B T

    2015-01-01

    A field study was conducted to estimate the amount of Cr, Mn, and Ni deposited in the respiratory system of 44 welders in two facilities. Each worker wore a nanoparticle respiratory deposition (NRD) sampler during gas metal arc welding (GMAW) of mild and stainless steel and flux-cored arc welding (FCAW) of mild steel. Several welders also wore side-by-side NRD samplers and closed-face filter cassettes for total particulate samples. The NRD sampler estimates the aerosol's nano-fraction deposited in the respiratory system. Mn concentrations for both welding processes ranged 2.8-199 μg/m3; Ni concentrations ranged 10-51 μg/m3; and Cr concentrations ranged 40-105 μg/m3. Cr(VI) concentrations ranged between 0.5-1.3 μg/m3. For the FCAW process the largest concentrations were reported for welders working in pairs. As a consequence this often resulted in workers being exposed to their own welding fumes and to those generated from the welding partner. Overall no correlation was found between air velocity and exposure (R2 = 0.002). The estimated percentage of the nano-fraction of Mn deposited in a mild-steel-welder's respiratory system ranged between 10 and 56%. For stainless steel welding, the NRD samplers collected 59% of the total Mn, 90% of the total Cr, and 64% of the total Ni. These results indicate that most of the Cr and more than half of the Ni and Mn in the fumes were in the fraction smaller than 300 nm.

  4. Study on micro fabricated stainless steel surface to anti-biofouling using electrochemical fabrication

    Science.gov (United States)

    Hwang, Byeong Jun; Lee, Sung Ho

    2017-12-01

    Biofilm formed on the surface of the object by the microorganism resulting in fouling organisms. This has led to many problems in daily life, medicine, health and industrial community. In this study, we tried to prevent biofilm formation on the stainless steel (SS304) sheet surface with micro fabricated structure. After then forming the microscale colloid patterns on the surface of stainless steel by using an electrochemical etching forming a pattern by using a FeCl3 etching was further increase the surface roughness. Culturing the Pseudomonas aeruginosa on the stainless steel fabricated with a micro structure on the surface was observed a relationship between the surface roughness and the biological fouling of the micro structure. As a result, the stainless steel surface with a micro structure was confirmed to be the biological fouling occurs less. We expect to be able to solve the problems caused by biological fouling in various fields such as medicine, engineering, using this research.

  5. Surface modification of austenitic stainless steel by titanium ion implantation

    International Nuclear Information System (INIS)

    Evans, P.J.; Hyvarinen, J.; Samandi, M.

    1995-01-01

    The wear properties of AISI 316 austenitic stainless steel implanted with Ti were investigated for ion doses in the range (2.3-5.4)x10 16 ionscm -2 and average ion energies of 60 and 90keV. The implanted layer was examined by Rutherford backscattering, from which the retained doses were determined, and glow discharge optical emission spectroscopy. Following implantation, the surface microhardness was observed to increase with the greatest change occurring at higher ion energy. Pin-on-disc wear tests and associated friction measurements were also performed under both dry and lubricated conditions using applied loads of 2N and 10N. In the absence of lubrication, breakthrough of the implanted layer occurred after a short sliding time; only for a dose of 5.1x10 16 ionscm -2 implanted at an average energy of 90keV was the onset of breakthrough appreciably delayed. In contrast, the results of tests with lubrication showed a more gradual variation, with the extent of wear decreasing with implant dose at both 2N and 10N loads. Finally, the influence of Ti implantation on possible wear mechanisms is discussed in the light of information provided by several surface characterization techniques. ((orig.))

  6. Plasma decontamination of uranium oxide from stainless steel surfaces

    International Nuclear Information System (INIS)

    Veilleux, J.M.; El-Genk, M.S.; Chamberlin, E.P.

    1997-01-01

    The U.S. Department of Energy (DOE) is expected to have 845000 m 3 of transuranic (TRU) waste by the year 2000 that has accumulated during the development and assembly of the nation's nuclear stockpile. The TRU disposal costs alone range up to $28000/m 3 , which could be reduced to $1800/m 3 or less by treating and converting the material to low-level waste. Plasma-based processes have been shown to remove plutonium and uranium surface contaminants from metallic components and could be used to treat TRU with significant cost avoidance, estimated at over $1.0 billion. Martz and Hess conducted the initial work of plutonium etching in low-power radio-frequency (rf) plasma with etch rates ranging from 0.007 to 0.025 kg/m 2 ·h. Veilleux et al. reported that plasma decontamination of uranium from the interior of aluminum objects results in etch rates an order of magnitude greater. The current work reports on removal rates of uranium from stainless steel surfaces and includes estimates of the etch rates and characteristic times for removal

  7. SURFACE ROUGHNESS AND CUTTING FORCES IN CRYOGENIC TURNING OF CARBON STEEL

    Directory of Open Access Journals (Sweden)

    T. C. YAP

    2015-07-01

    Full Text Available The effect of cryogenic liquid nitrogen on surface roughness, cutting forces, and friction coefficient of the machined surface when machining of carbon steel S45C in wet, dry and cryogenic condition was studied through experiments. The experimental results show that machining with liquid nitrogen increases the cutting forces, reduces the friction coefficient, and improves the chips produced. Beside this, conventional machining with cutting fluid is still the most suitable method to produce good surface in high speed machining of carbon steel S45C whereas dry machining produced best surface roughness in low speed machining. Cryogenic machining is not able to replace conventional cutting fluid in turning carbon steel.

  8. Mild and modular surface modification of cellulose via hetero Diels-Alder (HDA) cycloaddition.

    Science.gov (United States)

    Goldmann, Anja S; Tischer, Thomas; Barner, Leonie; Bruns, Michael; Barner-Kowollik, Christopher

    2011-04-11

    A combination of reversible addition-fragmentation chain transfer (RAFT) polymerization and hetero Diels-Alder (HDA) cycloaddition was used to effect, under mild (T ≈ 20 °C), fast, and modular conditions, the grafting of poly(isobornyl acrylate) (M(n) = 9800 g mol(-1), PDI = 1.19) onto a solid cellulose substrate. The active hydroxyl groups expressed on the cellulose fibers were converted to tosylate leaving groups, which were subsequently substituted by a highly reactive cyclopentadienyl functionality (Cp). By employing the reactive Cp-functionality as a diene, thiocarbonyl thio-capped poly(isobornyl acrylate) synthesized via RAFT polymerization (mediated by benzyl pyridine-2-yldithioformiate (BPDF)) was attached to the surface under ambient conditions by an HDA cycloaddition (reaction time: 15 h). The surface-modified cellulose samples were analyzed in-depth by X-ray photoelectron spectroscopy, scanning electron microscopy, elemental analysis, Fourier transform infrared (FT-IR) spectroscopy as well as Fourier transform infrared microscopy employing a focal plane array detector for imaging purposes. The analytical results provide strong evidence that the reaction of suitable dienophiles with Cp-functional cellulose proceeds under mild reaction conditions (T ≈ 20 °C) in an efficient fashion. In particular, the visualization of individual modified cellulose fibers via high-resolution FT-IR microscopy corroborates the homogeneous distribution of the polymer film on the cellulose fibers.

  9. Investigation of using steel slag in hot mix asphalt for the surface course of flexible pavements

    Science.gov (United States)

    Nguyen, Hien Q.; Lu, Dai X.; Le, Son D.

    2018-04-01

    The rapid development of heavy industry in Vietnam leads to the establishments of steel industry. Steel slag, a by-product of steelwork industry, under Vietnamese’s law, was considered as a deleterious solid waste which needed to be processed and landfilled. However, this has changed recently, and steel slag is now seen as a normal or non-deleterious solid waste, and has been studied for reuse in the construction industry. In this study, steel slag was used, as a replacement for mineral aggregate, in hot mix asphalt. Two hot mix asphalt mixtures with an equivalent nominal aggregate size of 12.5 (C12.5) and 19 mm (C19) were produced using steel slag. In addition, one conventional hot mix asphalt mixture of C19 was produced using mineral aggregate for comparison purpose. Investigation in laboratory condition and trial sections was carried out on Marshall tests, surface roughness, skid resistance, and modulus of the pavement before and after applying a new surface course of hot mix asphalt. The study showed that all steel slag asphalt mixtures passed the Marshall stability and flow test requirements. The skid resistance of steel slag hot mix asphalt mixtures for the surface course satisfied the Vietnamese specification for asphalt. Moreover, the pavement sections with the surface course of steel slag hot mix asphalt showed a considerable higher modulus than that of the conventional one. Only the roughness of the surface course paved with C19 did not pass the requirement of the specification.

  10. Non toxic biodegradable cationic gemini surfactants as novel corrosion inhibitor for mild steel in hydrochloric acid medium and synergistic effect of sodium salicylate: Experimental and theoretical approach

    Energy Technology Data Exchange (ETDEWEB)

    Mobin, Mohammad, E-mail: drmmobin@hotmail.com; Aslam, Ruby; Aslam, Jeenat

    2017-04-15

    Two biodegradable, non toxic cationic gemini surfactants having ester linkage in the spacer namely, C{sub m}H{sub 2m+1}(CH{sub 3}){sub 2}N{sup +}(CH{sub 2}COOCH{sub 2}){sub 2}N{sup +}(CH{sub 3}){sub 2}C{sub m}H{sub 2m+1}.2Cl{sup -} (m-E2-m, m = 12, 14), were synthesized and characterized using elemental analysis, FT-IR and {sup 1}H-NMR. The corrosion inhibition performance of synthesized compounds separately and in combination with sodium salicylate (SS), along with the nature and stability of inhibitive film, for mild steel (MS) in 1 M HCl solution at 30–60 °C was evaluated using weight loss, potentiodynamic polarization, EIS, UV–visible spectroscopy, FTIR, SEM/EDAX, TGA and quantum chemical calculations. Results of the studies confirm m-E2-m as effective corrosion inhibitor for MS in HCl; the inhibition effect being synergistically strengthened in presence of SS. The synthesized compounds act as mixed type inhibitor and adsorb on MS surface in accordance with Langmuir adsorption isotherm. Experimentally measured inhibition efficiencies are correlated with the molecular parameters obtained using PM6 semi-empirical method. Empirical results are in good agreement with the theoretical predictions. - Graphical abstract: (a) Optimized geometry of studied inhibitors by PM6 method with (b) HOMO and (c) LUMO orbital occupation. - Highlights: • Environment friendly gemini surfactants were studied as corrosion inhibitor for MS. • Studied compounds act as good inhibitor for MS corrosion in 1 M HCl at 30–60 °C. • η of inhibitors is synergistically increased in presence of sodium salicylate. • The synthesized cationic gemini surfactants act as mixed-type inhibitor. • Experimentally obtained results are in good agreement with theoretical results.

  11. Effect of operational conditions of electroerosion machining on the surface microgeometry parameters of steels and alloys

    International Nuclear Information System (INIS)

    Foteev, N.K.

    1976-01-01

    Studies the influence of pulse duration and a series of operating conditions of a ShGI-40-440 spark-machining generator on changes in the basic surface microgeometry characteristics of components of stainless steel 1Kh18N10T, steel St 45 and hard alloy T14K8. The microgeometry characteristics of spark-machined surfaces differ significantly from the corresponding characteristics of surfaces machined by cutting and vibro-rolling

  12. X-ray spectrum microanalysis of copper and stainless steel surface layer after electroerosion machining

    International Nuclear Information System (INIS)

    Abdukarimov, Eh.T.; Saidinov, S.Ya.

    1989-01-01

    The results of experimental investigations of the surface layer of copper and steel 12Kh18N10T after electroerrosion treatment by a rotating tungsten electrode in natural and distilled water are presented. It is established that the quantity of electrode material transferred to the surface of the steel treated grows with the spark discharge energy increase. Tungsten concentration in the surface layer reaches 5-10% with the average depth of penetration 40-50 μm

  13. A Steel Ball Surface Quality Inspection Method Based on a Circumferential Eddy Current Array Sensor.

    Science.gov (United States)

    Zhang, Huayu; Xie, Fengqin; Cao, Maoyong; Zhong, Mingming

    2017-07-01

    To efficiently inspect surface defects on steel ball bearings, a new method based on a circumferential eddy current array (CECA) sensor was proposed here. The best probe configuration, in terms of the coil quality factor (Q-factor), magnetic field intensity, and induced eddy current density on the surface of a sample steel ball, was determined using 3-, 4-, 5-, and 6-coil probes, for analysis and comparison. The optimal lift-off from the measured steel ball, the number of probe coils, and the frequency of excitation current suitable for steel ball inspection were obtained. Using the resulting CECA sensor to inspect 46,126 steel balls showed a miss rate of ~0.02%. The sensor was inspected for surface defects as small as 0.05 mm in width and 0.1 mm in depth.

  14. A Steel Ball Surface Quality Inspection Method Based on a Circumferential Eddy Current Array Sensor

    Directory of Open Access Journals (Sweden)

    Huayu Zhang

    2017-07-01

    Full Text Available To efficiently inspect surface defects on steel ball bearings, a new method based on a circumferential eddy current array (CECA sensor was proposed here. The best probe configuration, in terms of the coil quality factor (Q-factor, magnetic field intensity, and induced eddy current density on the surface of a sample steel ball, was determined using 3-, 4-, 5-, and 6-coil probes, for analysis and comparison. The optimal lift-off from the measured steel ball, the number of probe coils, and the frequency of excitation current suitable for steel ball inspection were obtained. Using the resulting CECA sensor to inspect 46,126 steel balls showed a miss rate of ~0.02%. The sensor was inspected for surface defects as small as 0.05 mm in width and 0.1 mm in depth.

  15. Effect of laser cutting parameters on surface roughness of stainless steel 307

    Directory of Open Access Journals (Sweden)

    Amal NASSAR

    2016-12-01

    Full Text Available Optimal parameters of laser cutting are an important step to improve surface quality of cutting edge in the laser cutting of stainless steel 307. This paper presents a new approach for optimizing the cutting parameters on stainless steel. Based on 33 full factorial experimental design, cutting experiments were conducted for stainless steel 307 plates using a laser machine (AMADA FONT 3015. The cutting parameters such as, cutting speed, cutting power and gas pressure are optimized for maximizing surface quality. The results indicated that cutting power and cutting speed play an important role in surface quality.

  16. Fatigue Life Estimation of Medium-Carbon Steel with Different Surface Roughness

    Directory of Open Access Journals (Sweden)

    Changyou Li

    2017-03-01

    Full Text Available Medium-carbon steel is commonly used for the rail, wire ropes, tire cord, cold heading, forging steels, cold finished steel bars, machinable steel and so on. Its fatigue behavior analysis and fatigue life estimation play an important role in the machinery industry. In this paper, the estimation of fatigue life of medium-carbon steel with different surface roughness using established S-N and P-S-N curves is presented. To estimate the fatigue life, the effect of the average surface roughness on the fatigue life of medium-carbon steel has been investigated using 75 fatigue tests in three groups with average surface roughness (Ra: 0.4 μm, 0.8 μm, and 1.6 μm, respectively. S-N curves and P-S-N curves have been established based on the fatigue tests. The fatigue life of medium-carbon steel is then estimated based on Tanaka-Mura crack initiation life model, the crack propagation life model using Paris law, and material constants of the S-N curves. Six more fatigue tests have been conducted to validate the presented fatigue life estimation formulation. The experimental results have shown that the presented model could estimate well the mean fatigue life of medium-carbon steel with different surface roughness.

  17. MILD CHOLESTEROL DEPLETION REDUCES AMYLOID-β PRODUCTION BY IMPAIRING APP TRAFFICKING TO THE CELL SURFACE

    Science.gov (United States)

    Guardia-Laguarta, Cristina; Coma, Mireia; Pera, Marta; Clarimón, Jordi; Sereno, Lidia; Agulló, José M.; Molina-Porcel, Laura; Gallardo, Eduard; Deng, Amy; Berezovska, Oksana; Hyman, Bradley T.; Blesa, Rafael; Gómez-Isla, Teresa; Lleó, Alberto

    2009-01-01

    It has been suggested that cellular cholesterol levels can modulate the metabolism of the amyloid precursor protein (APP) but the underlying mechanism remains controversial. In the current study, we investigate in detail the relationship between cholesterol reduction, APP processing and γ-secretase function in cell culture studies. We found that mild membrane cholesterol reduction led to a decrease in Aβ40 and Aβ42 in different cell types. We did not detect changes in APP intracellular domain or Notch intracellular domain generation. Western blot analyses showed a cholesterol-dependent decrease in the APP C-terminal fragments and cell surface APP. Finally, we applied a fluorescence resonance energy transfer (FRET)-based technique to study APP-Presenilin 1 (PS1) interactions and lipid rafts in intact cells. Our data indicate that cholesterol depletion reduces association of APP into lipid rafts and disrupts APP-PS1 interaction. Taken together, our results suggest that mild membrane cholesterol reduction impacts the cleavage of APP upstream of γ-secretase and appears to be mediated by changes in APP trafficking and partitioning into lipid rafts. PMID:19457132

  18. Comparison of adhesion of the food spoilage bacterium Shewanella putrefaciens to stainless steel and silver surfaces

    DEFF Research Database (Denmark)

    Hjelm, Mette; Hilbert, Lisbeth Rischel; Møller, Per

    2002-01-01

    The aim of this study is to compare the number of attached bacteria, Shewanella putrefaciens, on stainless steel with different silver surfaces. Thus evaluating if silver surfaces could contribute to a higher hygienic status in the food industry. Bacterial adhesion to three types of silver surfaces...... (new silver, tarnished silver and sulphide treated silver) was compared to adhesion to stainless steel (AISI 316). Numbers of attached bacteria (cfu cm-2) were estimated using the Malthus indirect conductance method. A lower number of attached bacteria were measured on new silver surfaces compared...... to stainless steel for samples taken after 24 hours. However this was not significant (P > 0.05). The numbers of attached bacteria were consistently lower when tarnished silver surfaces were compared to stainless steel and some, but not all, experiments showed statistically significant. A difference of more...

  19. Nano structure Formations and Improvement in Corrosion Resistance of Steels by Means of Pulsed Electron Beam Surface Treatment

    International Nuclear Information System (INIS)

    Zhang, K.M.; Zou, J.X.; Zou, J.X.; Grosdidier, T.; Zou, J.X.; Grosdidier, T.; Grosdidier, T.

    2013-01-01

    The corrosion of steels has long been the topic for materials scientists. It is established that surface treatment is an efficient way to improve the corrosion resistance of steels without changing the bulk properties and with low costs. In the present paper, different kinds of surface treatment techniques for steels are briefly reviewed. In particular, the surface modification involving nano structure formations of steels by using a low energy high pulsed electron beam (LEHCPEB) treatment is lightened in the case of an AISI 316L stainless steel and D2 steel. The overall results demonstrate the high potential of the LEHCPEB technique for improving the corrosion performance of steels The corrosion of steels has long been the topic for materials scientists. It is established that surface treatment is an efficient way to improve the corrosion resistance of steels without changing the bulk properties and with low costs. In the present paper, different kinds of surface treatment techniques for steels are briefly reviewed. In particular, the surface modification involving nano structure formations of steels by using a low energy high pulsed electron beam (LEHCPEB) treatment is lightened in the case of an AISI 316L stainless steel and D2 steel. The overall results demonstrate the high potential of the LEHCPEB technique for improving the corrosion performance of steels

  20. Inhibition of mild steel corrosion by 1,4,6-trimethyl-2-oxo-1,2-dihydropyridine-3-carbonitrile and synergistic effect of halide ion in 0.5 M H{sub 2}SO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Mourya, Punita, E-mail: mouryapunita025@gmail.com [Department of Chemistry, Indian Institute of Technology (Banaras Hindu University), Varanasi 221005 (India); Singh, Praveen [Department of Chemistry, Banaras Hindu University, Varanasi 221005 (India); Rastogi, R.B.; Singh, M.M. [Department of Chemistry, Indian Institute of Technology (Banaras Hindu University), Varanasi 221005 (India)

    2016-09-01

    Highlights: • TODPCN is a good corrosion inhibitor for mild steel in 0.5 M H{sub 2}SO{sub 4} solution. • Addition of iodide ion increases the inhibition efficiency of the studied nitrile derivative. • Inhibition efficiency successively increases with concentration. • XPS study has revealed the chemical composition of the protective film. - Abstract: The effect of iodide ions on inhibitive performance of 1,4,6-trimethyl-2-oxo-1,2-dihydropyridine-3-carbonitrile (TODPCN) on mild steel (MS) corrosion in 0.5 M H{sub 2}SO{sub 4} was studied using gravimetric and electrochemical measurements. TODPCN inhibits the corrosion of MS to the extent of 62.3% at its lowest concentration (0.5 mM) and its inhibition efficiency (η) further increases on increasing concentration at 298 K. The adsorption of TODPCN on MS was found to follow the Langmuir adsorption isotherm. The value of η increased on the addition of 2.0 mM KI. The value of synergism parameter being more than unity indicates that the enhanced η value in the presence of iodide ions is only due to synergism. Thus, a cooperative mechanism of inhibition exists between the iodide anion and TODPCN cations. The increase in surface coverage in the presence of KI indicates that iodide ions enhance the adsorption of TODPCN. The surface morphology of corroded/inhibited MS was studied by atomic force microscopy. X-ray photoelectron spectroscopy of inhibited MS surface was carried out to determine the composition of the adsorbed film. Some quantum chemical parameters and the Mulliken charge densities for TODPCN calculated by density functional theory provided further insight into the mechanism of inhibition.

  1. Studies on the effects of sulphate-reducing bacteria on mild carbon-steel relevant to radioactive waste disposal in the UK

    International Nuclear Information System (INIS)

    Philp, J.C.; Christofi, N.; Taylor, K.J.; West, J.M.

    1987-01-01

    Sulphate-reducing bacteria (SRB) have been used to determine their maximum effect on mild carbon-steel (BS4360 grade 43A) of relevance to waste disposal. Batch (static) and continuous culture studies were carried out and corrosion effects monitored by measuring weight loss and pitting. Results show that corrosion increases linearly with increased ferrous iron concentrations. Maximum corrosion was obtained in continuous culture where the organisms were maintained in the exponential phase of growth. Corrosion by SRB has been monitored in model systems mimicking low groundwater flow, deep rock formations in which steel coupons were subjected to a synthetic granitic water/bentonite environment with or without microorganisms. At termination of the experiment corrosion in the presence of SRB was almost three times higher than in their absence. (author)

  2. Surface modification of hydroturbine steel using friction stir processing

    Science.gov (United States)

    Grewal, H. S.; Arora, H. S.; Singh, H.; Agrawal, A.

    2013-03-01

    Friction stir processing (FSP) has proved to be a viable tool for enhancing the mechanical properties of materials, however, the major focus has been upon improving the bulk properties of light metals and their alloys. Hydroturbines are susceptible to damage owing to slurry and cavitation erosion. In this study, FSP of a commonly employed hydroturbine steel, 13Cr4Ni was undertaken. Microstructural characterization of the processed steel was conducted using optical microscopy (OM), scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and electron back scatter diffraction (EBSD) techniques. Mechanical characterization of the steel was undertaken in terms of microhardness and resistance to cavitation erosion (CE). FSP resulted in the refinement of the microstructure with reduction in grain size by a factor of 10. EBSD results confirmed the existence of submicron and ultrafine grained microstructure. The microhardness of the steel was found to enhance by 2.6 times after processing. The processed steel also showed 2.4 times higher resistance against cavitation erosion in comparison to unprocessed steel. The primary erosion mechanism for both the steels was identical in nature, with plastic deformation responsible for the loss of material.

  3. Isomers of Poly Aminophenol: Chemical Synthesis, Characterization, and Its Corrosion Protection Aspect on Mild Steel in 1 M HCl

    OpenAIRE

    Thenmozhi, G.; Arockiasamy, P.; Santhi, R. Jaya

    2014-01-01

    The oxidative chemical polymerizations of three isomers of aminophenol, ortho, meta, and para (PoAP, PmAP, and PpAP), were performed in aqueous HCl using ammonium persulfate as an oxidant at 0–3°C. The synthesized polymers were characterized by employing elemental analysis, GPC, UV-VIS-NIR, FT-IR, XRD, and TGA. The corrosion inhibition effect of these three polymers on mild steel in 1 M HCl solution was studied by using electrochemical techniques such as potentiodynamic polarization and elect...

  4. Corrosion resistance of hsla steel after various surface treatments in chloride environment

    Czech Academy of Sciences Publication Activity Database

    Borko, K.; Pastorek, F.; Fintová, Stanislava; Hadzima, B.

    2016-01-01

    Roč. 18, č. 4 (2016), s. 99-102 ISSN 1335-4205 Institutional support: RVO:68081723 Keywords : Corrosion properties * Iron phosphating * S355J steel Subject RIV: JK - Corrosion ; Surface Treatment of Materials

  5. Emerging surface characterization techniques for carbon steel corrosion: a critical brief review

    OpenAIRE

    Dwivedi, D.; Lepkova, K.; Becker, T.

    2017-01-01

    Carbon steel is a preferred construction material in many industrial and domestic applications, including oil and gas pipelines, where corrosion mitigation using film-forming corrosion inhibitor formulations is a widely accepted method. This review identifies surface analytical techniques that are considered suitable for analysis of thin films at metallic substrates, but are yet to be applied to analysis of carbon steel surfaces in corrosive media or treated with corrosion inhibitors. The rev...

  6. Detection and classification of orange peel on polished steel surfaces by interferometric microscopy

    International Nuclear Information System (INIS)

    2T Research GmbH, Viktor Kaplan Strasse 2, Wiener Neustadt 2700 (Austria))" data-affiliation=" (AC2T Research GmbH, Viktor Kaplan Strasse 2, Wiener Neustadt 2700 (Austria))" >Miranda-Medina, M L; 2T Research GmbH, Viktor Kaplan Strasse 2, Wiener Neustadt 2700 (Austria))" data-affiliation=" (AC2T Research GmbH, Viktor Kaplan Strasse 2, Wiener Neustadt 2700 (Austria))" >Somkuti, P; 2T Research GmbH, Viktor Kaplan Strasse 2, Wiener Neustadt 2700 (Austria))" data-affiliation=" (AC2T Research GmbH, Viktor Kaplan Strasse 2, Wiener Neustadt 2700 (Austria))" >Steiger, B

    2013-01-01

    In this work, we provide a general description of the so-called orange peel defect produced on polished steel surfaces. By characterizing a prototype set of samples with various degrees orange peel, we attempt to create a simple model that allows the classification of additional samples through the study of surface parameters. On those surfaces, the orange peel structure has roughness amplitudes in the nanometer range. Detecting surface features on that range requires the implementation of a high-precision technique, such as phase shifting interferometry (PSI). Therefore, we can contribute to the improvement of the manufacturing of polished steel surfaces as well as to the quality control by using optical techniques.

  7. Study of Surface Wear and Damage Induced by Dry Sliding of Tempered AISI 4140 Steel against Hardened AISI 1055 Steel

    Directory of Open Access Journals (Sweden)

    A. Elhadi

    2016-12-01

    Full Text Available In industry, the sliding mechanical systems are subject to friction and wear phenomena. These phenomena can be the origin of a reduction of the efficiency of the mechanical system even to be responsible for its incapacity. Generally, the materials of the parts which are moving relative (tribological couple of these systems are low alloy steels and carbon steels, thanks to their good mechanical and tribological properties. The present work aimed to study, the surface wear and damage induced by dry sliding of hard carbon steel AISI 1055 (disc against tempered low alloy steel AISI 4140 (pin with different hardness and applied loads was investigated. The results revealed that the interaction between the applied load and pin hardness result in complex thermo-mechanical behaviour of the worn surfaces. When a lower hardness pin is used, the main wear mechanisms observed on the discs were abrasion, adhesion, and oxidation. When a higher hardness pin is used, the wear of the discs is governed by delamination, oxidation, and plastic deformation. In particular, third-body wear occurs at high applied load resulting in higher wear rate of high hardness pins compared to low hardness pins.

  8. On the surface topography of ultrashort laser pulse treated steel surfaces

    International Nuclear Information System (INIS)

    Vincenc Obona, J.; Ocelík, V.; Skolski, J.Z.P.; Mitko, V.S.; Römer, G.R.B.E.; Huis in’t Veld, A.J.; De Hosson, J.Th.M.

    2011-01-01

    This paper concentrates on observations of the surface topography by scanning electron microscopy (SEM) on alloyed and stainless steels samples treated by ultrashort laser pulses with duration of 210 fs and 6.7 ps. Globular-like and jet-like objects were found depending on the various levels of the fluence applied. It is shown that these features appear due to solid-liquid and liquid-gas transitions within surface layer irradiated by intense laser light. The observations are confronted to the theory of short-pulsed laser light-matter interactions, including interference, excitation of electrons, electron-phonon coupling as well as subsequent ablation. It is shown that the orientation of small ripples does not always depend on the direction of the polarization of laser light.

  9. Some loop experiments in the NRX reactor to study the corrosion of mild steel by flowing water at 90oF

    International Nuclear Information System (INIS)

    Allison, G.M.

    1956-11-01

    This work was undertaken to find the water conditions necessary for minimum corrosion in the mild steel thermal shield recirculating systems in NRX and NRU. This report contains the chemical and corrosion results obtained by operating three mild steel loops in which water at 85-95 o F was recirculated through test sections located in J-rod positions in the NRX reactor. Lowest corrosion rates were found when the water was maintained at pH 10.5 with or without oxygen being present. In both cases the corrosion was general in nature and no pitting occurred. At pH 7 with oxygen present in the water severe pitting took place and the corrosion rate was several times higher than similar conditions without oxygen in the water. Under oxygen-free conditions the corrosion product was Fe 3 O 4 . At pH 7 and with 3-5 ppm of O 2 in the water the corrosion product was a mixture of Fe 3 O 4 and γ-Fe 2 O 3 . At high pH with oxygen present Fe 3 O 4 predominated with some traces of Fe 2 O 3 . The systems tested may he listed in order of increasing corrosiveness: High pH with or without O 2 in the water 2 present and continual purification 2 present and no purification or pH control 2 present. (author)

  10. Investigation of Mild Steel Thin-Wall Tubes in Unfilled and Foam-Filled Triangle, Square, and Hexagonal Cross Sections Under Compression Load

    Science.gov (United States)

    Rajak, Dipen Kumar; Kumaraswamidhas, L. A.; Das, S.

    2018-02-01

    This study has examined proposed structures with mild steel-reinforced LM30 aluminum (Al) alloy having diversely unfilled and 10 wt.% SiCp composite foam-filled tubes for improving axial compression performance. This class of material has novel physical, mechanical, and electrical properties along with low density. In the present experiment, Al alloy foams were prepared by the melt route technique using metal hydride powder as a foaming agent. Crash energy phenomena for diverse unfilled and foam-filled in mild steel thin-wall tubes (triangular, square and hexagonal) were studied as well. Compression deformation investigation was conducted at strain rates of 0.001-0.1/s for evaluating specific energy absorption (SEA) under axial loading conditions. The results were examined to measure plateau stress, maximum densification strain, and deformation mechanism of the materials. Specific energy absorption and total energy absorption capacities of the unfilled and filled sections were determined from the compressive stress-strain curves, which were then compared with each other.

  11. Influence of tannin content in Terminalia catappa leaves extracts resulted from maceration extraction on decreasing corrosion rate for mild steel in 1M H2SO4

    Science.gov (United States)

    Pramudita, M.; Sukirno; Nasikin, M.

    2018-04-01

    The ability of natural compounds as corrosion inhibitors is necessary to obtain safe corrosion inhibitors for the environment. The tannin compounds derived from plant extract has the ability to decrease the corrosion rate. The purpose of this research is to find the ability of tannin compounds in Terminalia catappa leaves extracts to decrease corrosion rate on mild steel. Terminalia catappa leaves that have been mashed in ethanol solvent extraction using maceration with the variable time 2.4 and 6 days. Mild steel that has been on the sandpaper and cleaned then soak into the 1 M H2SO4. Terminalia catappa leaves extract concentration used is 0, 250, 500, 500, 750, 1000 ppm, the immersion time is 3.6 and 9 hours. Calculating of corrosion rate is used the weight loss method, the analysis of the tannin concentration using GC-MS. The results indicate that highest tannin content equal to 7.23% in 6 days maceration time. The result showed that the corrosion rate was reduced in the presence of tannin content in Terminalia catappa leaves extract.

  12. Surface enhancement of cold work tool steels by friction stir processing with a pinless tool

    Science.gov (United States)

    Costa, M. I.; Verdera, D.; Vieira, M. T.; Rodrigues, D. M.

    2014-03-01

    The microstructure and mechanical properties of enhanced tool steel (AISI D2) surfaces produced using a friction stir welding (FSW) related procedure, called friction stir processing (FSP), are analysed in this work. The surface of the tool steel samples was processed using a WC-Co pinless tool and varying processing conditions. Microstructural analysis revealed that meanwhile the original substrate structure consisted of a heterogeneous distribution of coarse carbides in a ferritic matrix, the transformed surfaces consisted of very small carbides, homogenously distributed in a ferrite- bainite- martensite matrix. The morphology of the surfaces, as well as its mechanical properties, evaluated by hardness and tensile testing, were found to vary with increasing tool rotation speed. Surface hardness was drastically increased, relative to the initial hardness of bulk steel. This was attributed to ferrite and carbide refinement, as well as to martensite formation during solid state processing. At the highest rotation rates, tool sliding during processing deeply compromised the characteristics of the processed surfaces.

  13. Microstructure and properties of high chrome steel roller after laser surface melting

    Energy Technology Data Exchange (ETDEWEB)

    Li Meiyan, E-mail: lmy_102411@163.com [College of Electromechanical Engineering, China University of Petroleum, 271 Bei' er Road, Dongying 257061 (China); Wang Yong; Han Bin; Zhao Weimin; Han Tao [College of Electromechanical Engineering, China University of Petroleum, 271 Bei' er Road, Dongying 257061 (China)

    2009-06-15

    Laser surface melting of high chrome steels was achieved by a 5 kW continuous wave CO{sub 2} laser. The microstructure of the laser surface-melted steels was investigated by scanning electron microscopy, transmission electron microscopy and X-ray diffractometry, and the hardness profiles were determined by a Vickers hardness tester. The corrosion behavior in 3.5% NaCl solution was studied by electrochemical corrosion equipment. The large carbides of high chrome steels are completely dissolved and ultrafine dendrites of austenite with submicroscopic M{sub 23}C{sub 6} carbides precipitation are formed in the melted zone. The austenite in the melted zone has a high tempering stability. The corrosion resistance of the laser surface-melted steels is significantly improved due to the dissolution of carbides and the increase of the alloying elements in the solid solution as well as the large amount of austenite.

  14. Microstructure and properties of high chrome steel roller after laser surface melting

    International Nuclear Information System (INIS)

    Li Meiyan; Wang Yong; Han Bin; Zhao Weimin; Han Tao

    2009-01-01

    Laser surface melting of high chrome steels was achieved by a 5 kW continuous wave CO 2 laser. The microstructure of the laser surface-melted steels was investigated by scanning electron microscopy, transmission electron microscopy and X-ray diffractometry, and the hardness profiles were determined by a Vickers hardness tester. The corrosion behavior in 3.5% NaCl solution was studied by electrochemical corrosion equipment. The large carbides of high chrome steels are completely dissolved and ultrafine dendrites of austenite with submicroscopic M 23 C 6 carbides precipitation are formed in the melted zone. The austenite in the melted zone has a high tempering stability. The corrosion resistance of the laser surface-melted steels is significantly improved due to the dissolution of carbides and the increase of the alloying elements in the solid solution as well as the large amount of austenite.

  15. Steel

    International Nuclear Information System (INIS)

    Zorev, N.N.; Astafiev, A.A.; Loboda, A.S.; Savukov, V.P.; Runov, A.E.; Belov, V.A.; Sobolev, J.V.; Sobolev, V.V.; Pavlov, N.M.; Paton, B.E.

    1977-01-01

    Steels also containing Al, N and arsenic, are suitable for the construction of large components for high-power nuclear reactors due to their good mechanical properties such as good through-hardening, sufficiently low brittleness conversion temperature and slight displacement of the latter with neutron irradiation. Defined steels and their properties are described. (IHOE) [de

  16. Biofilm formation by Listeria monocytogenes on stainless steel surface and biotransfer potential

    Directory of Open Access Journals (Sweden)

    Maíra Maciel Mattos de Oliveira

    2010-03-01

    Full Text Available An experimental model was proposed to study biofilm formation by Listeria monocytogenes ATCC 19117 on AISI 304 (#4 stainless steel surface and biotransfer potential during this process. In this model, biofilm formation was conducted on the surface of stainless steel coupons, set on a stainless steel base with 4 divisions, each one supporting 21 coupons. Trypic Soy Broth was used as bacterial growth substrate, with incubation at 37 ºC and stirring of 50 rpm. The number of adhered cells was determined after 3, 48, 96, 144, 192 and 240 hours of biofilm formation and biotransfer potential from 96 hours. Stainless steel coupons were submitted to Scanning Electron Microscopy (SEM after 3, 144 and 240 hours. Based on the number of adhered cells and SEM, it was observed that L. monocytogenes adhered rapidly to the stainless steel surface, with mature biofilm being formed after 240 hours. The biotransfer potential of bacterium to substrate occurred at all the stages analyzed. The rapid capacity of adhesion to surface, combined with biotransfer potential throughout the biofilm formation stages, make L. monocytogenes a potential risk to the food industry. Both the experimental model developed and the methodology used were efficient in the study of biofilm formation by L. monocytogenes on stainless steel surface and biotransfer potential.

  17. Biofilm formation by Listeria monocytogenes on stainless steel surface and biotransfer potential.

    Science.gov (United States)

    de Oliveira, Maíra Maciel Mattos; Brugnera, Danilo Florisvaldo; Alves, Eduardo; Piccoli, Roberta Hilsdorf

    2010-01-01

    An experimental model was proposed to study biofilm formation by Listeria monocytogenes ATCC 19117 on AISI 304 (#4) stainless steel surface and biotransfer potential during this process. In this model, biofilm formation was conducted on the surface of stainless steel coupons, set on a stainless steel base with 4 divisions, each one supporting 21 coupons. Trypic Soy Broth was used as bacterial growth substrate, with incubation at 37 °C and stirring of 50 rpm. The number of adhered cells was determined after 3, 48, 96, 144, 192 and 240 hours of biofilm formation and biotransfer potential from 96 hours. Stainless steel coupons were submitted to Scanning Electron Microscopy (SEM) after 3, 144 and 240 hours. Based on the number of adhered cells and SEM, it was observed that L. monocytogenes adhered rapidly to the stainless steel surface, with mature biofilm being formed after 240 hours. The biotransfer potential of bacterium to substrate occurred at all the stages analyzed. The rapid capacity of adhesion to surface, combined with biotransfer potential throughout the biofilm formation stages, make L. monocytogenes a potential risk to the food industry. Both the experimental model developed and the methodology used were efficient in the study of biofilm formation by L. monocytogenes on stainless steel surface and biotransfer potential.

  18. Two new techniques for the remote evaluation of reactor steel condition - microscopic removal and surface examination

    International Nuclear Information System (INIS)

    Clayton, R.

    Much reactor inspection work involves an assessment of the condition of structural steel. This paper reviews two different techniques which provide information for such an assessment. The first - micro-sample removal (for the measurement of surface oxide thickness and chemical composition) - requires contact with the steel surface, whereas the second - a 'teach and learn' photographic technique (in which a special photogrammatic camera is used to obtain high-quality close-up photographs, to assess surface condition and corrosion growth) can obtain surface information on inaccessible components. (author)

  19. Laser surface alloying of 316L stainless steel with Ru and Ni mixtures

    CSIR Research Space (South Africa)

    Lekala, MB

    2012-05-01

    Full Text Available an economically sound approach of modifying corrosion properties of alloys. Furthermore, since corrosion is a surface phenomenon, an equally cost-effective approach is to add these only on the surface, where protection is most required. Laser surface... powders were preplaced on the steel surface using a chemical binder. The thickness of the preplaced powder coatings could be controlled to approxi- mately 1mm. The laser surface alloying was performed with a Rofin Sinar DY044 continuous wave Nd : YAG...

  20. Experimental study on the formation and growth of electroless nickel-boron coatings from borohydride-reduced bath on mild steel

    Energy Technology Data Exchange (ETDEWEB)

    Vitry, Veronique, E-mail: veronique.vitry@umons.ac.be [Service de Metallurgie, Universite de Mons, Rue de l' Epargne 56, 7000 Mons (Belgium); Sens, Adeline [Service de Metallurgie, Universite de Mons, Rue de l' Epargne 56, 7000 Mons (Belgium); Kanta, Abdoul-Fatah [Service de Sciences des Materiaux, Universite de Mons, Rue de l' Epargne 56, 7000 Mons (Belgium); Delaunois, Fabienne [Service de Metallurgie, Universite de Mons, Rue de l' Epargne 56, 7000 Mons (Belgium)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer Initiation mechanism of electroless Ni-B on St-37 steel has been identified. Black-Right-Pointing-Pointer Different phases of the plating process were observed and identified. Black-Right-Pointing-Pointer Influence of chemical heterogeneity on coating morphology was revealed. Black-Right-Pointing-Pointer Batch replenishment of the plating bath induces new germination phase. - Abstract: Quality and homogeneity of electroless nickel-boron coatings are very important for applications in corrosion and electronics and are completely dependent on the formation of the deposit. The growth and formation process of electroless nickel-boron was investigated by immersing mild steel (St-37) samples in an un-replenished bath for various periods of time (from 5 s to 1 h). The coatings obtained at the different stages of the process were then characterized: thickness was measured by SEM, morphology was observed, weight gain was recorded and top composition of the coatings was obtained from XPS. Three main phases were identified during the coating formation and links between plating time, instantaneous deposition rate, chemistry of last formed deposit and morphology were established. The mechanism for initial deposition on steel substrate for borohydride-reduced electroless nickel bath was also observed. Those results were confronted with chemistry evolution in the unreplenished plating bath during the process. This allowed getting insight about phenomena occurring in the plating bath and their influence on coating formation.

  1. Effects of surface roughness, texture and polymer degradation on cathodic delamination of epoxy coated steel samples

    International Nuclear Information System (INIS)

    Khun, N.W.; Frankel, G.S.

    2013-01-01

    Highlights: ► Cathodic delamination of epoxy coated steel samples was studied using SKP. ► Delamination of the coating decreased with increased substrate surface roughness. ► Delamination of the coating was faster on the substrate with parallel surface scratches. ► Delamination of the coating exposed to weathering conditions increased with prolonged exposure. - Abstract: The Scanning Kelvin Probe (SKP) technique was used to investigate the effects of surface roughness, texture and polymer degradation on cathodic delamination of epoxy coated steel. The cathodic delamination rate of the epoxy coatings dramatically decreased with increased surface roughness of the underlying steel substrate. The surface texture of the steel substrates also had a significant effect in that samples with parallel abrasion lines exhibiting faster cathodic delamination in the direction of the lines compared to the direction perpendicular to the lines. The cathodic delamination kinetics of epoxy coatings previously exposed to weathering conditions increased with prolonged exposure due to pronounced polymer degradation. SEM observation confirmed that the cyclic exposure to UV radiation and water condensation caused severe deterioration in the polymer structures with surface cracking and erosion. The SKP results clearly showed that the cathodic delamination of the epoxy coatings was significantly influenced by the surface features of the underlying steel substrates and the degradation of the coatings.

  2. Surface and sliding wear behaviour of different coatings and steels

    Energy Technology Data Exchange (ETDEWEB)

    Vera-Cardenas, E.E. [Universidad Politecnica de Pachuca, Zempoala, Hidalgo (Mexico)]. E-mail: evera@upp.edu.mx; Vite-Torres, M. [Instituto Politecnico Nacional, Mexico D.F. (Mexico)]. E-mail: drmanulvite9@hotmail.com; Lewis, R. [University of Sheffield (United Kingdom)]. E-mail: roger.lewis@sheffield.ac.uk

    2012-01-15

    In this work, the sliding wear behaviour of the coatings TiN, CrN and WC/C applied on steel substrates was studied using a reciprocating wear test machine. All tests were carried out in dry conditions, at room temperature (20-23 degrees Celsius and 45% - 50% relative humidity). The average sliding velocity was 0.08 m/s and an amplitude of 2 mm was used. The applied loads were 11.76 N (Po = 1.74 GPa) and 7.84 N (Po = 1.52 GPa). Optical microscopy was used to observe the characteristics of wear scars and spalls and possible causes of their formation. The variation of the friction coefficient against the number of cycles was obtained. This was used to determine more precisely the time (number of cycles) where the coating presented the first signs of wear, in addition Energy Dispersive X-ray analysis (EDS) was performed, as well as Scanning Electron Microscopy (SEM) and hardness tests on the wear traces, which reinforced the previous observations. Thus it was possible to know the wear life of different coatings and possible causes of variation. Increasing the load was an important factor in the variation of wear life results. But it is also important to consider other factors such as surface roughness and thickness of coatings. [Spanish] En este trabajo se estudio el comportamiento en desgaste por deslizamiento de los recubrimientos de TiN, CrN y WC/C aplicados sobre sustratos de acero. Las pruebas se realizaron con una maquina reciprocante en condiciones secas a temperatura ambiente (20-23 grados centigrados y 45% - 50% de humedad relativa). Se empleo una velocidad promedio de 0.08 m/s y una amplitud de 2 mm. Las cargas aplicadas fueron de 11.76N (Po = 1.74 GPa) y de 7.84 N (Po = 1.52 GPa). Se realizo microscopia optica para observar las caracteristicas de las zonas de desgaste y sus posibles causas de formacion. Se obtuvo graficamente la variacion del coeficiente de friccion con el numero de ciclos. Estos datos se emplearon para determinar con mayor precision el

  3. X-ray fractography on fatigue fracture surface of high manganese austenitic steel

    International Nuclear Information System (INIS)

    Akita, Koichi; Misawa, Hiroshi; Kodama, Shotaro; Saito, Tetsuro.

    1997-01-01

    Fatigue tests were carried out under constant stress amplitude, using a non-magnetic high manganese Mn-Cr steel. X-ray fractography was applied on the fatigue fractured surface to investigate the relationship between stress intensity factor and residual stress or half-value breadth of the X-ray diffraction profile. The fatigue crack propagation rate of this non-magnetic Mn-Cr steel had the same tendency as in the ordinary structural ferritic steels. The relationship between stress intensity factor and the residual stress or half-value breadth of the steel was almost the same as that of the ferritic cyclic work hardening steels. No stress induced transformation was observed on the fracture surface, but the residual stress on the fractured surface was compressive in the high stress intensity factors range, which is typical in the cyclic work hardening steels. The half-value breadth on the fractured surface increased with increasing effective stress intensity factor range. The relationship between the half-value breadth and stress intensity factor range was represented by a linear line regardless of the stress ratio. Therefore, the acting stress intensity factor range at the time of fracture can be estimated from the half-value breadth. The depth of monotonic plastic zone was estimated from the distribution of half-value breadth beneath the fractured surface. The relationship between the maximum stress intensity factor and half-value breadth was expressed by the equation ω m α(K max /σ y ) 2 , where the value of α was 0.025. This is about one sixth of the value for ferritic steels, and the fact shows the severe work hardening occuring in the plastic zone in this manganese steel. (author)

  4. Finite element simulation of photoacoustic fiber optic sensors for surface corrosion detection on a steel rod

    Science.gov (United States)

    Tang, Qixiang; Owusu Twumasi, Jones; Hu, Jie; Wang, Xingwei; Yu, Tzuyang

    2018-03-01

    Structural steel members have become integral components in the construction of civil engineering infrastructures such as bridges, stadiums, and shopping centers due to versatility of steel. Owing to the uniqueness in the design and construction of steel structures, rigorous non-destructive evaluation techniques are needed during construction and operation processes to prevent the loss of human lives and properties. This research aims at investigating the application of photoacoustic fiber optic transducers (FOT) for detecting surface rust of a steel rod. Surface ultrasonic waves propagation in intact and corroded steel rods was simulated using finite element method (FEM). Radial displacements were collected and short-time Fourier transform (STFT) was applied to obtain the spectrogram. It was found that the presence of surface rust between the FOT and the receiver can be detected in both time and frequency domain. In addition, spectrogram can be used to locate and quantify surface rust. Furthermore, a surface rust detection algorithm utilizing the FOT has been proposed for detection, location and quantification of the surface rust.

  5. A real-time surface inspection system for precision steel balls based on machine vision

    Science.gov (United States)

    Chen, Yi-Ji; Tsai, Jhy-Cherng; Hsu, Ya-Chen

    2016-07-01

    Precision steel balls are one of the most fundament components for motion and power transmission parts and they are widely used in industrial machinery and the automotive industry. As precision balls are crucial for the quality of these products, there is an urgent need to develop a fast and robust system for inspecting defects of precision steel balls. In this paper, a real-time system for inspecting surface defects of precision steel balls is developed based on machine vision. The developed system integrates a dual-lighting system, an unfolding mechanism and inspection algorithms for real-time signal processing and defect detection. The developed system is tested under feeding speeds of 4 pcs s-1 with a detection rate of 99.94% and an error rate of 0.10%. The minimum detectable surface flaw area is 0.01 mm2, which meets the requirement for inspecting ISO grade 100 precision steel balls.

  6. Silver deposition on stainless steel container surfaces in contact with disinfectant silver aqueous solutions

    International Nuclear Information System (INIS)

    Petala, M.; Tsiridis, V.; Mintsouli, I.; Pliatsikas, N.; Spanos, Th.; Rebeyre, P.; Darakas, E.; Patsalas, P.; Vourlias, G.; Kostoglou, M.; Sotiropoulos, S.; Karapantsios, Th.

    2017-01-01

    Highlights: • Silver is one of the biocides of water consumed in the International Space Station. • Ionic silver is depleted from potable water when in contact with stainless steel (SS). • SEM and XPS analysis reveal a uniform silver deposition over the SS surface. • Silver deposits in its metallic form, in line with a galvanic deposition mechanism. • Evidence is provided that Cr and/ or Ni oxide builds-up on SS surfaces. - Abstract: Silver is the preservative used on the Russian segment of the International Space Station (ISS) to prevent microbial proliferation within potable water supplies. Yet, in the frame of the European Automated Transfer Vehicle (ATV) missions to ISS, silver depletion from water has been detected during ground transportation of this water to launch site, thereby indicating a degradation of water quality. This study investigates the silver loss from water when in contact with stainless steel surfaces. Experiments are conducted with several types of stainless steel surfaces being exposed to water containing 10 or 0.5 mg/L silver ions. Results show that silver deposits on stainless steel surfaces even when a passivation layer protects the metallic surface. The highest protection to silver deposition is offered by acid passivated and electropolished SS 316L. SEM and XPS experiments were carried out at several locations of the sample area that was in contact with the Ag solution and found similar morphological (SEM) and compositional (sputter-etch XPS) results. The results reveal that silver deposits uniformly across the wetted surface to a thickness larger than 3 nm. Moreover, evidence is provided that silver deposits in its metallic form on all stainless steel surfaces, in line with a galvanic deposition mechanism. Combination of ICP-MS and XPS results suggests a mechanism for Ag deposition/reduction with simultaneous substrate oxidation resulting in oxide growth at the exposed stainless steel surface.

  7. Silver deposition on stainless steel container surfaces in contact with disinfectant silver aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Petala, M., E-mail: petala@civil.auth.gr [Department of Civil Engineering, Aristotle University of Thessaloniki, Thessaloniki, 54124 (Greece); Tsiridis, V. [Department of Civil Engineering, Aristotle University of Thessaloniki, Thessaloniki, 54124 (Greece); Mintsouli, I. [Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki, 54124 (Greece); Pliatsikas, N. [Department of Physics, Aristotle University of Thessaloniki, Thessaloniki, 54124 (Greece); Spanos, Th. [Department of Petroleum and Mechanical Engineering Sciences, Eastern Macedonia and Thrace Institute of Technology, Kavala, 65404 (Greece); Rebeyre, P. [ESA/ESTEC, P.O.Box 299, 2200 AG, Noordwijk (Netherlands); Darakas, E. [Department of Civil Engineering, Aristotle University of Thessaloniki, Thessaloniki, 54124 (Greece); Patsalas, P.; Vourlias, G. [Department of Physics, Aristotle University of Thessaloniki, Thessaloniki, 54124 (Greece); Kostoglou, M.; Sotiropoulos, S.; Karapantsios, Th. [Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki, 54124 (Greece)

    2017-02-28

    Highlights: • Silver is one of the biocides of water consumed in the International Space Station. • Ionic silver is depleted from potable water when in contact with stainless steel (SS). • SEM and XPS analysis reveal a uniform silver deposition over the SS surface. • Silver deposits in its metallic form, in line with a galvanic deposition mechanism. • Evidence is provided that Cr and/ or Ni oxide builds-up on SS surfaces. - Abstract: Silver is the preservative used on the Russian segment of the International Space Station (ISS) to prevent microbial proliferation within potable water supplies. Yet, in the frame of the European Automated Transfer Vehicle (ATV) missions to ISS, silver depletion from water has been detected during ground transportation of this water to launch site, thereby indicating a degradation of water quality. This study investigates the silver loss from water when in contact with stainless steel surfaces. Experiments are conducted with several types of stainless steel surfaces being exposed to water containing 10 or 0.5 mg/L silver ions. Results show that silver deposits on stainless steel surfaces even when a passivation layer protects the metallic surface. The highest protection to silver deposition is offered by acid passivated and electropolished SS 316L. SEM and XPS experiments were carried out at several locations of the sample area that was in contact with the Ag solution and found similar morphological (SEM) and compositional (sputter-etch XPS) results. The results reveal that silver deposits uniformly across the wetted surface to a thickness larger than 3 nm. Moreover, evidence is provided that silver deposits in its metallic form on all stainless steel surfaces, in line with a galvanic deposition mechanism. Combination of ICP-MS and XPS results suggests a mechanism for Ag deposition/reduction with simultaneous substrate oxidation resulting in oxide growth at the exposed stainless steel surface.

  8. Defining the Post-Machined Sub-surface in Austenitic Stainless Steels

    Science.gov (United States)

    Srinivasan, N.; Sunil Kumar, B.; Kain, V.; Birbilis, N.; Joshi, S. S.; Sivaprasad, P. V.; Chai, G.; Durgaprasad, A.; Bhattacharya, S.; Samajdar, I.

    2018-06-01

    Austenitic stainless steels grades, with differences in chemistry, stacking fault energy, and thermal conductivity, were subjected to vertical milling. Anodic potentiodynamic polarization was able to differentiate (with machining speed/strain rate) between different post-machined sub-surfaces in SS 316L and Alloy A (a Cu containing austenitic stainless steel: Sanicroe 28™), but not in SS 304L. However, such differences (in the post-machined sub-surfaces) were revealed in surface roughness, sub-surface residual stresses and misorientations, and in the relative presence of sub-surface Cr2O3 films. It was shown, quantitatively, that higher machining speed reduced surface roughness and also reduced the effective depths of the affected sub-surface layers. A qualitative explanation on the sub-surface microstructural developments was provided based on the temperature-dependent thermal conductivity values. The results herein represent a mechanistic understanding to rationalize the corrosion performance of widely adopted engineering alloys.

  9. Defining the Post-Machined Sub-surface in Austenitic Stainless Steels

    Science.gov (United States)

    Srinivasan, N.; Sunil Kumar, B.; Kain, V.; Birbilis, N.; Joshi, S. S.; Sivaprasad, P. V.; Chai, G.; Durgaprasad, A.; Bhattacharya, S.; Samajdar, I.

    2018-04-01

    Austenitic stainless steels grades, with differences in chemistry, stacking fault energy, and thermal conductivity, were subjected to vertical milling. Anodic potentiodynamic polarization was able to differentiate (with machining speed/strain rate) between different post-machined sub-surfaces in SS 316L and Alloy A (a Cu containing austenitic stainless steel: Sanicroe 28™), but not in SS 304L. However, such differences (in the post-machined sub-surfaces) were revealed in surface roughness, sub-surface residual stresses and misorientations, and in the relative presence of sub-surface Cr2O3 films. It was shown, quantitatively, that higher machining speed reduced surface roughness and also reduced the effective depths of the affected sub-surface layers. A qualitative explanation on the sub-surface microstructural developments was provided based on the temperature-dependent thermal conductivity values. The results herein represent a mechanistic understanding to rationalize the corrosion performance of widely adopted engineering alloys.

  10. Galvanic Liquid Applied Coating System for Protection of Embedded Steel Surfaces from Corrosion

    Science.gov (United States)

    Curran, Joseph; MacDowell, Louis; Voska, N. (Technical Monitor)

    2002-01-01

    The corrosion of reinforcing steel in concrete is an insidious problem for the Kennedy Space Center, government agencies, and the general public. Existing corrosion protection systems on the market are costly, complex, and time-consuming to install, require continuous maintenance and monitoring, and require specialized skills for installation. NASA's galvanic liquid-applied coating offers companies the ability to conveniently protect embedded steel rebar surfaces from corrosion. Liquid-applied inorganic galvanic coating contains one ore more of the following metallic particles: magnesium, zinc, or indium and may contain moisture attracting compounds that facilitate the protection process. The coating is applied to the outer surface of reinforced concrete so that electrical current is established between metallic particles and surfaces of embedded steel rebar; and electric (ionic) current is responsible for providing the necessary cathodic protection for embedded rebar surfaces.

  11. Surface transformation hardening on steels treated with solar energy in central tower and heliostats field

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, G.P.; Lopez, V.; de Damborenea, J.J.; Vazquez, A.J. [Centro Nacional de Investigaciones Metalurgicas CENIM/CSIC, Madrid (Spain)

    1995-04-28

    The possibility of surface hardening on AISI 4140 steel treated with concentrated solar energy in solar installations for electricity production has been studied. The samples were slides from a 35 mm diameter steel bar and their height was 35 mm. The quenching was made in water but also was considered the possibility of self-quenching by cooling in air. The amount of the surface hardness and the different structures obtained in both cases are presented, and some discussion is made with reference to the surface hardness, the hardness profiles and the structures obtained. The heating of steel with concentrated solar energy may produce similar hardening to that obtained with more conventional techniques of surface hardening

  12. Investigation of Selected Surface Integrity Features of Duplex Stainless Steel (DSS) after Turning

    Czech Academy of Sciences Publication Activity Database

    Krolczyk, G.; Nieslony, P.; Legutko, S.; Hloch, Sergej; Samardžić, I.

    2015-01-01

    Roč. 54, č. 1 (2015), s. 91-94 ISSN 0543-5846 Institutional support: RVO:68145535 Keywords : duplex stainless steel * machining * turning * surface integrity * surface roughness Subject RIV: JQ - Machines ; Tools Impact factor: 0.959, year: 2014 http://hrcak.srce.hr/126702

  13. Surface electrical properties of stainless steel fibres: An AFM-based study

    International Nuclear Information System (INIS)

    Yin, Jun; D’Haese, Cécile; Nysten, Bernard

    2015-01-01

    Highlights: • Surface electrical conductivity of stainless steel fibre is measured and mapped by CS-AFM. • Surface potential of stainless steel fibre is measured and mapped by KPFM. • Surface electronic properties are governed by the chromium oxide passivation layer. • Electron tunnelling through the passivation layer is the dominant mechanisms for conduction. - Abstract: Atomic force microscopy (AFM) electrical modes were used to study the surface electrical properties of stainless steel fibres. The surface electrical conductivity was studied by current sensing AFM and I–V spectroscopy. Kelvin probe force microscopy was used to measure the surface contact potential. The oxide film, known as passivation layer, covering the fibre surface gives rise to the observation of an apparently semiconducting behaviour. The passivation layer generally exhibits a p-type semiconducting behaviour, which is attributed to the predominant formation of chromium oxide on the surface of the stainless steel fibres. At the nanoscale, different behaviours are observed from points to points, which may be attributed to local variations of the chemical composition and/or thickness of the passivation layer. I–V curves are well fitted with an electron tunnelling model, indicating that electron tunnelling may be the predominant mechanism for electron transport

  14. Modulation of dry tribological property of stainless steel by femtosecond laser surface texturing

    Science.gov (United States)

    Wang, Zhuo; Zhao, Quanzhong; Wang, Chengwei; Zhang, Yang

    2015-06-01

    We reported on the modification of tribological properties of stainless steel by femtosecond laser surface microstructuring. Regular arranged micro-grooved textures with different spacing were produced on the AISI 304L steel surfaces by an 800-nm femtosecond laser. The tribological properties of smooth surface and textured surface were investigated by carrying out reciprocating ball-on-flat tests against Al2O3 ceramic balls under dry friction. Results show that the spacing of micro-grooves had a significant impact on friction coefficient of textured surfaces. Furthermore, the wear behaviors of smooth and textured surface were also investigated. Femtosecond laser surface texturing had a marked potential for modulating friction and wear properties if the micro-grooves were distributed in an appropriate manner.

  15. AISI/DOE Technology Roadmap Program: Improved Surface Quality of Exposed Automotive Sheet Steels

    Energy Technology Data Exchange (ETDEWEB)

    John G. Speer; David K. Matlock; Noel Meyers; Young-Min Choi

    2002-10-10

    Surface quality of sheet steels is an important economic and technical issue for applications such as critical automotive surfaces. This project was therefore initiated to develop a more quantitative methodology for measuring surface imperfections, and to assess their response to forming and painting, particularly with respect to their visibility or invisibility after painting. The objectives were met, and included evaluation of a variety of imperfections present on commercial sheet surfaces or simulated using methods developed in the laboratory. The results are expected to have significant implications with respect to the methodology for assessing surface imperfections, development of quantitative criteria for surface inspection, and understanding and improving key painting process characteristics that influence the perceived quality of sheet steel surfaces.

  16. Application of phosphating techniques to aluminium and carbon steel surfaces using nitro guanidine as oxidizing agent

    International Nuclear Information System (INIS)

    Briseno M, S.A.

    1995-01-01

    Phosphate coatings are inorganic crystalline deposits laid down uniformly on properly prepared surfaces by a chemical reaction with the treated base metal. The reaction consists in dissolving some surface metal by acid attack and then causing surface neutralization of the phosphate solution with consequent precipitation of the phosphate coating. Phosphate coatings do not provide appreciable corrosion protection in themselves. They are useful mainly as a base for paints, ensuring good adherence of paint to steel and decreasing the tendency for corrosion to under cut the paint film at scratches or other defects. In this work firstly were realized phosphate on standard carbon steel, employing technical of cold phosphate (at 40 Centigrade degrees and with a treatment time of 30 minutes) and hot phosphate (at 88 Centigrade degrees and with a treatment time of 15 minutes), where with this last were obtained the best results. Both methods used phosphate solutions of Zn/Mn and using as catalyst Nitro guanidine. Aluminium surfaces were phosphate used solutions of Cr and as catalyst Sodium bi fluoride. The phosphating on this surface were realized at temperature of 50 Centigrade degrees and with a treatment time of 10 minutes. In this work were obtained a new phosphate coatings on steel surfaces, these coatings were realized with a phosphate solution manufactured with the precipitates gathered during the hot phosphating on carbon steel. These coatings show excellent physical characteristics and of corrosion resistance. Were determined the physical testings of the coatings phosphate obtained on carbon steel and aluminium surfaces. These testing were: roughness, thickness, microhardness and adhesion. The best results were showed in carbon steel phosphate with precipitated solutions. The technical of analysis for activation with thermic neutrons was used to determine the phosphate coatings composition. Finally, corrosion testings were realized by means of two methods

  17. Synthesis, characterization and corrosion inhibition properties of benzamide-2-chloro-4-nitrobenzoic acid and anthranilic acid-2-chloro-4-nitrobenzoic acid for mild steel corrosion in acidic medium

    Science.gov (United States)

    Pandey, Archana; Verma, Chandrabhan; Singh, B.; Ebenso, Eno E.

    2018-03-01

    The present study deals with the synthesis of two new compounds namely, benzamide - 2-chloro-4-nitrobenzoic acid (BENCNBA) and anthranilic acid-2-chloro-4-nitrobenzoic acid (AACNBA) using solid phase reactions. The phase diagram studies revealed that formation of the investigated compounds occurs in 1:1 molar ratio. The synthesized compounds were characterized using several spectral techniques such as FT-IR, 1H and 13C NMR, UV-Vis, powder X-ray diffraction (PXRD). Single crystal XRD (SCXRD) study showed that both BENCNBA and AACNBA compounds crystallize in triclinic crystal system with P-1 space group. Further, the presence of intermolecular hydrogen bonding between the constituent components was also supported by single crystal X-ray diffraction (SCXRD) method. Heat of mixing, entropy of fusion, roughness parameter, interfacial energy and excess thermodynamic functions have also been computed using the enthalpy of fusion values derived from differential scanning calorimeter (DSC) study. The inhibition effect of BENCNBA and AACNBA on the mild steel corrosion in hydrochloric acid solution was tested using electrochemical methods. Electrochemical impedance spectroscopy (EIS) study revealed that both BENCNBA and AACNBA behaved as interface corrosion inhibitors and showed maximum inhibition efficiencies of 95.71% and 96.42%, respectively at 400 ppm (1.23 × 10-3 M) concentration. Potentiodynamic polarization (PDP) measurements suggested that BENCNBA and AACNBA acted as mixed type corrosion inhibitors. EIS and PDP results showed that BENCNBA and AACNBA act as efficient corrosion inhibitors for mild steel and their inhibition efficiencies enhances on increasing their concentrations.

  18. Some loop experiments in the NRX reactor to study the corrosion of mild steel by flowing water at 90{sup o}F

    Energy Technology Data Exchange (ETDEWEB)

    Allison, G. M.

    1956-11-15

    This work was undertaken to find the water conditions necessary for minimum corrosion in the mild steel thermal shield recirculating systems in NRX and NRU. This report contains the chemical and corrosion results obtained by operating three mild steel loops in which water at 85-95{sup o}F was recirculated through test sections located in J-rod positions in the NRX reactor. Lowest corrosion rates were found when the water was maintained at pH 10.5 with or without oxygen being present. In both cases the corrosion was general in nature and no pitting occurred. At pH 7 with oxygen present in the water severe pitting took place and the corrosion rate was several times higher than similar conditions without oxygen in the water. Under oxygen-free conditions the corrosion product was Fe{sub 3}O{sub 4}. At pH 7 and with 3-5 ppm of O{sub 2} in the water the corrosion product was a mixture of Fe{sub 3}O{sub 4} and {gamma}-Fe{sub 2}O{sub 3}. At high pH with oxygen present Fe{sub 3}O{sub 4} predominated with some traces of Fe{sub 2}O{sub 3}. The systems tested may he listed in order of increasing corrosiveness: High pH with or without O{sub 2} in the water < water at pH 7 with no O{sub 2} present and continual purification < water with no O{sub 2} present and no purification or pH control < water at pH 7 with 3-5 ppm of O{sub 2} present. (author)

  19. Potentiodynamic studies of Ni-P-TiO{sub 2} nano-composited coating on the mild steel deposited by electroless plating method

    Energy Technology Data Exchange (ETDEWEB)

    Uttam, Vibha, E-mail: vibhauttam74@gmail.com; Duchaniya, R. K., E-mail: rkduchaniya.meta@mnit.ac.in [Department of Metallurgical and Materials Engineering, MNIT Jaipur (India)

    2016-05-06

    Now a days, corrosion studies are important for reducing the wastage of metals. The importance of corrosion studies is two folds i.e. first is economic, including the reduction of material losses resulting from the wasting away or sudden failure of materials and second is conservation Electroless process is an autocatalytic reduction method in which metallic ions are reduced in the solution. Nanocomposite coatings of Ni-P-TiO{sub 2} on mild steel are deposited by varying volume of TiO{sub 2} nano-powder by electroless method from Ni-P plating bath containing Nickel Sulphate as a source of nickel ions, sodium hypophosphite as the reducing agent, lactic acid as a complexing agents and TiO{sub 2} nano powder. Electroless Ni-P-TiO{sub 2} coating have been widely used in the chemical process industries, mechanical industries, electronic industries and chloroalkali industries due to their excellent corrosion with mechanical properties. In the present work, deposition of Ni-P alloy coating and Ni-P-TiO{sub 2} nanocomposited coatings were done on the mild steel and corrosion properties were studied with Potentio-dynamic polarization measurements method in 3.5 wt% sodium chloride solution. It showed in the experiments that Ni-P-TiO{sub 2} nanocomposited coating has better corrosion resistance as comparedthan Ni-P alloy coating. Morphological studies were done by field emission scanning electron microscopy (FESEM), energy–dispersive analysis of X-ray (EDAX) and X-ray diffraction (XRD). These studies confirmed the deposition of Ni-P alloy coating and Ni-P-TiO{sub 2} nanocomposited coating.

  20. Potentiodynamic studies of Ni-P-TiO2 nano-composited coating on the mild steel deposited by electroless plating method

    Science.gov (United States)

    Uttam, Vibha; Duchaniya, R. K.

    2016-05-01

    Now a days, corrosion studies are important for reducing the wastage of metals. The importance of corrosion studies is two folds i.e. first is economic, including the reduction of material losses resulting from the wasting away or sudden failure of materials and second is conservation Electroless process is an autocatalytic reduction method in which metallic ions are reduced in the solution. Nanocomposite coatings of Ni-P-TiO2 on mild steel are deposited by varying volume of TiO2 nano-powder by electroless method from Ni-P plating bath containing Nickel Sulphate as a source of nickel ions, sodium hypophosphite as the reducing agent, lactic acid as a complexing agents and TiO2 nano powder. Electroless Ni-P-TiO2 coating have been widely used in the chemical process industries, mechanical industries, electronic industries and chloroalkali industries due to their excellent corrosion with mechanical properties. In the present work, deposition of Ni-P alloy coating and Ni-P-TiO2 nanocomposited coatings were done on the mild steel and corrosion properties were studied with Potentio-dynamic polarization measurements method in 3.5 wt% sodium chloride solution. It showed in the experiments that Ni-P-TiO2 nanocomposited coating has better corrosion resistance as comparedthan Ni-P alloy coating. Morphological studies were done by field emission scanning electron microscopy (FESEM), energy-dispersive analysis of X-ray (EDAX) and X-ray diffraction (XRD). These studies confirmed the deposition of Ni-P alloy coating and Ni-P-TiO2 nanocomposited coating.

  1. Surface enrichment with chrome and nitriding of IF steel under an abnormal glow discharge

    International Nuclear Information System (INIS)

    Meira, S.R.; Borges, P.C.; Bernardelli, E.A.

    2014-01-01

    The objective of this work is to evaluate the influence of surface enrichment of IF steel with chrome, and nitriding, the formation of the nitrided layer. Thus, IF steel samples were subjected to surface enrichment process, using 409 stainless steel as a target for sputtering, followed by plasma nitriding, both under a dc abnormal glow discharge. The enrichment treatment was operated at 1200 ° C for 3h. The nitriding treatment was operated at 510 ° C for 2 h. The influence of the treatments on the layers formed was studied through optical microscopy (OM), scan electron microscopy (SEM), X-ray diffraction (XRD) and Vickers microindentation. The results show that the enrichment is effective to enrich the IF surface, furthermore, improves the characteristics of nitriding, comparing nitriding samples to nitriding and enriched, was observed needles of nitrides, as well as a higher hardness, which is associated with the nitrides of chrome, on the nitriding and enriched samples. (author)

  2. X-ray impact induced desorption of gases from stainless steel surfaces

    International Nuclear Information System (INIS)

    Brumbach, S.; Kaminsky, M.

    1975-01-01

    During the operation of plasma devices the interaction of energetic photons with surfaces can cause gas release by photodesorption, and thereby contribute to plasma contamination. Measurements of gases released from stainless steel surfaces were made in an ultrahigh vacuum environment using x-rays characteristic for a tungsten target bremsstrahlung spectrum for electron energies varying from 15 to 50 keV. The predominant gas species observed mass spectrometically are CO 2 (m/e = 44), CO (m/e = 28), and O 2 (m/e = 32). Mean quantum yields for the release of these species from stainless steel were determined. For example, for fresh stainless steel surfaces irradiated by x-rays produced by 50 keV electrons, a mean quantum yield for molecular CO 2 release of 3 x 10 -4 molecules per photons in a bremsstrahlung spectrum at 50 keV electron energy was observed. Based on such a quantum yield an outgassing rate was determined

  3. PERFORMANCE OF RC AND FRC WALL PANELS REINFORCED WITH MILD STEEL AND GFRP COMPOSITES IN BLAST EVENTS

    Energy Technology Data Exchange (ETDEWEB)

    Timothy Garfield; William D. Richins; Thomas K. Larson; Chris P. Pantelides; James E. Blakeley

    2011-06-01

    The structural integrity of reinforced concrete structures in blast events is important for critical facilities. This paper presents experimental data generated for calibrating detailed finite element models that predict the performance of reinforced concrete wall panels with a wide range of construction details under blast loading. The test specimens were 1.2 m square wall panels constructed using Normal Weight Concrete (NWC) or Fiber Reinforced Concrete (FRC). FRC consists of macro-synthetic fibers dispersed in NWC. Five types of panels were tested: NWC panels with steel bar reinforcement (Type A); FRC panels without additional reinforcement (Type B); FRC panels with steel bar reinforcement (Type C); NWC panels with glass fiber reinforced polymer (GFRP) bar reinforcement (Type D); and NWC panels reinforced with steel bar reinforcement and external bidirectional GFRP overlays on both faces (Type E). An additional three Type C panels were used as control specimens (CON). Each panel type was constructed with three thicknesses: 152 mm, 254 mm, and 356 mm. The panels were instrumented with strain gauges, and accelerometers; in addition, pressure sensors and high speed videos were employed during the blast events. Panel types C and E had the best performance, whereas panel type B did not perform well. Preliminary dynamic simulations show crack patterns similar to the experimental results.

  4. Comparison of surface fractal dimensions of chromizing coating and P110 steel for corrosion resistance estimation

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Naiming, E-mail: lnmlz33@163.com [Research Institute of Surface Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Guo, Junwen [Research Institute of Surface Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Xie, Faqin [School of Aeronautics, Northwestern Polytechnical University, Xi’an 710072 (China); Zou, Jiaojuan; Tian, Wei [Research Institute of Surface Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Yao, Xiaofei [School of Materials and Chemical Engineering, Xi’an Technological University, Xi’an 710032 (China); Zhang, Hongyan; Tang, Bin [Research Institute of Surface Engineering, Taiyuan University of Technology, Taiyuan 030024 (China)

    2014-08-30

    Highlights: • Continuous chromizing coating was synthesized on P110 steel by pack cementation. • The chromizing coating showed better corrosion resistance. • Comparison of surface fractal dimensions can estimate corrosion resistance. - Abstract: In the field of corrosion research, mass gain/loss, electrochemical tests and comparing the surface elemental distributions, phase constitutions as well as surface morphologies before and after corrosion are extensively applied to investigate the corrosion behavior or estimate the corrosion resistance of materials that operated in various environments. Most of the above methods are problem oriented, complex and longer-period time-consuming. However from an object oriented point of view, the corroded surfaces of materials often have self-similar characterization: fractal property which can be employed to efficiently achieve damaged surface analysis. The present work describes a strategy of comparison of the surface fractal dimensions for corrosion resistance estimation: chromizing coating was synthesized on P110 steel surface to improve its performance via pack cementation. Scanning electron microscope (SEM) was used to investigate the surface morphologies of the original and corroded samples. Surface fractal dimensions of the detected samples were calculated by binary images related to SEM images of surface morphologies with box counting algorithm method. The results showed that both surface morphologies and surface fractal dimensions of P110 steel varied greatly before and after corrosion test, but the chromizing coating changed slightly. The chromizing coating indicated better corrosion resistance than P110 steel. Comparison of surface fractal dimensions of original and corroded samples can rapidly and exactly realize the estimation of corrosion resistance.

  5. Comparison of surface fractal dimensions of chromizing coating and P110 steel for corrosion resistance estimation

    International Nuclear Information System (INIS)

    Lin, Naiming; Guo, Junwen; Xie, Faqin; Zou, Jiaojuan; Tian, Wei; Yao, Xiaofei; Zhang, Hongyan; Tang, Bin

    2014-01-01

    Highlights: • Continuous chromizing coating was synthesized on P110 steel by pack cementation. • The chromizing coating showed better corrosion resistance. • Comparison of surface fractal dimensions can estimate corrosion resistance. - Abstract: In the field of corrosion research, mass gain/loss, electrochemical tests and comparing the surface elemental distributions, phase constitutions as well as surface morphologies before and after corrosion are extensively applied to investigate the corrosion behavior or estimate the corrosion resistance of materials that operated in various environments. Most of the above methods are problem oriented, complex and longer-period time-consuming. However from an object oriented point of view, the corroded surfaces of materials often have self-similar characterization: fractal property which can be employed to efficiently achieve damaged surface analysis. The present work describes a strategy of comparison of the surface fractal dimensions for corrosion resistance estimation: chromizing coating was synthesized on P110 steel surface to improve its performance via pack cementation. Scanning electron microscope (SEM) was used to investigate the surface morphologies of the original and corroded samples. Surface fractal dimensions of the detected samples were calculated by binary images related to SEM images of surface morphologies with box counting algorithm method. The results showed that both surface morphologies and surface fractal dimensions of P110 steel varied greatly before and after corrosion test, but the chromizing coating changed slightly. The chromizing coating indicated better corrosion resistance than P110 steel. Comparison of surface fractal dimensions of original and corroded samples can rapidly and exactly realize the estimation of corrosion resistance

  6. PENGARUH PERBEDAAN POSISI PENGELASAN TERHADAP KEKUATAN SAMBUNGAN T-Joint PENGELASAN FILLET DENGAN LAS FCAW PADA PLAT MILD STEEL

    Directory of Open Access Journals (Sweden)

    Sarjito Jokosisworo

    2012-07-01

    Full Text Available To get quality of good weld joint that in scheme of construction welder of hull must be planned about way of welder, way of inspection, welding flux and weld type which would in utilizing. By karna to get quality of good weld of welder engineering at ship must be followed by will have an effect on to end result from welder process and mechanical properties yielded at construction welder process of ship steel which in the end will influence strength of construction weld joint of ship steel. How big the influence can be done with assaying of mechanical properties at steel plate weld joint. Data analysis result of the assaying can be taken a a real conclusion assists in increasing grade and security and safety of weld joint. This research aim to know strength of joint T-join at weld material to influence position of welder at buckling strength, and visually with EDSA. By using low alloy steel containing grade C=0,15%, Si=0,24%, Mn=0,88%, P=0,018%, S=0,034%. Material is given [by] treatment of welder with various position of welder Horizontal ( 2F , Vertical ( 3F , Overhead ( 4F by using weld FCAW ( Flux cord Arc Welding with electrode E71T-1, Ø cord 1,2 mm, applies gas CO2, Pada joint type Tjoin welder fillet. Method used in this research is experiment method, that is experimental method directly to object. In this case steel ST42 joint Tjoin with Thick plate 8 mm Marine Plate 18 piece weld by using gas CO2.To get research data is applied [by] observation method by using testing machine bending and test EDSA. Data which collected then is analysed difference of result from visual and mechanic assaying. Result of research shows existence of difference from strength of bending and its(the visulisation is especially to level of weave bead formed between differences of position of Horizontal ( 2F , Vertical ( 3F , Overhead ( 4F. And level of influence position of welder to strain bending 72,65 %.. At execution of workmanship of construction of welder

  7. Integrated Computational Modelling of Thermochemical Surface Engineering of Stainless Steel

    DEFF Research Database (Denmark)

    Kücükyildiz, Ömer Can; Sonne, Mads Rostgaard; Thorborg, Jesper

    2017-01-01

    An implicit finite difference method (FDM) based numerical model for the prediction of composition- and stress-depth profiles developing during low temperature gas nitriding (LTGN) of 316 stainless steel is presented. The essential effects governing the kinetics of composition and coupled stress...... a plane-stress mechanical state. Huge compressive stress levels and steep stress gradients have previously been suggested to have an influence on the concentration profile. The corresponding large plastic deformation that occurs in the developing case is addressed in the model by isotropic plasticity...

  8. Experimental Study on Tribological Properties of Laser Textured 45 Steel Surface

    Directory of Open Access Journals (Sweden)

    Li Zhi Peng

    2016-01-01

    Full Text Available In order to study the influence of pits’ size parameters on the tribological properties of textured friction pairs, using the Nd:YAG laser micro machining system and the “single pulse at the same point, interval more times” processing technics to process the pits on the surface of 45 steel. The dimension parameters of pits texture were obtained by orthogonal experimental design. The tribological experiment of GCr15 pin/45 steel disc was carried out by UMT-2 test machine. The surface morphology of the specimens was analyzed by using scanning electron microscopy. The experimental results show that the pits texture on the surface of 45 steel can effectively reduce the friction coefficient and the wear on the condition of oil-rich lubrication. The textured specimen with diameter 60μm, depth 6μm and surface density 10% has the lowest friction coefficient, and the friction coefficient is reduced by 21% compared with the smooth specimen. By analyzing the wear morphology on the surface of 45 steel, it is found that the surface of pits texture can obviously reduce the wear.

  9. Influence of the chemical composition, heat and surface treatment in the biofouling of austenitic stainless steels

    International Nuclear Information System (INIS)

    Sarro, M. I.; Aleman, O.; Moreno, D. A.; Roso, M.; Ranninger, C.

    2004-01-01

    The main objective of this study was to analyse the biofouling processes in the kinds of stainless steels used normally in industry (UNS S30400, UNS S30403 and UNS S31600), with different surface treatments after grinding and polishing. The study was developed using two microscopy techniques. Scanning Electron Microscopy (SEM was used to evaluate the microorganisms distribution in the materials, and Epi fluorescence Microscopy was used to evaluate the viability of cells in the biofilm. The results revealed the influence of the material, heat treatment, surface treatment and roughness in the biofouling processes in the stainless steel assays. (Author) 33 refs

  10. Combating Wear of ASTM A36 Steel by Surface Modification Using Thermally Sprayed Cermet Coatings

    OpenAIRE

    Shibe, Vineet; Chawla, Vikas

    2016-01-01

    Thermal spray coatings can be applied economically on machine parts to enhance their requisite surface properties like wear, corrosion, erosion resistance, and so forth. Detonation gun (D-Gun) thermal spray coatings can be applied on the surface of carbon steels to improve their wear resistance. In the present study, alloy powder cermet coatings WC-12% Co and Cr3C2-25% NiCr have been deposited on ASTM A36 steel with D-Gun thermal spray technique. Sliding wear behavior of uncoated ASTM A36 ste...

  11. Effects of short immersion time and cooling rates of copperizing process to the evolution of microstructures and copper behavior in the dead mild steel

    Science.gov (United States)

    Jatimurti, Wikan; Sutarsis, Cunika, Aprida Ulya

    2017-01-01

    In a dead mild steel with maximum carbon content of 0.15%, carbon does not contribute much to its strength. By adding copper as an alloying element, a balance between strength and ductility could be obtained through grain refining, solid solution, or Cu precipitation. This research aimed to analyse the changes in microstructures and copper behaviour on AISI 1006, including the phases formed, composition, and Cu dispersion. The addition of cooper was done by immersing steel into molten copper or so we called, copperizing using the principles of diffusion. Specimens were cut with 6 × 3 × 0.3 cm measurement then preheated to 900°C and melting the copper at 1100°C. Subsequently, the immersion of the specimens into molten copper varied to 5 and 7 minutes, and also varying the cooling rate to annealing, normalizing, and quenching. A series of test being conduct were optical microscope test, scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), optical emission spectroscopy (OES), and X-ray diffraction (XRD). The results showed that the longer the immersion time and slower cooling rate, the more Cu diffused causing smaller grain size with the highest Cu diffused recorded was 0.277% in the copperized AISI 1006 steel with 7 minutes of immersion and was annealed. The grain size reduced to 23041.5404 µm2. The annealed specimens show ferrite phase, the normalized ones show polygonal ferrite phase, while the quenched ones show granular bainite phase. The phase formed is single phase Cu. In addition, the normalized and quenched specimens show that Cu dissolved in Fe crystal forming solid solution.

  12. Radiation-heterogeneous processes on the surface of stainless steel in contact with water

    International Nuclear Information System (INIS)

    Garibov, A.; Agayev, T.N.; Velibekova, G.Z.; Ismayilov, Sh.S.; Aliyev, A.G.

    2003-01-01

    Full text: Stainless steels are one of prevailing materials of nuclear power engineering. Under operating conditions in real systems they are exposed to influence of ionizing radiation in contact with various environments. Therefore in the processes of corrosion and destruction of stainless steels special significance takes on surface processes and subsequent heterogeneous processes with their participation. In this report the results of research of nuclear-heterogeneous processes regularities in contact with stainless steel of nuclear reactors with water under influence of γ-quanta in the temperature range 300-573 K are given. Radiolytic processes in water are investigated comprehensively and therefore it was taken as modelling system for titration of surface defects and secondary electrons, emitted from metal. It was determined, that radiation processes in stainless steel give rise to the increasing of energy output of molecular hydrogen at water radiolysis from 0.45 molecule/100 eV at pure water radiolysis at 296 K up to 3.4 molecule/100 eV at the presence of stainless steel at 300 K. With increase of temperature the output of molecular hydrogen increases up to 8.2 molecule/100 eV at 573 K. Processes of lattice damage in samples of stainless steel under influence of γ-rays were investigated by electrophysical method. Influence of γ-radiation on stainless steel in contact with water at temperatures T ≤ 423 K and initial values of radiation dose D ≤ 200 kGy given rise to the reduction of electrical resistivity of samples. At doses D≥200 kGy electrical resistivity is increased. Increase of temperature from 333 K up to 423 K lead to the reduction of dose value, at which the transition to resistance increase, from 200 kGy up to 100 kGy occurs. At T≥523 K insoluble oxide phase is formed on a surface of metal which give rise to the increase of electrical resistivity of stainless steel samples. Surface oxide film formed in contact of stainless steel + H 2 O

  13. Effect of metal surface composition on deposition behavior of stainless steel component dissolved in liquid sodium

    International Nuclear Information System (INIS)

    Yokota, Norikatsu; Shimoyashiki, Shigehiro

    1988-01-01

    Deposition behavior of corrosion products has been investigated to clarify the effect of metal surface composition on the deposition process in liquid sodium. For the study a sodium loop made of Type 304 stainless steel was employed. Deposition test pieces, which were Type 304 stainless steel, iron, nickel or Inconel 718, were immersed in the sodium pool of the test pot. Corrosion test pieces, which were Type 304 stainless steel, 50 at% Fe-50 at%Mn and Inconel 718, were set in a heater pin assembly along the axial direction of the heater pin surface. Sodium temperatures at the outlet and inlet of the heater pin assembly were controlled at 943 and 833 K, respectively. Sodium was purified at a cold trap temperature of 393 K and the deposition test was carried out for 4.3 x 10 2 - 2.9 x 10 4 ks. Several crystallized particles were observed on the surface of the deposition test pieces. The particles had compositions and crystal structures which depended on both the composition of deposition test pieces and the concentration of iron and manganese in sodium. Only iron-rich particles having a polyhedral shape deposited on the iron surface. Two types of particles, iron-rich α-phase and γ-phase with nearly the same composition as stainless steel, were deposited on Type 304 stainless steel. A Ni-Mn alloy was deposited on the nickel surface in the case of a higher concentration of manganese in sodium. On the other hand, for a lower manganese concentration, a Fe-Ni alloy was precipitated on the nickel surface. Particles deposited on nickel had a γ-phase crystal structure similar to the deposition test piece of nickel. Hence, the deposition process can be explained as follows: Corrosion products in liquid sodium were deposited on the metal surface by forming a metal alloy selectively with elements of the metal surface. (author)

  14. Investigation of Steel Surfaces Treated by a Hybrid Ion Implantation Technique

    International Nuclear Information System (INIS)

    Reuther, H.; Richter, E.; Prokert, F.; Ueda, M.; Beloto, A. F.; Gomes, G. F.

    2004-01-01

    Implantation of nitrogen ions into stainless steel in combination with oxidation often results in a decrease or even complete removal of the chromium in the nitrogen containing outermost surface layer. While iron nitrides can be formed easily by this method, due to the absence of chromium, the formation of chromium nitrides is impossible and the beneficial influence of chromium in the steel for corrosion resistance cannot be used. To overcome this problem we use the following hybrid technique. A thin chromium layer is deposited on steel and subsequently implanted with nitrogen ions. Chromium can be implanted by recoil into the steel surface and thus the formation of iron/chromium nitrides should be possible. Both beam line ion implantation and plasma immersion ion implantation are used. Due to the variation of the process parameters, different implantation profiles and different compounds are produced. The produced layers are characterized by Auger electron spectroscopy, conversion electron Moessbauer spectroscopy and X-ray diffraction. The obtained results show that due to the variation of the implantation parameters, the formation of iron/chromium nitrides can be achieved and that plasma immersion ion implantation is the most suitable technique for the enrichment of chromium in the outermost surface layer of the steel when compared to the beam line implantation.

  15. Laser Surface Modification of H13 Die Steel using Different Laser Spot Sizes

    Science.gov (United States)

    Aqida, S. N.; Naher, S.; Brabazon, D.

    2011-05-01

    This paper presents a laser surface modification process of AISI H13 tool steel using three sizes of laser spot with an aim to achieve reduced grain size and surface roughness. A Rofin DC-015 diffusion-cooled CO2 slab laser was used to process AISI H13 tool steel samples. Samples of 10 mm diameter were sectioned to 100 mm length in order to process a predefined circumferential area. The parameters selected for examination were laser peak power, overlap percentage and pulse repetition frequency (PRF). Metallographic study and image analysis were done to measure the grain size and the modified surface roughness was measured using two-dimensional surface profilometer. From metallographic study, the smallest grain sizes measured by laser modified surface were between 0.51 μm and 2.54 μm. The minimum surface roughness, Ra, recorded was 3.0 μm. This surface roughness of the modified die steel is similar to the surface quality of cast products. The grain size correlation with hardness followed the findings correlate with Hall-Petch relationship. The potential found for increase in surface hardness represents an important method to sustain tooling life.

  16. Chemical state analysis of oxidation products on steel surface by conversion electron Moessbauer spectrometry

    International Nuclear Information System (INIS)

    Ujihira, Yusuke; Nomura, Kiyoshi

    1978-01-01

    The polished NT-70H steel (Fe: 95.97%, C: 0.56%, diameter: 5 cm, thickness: 0.5 cm) was immersed in deionized water or in solutions containing (0.25 -- 0.5) M of chloride, sulfate and nitrate ions. The chemical states of oxidation products of iron on the surface were identified through the analysis of conversion electron Moessbauer spectra (CEMS). CEMS of the steel surface, which had been dipped in deionized water, revealed that γ-FeOOH was formed on the surface. The thickness of γ-FeOOH layer increased with the increase of the duration of dipping. Dissolved oxygen in the solution played an essential role in the oxidation of iron to γ-FeOOH. Oxidation product of iron dipped in the 0.5 M sodium chloride solution was identified as γ-FeOOH. Amorphous paramagnetic iron (III) compound tended to form in the presence of hydrogen peroxide or ammonium ions in the solutions. The increase of alkalinity of the solution up to pH 12 suppressed the oxidation rate and assisted the formation of green rust, which was confirmed by the appearance of the quadrupole splitting peaks of the green rust. In the 0.25 M sodium sulfate solution, oxidation of the steel surface proceeded slowly and the quadrupole splitting peaks of Fe(OH) 2 were seen in the CEMS. The peak intensity of Fe(OH) 2 gradually decreased and that of γ-FeOOH increased by the extension of immersion of steel in the solution. Magnetite (Fe 3 O 4 ) layer was developed beneath the γ-FeOOH layer, when steel was dipped in 0.5 M sodium nitrate solution. However, the peaks of Fe 3 O 4 were not seen on CEMS of steel surface immersed in 0.5 M ammonium nitrate solution. Thus, applying the feasibility of CEMS for the characterization of oxidated compounds of iron on the steel surface formed by the immersion in solutions, the oxidation mechanism of the steel surface was discussed based upon the results of chemical state analyses. (author)

  17. Micro/nano engineering on stainless steel substrates to produce superhydrophobic surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Beckford, Samuel; Zou Min, E-mail: mzou@uark.edu

    2011-12-30

    Creating micro-/nano-scale topography on material surfaces to change their wetting properties has been a subject of much interest in recent years. Wenzel in 1936 and Cassie and Baxter in 1944 proposed that by microscopically increasing the surface roughness of a substrate, it is possible to increase its hydrophobicity. This paper reports the fabrication of micro-textured surfaces and nano-textured surfaces, and the combination of both on stainless steel substrates by sandblasting, thermal evaporation of aluminum, and aluminum-induced crystallization (AIC) of amorphous silicon (a-Si). Meanwhile, fluorinated carbon films were used to change the chemical composition of the surfaces to render the surfaces more hydrophobic. These surface modifications were investigated to create superhydrophobic surfaces on stainless steel substrates. The topography resulting from these surface modifications was analyzed by scanning electron microscopy and surface profilometry. The wetting properties of these surfaces were characterized by water contact angle measurement. The results of this study show that superhydrophobic surfaces can be produced by either micro-scale surface texturing or nano-scale surface texturing, or the combination of both, after fluorinated carbon film deposition.

  18. Surface Nb-ALLOYING on 0.4C-13Cr Stainless Steel: Microstructure and Tribological Behavior

    Science.gov (United States)

    Yu, Shengwang; You, Kai; Liu, Xiaozhen; Zhang, Yihui; Wang, Zhenxia; Liu, Xiaoping

    2016-02-01

    0.4C-13Cr stainless steel was alloyed with niobium using double glow plasma surface alloying and tribological properties of Nb-alloyed steel such as hardness, friction and wear were measured. Effects of the alloying temperature on microstructure and the tribological behavior of the alloyed steel were investigated compared with untreated steel. Formation mechanisms of Nb-alloyed layers and increased wear resistance were also studied. The result shows that after surface Nb-alloying treatment, the 0.4C-13Cr steel exhibits a diffusion adhesion at the alloyed layer/substrate interface and improved tribological property. The friction coefficient of Nb-alloyed steel is decreased by about 0.3-0.45 and the wear rate after Nb-alloying is only 2-5% of untreated steel.

  19. A Novel Approach for Evaluating the Contraction of Hypo-Peritectic Steels during Initial Solidification by Surface Roughness

    Directory of Open Access Journals (Sweden)

    Junli Guo

    2018-04-01

    Full Text Available The contraction of peritectic steels in the initial solidification has an important influence on the formation of surface defects of continuously cast slabs. In order to understand the contraction behavior of the initial solidification of steels in the mold, the solidification process and surface roughness in a commercial hypo-peritectic and several non-peritectic steels were investigated using Confocal Scanning Laser Microscope (CSLM. The massive transformation of delta-Fe (δ to austenite (γ was documented in the hypo-peritectic steel, which caused surface wrinkles and greatly increases the surface roughness of samples in the experiments. Surface roughness (Ra(δ→γ was calculated to evaluate the contraction level of the hypo-peritectic steel due to δ–γ transformation. The result shows that the surface roughness method can facilitate the estimation of the contraction level of peritectic transformation over a wide range of cooling rates.

  20. Effect of laser parameters on surface roughness of laser modified tool steel after thermal cyclic loading

    Science.gov (United States)

    Lau Sheng, Annie; Ismail, Izwan; Nur Aqida, Syarifah

    2018-03-01

    This study presents the effects of laser parameters on the surface roughness of laser modified tool steel after thermal cyclic loading. Pulse mode Nd:YAG laser was used to perform the laser surface modification process on AISI H13 tool steel samples. Samples were then treated with thermal cyclic loading experiments which involved alternate immersion in molten aluminium (800°C) and water (27°C) for 553 cycles. A full factorial design of experiment (DOE) was developed to perform the investigation. Factors for the DOE are the laser parameter namely overlap rate (η), pulse repetition frequency (f PRF) and peak power (Ppeak ) while the response is the surface roughness after thermal cyclic loading. Results indicate the surface roughness of the laser modified surface after thermal cyclic loading is significantly affected by laser parameter settings.

  1. Effect of surface decarburization on the mechanical properties of high strength low alloy steel

    International Nuclear Information System (INIS)

    Saqib, S.

    1993-01-01

    An attempt has been made to study the relationship of mechanical properties with the microstructure of a high strength low alloy steel. A thorough investigation was conducted on the steel sheet and variation in mechanical properties was observed across its thickness with a change in the microstructure. Change in hardness and tensile strength at the surface compare to the core of the material is attributed to decarburization. The current research indicates that the correlation between hardness and tensile strength is not valid for steels if the hardness is determined on the surface only. Great care should be taken at the time of determination of tensile strength by using conversion charts/tables on the basis of hardness values obtained by practical means. (author)

  2. Study of surface layer on 08Kh15N5D2T steel

    International Nuclear Information System (INIS)

    Tyurin, A.G.; Povolotskij, V.D.; Zhivotovskij, Eh.A.; Berg, B.N.

    1986-01-01

    08Kh15N5D2T steel phase composition is investigated. Its surface layer was determined by X-ray diffraction analysis method. It is shown, that a subscale appears to be the reason for corrosion of products, made of EhP410 steel. Under the existing smelling technology the carbon content in it is ≥ 0.05%. Therefore to avoid the metal surface depletion with chromium, one must provide for titanium relation to carbon of not less than 4.5 and carry out the rolled product thermal treatment in a protective atmosphere; otherwise, the technology must include not only the removal of scale from steel but the metal subscale layer as well

  3. The effects of sulphate reducing bacteria on the corrosion of mild steel embedded in a bentonite-granitic groundwater paste

    International Nuclear Information System (INIS)

    Philp, J.C.; Taylor, K.J.

    1987-08-01

    Preliminary experiments were set up to investigate how the corrosion of forged 0.2% carbon steel is affected by the presence of sulphate reducing bacteria (SRB). The tests used cultures of a thermophilic bacterium Desulphotomaculum nigrificans mixed with bentonite and synthetic groundwater, to simulate a bacteria contaminated backfill, and placed in contact with carbon steel disc specimens held in perspex cells at 50 0 C under anaerobic conditions. The rate of corrosion with exposure was monitored by electrochemical techniques, together with changes in near field redox potential, during the course of the tests. After 340 days exposure the test cells were dismantled to measure the nature and extent of any corrosion that had occurred and to assess the residual SRB content of the bentonite. Recovery of relatively large numbers of bacteria after almost a year's incubation at 50 0 C in this moderately alkaline (pH 9.5) medium has confirmed the pH tolerance of the strain. There was evidence of the initiation of enhanced corrosion occurring in at least two of the five cells that contained SRB, at about three times the rate of the control. This was probably associated with the presence of SRB despite the nutritionally poor environment which existed in the bentonite gel. (author)

  4. Preparation and High-temperature Anti-adhesion Behavior of a Slippery Surface on Stainless Steel.

    Science.gov (United States)

    Zhang, Pengfei; Huawei, Chen; Liu, Guang; Zhang, Liwen; Zhang, Deyuan

    2018-03-29

    Anti-adhesion surfaces with high-temperature resistance have a wide application potential in electrosurgical instruments, engines, and pipelines. A typical anti-wetting superhydrophobic surface easily fails when exposed to a high-temperature liquid. Recently, Nepenthes-inspired slippery surfaces demonstrated a new way to solve the adhesion problem. A lubricant layer on the slippery surface can act as a barrier between the repelled materials and the surface structure. However, the slippery surfaces in previous studies rarely showed high-temperature resistance. Here, we describe a protocol for the preparation of slippery surfaces with high-temperature resistance. A photolithography-assisted method was used to fabricate pillar structures on stainless steel. By functionalizing the surface with saline, a slippery surface was prepared by adding silicone oil. The prepared slippery surface maintained the anti-wetting property for water, even when the surface was heated to 300 °C. Also, the slippery surface exhibited great anti-adhesion effects on soft tissues at high temperatures. This type of slippery surface on stainless steel has applications in medical devices, mechanical equipment, etc.

  5. Combating Wear of ASTM A36 Steel by Surface Modification Using Thermally Sprayed Cermet Coatings

    Directory of Open Access Journals (Sweden)

    Vineet Shibe

    2016-01-01

    Full Text Available Thermal spray coatings can be applied economically on machine parts to enhance their requisite surface properties like wear, corrosion, erosion resistance, and so forth. Detonation gun (D-Gun thermal spray coatings can be applied on the surface of carbon steels to improve their wear resistance. In the present study, alloy powder cermet coatings WC-12% Co and Cr3C2-25% NiCr have been deposited on ASTM A36 steel with D-Gun thermal spray technique. Sliding wear behavior of uncoated ASTM A36 steel and D-Gun sprayed WC-12% Co and Cr3C2-25% NiCr coatings on base material is observed on a Pin-On-Disc Wear Tester. Sliding wear performance of WC-12% Co coating is found to be better than the Cr3C2-25% NiCr coating. Wear performance of both these cermet coatings is found to be better than uncoated ASTM A36 steel. Thermally sprayed WC-12% Co and Cr3C2-25% NiCr cermet coatings using D-Gun thermal spray technique is found to be very useful in improving the sliding wear resistance of ASTM A36 steel.

  6. Influence of surface defects on the fatigue crack initiation in pearlitic steel

    Directory of Open Access Journals (Sweden)

    Toribio Jesús

    2014-06-01

    Full Text Available Tensile fatigue tests were performed under load control, with constant stress range Δσ on pearlitic steel wires, from the hot rolled bar to the commercial prestressing steel wire (which has undergone seven cold drawing steps. Results show that fatigue cracks in pearlitic steels initiate at the wire surface starting from small defects, whose size decreases with the drawing process. Fatigue cracks created from defects (initiation phase exhibit a fractographic appearance consisting of ductile microtearing events which can be classified as tearing topography surface or TTS, and exhibit a remarkably lower spacing in the prestressing steel wire than in the hot rolled bar. In addition, some S-N tests were performed in both material forms under a stress range of about half the yield strength. In these tests, the main part of the fatigue life corresponds to the propagation stage in the hot rolled bar whereas such a main part of the life is associated with the initiation stage in the case of the prestressing steel wire.

  7. Influence of Surface Roughness of Stainless steel on Microbial Adhesion

    DEFF Research Database (Denmark)

    Bagge, D.; Hilbert, Lisbeth Rischel; Gram, L.

    2002-01-01

    Bacterial adhesion and biofilm formation is of growing interest in the food processing industry where bacteria can survive on surfaces and resist cleaning and disinfection. The condition of the surfaces (eg lack of cracks) and their general roughness is assumed to be important for the hygienic...

  8. Surface damage of 316 stainless steel irradiated with 4He+ to high doses

    International Nuclear Information System (INIS)

    Kaminsky, M.; Das, S.K.

    1978-01-01

    Surface blistering of niobium by implantation with helium ions in the 9 to 15 keV range was investigated. The apparent disappearance of blisters at sufficiently high doses was believed to be an equilibrium effect. To determine whether high temperature annealing causes the equilibrium condition, stainless steel-316 samples were irradiated at a constant 450 0 C. Results are presented

  9. On the formation of protective sulphide coatings on carbon steel surfaces

    International Nuclear Information System (INIS)

    Das, C.; Venkateswaran, G.

    1987-01-01

    A chemical method for protecting carbon steel surfaces by forming pyrrhotite/pyrite coatings has been developed. The protective nature of the coatings has been studied by weight loss kinetics, scanning electron microscopy and electrochemical measurements. A comparison is drawn between the protective nature of pyrite coating with that of magnetite coating. (author)

  10. Experimental Investigation of Membrane Materials used in Multilayer Surfacing Systems for Orthotropic Steel Deck Bridges

    NARCIS (Netherlands)

    Tzimiris, G.

    2017-01-01

    In the Netherlands asphaltic surfacings on orthotropic steel deck bridges (OSDB) mostly consist of two structural layers. The upper layer consists of what is known as very open porous asphalt (ZOAB) for noise reduction. For the lower layer Guss Asphalt (GA) is used. Earlier investigations have shown

  11. Influence of surface texture on the galling characteristics of lean duplex and austenitic stainless steels

    DEFF Research Database (Denmark)

    Wadman, Boel; Eriksen, J.; Olsson, M.

    2010-01-01

    Two simulative test methods were used to study galling in sheet forming of two types of stainless steel sheet: austenitic (EN 1.4301) and lean duplex LDX 2101 (EN 1.4162) in different surface conditions. The pin-on-disc test was used to analyse the galling resistance of different combinations of ...

  12. Influence of the surface finishing on electrochemical corrosion characteristics of AISI 316L stainless steel

    Czech Academy of Sciences Publication Activity Database

    Dundeková, S.; Hadzima, B.; Fintová, Stanislava

    2015-01-01

    Roč. 22, č. 2 (2015), s. 77-84 ISSN 1335-0803 Institutional support: RVO:68081723 Keywords : AISI 316L stainless steel * EIS * Corrosion Subject RIV: JK - Corrosion ; Surface Treatment of Materials http://ojs.mateng.sk/index.php/Mateng/article/view/167/278

  13. Thermomechanical modelling of laser surface glazing for H13 tool steel

    Science.gov (United States)

    Kabir, I. R.; Yin, D.; Tamanna, N.; Naher, S.

    2018-03-01

    A two-dimensional thermomechanical finite element (FE) model of laser surface glazing (LSG) has been developed for H13 tool steel. The direct coupling technique of ANSYS 17.2 (APDL) has been utilised to solve the transient thermomechanical process. A H13 tool steel cylindrical cross-section has been modelled for laser power 200 W and 300 W at constant 0.2 mm beam width and 0.15 ms residence time. The model can predict temperature distribution, stress-strain increments in elastic and plastic region with time and space. The crack formation tendency also can be assumed by analysing the von Mises stress in the heat-concentrated zone. Isotropic and kinematic hardening models have been applied separately to predict the after-yield phenomena. At 200 W laser power, the peak surface temperature achieved is 1520 K which is below the melting point (1727 K) of H13 tool steel. For laser power 300 W, the peak surface temperature is 2523 K. Tensile residual stresses on surface have been found after cooling, which are in agreement with literature. Isotropic model shows higher residual stress that increases with laser power. Conversely, kinematic model gives lower residual stress which decreases with laser power. Therefore, both plasticity models could work in LSG for H13 tool steel.

  14. Atomic force microscopy of surface topography of nitrogen plasma treated steel

    CERN Document Server

    Mahboubi, F

    2002-01-01

    Nitriding of steels, using plasma environments has been practiced for many years. A lot of efforts have been put on developing new methods, such as plasma immersion ion implantation (Pl sup 3) and radio frequency (RF) plasma nitriding, for mass transfer of nitrogen into the surface of the work piece. This article presents the results obtained from an in depth investigation of the surface morphology of the treated samples, carried out using an atomic force microscope. Samples from a microalloyed steel, were treated by both methods for 5 hours at different temperatures ranging from 350 to 550 sup d eg sup C in 75% N sub 2 -25% H sub 2 atmosphere. It has been found that the surface of the samples treated by PI sup 3 technique, although having more favorable properties, were rougher than the surfaces treated by RF plasma nitriding.

  15. AFM surface imaging of AISI D2 tool steel machined by the EDM process

    International Nuclear Information System (INIS)

    Guu, Y.H.

    2005-01-01

    The surface morphology, surface roughness and micro-crack of AISI D2 tool steel machined by the electrical discharge machining (EDM) process were analyzed by means of the atomic force microscopy (AFM) technique. Experimental results indicate that the surface texture after EDM is determined by the discharge energy during processing. An excellent machined finish can be obtained by setting the machine parameters at a low pulse energy. The surface roughness and the depth of the micro-cracks were proportional to the power input. Furthermore, the AFM application yielded information about the depth of the micro-cracks is particularly important in the post treatment of AISI D2 tool steel machined by EDM

  16. AFM surface imaging of AISI D2 tool steel machined by the EDM process

    Science.gov (United States)

    Guu, Y. H.

    2005-04-01

    The surface morphology, surface roughness and micro-crack of AISI D2 tool steel machined by the electrical discharge machining (EDM) process were analyzed by means of the atomic force microscopy (AFM) technique. Experimental results indicate that the surface texture after EDM is determined by the discharge energy during processing. An excellent machined finish can be obtained by setting the machine parameters at a low pulse energy. The surface roughness and the depth of the micro-cracks were proportional to the power input. Furthermore, the AFM application yielded information about the depth of the micro-cracks is particularly important in the post treatment of AISI D2 tool steel machined by EDM.

  17. Development of a surface topography instrument for automotive textured steel plate

    Science.gov (United States)

    Wang, Zhen; Wang, Shenghuai; Chen, Yurong; Xie, Tiebang

    2010-08-01

    The surface topography of automotive steel plate is decisive to its stamping, painting and image clarity performances. For measuring this kind of surface topography, an instrument has been developed based on the principle of vertical scanning white light microscopy interference principle. The microscopy interference system of this instrument is designed based on the structure of Linnik interference microscopy. The 1D worktable of Z direction is designed and introduced in details. The work principle of this instrument is analyzed. In measuring process, the interference microscopy is derived as a whole and the measured surface is scanned in vertical direction. The measurement accuracy and validity is verified by templates. Surface topography of textured steel plate is also measured by this instrument.

  18. Experimental investigation into effect of cutting parameters on surface integrity of hardened tool steel

    Science.gov (United States)

    Bashir, K.; Alkali, A. U.; Elmunafi, M. H. S.; Yusof, N. M.

    2018-04-01

    Recent trend in turning hardened materials have gained popularity because of its immense machinability benefits. However, several machining processes like thermal assisted machining and cryogenic machining have reveal superior machinability benefits over conventional dry turning of hardened materials. Various engineering materials have been studied. However, investigations on AISI O1 tool steel have not been widely reported. In this paper, surface finish and surface integrity dominant when hard turning AISI O1 tool steel is analysed. The study is focused on the performance of wiper coated ceramic tool with respect to surface roughness and surface integrity of hardened tool steel. Hard turned tool steel was machined at varying cutting speed of 100, 155 and 210 m/min and feed rate of 0.05, 0.125 and 0.20mm/rev. The depth of cut of 0.2mm was maintained constant throughout the machining trials. Machining was conducted using dry turning on 200E-axis CNC lathe. The experimental study revealed that the surface finish is relatively superior at higher cutting speed of 210m/min. The surface finish increases when cutting speed increases whereas surface finish is generally better at lower feed rate of 0.05mm/rev. The experimental study conducted have revealed that phenomena such as work piece vibration due to poor or improper mounting on the spindle also contributed to higher surface roughness value of 0.66Ra during turning at 0.2mm/rev. Traces of white layer was observed when viewed with optical microscope which shows evidence of cutting effects on the turned work material at feed rate of 0.2 rev/min

  19. Surface Roughness Analysis in the Hard Milling of JIS SKD61 Alloy Steel

    OpenAIRE

    Huu-That Nguyen; Quang-Cherng Hsu

    2016-01-01

    Hard machining is an efficient solution that can be used to replace the grinding operation in the mold and die manufacturing industry. In this study, an attempt is made to analyze the effect of process parameters on workpiece surface roughness (Ra) in the hard milling of JIS (Japanese Industrial Standard) SKD61 steel, based on a combination of the Taguchi method and response surface methodology (RSM). The cutting parameters are selected based on the structural dynamic analysis of the machine ...

  20. Laser surface pretreatment of 100Cr6 bearing steel – Hardening effects and white etching zones

    International Nuclear Information System (INIS)

    Buling, Anna; Sändker, Hendrik; Stollenwerk, Jochen; Krupp, Ulrich; Hamann-Steinmeier, Angela

    2016-01-01

    Highlights: • Laser surface pretreatment of the bearing steel 100Cr6 is performed. • Microstructural changes of the surface are examined by light microscopy and SEM. • Topographical changes are observed using white light interferometry. • Micro-hardness testing show the existence of very hard white etching zones (WEZ). • WEZ are attributed to near-surface reaustenitization and rapid quenching. • Dark etching zones (DEZ) are found at the laser path edges after laser pretreatment. - Abstract: In order to achieve a surface pretreatment of the bearing steel 100Cr6 (1–1.5 wt.% Cr) a laser-based process was used. The obtained modification may result in an optimization of the adhesive properties of the surface with respect to an anticorrosion polymer coating on the basis of PEEK (poly-ether-ether-ketone), which is applied on the steel surface by a laser melting technique. This work deals with the influence of the laser-based pretreatment regarding the surface microstructure and the micro-hardness of the steel, which has been examined by scanning electron microscopy (SEM), light microscopy and automated micro-hardness testing. The most suitable parameter set for the laser-based pretreatment leads to the formation of very hard white etching zones (WEZ) with a thickness of 23 μm, whereas this pretreatment also induces topographical changes. The occurrence of the white etching zones is attributed to near-surface re-austenitization and rapid quenching. Moreover, dark etching zones (DEZ) with a thickness of 32 μm are found at the laser path edges as well as underneath the white etching zones (WEZ). In these areas, the hardness is decreased due to the formation of oxides as a consequence of re-tempering.

  1. Laser surface pretreatment of 100Cr6 bearing steel – Hardening effects and white etching zones

    Energy Technology Data Exchange (ETDEWEB)

    Buling, Anna, E-mail: a.buling@hs-osnabrueck.de [Faculty of Engineering and Computer Science, University of Applied Sciences, 49009 Osnabrück (Germany); Sändker, Hendrik; Stollenwerk, Jochen [Fraunhofer Institute for Laser Technology ILT, Steinbachstrasse 15, 52074 Aachen (Germany); Krupp, Ulrich; Hamann-Steinmeier, Angela [Faculty of Engineering and Computer Science, University of Applied Sciences, 49009 Osnabrück (Germany)

    2016-08-15

    Highlights: • Laser surface pretreatment of the bearing steel 100Cr6 is performed. • Microstructural changes of the surface are examined by light microscopy and SEM. • Topographical changes are observed using white light interferometry. • Micro-hardness testing show the existence of very hard white etching zones (WEZ). • WEZ are attributed to near-surface reaustenitization and rapid quenching. • Dark etching zones (DEZ) are found at the laser path edges after laser pretreatment. - Abstract: In order to achieve a surface pretreatment of the bearing steel 100Cr6 (1–1.5 wt.% Cr) a laser-based process was used. The obtained modification may result in an optimization of the adhesive properties of the surface with respect to an anticorrosion polymer coating on the basis of PEEK (poly-ether-ether-ketone), which is applied on the steel surface by a laser melting technique. This work deals with the influence of the laser-based pretreatment regarding the surface microstructure and the micro-hardness of the steel, which has been examined by scanning electron microscopy (SEM), light microscopy and automated micro-hardness testing. The most suitable parameter set for the laser-based pretreatment leads to the formation of very hard white etching zones (WEZ) with a thickness of 23 μm, whereas this pretreatment also induces topographical changes. The occurrence of the white etching zones is attributed to near-surface re-austenitization and rapid quenching. Moreover, dark etching zones (DEZ) with a thickness of 32 μm are found at the laser path edges as well as underneath the white etching zones (WEZ). In these areas, the hardness is decreased due to the formation of oxides as a consequence of re-tempering.

  2. Study of the temperature effect on the surface of stainless steel using fission track technique

    Energy Technology Data Exchange (ETDEWEB)

    Dhawan, M M; Nagpaul, K K [Kurukshetra Univ. (India). Dept. of Physics

    1977-01-01

    Solid state track technique has been used to determine trace amounts of uranium in steel. Steel samples of the size 1 cm x 1 cm x 0.6 cm were ground, polished, heated to various temperatures ranging from room temperature to 900 deg C and then packed alternately with lexan detectors in an aluminium capsule for thermal neutron irradiation. After irradiation, lexan discs were removed and etched. Their surfaces were scanned under an optical microscope for measurement of track density. Uranium contents of the samples was found to vary from 6 ppm to 9 ppm.

  3. Modification of the Steel Surface Treated by a Volume Discharge Plasma in Nitrogen at Atmospheric Pressure

    Science.gov (United States)

    Erofeev, M. V.; Shulepov, M. A.; Ivanov, Yu. F.; Oskomov, K. V.; Tarasenko, V. F.

    2016-03-01

    Effect of volume discharge plasma initiated by an avalanche electron beam on the composition, structure, and properties of the surface steel layer is investigated. Voltage pulses with incident wave amplitude up to 30 kV, full width at half maximum of about 4 ns, and wave front of about 2.5 ns were applied to the gap with an inhomogeneous electric field. Changes indicating the hardening effect of the volume discharge initiated by an avalanche electron beam are revealed in St3-grade steel specimens treated by the discharge of this type.

  4. Investigation of surface residual stress profile on martensitic stainless steel weldment with X-ray diffraction

    Directory of Open Access Journals (Sweden)

    I.I. Ahmed

    2018-04-01

    Full Text Available The development of residual stresses during fabrication is inevitable and often neglected with dire consequences during the service life of the fabricated components. In this work, the surface residual stress profile following the martensitic stainless steel (MSS pipe welding was investigated with X-ray diffraction technique. The results revealed the presence of residual stresses equilibrated across the weldment zones. Tensile residual stress observed in weld metal was balanced by compressive residual stresses in the parent material on the opposing sides of weld metal. Keywords: Residual stress, Weld, Stainless steel, X-ray, HAZ

  5. Wedge cutting of mild steel by CO 2 laser and cut-quality assessment in relation to normal cutting

    Science.gov (United States)

    Yilbas, B. S.; Karatas, C.; Uslan, I.; Keles, O.; Usta, Y.; Yilbas, Z.; Ahsan, M.

    2008-10-01

    In some applications, laser cutting of wedge surfaces cannot be avoided in sheet metal processing and the quality of the end product defines the applicability of the laser-cutting process in such situations. In the present study, CO 2 laser cutting of the wedge surfaces as well as normal surfaces (normal to laser beam axis) is considered and the end product quality is assessed using the international standards for thermal cutting. The cut surfaces are examined by the optical microscopy and geometric features of the cut edges such as out of flatness and dross height are measured from the micrographs. A neural network is introduced to classify the striation patterns of the cut surfaces. It is found that the dross height and out of flatness are influenced significantly by the laser output power, particularly for wedge-cutting situation. Moreover, the cut quality improves at certain value of the laser power intensity.

  6. Surface modification of steels and magnesium alloy by high current pulsed electron beam

    Science.gov (United States)

    Hao, Shengzhi; Gao, Bo; Wu, Aimin; Zou, Jianxin; Qin, Ying; Dong, Chuang; An, Jian; Guan, Qingfeng

    2005-11-01

    High current pulsed electron beam (HCPEB) is now developing as a useful tool for surface modification of materials. When concentrated electron flux transferring its energy into a very thin surface layer within a short pulse time, superfast processes such as heating, melting, evaporation and consequent solidification, as well as dynamic stress induced may impart the surface layer with improved physico-chemical and mechanical properties. This paper presents our research work on surface modification of steels and magnesium alloy with HCPEB of working parameters as electron energy 27 keV, pulse duration ∼1 μs and energy density ∼2.2 J/cm2 per pulse. Investigations performed on carbon steel T8, mold steel D2 and magnesium alloy AZ91HP have shown that the most pronounced changes of phase-structure state and properties occurring in the near-surface layers, while the thickness of the modified layer with improved microhardness (several hundreds of micrometers) is significantly greater than that of the heat-affected zone. The formation mechanisms of surface cratering and non-stationary hardening effect in depth are discussed based on the elucidation of non-equilibrium temperature filed and different kinds of stresses formed during pulsed electron beam melting treatment. After the pulsed electron beam treatments, samples show significant improvements in measurements of wear and corrosion resistance.

  7. Surface modification of steels and magnesium alloy by high current pulsed electron beam

    International Nuclear Information System (INIS)

    Hao, Shengzhi; Gao, Bo; Wu, Aimin; Zou, Jianxin; Qin, Ying; Dong, Chuang; An, Jian; Guan, Qingfeng

    2005-01-01

    High current pulsed electron beam (HCPEB) is now developing as a useful tool for surface modification of materials. When concentrated electron flux transferring its energy into a very thin surface layer within a short pulse time, superfast processes such as heating, melting, evaporation and consequent solidification, as well as dynamic stress induced may impart the surface layer with improved physico-chemical and mechanical properties. This paper presents our research work on surface modification of steels and magnesium alloy with HCPEB of working parameters as electron energy 27 keV, pulse duration ∼1 μs and energy density ∼2.2 J/cm 2 per pulse. Investigations performed on carbon steel T8, mold steel D2 and magnesium alloy AZ91HP have shown that the most pronounced changes of phase-structure state and properties occurring in the near-surface layers, while the thickness of the modified layer with improved microhardness (several hundreds of micrometers) is significantly greater than that of the heat-affected zone. The formation mechanisms of surface cratering and non-stationary hardening effect in depth are discussed based on the elucidation of non-equilibrium temperature filed and different kinds of stresses formed during pulsed electron beam melting treatment. After the pulsed electron beam treatments, samples show significant improvements in measurements of wear and corrosion resistance

  8. Methods of improvement in hardness of composite surface layer on cast steel

    Directory of Open Access Journals (Sweden)

    J. Szajnar

    2008-08-01

    Full Text Available The paper presents a method of usable properties of surface layers improvement of cast carbon steel 200–450, by put directly in founding process a composite surface layer on the basis of Fe-Cr-C alloy and next its remelting with use of welding technology TIG – Tungsten Inert Gas. Technology of composite surface layer guarantee mainly increase in hardness and abrasive wear resistance of cast steel castings on machine elements. This technology can be competition for generally applied welding technology (surfacing by welding and thermal spraying. However the results of studies show, that is possible to connection of both methods founding and welding of surface hardening of cast steel castings. In range of experimental plan was made test castings with composite surface layer, which next were remelted with energy 0,8 and 1,6 kJ/cm. Usability for industrial applications of test castings was estimated by criterion of hardness and abrasive wear resistance of type metal-mineral.

  9. Influence of pre-heating on the surface modification of powder-metallurgy processed cold-work tool steel during laser surface melting

    Energy Technology Data Exchange (ETDEWEB)

    Šturm, Roman, E-mail: roman.sturm@fs.uni-lj.si [University of Ljubljana, Faculty of Mechanical Engineering, Aškerčeva 6, 1000 Ljubljana (Slovenia); Štefanikova, Maria [University of Ljubljana, Faculty of Mechanical Engineering, Aškerčeva 6, 1000 Ljubljana (Slovenia); Steiner Petrovič, Darja [Institute of Metals and Technology, Lepi pot 11, 1000 Ljubljana (Slovenia)

    2015-01-15

    Graphical abstract: - Highlights: • Heat-treatment protocol for laser surface melting of cold-work tool steel is proposed. • The laser melted steel surface is hardened, and morphologically modified. • The pre-heating of substrate creates a crack-and pore-free steel surface. • The optimum pre-heating temperature is determined to be 350 °C. • Using pre-heating the quantity of retained austenite is reduced. - Abstract: In this study we determine the optimal parameters for surface modification using the laser surface melting of powder-metallurgy processed, vanadium-rich, cold-work tool steel. A combination of steel pre-heating, laser surface melting and a subsequent heat treatment creates a hardened and morphologically modified surface of the selected high-alloy tool steel. The pre-heating of the steel prior to the laser surface melting ensures a crack- and pore-free modified surface. Using a pre-heating temperature of 350 °C, the extremely fine microstructure, which typically evolves during the laser-melting, became slightly coarser and the volume fraction of retained austenite was reduced. In the laser-melted layer the highest values of microhardness were achieved in the specimens where a subsequent heat treatment at 550 °C was applied. The performed thermodynamic calculations were able to provide a very valuable assessment of the liquidus temperature and, especially, a prediction of the chemical composition as well as the precipitation and dissolution sequence for the carbides.

  10. Investigation of selected surface integrity features of duplex stainless steel (DSS after turning

    Directory of Open Access Journals (Sweden)

    G. Krolczyk

    2015-01-01

    Full Text Available The article presents surface roughness profiles and Abbott - Firestone curves with vertical and amplitude parameters of surface roughness after turning by means of a coated sintered carbide wedge with a coating with ceramic intermediate layer. The investigation comprised the influence of cutting speed on the selected features of surface integrity in dry machining. The material under investigation was duplex stainless steel with two-phase ferritic-austenitic structure. The tests have been performed under production conditions during machining of parts for electric motors and deep-well pumps. The obtained results allow to draw conclusions about the characteristics of surface properties of the machined parts.

  11. Spreading of lithium on a stainless steel surface at room temperature

    Energy Technology Data Exchange (ETDEWEB)

    Skinner, C.H., E-mail: cskinner@pppl.gov [Princeton Plasma Physics Laboratory, Princeton, NJ 08543 (United States); Capece, A.M. [Princeton Plasma Physics Laboratory, Princeton, NJ 08543 (United States); Roszell, J.P.; Koel, B.E. [Department of Chemical and Biological Engineering, Princeton University, NJ 08540 (United States)

    2016-01-15

    Lithium conditioned plasma facing surfaces have lowered recycling and enhanced plasma performance on many fusion devices and liquid lithium plasma facing components are under consideration for future machines. A key factor in the performance of liquid lithium components is the wetting by lithium of its container. We have observed the surface spreading of lithium from a mm-scale particle to adjacent stainless steel surfaces using a scanning Auger microprobe that has elemental discrimination. The spreading of lithium occurred at room temperature (when lithium is a solid) from one location at a speed of 0.62 μm/day under ultrahigh vacuum conditions. Separate experiments using temperature programmed desorption (TPD) investigated bonding energetics between monolayer-scale films of lithium and stainless steel. While multilayer lithium desorption from stainless steel begins to occur just above 500 K (E{sub des} = 1.54 eV), sub-monolayer Li desorption occurred in a TPD peak at 942 K (E{sub des} = 2.52 eV) indicating more energetically favorable lithium-stainless steel bonding (in the absence of an oxidation layer) than lithium–lithium bonding.

  12. Portable hyperspectral fluorescence imaging system for detection of biofilms on stainless steel surfaces

    Science.gov (United States)

    Jun, Won; Lee, Kangjin; Millner, Patricia; Sharma, Manan; Chao, Kuanglin; Kim, Moon S.

    2008-04-01

    A rapid nondestructive technology is needed to detect bacterial contamination on the surfaces of food processing equipment to reduce public health risks. A portable hyperspectral fluorescence imaging system was used to evaluate potential detection of microbial biofilm on stainless steel typically used in the manufacture of food processing equipment. Stainless steel coupons were immersed in bacterium cultures, such as E. coli, Pseudomonas pertucinogena, Erwinia chrysanthemi, and Listeria innocula. Following a 1-week exposure, biofilm formations were assessed using fluorescence imaging. In addition, the effects on biofilm formation from both tryptic soy broth (TSB) and M9 medium with casamino acids (M9C) were examined. TSB grown cells enhance biofilm production compared with M9C-grown cells. Hyperspectral fluorescence images of the biofilm samples, in response to ultraviolet-A (320 to 400 nm) excitation, were acquired from approximately 416 to 700 nm. Visual evaluation of individual images at emission peak wavelengths in the blue revealed the most contrast between biofilms and stainless steel coupons. Two-band ratios compared with the single-band images increased the contrast between the biofilm forming area and stainless steel coupon surfaces. The 444/588 nm ratio images exhibited the greatest contrast between the biofilm formations and stainless coupon surfaces.

  13. Corrosion and surface conditions of EUROFER 97 steel in Pb-17Li at 500 deg C

    International Nuclear Information System (INIS)

    Zmitko, M.; Splichal, K.; Masarik, V.

    2004-01-01

    In this work the corrosion behaviour of EUROFER 97 was examined in flowing Pb-17Li at the temperature 500 deg C up to 2500 hours. Surface morphology and chemical composition profiles and weight changes were investigated. Interaction of EUROFER 97 specimens with Pb-17Li melt results in a material dissolution, which is demonstrated by surface morphology and specimen weight changes. The specimen surfaces investigated after 500 and 1000 hours of exposure in Pb-17Li show similar surface appearance in both as-received and polished conditions. The corrosive damage occurs locally and a major part of surface areas is not affected. The exposure after 2500 hours evidences some visible decrease in the surface roughness for both surface conditions. The surface overlapping was observed and industrial tube productions have to avoid such types of defects. A small weight changes after 500 and 1000 hours and a higher weight decrease after 2500 hours were observed. The absolute values of the weight change after 500 and 1000 hours are about one order of magnitude lower than ones of weight changes after 2500 hours exposure. There were no significant differences of weight changes between as-received and polished surface conditions. The weight decrease of about 1 mg/cm 2 after 2500 hours is in a sufficient correlation with the value of about 4 mg/cm 2 evaluated from data of Fe-12Cr-1MoVW steel. The experiments have shown that the surface corrosive attack revealed only after a certain incubation period. During this period the surface layers are relatively stable to a direct attack of the surface by the melt. In the course of exposure time those layers are not further resistant and can influence the dissolutions of steel components. Concentration profiles of steel components near the steel surface were examined by EDX line-scan and point analyses. Under the experimental conditions no considerable profile of Cr and Fe in surface layers, as higher soluble steel components in Pb-17Li, was

  14. Development of Fractal Dimension and Characteristic Roughness Models for Turned Surface of Carbon Steels

    Science.gov (United States)

    Zuo, Xue; Zhu, Hua; Zhou, Yuankai; Ding, Cong; Sun, Guodong

    2016-08-01

    Relationships between material hardness, turning parameters (spindle speed and feed rate) and surface parameters (surface roughness Ra, fractal dimension D and characteristic roughness τ∗) are studied and modeled using response surface methodology (RSM). The experiments are carried out on a CNC lathe for six carbon steel material AISI 1010, AISI 1020, AISI 1030, AISI 1045, AISI 1050 and AISI 1060. The profile of turned surface and the surface roughness value are measured by a JB-5C profilometer. Based on the profile data, D and τ∗ are computed through the root-mean-square method. The analysis of variance (ANOVA) reveals that spindle speed is the most significant factors affecting Ra, while material hardness is the most dominant parameter affecting τ∗. Material hardness and spindle speed have the same influence on D. Feed rate has less effect on three surface parameters than spindle speed and material hardness. The second-order models of RSM are established for estimating Ra, D and τ∗. The validity of the developed models is approximately 80%. The response surfaces show that a surface with small Ra and large D and τ∗ can be obtained by selecting a high speed and a large hardness material. According to the established models, Ra, D and τ∗ of six carbon steels surfaces can be predicted under cutting conditions studied in this paper. The results have an instructive meaning to estimate the surface quality before turning.

  15. Combined slurry and cavitation erosion resistance of surface modified SS410 stainless steel

    Science.gov (United States)

    Amarendra, H. J.; Pratap, M. S.; Karthik, S.; Punitha Kumara, M. S.; Rajath, H. C.; Ranjith, H.; Shubhatunga, S. V.

    2018-03-01

    Slurry erosion and combined slurry and cavitation erosion resistance of thermal spray coatings are studied and compared with the as-received martensitic stainless steel material. 70Ni-Cr coatings are deposited on SS 410 material through plasma thermal spray process. The synergy effect of the combined slurry and cavitation erosion resistance of plasma thermal spray coatings were investigated in a slurry pot tester in the presence of bluff bodies known as Cavitation Inducers. Results showed the combined slurry and cavitation erosion resistance of martensitic stainless steel - 410 can be improved by plasma thermal spray coating. It is observed that the plasma spray coated specimens are better erosion resistant than the as- received material, subjected to erosion test under similar conditions. As-received and the surface modified steels are mechanically characterized for its hardness, bending. Morphological studies are conducted through scanning electron microscope.

  16. A Study on the Fatigue-Fractured Surface of Normalized SS41 Steel and M.E.F. Dual Phase Steel by an X-ray Diffraction Technique

    International Nuclear Information System (INIS)

    Oh, Sae Wook; Park, Young Chul; Park, Soo Young; Kim, Deug Jin; Hue, Sun Chul

    1996-01-01

    This study verified the relationship between fracture mechanics parameters and X-ray parameters for normalized SS41 steel with homogeneous crystal structure and M.E.F. dual phase steel(martensite encapsulated islands of ferrite). The fatigue crack propagation test were carried out and X-ray diffraction technique was applied to fatigue fractured surface. The change in X-ray parameters(residual stress, half-value breadth) according to the depth of fatigue fractured surface were investigated. The depth of maximum plastic zone, W y , were determined on the basis of the distribution of the half-value breadth for normalized SS41 steel and that of the residual stress for M.E.F. dual phase steel. K max could be estimated by the measurement of W y

  17. Small Punch Tests at Oxide Scales Surface of Structural Steel and Low Silicon Steel

    Czech Academy of Sciences Publication Activity Database

    Hrabovský, J.; Dobeš, Ferdinand; Horský, J.

    2014-01-01

    Roč. 82, 3-4 (2014), s. 297-310 ISSN 0030-770X Institutional support: RVO:68081723 Keywords : Small punch * Oxide scales * X-ray diffraction * Mechanical properties Subject RIV: JK - Corrosion ; Surface Treatment of Materials Impact factor: 1.140, year: 2014

  18. Modification of steel surface by plasma electrolytic saturation with nitrogen and carbon

    Energy Technology Data Exchange (ETDEWEB)

    Kusmanov, S.A., E-mail: sakusmanov@yandex.ru; Kusmanova, Yu.V., E-mail: yulia.kusmanova@yandex.ru; Smirnov, A.A., E-mail: sciencealexsm@gmail.com; Belkin, P.N., E-mail: belkinp@yandex.ru

    2016-06-01

    The effect of the electrolyte composition with ammonia, acetone, and ammonium chloride on the structure and properties of low carbon steel was studied in anode plasma electrolytic nitrocarburising. An X-ray diffractometer, a scanning electron microscopy (SEM) and an optical microscope were used to characterize the phase composition of the modified layer and its surface morphology. Surface roughness was studied with a profilometer–profilograph. The hardness of the treated and untreated samples was measured using a microhardness tester. The sources of nitrogen and carbon are shown to be the products of evaporation and thermal decomposition of the electrolyte components. It is established that the influence of concentration of ammonia, acetone, and ammonium chloride on the size of the structural components of the hardened layer is explained by the competition of the anode dissolution, high-temperature oxidation and diffusion of the saturating component. The electrolyte composition (10–12.5% ammonium chloride, 5% acetone, 5% ammonia) and processing mode (800 °C, 5–10 min) of low carbon steels allowing to obtain the hardened surface layer up to 0.2 mm with microhardness 930 HV and with decrease in the roughness (R{sub a}) from 1.013 to 0.054 μm are proposed. The anode plasma electrolytic nitricarburising is able to decrease friction coefficient of the treated low carbon steel from 0.191 to 0.169 and wear rate from 13.5 mg to 1.0 mg. - Highlights: • Aqueous solution (12.5% NH{sub 4}Cl, 5% ammonia, 5% acetone) is proposed for PEN/C steels. • Microhardness of steel (0.2% C) is 930 HV due to PEN/C for 5–10 min at 800 °C. • Anode PEN/C of low carbon steel decreases its roughness (R{sub a}) from 1.013 to 0.054 μm. • Anode PEN/C decreases friction coefficient of low carbon steel from 0.191 to 0.169 • Anode PEN/C decreases wear loss of low carbon steel from 13.5 mg to 1.0 mg.

  19. Selective surface oxidation and segregation upon short term annealing of model alloys and industrial steel grades

    Energy Technology Data Exchange (ETDEWEB)

    Swaminathan, S.

    2007-07-01

    Segregation and selective oxidation phenomena of minor alloying elements during annealing of steel sheets lead to the formation of bare spots after hot-dip galvanizing. This thesis highlights the influence of annealing conditions and the effect of alloying elements on the selective oxidation in model alloys and some industrial steel grades. Model alloys of binary (Fe-2Si, Fe-2Mn, Fe-0.8Cr), ternary (Fe-2Mn-2Si, Fe-2Mn-0.8Cr, Fe-1Mn-0.8Cr, Fe-1Si-0.8Cr, Fe-2Si-0.8Cr) and quarternary (Fe-2Mn-2Si-0.8Cr) systems were studied. In the case of steels, standard grade interstitial free (IF) steels and experimental grade tensile strength 1000 MPa steel were investigated. All specimens were annealed at 820 C in N{sub 2}-5%H{sub 2} gas atmospheres with the wide range of dew points (i.e. -80 to 0 C). The surface chemistry after annealing and its wettability with liquid Zn have been correlated as a function of dew points by simulating the hot-dip galvanizing process at laboratory scale. (orig.)

  20. STM study on surface relief, ultra-fine structure and transformation mechanism of bainite in steels

    International Nuclear Information System (INIS)

    Fang, H.S.; Yang, Z.G.; Wang, J.J.; Zheng, Y.K.

    1995-01-01

    The surface reliefs accompanying lower bainite transformation in steels have been studied by scanning tunneling microscopy (STM). With the exclusive vertical resolution of STM, we observed that the surface relief associated with bainite is a group of surface reliefs related to subplates, subunits and sub-subunits. From the bainite plate to the sub-subunit in it, the reliefs are in a tent shape, not of invariant plane strain (IPS) type. The fine structure of bainite in a steel has also been shown by STM and TEM that bainite plate is composed of subplates, subunits and sub-subunits. On the basis of the fine structure inside a bainitic ferrite plate observed under STM, sympathetic-ledgewise mechanism of bainite formation is proposed. (orig.)

  1. The surface cleanliness of 316 L + N stainless steel studied by SIMS and AES

    CERN Document Server

    Mathewson, A G

    1974-01-01

    Some cleaning methods for 316 L+N stainless steel including solvent cleaning, high temperature treatment in vacuo and gas discharge cleaning have been studied by SIMS and AES with a view to providing a clean vacuum chamber surface with low gas desorption under ion bombardment. After solvent cleaning the main surface contaminant was found to be C and its associated compounds. Laboratory investigations on small samples of stainless steel showed that clean surfaces could be obtained by heating in vacuo to 800 degrees C followed by exposure to air and by argon or argon/10% oxygen discharge cleaning. Due to a cross contamination within the vacuum system, the 800 degrees C treated chamber gave positive desorption coefficients under ion bombardment. The pure argon discharge cleaned chambers proved stable giving negative desorption coefficients up to 2200 eV ion energy even after several weeks storage discharge treatment and installation. (10 refs).

  2. X-ray analysis on the fatigue fracture surface of stainless steels

    International Nuclear Information System (INIS)

    Yoshioka, Yasuo; Guimard, B.

    1986-01-01

    Several X-ray diffraction parameters were observed on the fatigue fracture surface and its vicinity of both of SUS420J1 martensitic and SUS304 austenitic stainless steels and we discussed the relation between the stress intensity factor and these parameters. Monotonic plastic zone depth determined by the measurement of residual stress distribution proportionals to the squre of the maximum stress intensity factor as well as the case of ferritic steel. However, it is very difficult to find the relation between the stress intensity factor and residual stress or half value breadth of X-ray diffraction profile in the fracture surface for both materials. On the other hand, the amount of martensite induced by the transformation during fatigue process in SUS304 is related to the maximum stress intensity factor in the fracture surface regardless the stress ratio R. (author)

  3. Simultaneous surface engineering and bulk hardening of precipitation hardening stainless steel

    DEFF Research Database (Denmark)

    Frandsen, Rasmus Berg; Christiansen, Thomas; Somers, Marcel A. J.

    2006-01-01

    This article addresses simultaneous bulk precipitation hardening and low temperature surface engineering of two commercial precipitation hardening stainless steels: Sandvik Nanoflex® and Uddeholm Corrax®. Surface engineering comprised gaseous nitriding or gaseous carburising. Microstructural....... The duration and temperature of the nitriding/carburising surface hardening treatment can be chosen in agreement with the thermal treatment for obtaining optimal bulk hardness in the precipitation hardening stainless steel....... characterisation of the cases developed included X-ray diffraction analysis, reflected light microscopy and micro-hardness testing. It was found that the incorporation of nitrogen or carbon resulted in a hardened case consisting of a combination of (tetragonal) martensite and expanded (cubic) austenite...

  4. An evaluation of the effect of surface chromium concentration on the oxidation of a stainless steel

    International Nuclear Information System (INIS)

    Lobb, R.C.; Evans, H.E.

    1983-01-01

    Short-term oxidation tests have been performed at 850 deg C in a CO 2 -based atmosphere on 20Cr-25Ni-Nb-stabilized steels previously exposed to dynamic vacuum at 1000 deg C. This pre-treatment preferentially removes chromium from the metal surface and is always detrimental to the oxidation properties. It is shown that porous, iron-rich oxides initially form on specimens with surface chromium concentrations 18.5 w/o chromium, a protective surface layer is produced. It is suggested that the transition between these extremes is determined by nucleation conditions and, in the present steels, it is shown how the metal grain size plays a significant role. (author)

  5. Diffusion of C and Cr During Creation of Surface Layer on Cast Steel Casting

    Directory of Open Access Journals (Sweden)

    Szajnar J.

    2014-10-01

    Full Text Available In paper a method of improvement in utility properties of unalloyed cast steel casting in result of diffusion of C and Cr in process of creation of surface layer is presented. The aim of paper was determination of diffusion range of basic elements of alloyed surface layer. Moreover a quantitative analysis of carbides phase strengthens alloyed surface layer of casting was carried out. The results of studies shown that important factors of surface layer creation are maximal temperature Tmax on granular insert – cast steel boundary dependent of pouring temperature, granularity Zw of Fe-Cr-C alloy insert and thickness of casting wall gśo. On the basis of obtained results was affirmed that with increase of thickness of casting wall increases range of diffusion in solid state in Fe-Cr-C grains and in liquid state. Moreover the range of Tmax = 13001500oC favours creation of the proper alloyed surface layers on cast steel.

  6. Effect of surface finishing on the oxidation behaviour of a ferritic stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Ardigo-Besnard, M.R., E-mail: maria-rosa.ardigo-besnard@u-bourgogne.fr [Laboratoire Interdisciplinaire Carnot de Bourgogne (ICB), UMR 6303 CNRS—Université de Bourgogne Franche-Comté, BP 47870, 21078 Dijon Cedex (France); Popa, I.; Heintz, O.; Chassagnon, R. [Laboratoire Interdisciplinaire Carnot de Bourgogne (ICB), UMR 6303 CNRS—Université de Bourgogne Franche-Comté, BP 47870, 21078 Dijon Cedex (France); Vilasi, M. [Institut Jean Lamour, UMR 7198 CNRS—Université de Lorraine, Parc de Saurupt, 54011 Nancy (France); Herbst, F. [Laboratoire Interdisciplinaire Carnot de Bourgogne (ICB), UMR 6303 CNRS—Université de Bourgogne Franche-Comté, BP 47870, 21078 Dijon Cedex (France); Girardon, P. [APERAM, Centre de Recherche, BP15, 62330 Isbergues (France); Chevalier, S. [Laboratoire Interdisciplinaire Carnot de Bourgogne (ICB), UMR 6303 CNRS—Université de Bourgogne Franche-Comté, BP 47870, 21078 Dijon Cedex (France)

    2017-08-01

    Highlights: • Study of surface finishing effect on the corrosion behaviour of a stainless steel. • Mirror polished samples were compared to as-rolled material. • Two oxidation mechanisms were identified depending on the surface finishing. • Before oxidation, native chemical phases are identical for both samples. • Subsurface dislocations generated by the polishing process promote Cr{sub 2}O{sub 3} formation. - Abstract: The corrosion behaviour and the oxidation mechanism of a ferritic stainless steel, K41X (AISI 441), were evaluated at 800 °C in water vapour hydrogen enriched atmosphere. Mirror polished samples were compared to as-rolled K41X material. Two different oxidation behaviours were observed depending on the surface finishing: a protective double (Cr,Mn){sub 3}O{sub 4}/Cr{sub 2}O{sub 3} scale formed on the polished samples whereas external Fe{sub 3}O{sub 4} and (Cr,Fe){sub 2}O{sub 3} oxides grew on the raw steel. Moreover, isotopic marker experiments combined with SIMS analyses revealed different growth mechanisms. The influence of surface finishing on the corrosion products and growth mechanisms was apprehended by means of X-ray photoelectron spectroscopy (XPS) and residual stress analyses using XRD at the sample surfaces before ageing.

  7. Chemical nanocavitation of surfaces to enhance the utility of stainless steel as a medical material.

    Science.gov (United States)

    Rodriguez-Contreras, Alejandra; Guadarrama Bello, Dainelys; Flynn, Sam; Variola, Fabio; Wuest, James D; Nanci, Antonio

    2018-01-01

    While stainless steel is a broadly used alloy with interesting mechanical properties, its applications in medicine suffers from inherent biocompatibility limitations. An attractive opportunity to improve its performance is to alter its surface, but this has proven challenging. We now show how high range anodization conditions using H 2 SO 4 /H 2 O 2 as an atypical electrolyte can efficiently nanocavitate the surface of both stainless steel SS304 and SS316 and create a topography with advantageous biomedical characteristics. We describe the structural and chemical features of the resulting surfaces, and propose a nanocorrosion/transpassivation/repassivation mechanism for its creation. Our approach creates a thin mesoporous layer of crystalline oxide that selectively promotes mammalian cell activity and limits bacterial adhesion. The modified surfaces favor the formation and maturation of focal adhesion plaques and environment-sensing filopodia with abundant extra small lateral membrane protrusions, suggesting an increase in membrane fluidity. These protrusions represent a yet undescribed cellular response. Such surfaces promise to facilitate the integration of implantable SS devices, in general. In addition, our strategy simultaneously provides a simple, commercially attractive way to control the adhesion of microorganisms, making nanostructured stainless steel broadly useful in hospital environments, in manufacturing medical devices, as well as offering possibilities for non-medical applications. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

  8. Microscopic work function anisotropy and surface chemistry of 316L stainless steel using photoelectron emission microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Barrett, N., E-mail: nick.barrett@cea.fr [CEA, IRAMIS, SPEC, LENSIS, F-91191 Gif-sur-Yvette (France); Renault, O. [CEA, LETI, Minatec Campus, F-38054 Grenoble Cedex 09 (France); Lemaître, H. [Université de Cergy-Pontoise, Rue d’Eragny, Neuville sur Oise, 95 031 Cergy-Pontoise (France); Surface Dynamics Laboratory, Institut for Fysik og Astronomi Aarhus Universitet, Ny Munkegade 120, 8000 Aarhus C (Denmark); Bonnaillie, P. [CEA, DEN, DANS, DMN, SRMP, F-91191 Gif-sur-Yvette (France); Barcelo, F. [CEA, DEN, DANS, DMN, SRMA, LA2M, F-91191 Gif-sur-Yvette (France); Miserque, F. [CEA, DEN, DANS, DPC, SCCME, LECA, F-91191 Gif-sur-Yvette (France); Wang, M.; Corbel, C. [Laboratoire des Solides Irradis, Ecole Polytechnique, route de Saclay, F-91128 Palaiseau (France)

    2014-08-15

    Highlights: • PEEM and EBSD study of spatial variations in local work function of 316L steel. • Correlation between work function and crystal grain orientation at the surface of 316L steel. • Spatially resolved chemistry of residual oxide layer. - Abstract: We have studied the variation in the work function of the surface of sputtered cleaned 316L stainless steel with only a very thin residual oxide surface layer as a function of grain orientation using X-ray photoelectron emission microscopy (XPEEM) and Electron Backscattering Diffraction. The grains are mainly oriented [1 1 1] and [1 0 1]. Four distinct work function values spanning a 150 meV energy window are measured. Grains oriented [1 1 1] have a higher work function than those oriented [1 0 1]. From core level XPEEM we deduce that all grain surfaces are Cr enriched and Ni depleted whereas the Cr/Fe ratio is similar for all grains. The [1 1 1] oriented grains show evidence for a Cr{sub 2}O{sub 3} surface oxide and a higher concentration of defective oxygen sites.

  9. Development of stress corrosion cracking resistant welds of 321 stainless steel by simple surface engineering

    Science.gov (United States)

    Mankari, Kamal; Acharyya, Swati Ghosh

    2017-12-01

    We hereby report a simple surface engineering technique to make AISI grade 321 stainless steel (SS) welds resistant to stress corrosion cracking (SCC) in chloride environment. Heat exchanger tubes of AISI 321 SS, welded either by (a) laser beam welding (LBW) or by (b) metal inert gas welding (MIG) were used for the study. The welds had high magnitude of tensile residual stresses and had undergone SCC in chloride environment while in service. The welds were characterized using field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD). Subsequently, the welded surfaces were subjected to buffing operation followed by determination of residual stress distribution and surface roughness by XRD and surface profilometer measurements respectively. The susceptibility of the welds to SCC was tested in buffed and un-buffed condition as per ASTM G-36 in boiling MgCl2 for 5 h and 10 h, followed by microstructural characterization by using optical microscope and FESEM. The results showed that the buffed surfaces (both welds and base material) were resistant to SCC even after 10 h of exposure to boiling MgCl2 whereas the un-buffed surfaces underwent severe SCC for the same exposure time. Buffing imparted high magnitude of compressive stresses on the surface of stainless steel together with reduction in its surface roughness and reduction in plastic strain on the surface which made the welded surface, resistant to chloride assisted SCC. Buffing being a very simple, portable and economic technique can be easily adapted by the designers as the last step of component fabrication to make 321 stainless steel welds resistant to chloride assisted SCC.

  10. The effects of parametric changes in electropolishing process on surface properties of 316L stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Rahman, Zia ur [School of Engineering and Technology, Central Michigan University, Mt. Pleasant, MI 48859 (United States); Science of Advanced Materials, Central Michigan University, Mt. Pleasant, MI 48859 (United States); Deen, K.M. [Department of Materials Engineering, University of British Columbia, Vancouver, BC V6T 1Z4 (Canada); Department of Metallurgy and Materials Engineering, CEET, University of the Punjab, Lahore, 54590 (Pakistan); Cano, Lawrence [Department of Mechanical Engineering, The University of Texas Rio Grande Valley, Edinburg, TX 78539 (United States); Haider, Waseem, E-mail: haide1w@cmich.edu [School of Engineering and Technology, Central Michigan University, Mt. Pleasant, MI 48859 (United States); Science of Advanced Materials, Central Michigan University, Mt. Pleasant, MI 48859 (United States)

    2017-07-15

    Highlights: • 316L stainless steel was electropolished at the oxygen evolution (EPO) and below the oxygen evolution (EPBO) potentials. • EPBO samples displayed low fractional polarity and surface roughness when compared to EPO. • Both electropolished samples (EPO and EPBO) showed higher resistance to corrosion when compared to mechanically polished samples. • EPO and EPBO samples showed enhanced cell proliferation and stellar morphology after 24 h. - Abstract: Corrosion resistance and biocompatibility of 316L stainless steel implants depend on the surface features and the nature of the passive film. The influence of electropolishing on the surface topography, surface free energy and surface chemistry was determined by atomic force microscopy, contact angle meter and X-ray photoelectron spectroscopy, respectively. The electropolishing of 316L stainless steel was conducted at the oxygen evolution potential (EPO) and below the oxygen evolution potential (EPBO). Compared to mechanically polished (MP) and EPO, the EPBO sample depicted lower surface roughness (Ra = 6.07 nm) and smaller surface free energy (44.21 mJ/m{sup 2}). The relatively lower corrosion rate (0.484 mpy) and smaller passive current density (0.619 μA/cm{sup 2}) as determined from cyclic polarization scans was found to be related with the presence of OH, Cr(III), Fe(0), Fe(II) and Fe(III) species at the surface. These species assured the existence of relatively uniform passive oxide film over EPBO surface. Moreover, the relatively large charge transfer (R{sub ct}) and passive film resistance (R{sub f}) registered by EPBO sample from impedance spectroscopy analysis confirmed its better electrochemical performance. The in vitro response of these polished samples toward MC3T3 pre-osteoblast cell proliferation was determined to be directly related with their surface and electrochemical properties.

  11. Characterization of the thrombogenic potential of surface oxides on stainless steel for implant purposes

    International Nuclear Information System (INIS)

    Shih, C.-C.; Shih, C.-M.; Su, Y.-Y.; Chang, M.-S.; Lin, S.-J.

    2003-01-01

    Marketed stents are manufactured from various metals and passivated with different degrees of surface oxidation. The functional surface oxides on the degree of antithrombotic potential were explored through a canine femoral extracorporeal circuit model. Related properties of these oxide films were studied by open-circuit potential, current density detected at open-circuit potential, the electrochemical impedance spectroscopy, transmission electron microscopy, Auger spectroscopy (AES), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy. Experimental evidences showed that blood clot weight after a 30-min follow-up was significantly lower for the stainless steel wire passivated with amorphous oxide (AO) compared to the wire passivated with polycrystalline oxide (PO) or commercial as-received wire coils (AS). Surface characterizations showed that a stable negative current density at open-circuit potential and a significant lower potential were found for the wire surface passivated with AO than for the surface passivated with PO. Time constant of AO is about 25 times larger than that of polycrystalline oxide. Significant difference in oxide grain sizes was found between PO and AO. Surface chemistries revealed by the AES and XPS spectra indicated the presence of a Cr- and oxygen-rich surface oxide for AO, and a Fe-rich and oxygen-lean surface oxide for PO. These remarkable characteristics of AO surface film might have a potential to provide for excellent antithrombotic characteristics for the 316L stainless steel stents

  12. Wear characterization of a tool steel surface modified by melting and gaseous alloying

    International Nuclear Information System (INIS)

    Rizvi, S.A.

    1999-01-01

    Hot forging dies are subjected to laborious service conditions and so there is a need to explore means of improving die life to increase productivity and quality of forgings. Surface modification in order to produce wear resistant surface is an attractive method as it precludes the need to use expensive and highly alloyed steels. In this study, a novel, inexpensive surface modification technique is used to improve the tri biological properties of an H13 tool steel. Surface melting was achieved using a tungsten heat source and gaseous alloying produced under a shield of argon, carbon dioxide, carbon dioxide-argon mixture and nitrogen gases. The change in wear behaviour was compared through micro-hardness indentation measurements and using a dry sliding pin-on-plate wear testing machine. This study shows superior wear behaviour of the modified surfaces when compared to the untreated surfaces. The increase in wear resistance is attributed to the formation of carbides when surfaces are melted under a carbon dioxide shield. However, in the case of nitrogen and argon gaseous alloying, an increase in wear resistance can be attributed to an increase in surface hardness which in turn effects surface deformation behaviour. (author)

  13. Surface composition effect of nitriding Ni-free stainless steel as bipolar plate of polymer electrolyte fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Yang; Shironita, Sayoko [Nagaoka University of Technology, 1603-1, Kamitomioka, Nagaoka, Niigata 940-2188 (Japan); Nakatsuyama, Kunio [Nakatsuyama Heat Treatment Co., Ltd., 1-1089-10, Nanyou, Nagaoka, Niigata 940-1164 (Japan); Souma, Kenichi [Nagaoka University of Technology, 1603-1, Kamitomioka, Nagaoka, Niigata 940-2188 (Japan); Hitachi Industrial Equipment Systems Co., Ltd., 3 Kanda Neribei, Chiyoda, Tokyo 101-0022 (Japan); Umeda, Minoru, E-mail: mumeda@vos.nagaokaut.ac.jp [Nagaoka University of Technology, 1603-1, Kamitomioka, Nagaoka, Niigata 940-2188 (Japan)

    2016-12-01

    Graphical abstract: The anodic current densities in the passive region of nitrided SUS445-N stainless steel are lower than those of a non heat-treated SUS445 stainless steel and heat-treated SUS445-Ar stainless steel under an Ar atmosphere. It shows a better corrosion resistance for the SUS445 stainless steel after the nitriding heat treatment. - Highlights: • The nitriding heat treatment was carried out using Ni-free SUS445 stainless steel. • The corrosion resistance of the nitrided SUS445-N stainless steel was improved. • The structure of the nitrided SUS445-N stainless steel changed from α-Fe to γ-Fe. • The surface elemental components present in the steels affect the corrosion resistance. - Abstract: In order to increase the corrosion resistance of low cost Ni-free SUS445 stainless steel as the bipolar plate of a polymer electrolyte fuel cell, a nitriding surface treatment experiment was carried out in a nitrogen atmosphere under vacuum conditions, while an Ar atmosphere was used for comparison. The electrochemical performance, microstructure, surface chemical composition and morphology of the sample before and after the electrochemical measurements were investigated using linear sweep voltammetry (LSV), X-ray diffraction (XRD), glow discharge optical emission spectroscopy (GDS) and laser scanning microscopy (LSM) measurements. The results confirmed that the nitriding heat treatment not only increased the corrosion resistance, but also improved the surface conductivity of the Ni-free SUS445 stainless steel. In contrast, the corrosion resistance of the SUS445 stainless steel decreased after heat treatment in an Ar atmosphere. These results could be explained by the different surface compositions between these samples.

  14. Isomers of Poly Aminophenol: Chemical Synthesis, Characterization, and Its Corrosion Protection Aspect on Mild Steel in 1 M HCl

    Directory of Open Access Journals (Sweden)

    G. Thenmozhi

    2014-01-01

    Full Text Available The oxidative chemical polymerizations of three isomers of aminophenol, ortho, meta, and para (PoAP, PmAP, and PpAP, were performed in aqueous HCl using ammonium persulfate as an oxidant at 0–3°C. The synthesized polymers were characterized by employing elemental analysis, GPC, UV-VIS-NIR, FT-IR, XRD, and TGA. The corrosion inhibition effect of these three polymers on mild steel in 1 M HCl solution was studied by using electrochemical techniques such as potentiodynamic polarization and electrochemical impedance spectroscopy. These measurements reveal that the inhibition efficiency obtained by these polymers increased by increasing their concentration. The inhibition efficiency follows the order PpAP > PoAP > PmAP. The results further revealed that PpAP at a concentration of 250 mg/L furnishes maximum inhibition efficiency (96.5%. Polarization studies indicated that these three polymers act as the mixed type corrosion inhibitors.

  15. Characterisations Of Al2O3-13% Wt TiO2 Deposition On Mild Steel Via Plasma Spray Method

    International Nuclear Information System (INIS)

    Yusoff, N. H.; Isa, M. C.; Ghazali, M. J.; Muchtar, A.; Forghani, S.; Daud, A. R.

    2011-01-01

    To date, plasma sprayed alumina titania have been widely used as wear resistance coatings in textile, machinery and printing industries. Previous studies showed that the coating microstructures and properties were strongly depended on various parameters such as ceramic composition, grain size powders and spray parameters, thus, influencing the melting degree of the alumina titania during the deposition process. The aim of this study focuses on the evolution of the micron sizes of alumina-13%wt titania at different plasma spray power, ranging from 20kW to 40kW. It was noted that the coating porosity of alumina-13%wt titania were decreased from 6.2% to 4% by increasing the plasma power from 20 to 40 kW. At lower power value, partially melted powders were deposited, generating over 6% porosity within the microstructures. Percentage of porosity about 5.6% gave the best ratio of bi-modal structures, providing the highest microhardness value. Furthermore, the effect of microstructure and porosity formation on wear resistance was also discussed. Coatings with less porosity exhibited better resistance to wear, in which the wear resistance of coated mild steel possessed only ∼5 x 10 -4 cm 3 /Nm with 4% of porosity.

  16. Investigation on microstructural, anti-corrosion and mechanical properties of doped Zn–Al–SnO2 metal matrix composite coating on mild steel

    International Nuclear Information System (INIS)

    Fayomi, O.S.I.; Popoola, A.P.I.; Aigbodion, V.S.

    2015-01-01

    Highlights: • Properties of nanocomposite Zn–Al coating containing SnO 2 nanoparticles. • The morphology and structure of the coating were analysed. • The anticorrosion activities of the coating prepared. • The mechanical properties were found to improve with the amount of the SnO 2 embedded. - Abstract: In this study, the microstructural, mechanical and anti-corrosion properties of nanocomposite Zn–Al coating containing SnO 2 nanoparticles prepared from sulphates electrolyte by electrodeposition on mild steel substrate was investigated. The morphologies of the coating were analysed using SEM/EDS, AFM Raman and X-ray diffraction. The anticorrosion behaviour of the coating prepared with different concentrations of SnO 2 (7 and 13 g/L) and potential of (0.3 and 0.5 V) was examined in 3.65% NaCl solution by using linear polarization techniques. The wear and hardness properties of the coatings were performed under accelerated reciprocating dry sliding wear tests and diamond micro-hardness tester respectively. The results obtained showed that the incorporation of SnO 2 in the plating bath brings an increase in corrosion resistance and mechanical properties of Zn–Al–SnO 2 composite coatings. The SEM images showed a homogeneous grain structure and finer morphology of the coatings. The hardness values was found to improve with the amount of the SnO 2 embedded into the Zn–Al metal deposit and effective deposition parameters

  17. Surface analysis of 316 stainless steel treated with cold atmospheric plasma

    Energy Technology Data Exchange (ETDEWEB)

    Williams, David F., E-mail: david.williams@surrey.ac.uk [Department of Mechanical Engineering Sciences, University Of Surrey, Guildford, Surrey GU2 7XH (United Kingdom); TWI Ltd Granta Park Great Abington, Cambridge CB21 6AL (United Kingdom); Kellar, Ewen J.C. [TWI Ltd Granta Park Great Abington, Cambridge CB21 6AL (United Kingdom); Jesson, David A.; Watts, John F. [Department of Mechanical Engineering Sciences, University Of Surrey, Guildford, Surrey GU2 7XH (United Kingdom)

    2017-05-01

    Highlights: • Reduction in carbon contamination from ∼80 at.% to 40 at.% after 15 s treatment. • Associated carbon thickness reduction from 4.5 nm to 0.5 nm. • Area treated by torch has a diameter of 11 mm measured using imaging XPS. - Abstract: The surface of 316 stainless steel has been modified using cold atmospheric plasma (CAP) to increase the surface free energy (by cleaning the and chemically activating the surface)IN preparation for subsequent processes such as painting, coating or adhesive bonding. The analyses carried out, on CAP treated 316 stainless steel surfaces, includes X-ray photoelectron spectroscopy (XPS), imaging XPS (iXPS), and surface free energy (SFE) analysis using contact angle measurements. The CAP treatment is shown to increase the SFE of as-received 316 stainless steel from ∼39 mJ m{sup −1} to >72 mJ m{sup −1} after a short exposure to the plasma torch. This was found to correlate to a reduction in adventitious carbon, as determined by XPS analysis of the surface. The reduction from ∼90 at% to ∼30% and ∼39 at%, after being plasma treated for 5 min and 15 s respectively, shows that the process is relatively quick at changing the surface. It is suggested that the mechanism that causes the increase in surface free energy is chain scission of the hydrocarbon contamination triggered by free electrons in the plasma plume followed by chemical functionalisation of the metal oxide surface and some of the remaining carbon contamination layer.

  18. The effect of machining parameters on surface roughness during turning of stainless steel

    International Nuclear Information System (INIS)

    El-Belazi, Khalid M.

    1991-03-01

    Surface roughness is a direct consequence of the cutting tool action, its assessment and control represent an effective way by which the machining process can be studied. The control of surface roughness has become increasingly important during the last thirty years, because the quality of surface is extremely important for machined components that have been designed to stand to static and cyclic loads. This work has two major goals. The first is to develop a new theoretical model based on the assumption that the shape of the cutting tool nose is elliptical to evaluate the surface roughness parameters. The second is to investigate the effect of cutting speed, feed rate, overhang length, tool nose radius (circular sharp), and depth of cut on surface roughness of turned surfaces of austenitic stainless steel grade 12X18H10T. It was found from the theoretical part that the surface roughness values obtained from the elliptical model are much better than those obtained from the other models. It was found from the experimental work that the surface roughness values increase by increasing cutting speed, feed rate, depth of cut, and overhang length, and fluctuates when using cutting tools with various nose radii, during turning of the above mentioned steel by using a brazed carbide cutting tool. (author)

  19. Antibacterial isoeugenol coating on stainless steel and polyethylene surfaces prevents biofilm growth.

    Science.gov (United States)

    Nielsen, C K; Subbiahdoss, G; Zeng, G; Salmi, Z; Kjems, J; Mygind, T; Snabe, T; Meyer, R L

    2018-01-01

    Pathogenic bacteria can spread between individuals or between food items via the surfaces they share. Limiting the survival of pathogens on surfaces, therefore, presents an opportunity to limit at least one route of how pathogens spread. In this study, we propose that a simple coating with the essential oil isoeugenol can be used to circumvent the problem of bacterial transfer via surfaces. Two commonly used materials, stainless steel and polyethylene, were coated by physical adsorption, and the coatings were characterized by Raman spectroscopy, atomic force microscopy and water contact angle measurements. We quantified and visualized the colonization of coated and uncoated surfaces by three bacteria: Staphylococcus aureus, Listeria monocytogenes and Pseudomonas fluorescens. No viable cells were detected on surfaces coated with isoeugenol. The isoeugenol coating prepared with simple adsorption proved effective in preventing biofilm formation on stainless steel and polyethylene surfaces. The result was caused by the antibacterial effect of isoeugenol, as the coating did not diminish the adhesive properties of the surface. Our study demonstrates that a simple isoeugenol coating can prevent biofilm formation of S. aureus, L. monocytogenes and P. fluorescens on two commonly used surfaces. © 2017 The Society for Applied Microbiology.

  20. Multi-Parameter Analysis of Surface Finish in Electro-Discharge Machining of Tool Steels

    Directory of Open Access Journals (Sweden)

    Cornelia Victoria Anghel

    2006-10-01

    Full Text Available The paper presents a multi- parameter analysis of surface finish imparted to tool-steel plates by electro-discharge machining (EDM is presented. The interrelationship between surface texture parameters and process parameters is emphasized. An increased number of parameters is studied including amplitude, spacing, hybrid and fractal parameters,, as well. The correlation of these parameters with the machining conditions is investigated. Observed characteristics become more pronounced, when intensifying machining conditions. Close correlation exists between certain surface finish parameters and EDM input variables and single and multiple statistical regression models are developed.

  1. Study on surface modification of M2 steel induced by Cu ions and Al ions implantation

    International Nuclear Information System (INIS)

    Wang Chao; Liu Zhengmin

    2001-01-01

    Changes of surface hardness and wear resistances in M2 type steel implanted by Cu Al ions were reported. The dependence of surface strengthening on ion species and dose was studied by X-ray diffraction (XRD) and Rutherford Backscattering Spectroscopy (RBS) for microhardness and wear resistances measurement. It is shown that both hardness and wear resistance increases apparently after ion implantation. XRD analysis indicates that different phases formed after Al Cu ions implanted. It is also suggested that Cu, Al ions have different role in surface strengthening

  2. Wear of Polished Steel Surfaces in Dry Friction Linear Contact on Polimer Composites with Glass Fibres

    Directory of Open Access Journals (Sweden)

    D. Rus

    2013-12-01

    Full Text Available It is generally known that the friction and wear between polymers and polished steel surfaces has a special character, the behaviour to friction and wear of a certain polymer might not be valid for a different polymer, moreover in dry friction conditions. In this paper, we study the reaction to wear of certain polymers with short glass fibres on different steel surfaces, considering the linear friction contact, observing the friction influence over the metallic surfaces wear. The paper includes also its analysis over the steel’s wear from different points of view: the reinforcement content influence and tribological parameters (load, contact pressure, sliding speed, contact temperature, etc.. Thus, we present our findings related to the fact that the abrasive component of the friction force is more significant than the adhesive component, which generally is specific to the polymers’ friction. Our detections also state that, in the case of the polyamide with 30% glass fibres, the steel surface linear wear rate order are of 10-4 mm/h, respectively the order of volumetric wear rate is of 10-6 cm3 /h. The resulting volumetric wear coefficients are of the order (10-11 – 10-12 cm3/cm and respectively linear wear coefficients of 10-9 mm/cm.

  3. Inhibitory activity of Paenibacillus polymyxa on the biofilm formation of Cronobacter spp. on stainless steel surfaces.

    Science.gov (United States)

    Yang, Soonwook; Kim, Seonhwa; Ryu, Jee-Hoon; Kim, Hoikyung

    2013-07-01

    The objective of this study was to control the survival or biofilm formation of Cronobacter spp. on stainless steel surfaces using Paenibacillus polymyxa. The antibacterial activity of a cell-free culture supernatant (CFCS) of P. polymyxa against Cronobacter spp. was found to vary with P. polymyxa incubation time. Maximum activity occurred when P. polymyxa was incubated at 25 or 30 °C for 96 h. When the CFCS was introduced to Cronobacter spp. adhered to stainless steel strips at 25 °C for up to 72 h, the CFCS successfully inhibited Cronobacter biofilm formation. Additionally, stainless steel surfaces with a preformed P. polymyxa biofilm were exposed to Cronobacter spp. suspensions in PBS or 0.1% peptone water at 3, 5, or 7 log CFU/mL to facilitate its attachment. The Cronobacter population significantly decreased on this surface, regardless of inoculum level or carrier, when the P. polymyxa biofilm was present. However, the microbial population decreased within 6 h and remained unchanged thereafter when the surface was immersed in an inoculum suspended in 0.1% peptone water at 5 or 7 log CFU/mL. These results indicate that P. polymyxa is able to use a promising candidate competitive-exclusion microorganism to control Cronobacter spp. © 2013 Institute of Food Technologists®

  4. Effect of dew point on the formation of surface oxides of twinning-induced plasticity steel

    International Nuclear Information System (INIS)

    Kim, Yunkyum; Lee, Joonho; Shin, Kwang-Soo; Jeon, Sun-Ho; Chin, Kwang-Geun

    2014-01-01

    The surface oxides of twinning-induced plasticity (TWIP) steel annealed at 800 °C for 43 s were investigated using transmission electron microscopy. During the annealing process, the oxygen potential was controlled by adjusting the dew point in a 15%H 2 –N 2 gas atmosphere. It was found that the type of surface oxides formed and the thickness of the oxide layer were determined by the dew point. In a gas mixture with a dew point of − 20 °C, a MnO layer with a thickness of ∼ 100 nm was formed uniformly on the steel surface. Under the MnO layer, a MnAl 2 O 4 layer with a thickness of ∼ 15 nm was formed with small Mn 2 SiO 4 particles that measured ∼ 70 nm in diameter. Approximately 500 nm below the MnAl 2 O 4 layer, Al 2 O 3 was formed at the grain boundaries. On the other hand, in a gas mixture with a dew point of − 40 °C, a MnAl 2 O 4 layer with a thickness of ∼ 5 nm was formed on most parts of the surface. On some parts of the surface, Mn 2 SiO 4 particles were formed irregularly up to a thickness of ∼ 50 nm. Approximately 200 nm below the MnAl 2 O 4 layer, Al 2 O 3 was found at the grain boundaries. Thermodynamic calculations were performed to explain the experimental results. The calculations showed that when a O2 > ∼ 1.26 × 10 −28 , MnO, MnAl 2 O 4 , and Mn 2 SiO 4 can be formed together, and the major oxide is MnO. When a O2 is in the range of 1.26 × 10 −28 –2.51 × 10 −31 , MnO is not stable but MnAl 2 O 4 is the major oxide. When a O2 < ∼ 2.51 × 10 −31 , only Al 2 O 3 is stable. Consequently, the effective activity of oxygen is considered the dominant factor in determining the type and shape of surface oxides of TWIP steel. - Highlights: • The surface oxides of TWIP steel annealed at 800 °C were investigated using TEM. • The surface oxides were determined by the dew point during the annealing process. • The activity of oxygen is the major factor determining the oxides of TWIP steel

  5. The performance of a surface-applied corrosion inhibitor for the carbon steel in saturated Ca(OH)2 solutions

    International Nuclear Information System (INIS)

    Zheng, Haibing; Li, Weihua; Ma, Fubin; Kong, Qinglin

    2014-01-01

    In the present work, the performance of an amino alcohol based surface applied inhibitor was studied by the electrochemical techniques in saturated Ca(OH) 2 solutions. The surface morphology of the carbon steel was observed by scanning electron microscope, and the energy diffraction spectrum was also tested. Results showed that the inhibitor used in this work demonstrated obvious inhibition efficiency on the carbon steel in saturated Ca(OH) 2 solutions. The inhibition mechanism of the inhibitor lies in the quick adsorption of the active component on carbon steel surface

  6. Impact of roughness, wettability and hydrodynamic conditions on the incrustation on stainless steel surfaces

    International Nuclear Information System (INIS)

    Bogacz, Wojciech; Lemanowicz, Marcin; Al-Rashed, Mohsen H.; Nakonieczny, Damian; Piotrowski, Tomasz; Wójcik, Janusz

    2017-01-01

    Highlights: • Steel plates (X5CrNi18-10) with different roughness and wettability were prepared. • Incrustation of MgSO 4 ·7H 2 O under laminar flow (Re = 59–178) was investigated. • Influence of surface properties and fluid velocity on incrustation was found. • Wettability and surface roughness cannot be considered separately. • Analysis of heat transfer and incrustation time-lapse videos are presented. - Abstract: The goal of this work was to investigate the influence of the stainless steel surface roughness and wettability on incrustation of MgSO 4 ·7H 2 O from aqueous solutions and resulting heat transfer resistance. The experiments were done for laminar flow (Re = 59–178) which is characteristic for regions of apparatus where fouling usually begin. A series of steel plates (X5CrNi18-10) were prepared and used as a heat transfer surfaces. Their properties, i.e. roughness, wettability and elementary composition of surfaces were determined. The experiments were done using specially designed flow cell equipped with Peltier element. Each incrustation measurement lasted for two hours, during which heat transfer resistance was measured as a function of time. After the experiments the mass of crystalline deposit was weighted. It was proved that wettability as well as surface roughness cannot be considered separately in the case of incrustation phenomenon. The knowledge of surface roughness is insufficient due to the fact, that it is possible to obtain surfaces with similar roughness but substantially different wettability for the same material.

  7. Surface analysis in steel nitrides by using Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Figueiredo, R.S. de.

    1991-07-01

    The formation of iron nitride layer at low temperatures, 600-700 K, by Moessbauer spectroscopy is studied. These layers were obtained basically through two different processes: ion nitriding and ammonia gas nitriding. A preliminary study about post-discharge nitriding was made using discharge in hollow cathode as well as microwave excitation. The assembly of these chambers is also described. The analysis of the nitrided samples was done by CEMS and CXMS, aided by optical microscopy, and the CEMS and CXMS detectors were constructed by ourselves. We also made a brief study about these detectors, testing as acetone as the mixture 80% He+10% C H 4 as detection gases for the use of CEMS. The surface analysis of the samples showed that in the ammonia gas process nitriding the nitrided layer starts by the superficial formation of an iron nitride rich nitrogen. By thermal evolution this nitride promotes the diffusion of nitrogen and the formation of other more stable nitrides. (author)

  8. Structural changes in surface layer of steel 08Kh18N10T during machining

    International Nuclear Information System (INIS)

    Palenik, J.; Vodarek, V.

    1989-01-01

    The results are reported of a study of the surface layer of steel 08Kh18N10T affected by machining. Structural changes were studied caused by finish turning and by additional roller burnishing. Multiple deformation bands were observed to occur under the given cutting conditions; they mainly consisted of deformation doublets and only in isolated cases of ε-martensite. The presence of α'-martensite was not shown in the specimen surface layer following finish turning. The deformation shear bands in the roller-burnished specimen consisted of both ε-martensite and of deformation doublets. The amount of ε-martensite in the structure was significantly higher than in the specimen worked by turning. Local presence of α'-martensite formations was observed inside the deformation bands. It thus follows that roller burnishing is unsuitable as part of the manufacture of components from steel 08Kh18N10T. (J.B.). 5 figs., 1 tab., 9 refs

  9. Effect of plasma nitriding time on surface properties of hard chromium electroplated AISI 1010 steel

    International Nuclear Information System (INIS)

    Kocabas, Mustafa; Uelker, Suekrue

    2015-01-01

    Properties of steel can be enhanced by surface treatments such as coating. In some cases, further treatments such as nitriding can also be used in order to get even better results. In order to investigate the properties of nitride layer on hard Cr coated AISI 1010 steel, substrates were electroplated to form hard Cr coatings. Then hard Cr coatings were plasma nitrided at 700 C for 3 h, 5 h and 7 h and nitride phases on the coatings were investigated by X-ray diffraction analysis. The layer thickness and surface properties of nitride films were investigated by scanning electron microscopy. The hardness and adhesion properties of Cr-N phases were examined using nano indentation and Daimler-Benz Rockwell C adhesion tests. The highest measured hardness was 24.1 GPa and all the three samples exhibited poor adhesion.

  10. Modification and characterization of the AISI 410 martensitic stainless steels surface

    International Nuclear Information System (INIS)

    Bincoleto, A.V.L.; Nascente, P.A.P.

    2010-01-01

    Steam turbines are used in the generation of more than half the electric energy produced in the world nowadays. It is important the study which aims to improve the efficiency by means of the optimization of leaks and of the aerodynamic profiles, as well as to maintain the integrity of the components. The martensitic stainless steels are widely employed due to the combination of their good mechanical properties with higher corrosion resistance. However, their lower wear resistance and their poor tribological behavior limit their use, since they decrease the component life time. In order to evaluate the improvement in the performance of the AISI 410 stainless steel, several process of surface modification were employed. Five samples were produced: the first one was not treated, the second one received liquid nitriding, the third, gas nitriding, the forth, thermal aspersion of tungsten carbide, and the fifth, boronizing. The samples were characterized by optical microscopy, surface microhardness, and X-ray diffractometry. (author)

  11. Effect of plasma nitriding time on surface properties of hard chromium electroplated AISI 1010 steel

    Energy Technology Data Exchange (ETDEWEB)

    Kocabas, Mustafa [Yildiz Technical Univ., Istanbul (Turkey). Metallurgical and Materials Engineering Dept.; Danisman, Murat [Gedik Univ., Istanbul (Turkey). Electrical and Electronic Engineering Dept.; Cansever, Nurhan [Yildiz Technical Univ., Istanbul (Turkey); Uelker, Suekrue [Afyon Kocatepe Univ. (Turkey). Dept. of Mechanical Engineering

    2015-06-01

    Properties of steel can be enhanced by surface treatments such as coating. In some cases, further treatments such as nitriding can also be used in order to get even better results. In order to investigate the properties of nitride layer on hard Cr coated AISI 1010 steel, substrates were electroplated to form hard Cr coatings. Then hard Cr coatings were plasma nitrided at 700 C for 3 h, 5 h and 7 h and nitride phases on the coatings were investigated by X-ray diffraction analysis. The layer thickness and surface properties of nitride films were investigated by scanning electron microscopy. The hardness and adhesion properties of Cr-N phases were examined using nano indentation and Daimler-Benz Rockwell C adhesion tests. The highest measured hardness was 24.1 GPa and all the three samples exhibited poor adhesion.

  12. Plasma-induced surface degradation in 304 stainless steel used for TRIAM-1M limiter

    International Nuclear Information System (INIS)

    Tsukuda, N.; Kuramoto, E.; Tokunaga, K.; Muroga, T.; Yoshida, N.; Itoh, S.

    1994-01-01

    Surface degradation in a 304 stainless steel limiter of TRIAM-1M by long-pulse discharge during long period operation has been examined by means of X-ray diffraction, scanning electron microscopy and dynamical microindentation tests. Particular exfoliation and hardening of the surface of the electron drift side were observed. These result from the formation of α prime martensite induced by hydrogen in the plasma. The stability of the martensitic phase has been studied by annealing experiments on the cathodically hydrogen charged 316 stainless steel by X-ray diffraction. Both ε and α prime martensites were formed by 22 h cathodic charging. The former reverts to γ-phase and/or converts to α prime martensite below 723 K and the latter reverts to γ-phase below 923 K, repectively. ((orig.))

  13. Laser surface modification of 316 L stainless steel with bioactive hydroxyapatite.

    Science.gov (United States)

    Balla, Vamsi Krishna; Das, Mitun; Bose, Sreyashree; Ram, G D Janaki; Manna, Indranil

    2013-12-01

    Laser-engineered net shaping (LENS™), a commercial additive manufacturing process, was used to modify the surfaces of 316 L stainless steel with bioactive hydroxyapatite (HAP). The modified surfaces were characterized in terms of their microstructure, hardness and apatite forming ability. The results showed that with increase in laser energy input from 32 J/mm(2) to 59 J/mm(2) the thickness of the modified surface increased from 222±12 μm to 355±6 μm, while the average surface hardness decreased marginally from 403±18 HV0.3 to 372±8 HV0.3. Microstructural studies showed that the modified surface consisted of austenite dendrites with HAP and some reaction products primarily occurring in the inter-dendritic regions. Finally, the surface-modified 316 L samples immersed in simulated body fluids showed significantly higher apatite precipitation compared to unmodified 316 L samples. © 2013.

  14. Controlling the stainless steel surface wettability by nanosecond direct laser texturing at high fluences

    Science.gov (United States)

    Gregorčič, P.; Šetina-Batič, B.; Hočevar, M.

    2017-12-01

    This work investigates the influence of the direct laser texturing at high fluences (DLT-HF) on surface morphology, chemistry, and wettability. We use a Nd:YAG laser ( λ = 1064 nm) with pulse duration of 95 ns to process stainless steel surface. The surface morphology and chemistry after the texturing is examined by using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and electron backscatter diffraction (EBSD), while the surface wettability is evaluated by measuring the static contact angle. Immediately after the texturing, the surface is superhydrophilic in a saturated Wenzel regime. However, this state is not stable and the superhydrophilic-to-superhydrophobic transition happens if the sample is kept in atmospheric air for 30 days. After this period, the laser-textured stainless steel surface expresses lotus-leaf-like behavior. By using a high-speed camera at 10,000 fps, we measured that the water droplet completely rebound from this superhydrophobic surface after the contact time of 12 ms.

  15. Femtosecond laser-induced periodic surface structures on steel and titanium alloy for tribological applications

    Science.gov (United States)

    Bonse, J.; Koter, R.; Hartelt, M.; Spaltmann, D.; Pentzien, S.; Höhm, S.; Rosenfeld, A.; Krüger, J.

    2014-10-01

    Laser-induced periodic surface structures (LIPSS, ripples) were generated on stainless steel (100Cr6) and titanium alloy (Ti6Al4V) surfaces upon irradiation with multiple femtosecond laser pulses (pulse duration 30 fs, central wavelength 790 nm). The experimental conditions (laser fluence, spatial spot overlap) were optimized in a sample-scanning geometry for the processing of large surface areas (5 × 5 mm2) covered homogeneously by the nanostructures. The irradiated surface regions were subjected to white light interference microscopy and scanning electron microscopy revealing spatial periods around 600 nm. The tribological performance of the nanostructured surface was characterized by reciprocal sliding against a ball of hardened steel in paraffin oil and in commercial engine oil as lubricants, followed by subsequent inspection of the wear tracks. For specific conditions, on the titanium alloy a significant reduction of the friction coefficient by a factor of more than two was observed on the laser-irradiated (LIPSS-covered) surface when compared to the non-irradiated one, indicating the potential benefit of laser surface structuring for tribological applications.

  16. The formation of biofilms on superduplex UNS S32750 steel subjected to different surface treatments

    Energy Technology Data Exchange (ETDEWEB)

    Pagnin, Sergio [Petroleo Brasileiro S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil); Barreiro Junior, Walter Cravo; Bott, Ivani de S. [Pontificia Universidade Catolica do Rio de Janeiro (PUC-Rio), RJ (Brazil)

    2009-07-01

    Biocorrosion is a phenomenon involving metallic surface deterioration accelerated, or induced, by microorganisms. Such microbiological mechanisms occur when microorganisms are deposited on the surfaces exposed to the carrier fluids. Various factors influence the deposition mechanisms, such as the physical characteristics and chemical composition of the metallic surfaces, both of which can cause significant alterations in the processes that lead to the formation of biofilms. The current study evaluates the formation of biofilms, of a sulphate-reducing strain of bacteria (SRB), on superduplex UNS S32750 stainless steels exposed to synthetic seawater containing this bacterial strain. The experiments were carried out in a dynamic system using a controlled-flow test loop, and the steel surfaces were prepared using different techniques, such as polishing and shot peening, in order to present different physical surface conditions and, consequently, different deposition rates. The levels of organic acids, and of the sulphates consumed and produced, were measured. The morphologies of the biofilms produced were also analysed, by scanning electron microscopy, and surface roughness was measured by atom force microscopy. The level of biocorrosion was determined by counting the pits formed. The results obtained revealed that, despite high bacterial adhesion levels for the various treated surfaces examined, no relevant pitting had occurred, indicating that a corrosive process had not taken place for the testing conditions considered. (author)

  17. Hardness and structure changes at surface in electrical discharge machined steel C 3840

    International Nuclear Information System (INIS)

    Karastojkovic, Z.; Janjusevic, Z.

    2003-01-01

    The electrical discharge machining (EDM) of both hard and soft materials became an important technique in industrial applications. This technique has an advantage in producing of structural/tool parts of complex geometry. The EDM is based on electrical phenomena, when the treated surface undergoes to erosion. The first step in EDM, the melting of thin surface layer, frequently is neglected. In this paper the changes of hardness and structure at surface layer, after EDM is applied on steel C 3840, will be discussed. The steel C- 3840 was quenched and tempered to hardness of 63 HRC, at surface, and than machined by electrical discharging. The changed, white, layer is just a product of melting and decarburization processes. The white layer is registered at surface by using a metallographic investigation. Hardness profile is measured from surface to the interior of material. The achievement of local high temperatures during EDM is resulting on melt and erosion of material. Besides of these effects, during EDM were happened some minor but not a neglectible effects, primary on structure changes on treated surface. It would be expected that melting, even an evaporation of melted metal, and further the phase transformation have an important influence on the starting structure. (Original)

  18. Effect of surface roughness and stainless steel finish on Listeria monocytogenes attachment and biofilm formation.

    Science.gov (United States)

    Rodriguez, Andres; Autio, Wesley R; McLandsborough, Lynne A

    2008-01-01

    The purpose of this study was to evaluate the effect of surface roughness (Ra) and finish of mechanically polished stainless steel (Ra = 0.26 +/- 0.05, 0.49 +/- 0.10, and 0.69 +/- 0.05 microm) and electropolished stainless steel (Ra = 0.16 +/- 0.06, 0.40 +/- 0.003, and 0.67 +/- 0.02 microm) on Listeria adhesion and biofilm formation. A four-strain cocktail of Listeria monocytogenes was used. Each strain (0.1%) was added to 200 ml of tryptic soy broth (TSB), and coupons were inserted to the mixture for 5 min. For biofilm formation, coupons with adhesive cells were incubated in 1:20 diluted TSB at 32 degrees C for 48 h. The experiment was performed by a randomized block design. Our results show that the level of Listeria present after 48 h of incubation (mean = 7 log CFU/cm2) was significantly higher than after 5 min (mean = 6.0 log CFU/cm2) (P stainless steel (mean = 6.7 log CFU/cm2) (P > 0.05). Listeria initial adhesion (values ranged from 5.9 to 6.1 log CFU/cm2) or biofilm formation (values ranged from 6.9 to 7.2 log CFU/cm2) was not significantly correlated with Ra values (P > 0.05). Image analysis with an atomic force microscope showed that bacteria did not colonize the complete surface after 48 h but were individual cells or grouped in microcolonies that ranged from 5 to 10 microm in diameter and one to three cell layers in thickness. Exopolymeric substances were observed to be associated with the colonies. According to our results, electropolishing stainless steel does not pose a significant advantage for food sanitation over mechanically finished stainless steel.

  19. Investigation of the physical parameters of duplex stainless steel (DSS surface integrity after turning

    Directory of Open Access Journals (Sweden)

    G. Krolczyk

    2015-01-01

    Full Text Available The article presents the influence of machining parameters on the microhardness of surface integrity (SI after turning by means of a coated sintered carbide wedge with a coating with ceramic intermediate layer. The investigation comprised the influence of cutting speed on the SI microhardness in dry machining. The material under investigation was duplex stainless steel with two-phase ferritic-austenitic structure. The results obtained allow for conclusions concerning the exploitation features of processed machine parts.

  20. Influence of Plastic Deformation on Low Temperature Surface Hardening of Austenitic Stainless Steel by Gaseous Nitriding

    DEFF Research Database (Denmark)

    Bottoli, Federico; Winther, Grethe; Christiansen, Thomas Lundin

    2015-01-01

    This article addresses an investigation of the influence of plastic deformation on low temperature surface hardening by gaseous nitriding of two commercial austenitic stainless steels: AISI 304 and EN 1.4369. The materials were plastically deformed to different equivalent strains by uniaxial...... demonstrate that a case of expanded austenite develops and that, in particular, strain-induced martensite has a large influence on the nitrided zone....