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Sample records for annealed stainless steels

  1. Chromium depletion from stainless steels during vacuum annealing

    International Nuclear Information System (INIS)

    Smith, A.F.; Hales, R.

    1977-01-01

    During selective chromium oxidation of stainless steels the changes in chromium concentration at the metal surface and in the metal have an important bearing on the overall oxidation performance. It has been proposed that an analogue of chromium behaviour during selective oxidation is obtained from volatilisation of chromium during high temperature vacuum annealing. In the present report the evaporation of chromium from 316 type of steel, vacuum annealed at 1,000 0 C, has been investigated by means of energy dispersive X-ray analysis and by neutron activation analysis. It was established that chromium loss from austenitic stainless steels is rate controlled by interdiffusion in the alloy. As predicted the chromium concentration at the metal surface decreased with increasing vacuum annealing time. The chromium depletion profile in the metal was in good agreement with the previously derived model apart from an anomalous region near the surface. Here the higher resolution of the neutron activation technique indicated a zone within approximately 2μm of the surface where the chromium concentration decreased more steeply than expected. (orig.) [de

  2. Hardness evolution on annealing in AISI 304 stainless steel

    International Nuclear Information System (INIS)

    Lopez, A.; Alvarez de Sotomayor, A.; Herrera, E. J.

    2001-01-01

    The evolution of the microstructure and hardness of commercial AISI 304 stainless-steel samples with the heat treatment has been studied. Steel specimens in the as-received condition, and after 50% cold rolling, were soaked for 1 hour at various temperatures between 650 and 1200 degree centigree Samples maintain their grain size and hardness until about 900 degree centigree, thereafter, size increases with temperature, while hardness lightly diminishes. Recrystallization of cold-rolled specimens begins at 650 degree centigree, and finishes around 850 degree centigree. Recrystallized grain-size reaches the value found in the as received materials after the treatment at 900 degree centigree. For high her annealing temperatures both grain growth and hardness decrease following the same trend in cold-worked and non-deformed materials. (Author) 10 refs

  3. High Nitrogen Austenitic Stainless Steel Precipitation During Isothermal Annealing

    Directory of Open Access Journals (Sweden)

    Maria Domankova

    2016-07-01

    Full Text Available The time-temperature-precipitation in high-nitrogen austenitic stainless steel was investigated using light optical microscopy, transmission electron microscopy, selected area diffraction and energy-dispersive X-ray spectroscopy. The isothermal precipitation kinetics curves and the corresponding precipitation activation energy were obtained. The diffusion activation energy of M2N precipitation is 129 kJ/mol. The results show that critical temperature for M2N precipitation is about 825°C with the corresponding incubation period 2.5 min.

  4. Effect of cold working and annealing on stress corrosion cracking of AISI 304 stainless steel

    International Nuclear Information System (INIS)

    Yeon, Y.M.; Kwun, S.I.

    1983-01-01

    A study was made of the effects of cold working and annealing on the stress corrosion cracking of AISI 304 stainless steel in boiling 42% MgCl 2 solution. When the 60% or 76% of yield stress was applied, the resistance to SCC showed maximum at 30% of cold work. However, when the same load was applied to the annealed specimens after cold working, the resistance to SCC decreased abruptly at 675degC annealing. The fracture mode changed mode change mixed → intergranular → transgranular as the amount of cold work increased. (Author)

  5. Solid state alloying by plasma nitriding and diffusion annealing treatment for austenitic stainless steel

    International Nuclear Information System (INIS)

    Pinedo, C.E.; Vatavuk, J.; Oliveira, S.D. de; Tschiptschin, A.P.

    1999-01-01

    Nitrogen has been added to stainless steels to improve mechanical strength and corrosion resistance. High nitrogen steel production is limited by high gas pressure requirements and low nitrogen solubility in the melt. One way to overcome this limitation is the addition of nitrogen in solid state because of its higher solubility in austenite. However, gas and salt bath nitriding have been done at temperatures around 550 C, where nitrogen solubility in the steel is still very low. High temperature nitriding has been, thus proposed to increase nitrogen contents in the steel but the presence of oxide layers on top of the steel is a barrier to nitrogen intake. In this paper a modified plasma nitriding process is proposed. The first step of this process is a hydrogen plasma sputtering for oxide removal, exposing active steel surface improving nitrogen pickup. This is followed by a nitriding step where high nitrogen contents are introduced in the outermost layer of the steel. Diffusion annealing is then performed in order to allow nitrogen diffusion into the core. AISI 316 austenitic stainless steel was plasma nitrided and diffusion annealed at 1423K, for 6 hours, with 0.2 MPa nitrogen pressure. The nitrided steel presented ∝60 μm outermost compact layer of (Fe,Cr) 3 N and (Fe,Cr) 4 N with 11 wt.% N measured by surface depth profiling chemical analysis - GDS system. During the annealing treatment the nitride layer was dissolved and nitrogen diffused to the core of the sample leaving more even nitrogen distribution into the steel. Using this technique one-millimetre thick sample were obtained having high nitrogen content and uniform distribution through the thickness. (orig.)

  6. Effects of Solution Annealing Temperature on the Galvanic Corrosion Behavior of the Super Duplex Stainless Steels

    Science.gov (United States)

    Lee, Jun-Seob; Jeon, Soon-Hyeok; Park, Yong-Soo

    2013-02-01

    This study investigated the active dissolution of super duplex stainless steel (SDSS) at various solution annealing temperatures. The active dissolutions of the α-phase and γ-phase were compared, and the effects of the surface area ratio on the active dissolutions of both phases were investigated. There were two peaks in the active-passive transition region in the potentiodynamic test in the modified green-death solution. The two peaks changed as the solution annealing temperature was increased from 1050 to 1150 °C. The solution annealing temperature difference affected the critical anodic current densities. This provides useful information for determining the appropriate solution annealing temperature in the modified green-death solution for SDSS.

  7. Microstructural evolution and pitting resistance of annealed lean duplex stainless steel UNS S32304

    International Nuclear Information System (INIS)

    Zhang Ziying; Han Dong; Jiang Yiming; Shi Chong; Li Jin

    2012-01-01

    Highlights: ► The relationship between pitting corrosion resistance and annealing temperature for UNS S32304 was systemically studied. ► The specimens annealed at 1080 °C for 1 h, quenched in water exhibit the best pitting corrosion resistance. ► The relationship between microstructural evolution and pitting resistance of annealed UNS S32304 was discussed in detail. ► The pitting corrosion resistance is consistent with pitting resistance equivalent number of weaker phase for UNS S32304 alloy. - Abstract: The effect of annealing temperature in the range from 1000 to 1200 °C on the pitting corrosion behavior of duplex stainless steel UNS S32304 was investigated by the potentiodynamic polarization and potentiostatic critical pitting temperature techniques. The microstructural evolution and pit morphologies were studied using a scanning electron microscopy with energy dispersive X-ray spectroscopy. The results demonstrated that the nucleation of metastable pits transformed from austenite phase to ferrite phase with the increasing annealing temperature. As the annealing temperature increased, the pitting corrosion resistance firstly increased and then decreased. The highest pitting corrosion resistance was obtained at 1080 °C with the highest critical pitting temperature value and pitting nucleation resistance. The results could be well explained by the microstructural evolution of ferrite and austenite phases induced by annealing treatment.

  8. Changes in structure and phase composition of chromium diffusion layer on stainless steels after long annealing

    International Nuclear Information System (INIS)

    Knyazev, E.V.; Voshedchenko, B.M.; Voskresenskij, Yu.A.

    1985-01-01

    A study was made on the effect of elevated temperatures UU and long holdings at heat on structure, phase composition and properties of chromium diffusion layer on austenitic chromium-nickel stainless steels 10Kh18N10TVD, 10Kh15N30M4B, 10Kh11N23T3MR, 10Kh21N28V6M3. The following mechanism of processes taking place in diffusion chromium layer is presented. The steady drop of chromium concentrations is observed after diffusion saturation. Chromium redistribution related with system transformation to more equilibrium state and simultaneous decarburization of steel surfaces takes place in diffusion layers of 10Kh15N30M4B and 10Kh21N28V6M3 steels after annealing at different temperatures and holdings at heat. Decarburization of steel surface layers is practically excluded in diffusion layers of 10Kh18N10T-VD and 10Kh11N23T3MR steels. Diffusion chromium-saturated layer stays effective only on 10Kh18N10T-VD and 10Kh11N23T3MR steels on heating up to 1000 deq C with holding up to 250 h

  9. Annealing of a ferritic stainless steel 409 stabilized with titanium and zirconium additions

    Directory of Open Access Journals (Sweden)

    Zambrano, P.

    2011-02-01

    Full Text Available A ferritic stainless steel 409 stabilized with titanium and zirconium was subject to thermomechanical processing. It was heated at 1210 °C for one hour, followed by a 75 % hot reduction in three passes, this rolling schedule ended at 980 °C. Samples were cooled to 600 °C by water spraying followed by air-cooling. The alloy was pickled, and was reduced 80 % by cold rolling. The alloy was annealed at different temperatures for 105 s. Additional annealing treatments were carried out at temperatures of 800, 850 and 900 °C for different times. Mechanical testing and texture were made to corroborate the degree of annealing and formability. Mechanical properties and Texture analyses showed that the alloy annealed at 850 °C for 14 min was both completely recrystallized and a very good formability.

    Un acero inoxidable ferrítico 409 estabilizado con titanio y zirconio fue sujeto a procesos termomecánicos. El acero fue calentado a 1210 ºC durante una hora, seguido por un laminado en caliente del 75 % en tres pases, el proceso terminó a los 980 ºC. Las muestras fueron enfriadas hasta 600 ºC por agua atomizada seguido de enfriamiento al aire. La aleación fue decapada y laminada en frío un 80 %. Posteriormente de desarrollaron tratamientos térmicos de recocido a diferentes temperaturas por un tiempo de 105 s. Adicionalmente se desarrollaron tratamientos de recocido a temperaturas de 800, 850 y 900 ºC a diferentes tiempos. Pruebas mecánicas y textura fueron realizadas para corroborar el grado de recocido y su formalidad. El análisis de las propiedades mecánicas y la Textura mostraron que la aleación recocida a 850 ºC por 14 min (840 s fue completamente recristalizada obteniendo la mejor formabilidad.

  10. Microstructural Evolutions During Annealing of Plastically Deformed AISI 304 Austenitic Stainless Steel: Martensite Reversion, Grain Refinement, Recrystallization, and Grain Growth

    Science.gov (United States)

    Naghizadeh, Meysam; Mirzadeh, Hamed

    2016-08-01

    Microstructural evolutions during annealing of a plastically deformed AISI 304 stainless steel were investigated. Three distinct stages were identified for the reversion of strain-induced martensite to austenite, which were followed by the recrystallization of the retained austenite phase and overall grain growth. It was shown that the primary recrystallization of the retained austenite postpones the formation of an equiaxed microstructure, which coincides with the coarsening of the very fine reversed grains. The latter can effectively impair the usefulness of this thermomechanical treatment for grain refinement at both high and low annealing temperatures. The final grain growth stage, however, was found to be significant at high annealing temperatures, which makes it difficult to control the reversion annealing process for enhancement of mechanical properties. Conclusively, this work unravels the important microstructural evolution stages during reversion annealing and can shed light on the requirements and limitations of this efficient grain refining approach.

  11. Effect of phase instabilities on the correlation of nickel ion and neutron irradiation swelling in solution annealed 316 stainless steel

    International Nuclear Information System (INIS)

    Rowcliffe, A.F.; Lee, E.H.; Sklad, P.S.

    1979-01-01

    Annealed 316 stainless steel specimens were neutron irradiated to establish steady-state microstructures and then subjected to further high temperature irradiations with 4 MeV Ni ions. It is shown that void growth under neutron irradiation is simulated in ion irradiations carried out at approx. 180 0 C above reactor temperature. However, the precipitate microstructure developed during neutron irradiation is unstable during subsequent ion irradiation. As a result, the relative swelling rates at various reactor temperatures are not simulated correctly

  12. Effect of annealing treatment on microstructure evolution and the associated corrosion behavior of a super-duplex stainless steel

    International Nuclear Information System (INIS)

    Deng, B.; Jiang, Y.M.; Gao, J.; Li, J.

    2010-01-01

    The influence of annealing temperature on the pitting corrosion of a super-duplex stainless steel (SDSS) with mischmetal addition was investigated in chloride solution by critical pitting temperature (CPT) measurement. The corrosion behavior is strongly dependent on the microstructure, namely the presence of secondary phases, elemental partitioning behavior and volume fractions of ferrite and austenite. Based on CPT results and alloying rules, the optimal annealing temperature is determined as 1070 o C and a guideline for further development of improved SDSS is formulated.

  13. Magnetic and mechanical properties of Cu (75 wt%) – 316L grade stainless steels synthesized by ball milling and annealing

    Energy Technology Data Exchange (ETDEWEB)

    Mondal, Bholanath, E-mail: bholanath_mondal@yahoo.co.in [Department of Central Scientific Services, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032 (India); Chabri, Sumit [Department of Metallurgy and Materials Engineering, Indian Institute of Engineering Science and Technology, Shibpur, Howrah 711103 (India); Sardar, Gargi [Department of Zoology, Baruipur College, South 24 Parganas, 743610 (India); Bhowmik, Nandagopal [Department of Metallurgy and Materials Engineering, Indian Institute of Engineering Science and Technology, Shibpur, Howrah 711103 (India); Sinha, Arijit, E-mail: arijitsinha2@yahoo.co.in [School of Materials Science and Engineering, Indian Institute of Engineering Science and Technology, Shibpur, Howrah 711103 (India); Chattopadhyay, Partha Protim [Department of Metallurgy and Materials Engineering, Indian Institute of Engineering Science and Technology, Shibpur, Howrah 711103 (India)

    2015-05-01

    Elemental powders of Cu (75 wt%) and 316-stainless steel (25 wt%) has been subjected to ball milling upto 70 h followed by isothermal annealing at the temperature range of 350–750 °C for 1 h to investigate the microstructural evolution along with magnetic and mechanical properties. After 40 h of milling, the bcc Fe is almost dissolved in the solid solution of Cu but no significant change has been observed in the XRD pattern after 70 h of milling, Annealing of the alloy has resulted in precipitation of nanocrystalline bcc-Fe in Cu which triggers the soft ferromagnetic properties. The extensive mechanical characterization has been done at the microstructural scale by nanoindentation technique which demonstrates a hardening behavior of the compacted and annealed alloys due to possible precipitation of nanocrystalline bcc-Fe in Cu. - Highlights: • Nanocrystalline phases with partial amorphorization obtained after 70 h of milling. • Precipitation and grain coarsening of Fe and Cu after annealing as observed by XRD. • Annealing of the ball milled sample upto 550 {sup o}C has evolved ferromagnetic behavior. • Nanoindentation predicts a hardening behavior of annealed ball milled samples.

  14. Characterization Of Oxide Layers Produced On The AISI 321 Stainless Steel After Annealing

    Directory of Open Access Journals (Sweden)

    Bochnowski W.

    2015-09-01

    Full Text Available In this study, the structure, chemical composition and topography of oxide layers produced on the surface of the AISI 321 austenitic steel in the annealing process were analyzed. Heat treatment was done at 980°C temperature for 1 hour time in different conditions. The annealing was done in a ceramic furnace in oxidation atmosphere and in vacuum furnaces with cylindrical molybdenum and graphite chambers. The analysis was carried out using the following methods: a scanning electron microscope (SEM equipped with an energy-dispersive X-ray spectrometer (EDX, a transmission electron microscope (TEM equipped with an energy-dispersive X-ray spectrometer (EDX, an X-ray diffractometer (XRD, a secondary ion mass spectrometer with time-of-flight mass analyzer (TOF SIMS and an atomic force microscope (AFM. The oxide layer formed during annealing of the AISI 321 steel at 980°C consisted of sub-layers, diversified in the chemical composition. The thickness of the oxidized layer is depended on the annealing conditions. In a ceramic furnace in oxidation atmosphere, the thickness of the oxide layer was of 300-500 nm, in a vacuum furnace with molybdenum and graphite heating chambers, it ranged from 40 to 300 nm and from a few to 50 nm, respectively. TOF SIMS method allows to get average (for the surface of 100 μm × 100 μm depth profiles of concentration of particular elements and elements combined with oxygen. In oxide layers formed in vacuum furnaces there are no iron oxides. Titanium, apart from being bounded with carbon in carbides, is a component of the oxide layer formed on the surface of the AISI 321 steel.

  15. X-Ray diffraction study of strain hardening and annealing in an UNS S31803 duplex stainless steel

    International Nuclear Information System (INIS)

    Aguiar, Denilson Jose Marcolino de; Padilha, Angelo Fernando

    2010-01-01

    In the present work the phenomena of strain hardening, formation and reversion of the strain induced alpha-prime martensite (α', CCC, Ferromagnetic) in an UNS S31803 duplex stainless steel have been studied. Initially, the microstructure of the material in the solution annealed condition was characterized with aid of several complementary techniques of microstructural analysis. The volumetric fraction, crystalline structure, chemical composition, size and morphology of the two phases (ferrite and austenite) have been determined. The phenomena of strain hardening, formation and reversion of strain induced martensite in the austenite phase and recovery of austenite and ferrite phases have been studied, predominantly by using X-ray diffraction and the Rietveld method. (author)

  16. Weldability of Stainless Steels

    International Nuclear Information System (INIS)

    Saida, Kazuyoshi

    2010-01-01

    It gives an outline of metallographic properties of welding zone of stainless steels, generation and mechanisms of welding crack and decreasing of corrosion resistance of welding zone. It consists of seven chapters such as introduction, some kinds of stainless steels and properties, metallographic properties of welding zone, weld crack, toughness of welding zone, corrosion resistance and summary. The solidification modes of stainless steels, each solidification mode on the cross section of Fe-Cr-Ni alloy phase diagram, each solidification mode of weld stainless steels metal by electron beam welding, segregation state of alloy elements at each solidification mode, Schaeffler diagram, Delong diagram, effects of (P + S) mass content in % and Cr/Ni equivalent on solidification cracking of weld stainless steels metal, solidification crack susceptibility of weld high purity stainless steels metal, effects of trace impurity elements on solidification crack susceptibility of weld high purity stainless steels metal, ductile fracture susceptibility of weld austenitic stainless steels metal, effects of H2 and ferrite content on generation of crack of weld 25Cr-5N duplex stainless steels, effects of O and N content on toughness of weld SUS 447J1 metals, effect of ferrite content on aging toughness of weld austenitic stainless steel metal, corrosion morphology of welding zone of stainless steels, generation mechanism of knife line attack phenomenon, and corrosion potential of some kinds of metals in seawater at room temperature are illustrated. (S.Y.)

  17. Response to annealing and reirradiation of AISI 304L stainless steel following initial high-dose neutron irradiation in EBR-II

    International Nuclear Information System (INIS)

    Porter, D.L.; McVay, G.L.; Walters, L.C.

    1980-01-01

    The object of this study was to measure the stability of irradiation-induced microstructure upon annealing and, by selectively annealing out some of these features and reirradiating the material, it was expected that information could be gained concerning the role of microstructural changes in the void swelling process. Transmission electron microscopic examinations of isochronally annealed (200 to 1050 0 C) AISI 304L stainless steel, which had been irradiated at approximately 415 0 C to a fast (E > 0.1 MeV) neutron fluence of approximately 5.1 x 10 26 n/m 2 , verified that the two-stage hardness recovery with temperatures was related to a low temperature annealing of dislocation structures and a higher temperature annealing of voids and solute redistribution

  18. Corrosion inhibition of stainless steel type AISI 304 by Mn coating and subsequent annealing with flow of nitrogen at different temperatures

    Science.gov (United States)

    Grayeli-Korpi, Ali-Reza; Savaloni, Hadi; Habibi, Maryam

    2013-07-01

    This work reports the enhancement of stainless steel corrosion resistance coated with Mn and post-annealed with flow of nitrogen at different annealing temperatures. Crystallographic variation of the samples by annealing temperature is studied by X-ray diffraction (XRD) while their surface morphology and surface roughness was obtained by means of atomic force microscope (AFM) and scanning electron microscope (SEM) analyses before and after corrosion test respectively. Elemental analysis of samples after corrosion test was investigated by energy dispersive spectroscope (EDS) analysis. The corrosion behaviour of the samples was evaluated by potentiodynamic polarization test in 0.6 M NaCl solution. A critical annealing temperature is found at which the highest corrosion resistance can be achieved. Correlation between corrosion resistance, structural and surface morphology results is obtained.

  19. Effect of large strain warm rolling and subsequent annealing on the microstructure and mechanical properties of austenitic stainless steels

    Science.gov (United States)

    Odnobokova, M.; Yanushkevich, Z.; Belyakov, A.; Kaibyshev, R.

    2017-12-01

    The microstructural evolution of 304L and 316L steels during warm plate rolling to a strain of 3 and subsequent annealing as well as the structural effect on the mechanical properties were investigated. The warm rolled microstructures consisted of flattened wavy austenitic grains with transverse grain sizes of about 220 and 160 nm in 304L and 316L steels, respectively. The formation of the wavy austenite structures was facilitated by high density of microshear bands. The subsequent annealing was accompanied by the development of static recrystallization and grain growth. The 304L steel specimens were characterized by a lower stability against recrystallization and grain growth as compared to the 316L ones. The grain coarsening during annealing was accompanied by gradual softening. The hardness decreased by 50% in both steels after annealing at 800°C. The grain coarsening was accompanied by strength degradation, although the tensile strength above 900 and 1000 MPa remained in the 304L and 316L steel specimens, respectively, after annealing at 700°C.

  20. Stainless Steel Microstructure and Mechanical Properties Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Switzner, Nathan T

    2010-06-01

    A nitrogen strengthened 21-6-9 stainless steel plate was spinformed into hemispherical test shapes. A battery of laboratory tests was used to characterize the hemispheres. The laboratory tests show that near the pole (axis) of a spinformed hemisphere the yield strength is the lowest because this area endures the least “cold-work” strengthening, i.e., the least deformation. The characterization indicated that stress-relief annealing spinformed stainless steel hemispheres does not degrade mechanical properties. Stress-relief annealing reduces residual stresses while maintaining relatively high mechanical properties. Full annealing completely eliminates residual stresses, but reduces yield strength by about 30%.

  1. Articles comprising ferritic stainless steels

    Science.gov (United States)

    Rakowski, James M.

    2016-06-28

    An article of manufacture comprises a ferritic stainless steel that includes a near-surface region depleted of silicon relative to a remainder of the ferritic stainless steel. The article has a reduced tendency to form an electrically resistive silica layer including silicon derived from the steel when the article is subjected to high temperature oxidizing conditions. The ferritic stainless steel is selected from the group comprising AISI Type 430 stainless steel, AISI Type 439 stainless steel, AISI Type 441 stainless steel, AISI Type 444 stainless steel, and E-BRITE.RTM. alloy, also known as UNS 44627 stainless steel. In certain embodiments, the article of manufacture is a fuel cell interconnect for a solid oxide fuel cell.

  2. High Nitrogen Stainless Steel

    Science.gov (United States)

    2011-07-19

    crack growth (FCG) test (ASTM E 647-95a) - square bar specimen of 0.4x0.4x2.8 in. in L-orientation with a Charpy notch at the mid- length for SCC...Hydrogen Embrittlement in Steel by the Increment Loading Technique. Fractography: After the stress-life fatigue tests , the fracture surface morphology...NAWCADPAX/TR-2011/162 HIGH NITROGEN STAINLESS STEEL by E. U. Lee R. Taylor 19 July 2011 Approved for

  3. Comparative Stress Corrosion Cracking and General Corrosion Resistance of Annealed and Hardened 440 C Stainless Steel - New Techniques in Stress Corrosion Testing

    Science.gov (United States)

    Mendreck, M. J.; Hurless, B. E.; Torres, P. D.; Danford, M. D.

    1998-01-01

    The corrosion and stress corrosion cracking (SCC) characteristics of annealed and hardened 440C stainless steel were evaluated in high humidity and 3.5-percent NaCl solution. Corrosion testing consisted of an evaluation of flat plates, with and without grease, in high humidity, as well as electrochemical testing in 3.5-percent NaCl. Stress corrosion testing consisted of conventional, constant strain, smooth bar testing in high humidity in addition to two relatively new techniques under evaluation at MSFC. These techniques involve either incremental or constant rate increases in the load applied to a precracked SE(B) specimen, monitoring the crack-opening-displacement response for indications of crack growth. The electrochemical corrosion testing demonstrated an order of magnitude greater general corrosion rate in the annealed 440C. All techniques for stress corrosion testing showed substantially better SCC resistance in the annealed material. The efficacy of the new techniques for stress corrosion testing was demonstrated both by the savings in time and the ability to better quantify SCC data.

  4. Hydrogen effects in stainless steel

    International Nuclear Information System (INIS)

    Caskey, G.R. Jr.

    1983-01-01

    The effects of hydrogen on stainless steels have been reviewed and are summarized in this paper. Discussion covers hydrogen solution and transport in stainless steels as well as the effects of hydrogen on deformation and fracture under various loading conditions. Damage is caused also by helium that arises from decay of the hydrogen isotope tritium. Austenitic, ferritic, martensite, and precipitation-hardenable stainless steels are included in the discussion. 200 references

  5. Effect of annealing temperature on microstructure of ferritic stainless steels with high Mo content; Efeito da temperatura de recozimento na microestrutura em acos inoxidaveis ferriticos com alto teor de Mo

    Energy Technology Data Exchange (ETDEWEB)

    Abreu, H.F.G.; Miranda, H.C. [Universidade Federal do Ceara (UFC), Fortaleza (Brazil). Dept. de Engenharia Metalurgica e de Materiais; Herculano, L.F.G. [Universidade Federal do Ceara (UFC), Fortaleza (Brazil). Lab. de Caracterizacao de Materiais; Tavares, S.S.M. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Dept. de Engenharia Mecanica

    2006-07-01

    The petroleum refined in Brazilian refining plants is characterized by its high content of sulphur. This fact has increased problems related to naphtenic corrosion. It is known by the experience in refining that steels with high contents of Mo present good naphtenic corrosion resistance. This papers studied aspects referring to mechanical properties and microstructure of high Mo ferritic stainless steels developed in laboratory as a function of annealing temperature. Results showed that temperatures between 1000 and 1050 deg C were more suitable to the steels studied. (author)

  6. Hydrogenation of stainless steels implanted with nitrogen

    International Nuclear Information System (INIS)

    Silva Ramos, L.E. da.

    1989-01-01

    In the present work the effects of both ion implantation and hydrogenation on the fatigue behaviour of an AISI-304 type unstable stainless steel was studied. The material was tested under the following microstructural conditions: annealed; annealed plus hydrogenated; annealed plus ion-implanted; annealed, ion-implanted and hydrogeneted. The hydrogen induced phase transformations were also studied during the outgassing of the samples. The ion implanted was observed to retard the kinetics of the hydrogen induced phase transformations. It was also observed that the nitrogen ion implantation followed by both natural (for about 4 months) and artificial (100 0 C for 6 hours) aging treatments was beneficial to the fatigue life of both non hydrogenated and severely hydrogenated samples. (author) [pt

  7. Chromium-Makes stainless steel stainless

    Science.gov (United States)

    Kropschot, S.J.; Doebrich, Jeff

    2010-01-01

    Chromium, a steely-gray, lustrous, hard metal that takes a high polish and has a high melting point, is a silvery white, hard, and bright metal plating on steel and other material. Commonly known as chrome, it is one of the most important and indispensable industrial metals because of its hardness and resistance to corrosion. But it is used for more than the production of stainless steel and nonferrous alloys; it is also used to create pigments and chemicals used to process leather.

  8. Evaluation of stainless steel reinforcement construction project

    Science.gov (United States)

    2003-02-01

    Stainless steel reinforcement has greater corrosion resistance than that of the conventional reinforcement. In this project, bridge A6059, the first in Missouri utilizing stainless steel reinforcement in the deck, was constructed, along with bridge A...

  9. Plating on stainless steel alloys

    International Nuclear Information System (INIS)

    Dini, J.W.; Johnson, H.R.

    1981-01-01

    Quantitative adhesion data are presented for a variety of electroplated stainless steel type alloys. Results show that excellent adhesion can be obtained by using a Wood's nickel strike or a sulfamate nickel strike prior to final plating. Specimens plated after Wood's nickel striking failed in the deposit rather than at the interface between the substrate and the coating. Flyer plate quantitative tests showed that use of anodic treatment in sulfuric acid prior to Wood's nickel striking even further improved adhesion. In contrast activation of stainless steels by immersion or cathodic treatment in hydrochloric acid resulted in very reduced bond strengths with failure always occurring at the interface between the coating and substrate

  10. Nickel release from stainless steels.

    Science.gov (United States)

    Haudrechy, P; Mantout, B; Frappaz, A; Rousseau, D; Chabeau, G; Faure, M; Claudy, A

    1997-09-01

    In 1994, a study of nickel release and allergic contact dermatitis from nickel-plated metals and stainless steels was published in this journal. It was shown that low-sulfur stainless steel grades like AISI 304, 316L or 430 (S AISI 303-S approximately 0.3%) releases about 1.5 micrograms/cm2/week in this acid artificial sweat. Applied on patients sensitized to nickel, these metals elicit positive reactions in 96% and 14%, respectively, of the patients. The main conclusion was that low-sulfur stainless steels like AISI 304, 316L or 430, even when containing Ni, should not elicit nickel contact dermatitis, while metals having a mean corrosion resistance like a high-sulfur stainless steel (AISI 303) or nickel-plated steel should be avoided. The determining characteristic was in fact the corrosion resistance in chloride media, which, for stainless steels, is connected, among other factors, to the sulfur content. Thus, a question remained concerning the grades with an intermediate sulfur content, around 0.03%, which were not studied. They are the object of the study presented in this paper. 3 tests were performed: leaching experiments, dimethylglyoxime and HNO3 spot tests, and clinical patch tests; however, only stainless steels were tested: a low-sulfur AISI 304 and AISI 303 as references and 3 grades with a sulfur content around 0.03%: AISI 304L, AISI 304L added with Ca, AISI 304L+Cu. Leaching experiments showed that the 4 non-resulfurised grades released less than 0.5 microgram/cm2/week in acid sweat while the reulfurized AISI 303 released around or more than 0.5 microgram/cm2/week. This is explained by the poorer corrosion resistance of the resulfurized grade. Yet all these grades had the same reaction to the DMG test (negative result), which shows again its lack of sensitivity. In contrast, the HNO3 spot test distinguished AISI 303 from the non-resulfurized grades. Clinical patch tests again showed that some patients (4%) were intolerant to AISI 303, while none were

  11. Weld bonding of stainless steel

    DEFF Research Database (Denmark)

    Santos, I. O.; Zhang, Wenqi; Goncalves, V.M.

    2004-01-01

    This paper presents a comprehensive theoretical and experimental investigation of the weld bonding process with the purpose of evaluating its relative performance in case of joining stainless steel parts, against alternative solutions based on structural adhesives or conventional spot-welding. Th...

  12. Hybrid Stainless Steel Girder for Bridge Construction

    OpenAIRE

    Tetsuya Yabuki; Yasunori Arizumi; Tetsuhiro Shimozato; Samy Guezouli; Hiroaki Matsusita; Masayuki Tai

    2017-01-01

    The main object of this paper is to present the research results of the development of a hybrid stainless steel girder system for bridge construction undertaken at University of Ryukyu. In order to prevent the corrosion damage and reduce the fabrication costs, a hybrid stainless steel girder in bridge construction is developed, the stainless steel girder of which is stiffened and braced by structural carbon steel materials. It is verified analytically and experimentally that the ultimate stre...

  13. Micro-Abrasion Wear Resistance of Borided 316L Stainless Steel and AISI 1018 Steel

    Science.gov (United States)

    Reséndiz-Calderon, C. D.; Rodríguez-Castro, G. A.; Meneses-Amador, A.; Campos-Silva, I. E.; Andraca-Adame, J.; Palomar-Pardavé, M. E.; Gallardo-Hernández, E. A.

    2017-11-01

    The 316L stainless steel has high corrosion resistance but low tribological performance. In different industrial sectors (biomedical, chemical, petrochemical, and nuclear engineering), improvement upon wear resistance of 316L stainless steel components using accessible and inexpensive methods is critical. The AISI 1018 steel is widely used in industry, but its tribological performance is not the best among steels. Therefore, in this study the behavior of the borided 316L stainless steel and 1018 steel is evaluated under micro-abrasion wear. The boriding was carried out at 1223 K over 6 h of exposure time, resulting in a biphase layer composed of FeB/Fe2B phases. In order to evaluate Fe2B phase with no influence from FeB phase, AISI 1018 steel samples were borided at 1273 K for over 20 min and then diffusion annealed at 1273 K over 2 h to obtain a Fe2B mono-phase layer. Micro-abrasion wear resistance was evaluated by a commercial micro-abrasion testing rig using a mix of F-1200 SiC particles with deionized water as abrasive slurry. The obtained wear rates for FeB and Fe2B phases and for the 316L stainless steel were compared. Wear resistance of 316L stainless steel increases after boriding. The wear mechanisms for both phases and for the stainless steel were identified. Also, transient conditions for rolling and grooving abrasion were determined for the FeB and Fe2B phases.

  14. Anelasticity in austenitic stainless steel

    International Nuclear Information System (INIS)

    Time-dependent anelastic deformation mechanisms arise in austenitic stainless steel when load is removed during a high-temperature creep test. This phenomenon is investigated by conducting creep tests, with intermittent load removal, on AISI Type 316H austenitic stainless steel at 550 and 650 °C, supported by in situ measurement of creep-induced intergranular residual strains by neutron diffraction. All the cyclic tests exhibit anelastic behaviour on unloading and develop substantially lower load-on creep strain rates, reduced ductility and longer rupture times than baseline steady-load creep tests at similar conditions. The mechanisms underlying the observed anelastic behaviour and changes in macroscopic creep properties are discussed with reference to the development of intergranular strains and dislocation behaviour.

  15. Thermophysical properties of stainless steels

    International Nuclear Information System (INIS)

    Kim, C.S.

    1975-09-01

    Recommended values of the thermodynamic and transport properties of stainless steels Type 304L and Type 316L are given for temperatures from 300 to 3000 0 K. The properties in the solid region were obtained by extrapolating available experimental data to the melting range, while appropriate correlations were used to estimate the properties in the liquid region. The properties evaluated include the enthalpy, entropy, specific heat, vapor pressure, density, thermal expansion coefficient, thermal conductivity, thermal diffusivity, and viscosity. (9 fig, 11 tables)

  16. Nano-composite stainless steel

    Science.gov (United States)

    Dehoff, Ryan R.; Blue, Craig A.; Peter, William H.; Chen, Wei; Aprigliano, Louis F.

    2015-07-14

    A composite stainless steel composition is composed essentially of, in terms of wt. % ranges: 25 to 28 Cr; 11 to 13 Ni; 7 to 8 W; 3.5 to 4 Mo; 3 to 3.5 B; 2 to 2.5 Mn; 1 to 1.5 Si; 0.3 to 1.7 C; up to 2 O; balance Fe. The composition has an austenitic matrix phase and a particulate, crystalline dispersed phase.

  17. X-Ray diffraction study of strain hardening and annealing in an UNS S31803 duplex stainless steel; Estudo por difracao de raios-X do encruamento e do recozimento do aco inoxidavel duplex UNS S318031

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, Denilson Jose Marcolino de; Padilha, Angelo Fernando [Universidade de Sao Paulo (EP/USP), Sao Paulo, SP (Brazil). Departamento de Engenharia Metalurgica e de Materiais; Lima, Nelson Batista de [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2010-07-01

    In the present work the phenomena of strain hardening, formation and reversion of the strain induced alpha-prime martensite (α', CCC, Ferromagnetic) in an UNS S31803 duplex stainless steel have been studied. Initially, the microstructure of the material in the solution annealed condition was characterized with aid of several complementary techniques of microstructural analysis. The volumetric fraction, crystalline structure, chemical composition, size and morphology of the two phases (ferrite and austenite) have been determined. The phenomena of strain hardening, formation and reversion of strain induced martensite in the austenite phase and recovery of austenite and ferrite phases have been studied, predominantly by using X-ray diffraction and the Rietveld method. (author)

  18. Irradiation embrittlement of ferritic stainless steels

    International Nuclear Information System (INIS)

    Suganuma, K.; Kayano, H.

    1984-01-01

    The characteristics of the irradiation embrittlement of some ferritic stainless steels were examined by tensile tests. Steels selected in this investigation were classified into three groups: chi phase, precipitation hardened Fe-13Cr steels; tempered martensitic Fe-12Cr steels; and low alloy steels. The latter steels were chosen in order to compare the irradiation embrittlement characteristics with those of stainless steels. The stainless steels were superior to the low alloy steels with regard to the irradiation embrittlement (the changes in both ductile-brittle transition temperature (DBTT) and unstable plastic flow transition temperature (UPFTT)), irrespective of whether these stainless steels had chi phase precipitated structures or tempered martensitic structures. The suppression of the DBTT increase owing to irradiation results from low yield stress increase Δσsub(y) and high |[dσsub(y)(u)/dT]|, where u denotes unirradiated, in the stainless steels. The suppression of the UPFTT results from the high work hardening rate or the high work exponent and the low Lueders strain in the stainless steels. These characteristics of irradiation embrittlement in the ferritic stainless steels are thought to be caused by the defect structure, which is modified by Cr atoms. (author)

  19. Precipitation reactions in austenitic stainless steels

    International Nuclear Information System (INIS)

    Hoch, M.; Yung-Shih Chen

    1979-01-01

    The precipitation reactions for commercial austenitic stainless steels (AISI type 347, 321, 316, 316L, 304 and 304L) and Ti-modified AISI type 316 SS were studied in the temperature range of 750 0 C-1350 0 C. Specimens were held at the temperature for 15 to 25 hours to ensure that equilibrium conditions were reached and followed by a water quench to prevent further precipitation reactions during cooling process. The precipitates were extracted from bulk specimens by anodic dissolution and identified by x-ray diffraction analysis. In Ti-stabilized 321 SS, large TiN and Ti 2 S (Ti 4 C 2 S2) precipitates were present in solution treated and subsequent annealed specimens. Small TiC precipitates were present in specimens annealed below 1150 0 C. The M 23 C 6 precipitates were found to be present after annealing at 850 0 C for 25 hours. The amount of M 23 C 6 was found to increase with decreased Ti content as shown in the Ti-motified 316 SS. In Nb-stabilized 347 SS, Nb(CN) precipitates were present in solution treated as well as annealed specimens. The M 23 C 6 precipitates were detected at an annealing temperature of 1050 0 C, which is higher than the precipitation temperature detected in 321 SS. Thermodynamic calculations were carried out to obtain the temperature where precipitation starts, and the temperatures where 50, 90 and 99% of the precipitates should be formed. The experimental results are in very good agreement with the calculations. (orig.) [de

  20. Effects of microstructure on ultrasonic examination of stainless steel

    International Nuclear Information System (INIS)

    Kupperman, D.S.; Reimann, K.J.

    1976-01-01

    Ultrasonic inspection of cast stainless steel components or stainless steel welds is difficult, and the results obtained are hard to interpret. The present study describes the effects of stainless steel microstructure on ultrasonic test results. Welded coupons, 2.5 and 5.0 cm thick, were fabricated from Type 304 stainless steel, with Type 308 stainless steel as the weld material. Metallography of the base material shows grain sizes of 15 and 80 μm, and dendrites aligned from the top to the bottom surface in cast material. X-ray diffraction and ultrasonic velocity measurements indicate a random crystal orientation in the base material, but the cast sample had aligned dendrites. The weld material exhibits a dendritic structure with a preferred (100) direction perpendicular to the weld pass. Spectral analysis of ultrasonic broad-band signals through the base materials shows drastic attenuation of higher frequencies with increasing grain size (Rayleigh scattering). Annealing and recrystallization increases the ultrasonic attenuation and produces carbide precipitation at grain boundaries. The microstructural differences of the base metal, heat-affected zone, and weld metal affect the amplitude of ultrasonic reflections from artificial flaws in these zones. Data obtained from two samples of different grain sizes indicate that grain size has little effect when a 1-MHz transducer is used. When going from a 15 to an 80-μm crystalline structure, a 5-MHz unit suffers a 30-dB attenuation in the detection of a 1.2 mm deep notch. The anisotropy of the dendritic structure in stainless steel renewed the interest in the effect of shear-wave polarization. In the (110) crystallographic orientation of stainless steel, two modes of shear waves can be generated, which have velocities differing by a factor of two. This effect may be helpful in ''tuning'' of shear waves by polarization to obtain better penetration in large grain materials such as welds

  1. Solidification cracking in austenitic stainless steel welds

    Indian Academy of Sciences (India)

    M. Senthilkumar (Newgen Imaging) 1461 1996 Oct 15 13:05:22

    V Shankar et al. Although much research experience exists on the nature of hot cracking in stainless steels ... that crack-resistant weld deposits could be produced if the composition is adjusted to result in 5–35% fer- .... A large volume of literature is devoted to the prediction and measurement of δ-ferrite in stainless steel ...

  2. The comparison of frictional resistance in titanium, self-ligating stainless steel, and stainless steel brackets using stainless steel and TMA archwires: An in vitro study

    Directory of Open Access Journals (Sweden)

    Syed Altaf Khalid

    2012-01-01

    Full Text Available Aim: The aim of the study was to compare the frictional resistance of titanium, self-ligating stainless steel, and conventional stainless steel brackets, using stainless steel and titanium molybdenum alloy (TMA archwires. Materials and Methods: We compared the frictional resistance in 0.018 slot and 0.022 slot of the three brackets - titanium, self-ligating stainless steel, and conventional stainless steel - using stainless steel archwires and TMA archwires. An in vitro study of simulated canine retraction was undertaken to evaluate the difference in frictional resistance between titanium, self-ligating stainless steel, and stainless steel brackets, using stainless steel and TMA archwires. Results and Conclusion: We compared the frictional resistance of titanium, self-ligating stainless steel, and conventional stainless steel brackets, using stainless steel and TMA archwires, with the help of Instron Universal Testing Machine. One-way analysis of variance (ANOVA, Student′s "t" test, and post hoc multiple range test at level of <0.05 showed statistically significant difference in the mean values of all groups. Results demonstrated that the titanium, self-ligating stainless steel, and stainless steel brackets of 0.018-inch and 0.022-inch slot had no significant variations in frictional résistance. The self-ligating bracket with TMA archwires showed relatively less frictional resistance compared with the other groups. The titanium bracket with TMA archwires showed relatively less frictional resistance compared with the stainless steel brackets.

  3. Creep embrittlement of austenitic stainless steels with titanium addition

    International Nuclear Information System (INIS)

    Felsen, M.F.

    1983-04-01

    Some cold-worked austenitic stainless steels of the 316 type with titanium addition exhibit a low creep ductility and a notch sensitivity in the temperature range of 550 0 C to 750 0 C and for times to rupture from 10 to 10000 hours. It has been shown that this embrittlement increases highly with cold-work percentage, with solution annealing temperature, and depends on chemical composition because these factors can modify the difference of hardness between grains and grain boundaries

  4. Effects of the Cooling Rate After Annealing Treatment on the Microstructure and the Mechanical Properties of Super-Duplex Stainless Steel

    International Nuclear Information System (INIS)

    Kwon, Gi-Hyoun; Park, Yong-Ho; Na, Young-Sang; Yoo, Wee-Do; Lee, Jong-Hoon

    2012-01-01

    The aim of this study was to analyze the effect of the cooling rate after heat treatment on the microstructure and mechanical properties of 2507 duplex stainless steels. Heat treatment was carried out at 1050°C for 1 hr, followed by controlled cooling. The cooling rates were 175.6 × 10 - 3°C/s, 47.8 × 10 - 3°C/s, 33.3 × 10 - 3°C/s, 16.7 × 10 - 3°C/s, 11.7 × 10 - 3°C/s, 5.8 × 10 - 3°C/s and 2.8 × 10 - 3°C/s, which resulted in variations of the microstructure, such as the fractional change of the ferrite phase and sigma phase formation. Fatigue, hardness, impact and tensile tests were performed on the specimens with different cooling rates. The precipitation of the σ phase caused a hardness increase and a sharp decrease of toughness and tensile elongation. The fatigue limit of the sample with a cooling rate of 5.8 × 10 - 3°C/s was 26 MPa higher than that of the sample with a cooling rate of 175.6 × 10 - 3°C/s. Our observations of the fracture surface confirmed that the higher fatigue resistance of the specimen with a cooling rate of 5.8 × 10 - 3°C/s was caused by the delay of the fatigue crack growth, in addition to higher yield strength.

  5. Effects of the Cooling Rate After Annealing Treatment on the Microstructure and the Mechanical Properties of Super-Duplex Stainless Steel

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Gi-Hyoun; Park, Yong-Ho [Pusan National University, Pusan (Korea, Republic of); Na, Young-Sang; Yoo, Wee-Do; Lee, Jong-Hoon [Korea Institute of Materials Science, Changwon (Korea, Republic of)

    2012-10-15

    The aim of this study was to analyze the effect of the cooling rate after heat treatment on the microstructure and mechanical properties of 2507 duplex stainless steels. Heat treatment was carried out at 1050°C for 1 hr, followed by controlled cooling. The cooling rates were 175.6 × 10{sup -}3°C/s, 47.8 × 10{sup -}3°C/s, 33.3 × 10{sup -}3°C/s, 16.7 × 10{sup -}3°C/s, 11.7 × 10{sup -}3°C/s, 5.8 × 10{sup -}3°C/s and 2.8 × 10{sup -}3°C/s, which resulted in variations of the microstructure, such as the fractional change of the ferrite phase and sigma phase formation. Fatigue, hardness, impact and tensile tests were performed on the specimens with different cooling rates. The precipitation of the σ phase caused a hardness increase and a sharp decrease of toughness and tensile elongation. The fatigue limit of the sample with a cooling rate of 5.8 × 10{sup -}3°C/s was 26 MPa higher than that of the sample with a cooling rate of 175.6 × 10{sup -}3°C/s. Our observations of the fracture surface confirmed that the higher fatigue resistance of the specimen with a cooling rate of 5.8 × 10{sup -}3°C/s was caused by the delay of the fatigue crack growth, in addition to higher yield strength.

  6. Development of new high-performance stainless steels

    International Nuclear Information System (INIS)

    Park, Yong Soo

    2002-01-01

    This paper focused on high-performance stainless steels and their development status. Effect of nitrogen addition on super-stainless steel was discussed. Research activities at Yonsei University, on austenitic and martensitic high-performance stainless, steels, and the next-generation duplex stainless steels were introduced

  7. Hydrogen damage in stainless steel

    International Nuclear Information System (INIS)

    Caskey, G.R. Jr.

    1981-01-01

    Hydrogen damage has been studied in a wide variety of stainless steels. Both internal and external hydrogen damage were evaluated by ductility or J-integral under rising tensile loads and by fractography. Analysis of the data has emphasized the potential effects of strain-induced martensite on hydrogen damage. Strain-induced martensite was neither necessary nor sufficient for hydrogen damage in the alloys studied. Neither ductility loss nor fracture-mode change correlated generally with martensite formation. Alloy composition, particularly nickel and nitrogen contents, was the primary factor in resistance to hydrogen damage. Thermomechanical processing, however, could alter the degree of hydrogen damage in an alloy and was critical for optimizing resistance to hydrogen damage. 10 figures, 10 tables

  8. Special stainless steels for sea water service

    International Nuclear Information System (INIS)

    Tomaselli, A.C.

    1983-01-01

    Very exacting demands are made on the corrosion resistance and mechanical properties of materials which in their service come into contact with seawater, and in many cases simultaneously with corrosive process solutions. The demand for higher alloy stainless steels for seawater application is rising in pace with the increasing requirements for safety and operation economy. The corrosion conditions in seawater and the resistance of stainless steels in this medium will be dealt with in the following. Sanicro 28 will then be compared with stainless steels, types AISI 304, 316 and 317, as well as with Alloy 20, Alloy 825 and SANDVIK 2RK65. (Author) [pt

  9. Recycle of radiologically contaminated austenitic stainless steels

    International Nuclear Information System (INIS)

    Imrich, K.J.; Leader, D.R.; Iyer, N.C.; Louthan, M.R. Jr.

    1995-01-01

    The United States Department of Energy owns large quantities of radiologically contaminated austenitic stainless steel which could by recycled for reuse if appropriate release standards were in place. Unfortunately, current policy places the formulation of a release standard for USA industry years, if not decades, away. The Westinghouse Savannah River Company, Idaho National Engineering Laboratory and various university and industrial partners are participating in initiative to recycle previously contaminated austenitic stainless steels into containers for the storage and disposal of radioactive wastes. This paper describes laboratory scale experiments which demonstrated the decontamination and remelt of stainless steel which had been contaminated with radionuclides

  10. Internal microporosity formation in stainless steel powders: kinetics and mechanism

    International Nuclear Information System (INIS)

    Martinez, M.; Suwardijo, W.; Garcia, L.; Formoso, A.; Cores, A.

    2002-01-01

    The internal microporosity of stainless steel powders is obtained by a technology developed in the Metallurgical Research Center (CIME) in collaboration with ISPETP, which consists of carbon enrichment of alloy during the fusion process, and after powder atomization a subsequent decarburization annealing. The internal microporosity , which can reach up to 10 volume percent of the steel particle, reduces powder density and improves powder compressibility, while costs for technology installation are also reduced. In this paper the technology for obtaining the microporosity, the mathematical models of the process, and the structural transformations undergone by stainless steel powder are shown. It is concluded that for carbon contents lower than 0.05% internal microporosity tends to disappear. (Author) 17 refs

  11. Stainless steel reinforcement as a replacement for epoxy coated steel in bridge decks : final report.

    Science.gov (United States)

    2013-08-01

    The corrosion resistance of 2304 stainless steel reinforcement and stainless steel clad reinforcement was compared to conventional and epoxy-coated reinforcement (ECR). 2304 stainless steel was tested in both the as-received condition (dark mottled f...

  12. SELECTIVE SEPARATION OF URANIUM FROM FERRITIC STAINLESS STEELS

    Science.gov (United States)

    Beaver, R.J.; Cherubini, J.H.

    1963-05-14

    A process is described for separating uranium from a nuclear fuel element comprising a uranium-containing core and a ferritic stainless steel clad by heating said element in a non-carburizing atmosphere at a temperature in the range 850-1050 un. Concent 85% C, rapidly cooling the heated element through the temperature range 815 un. Concent 85% to 650 EC to avoid annealing said steel, and then contacting the cooled element with an aqueous solution of nitric acid to selectively dissolve the uranium. (AEC)

  13. Current status of stainless steel industry and development of stainless steel

    International Nuclear Information System (INIS)

    Lee, Yong Deuk; Lee, Chan Soo; Kim Kwang Tae

    2000-01-01

    Stainless steel is not only clean and smooth in its surface, but also it is superior in quality in terms of corrosion resistance and strength. So that, it is widely in use in the field of construction, chemical installations, and other industries. Growth of stainless steel industry started since the steel technology was developed for mass production in 1960s. Since then stainless steel industry grew rapidly on account of diversified development in this field and growth rate went up to 5.8% per year comparable to 2.3% of steel growth. The rapid growth is attributed to significant industry developments in Europe and Japan in the years of 1970s and 1980s. In addition to these the expansion of stainless steel industry in Korea and Taiwan. Presently Korea produces about 120,000 tons of stainless steel and occupies about 8% of international market. This means Korea become the second largest single country in world in stainless steel production. Moreover Korea is to reinforce its domestic production line by affiliating production companies, increasing of production capability, and specializing in types of stainless steel. This paper is to describe activity of material development, and types of stainless steel for industry use. (Hong, J. S.)

  14. Effect of ultrafine grain on tensile behaviour and corrosion resistance of the duplex stainless steel.

    Science.gov (United States)

    Jinlong, Lv; Tongxiang, Liang; Chen, Wang; Limin, Dong

    2016-05-01

    The ultrafine grained 2205 duplex stainless steel was obtained by cold rolling and annealing. The tensile properties were investigated at room temperature. Comparing with coarse grained stainless steel, ultrafine grained sample showed higher strength and plasticity. In addition, grain size changed deformation orientation. The strain induced α'-martensite was observed in coarse grained 2205 duplex stainless steel with large strain. However, the grain refinement inhibited the transformation of α'-martensite;nevertheless, more deformation twins improved the strength and plasticity of ultrafine grained 2205 duplex stainless steel. In addition, the grain refinement improved corrosion resistance of the 2205 duplex stainless steel in sodium chloride solution. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Horizontal electron beam welding for stainless steels

    International Nuclear Information System (INIS)

    Martin, P.; Olivera, J.J.

    1977-01-01

    Stainless steel samples have been realized by local vacuum apparatus for electron beam welding applications to reactor core shell realizations. The best welding parameters have been determined by a systematic study. The welds have been characterized by mechanical tests [fr

  16. Consitutive modeling of metastable austenitic stainless steel

    NARCIS (Netherlands)

    Perdahcioglu, Emin Semih; Perdahcioglu, Emin Semih

    2008-01-01

    Metastable austenitic stainless steels combine high formability and high strength, which are generally opposing properties in materials. This property is a consequence of the martensitic phase transformation that takes place during deformation. This transformation is purely mechanically induced

  17. Stainless Steel to Titanium Bimetallic Transitions

    Energy Technology Data Exchange (ETDEWEB)

    Kaluzny, J. A. [Fermilab; Grimm, C. [Fermilab; Passarelli, D. [Fermilab

    2015-01-01

    In order to use stainless steel piping in an LCLS-II (Linac Coherent Light Source Upgrade) cryomodule, stainless steel to titanium bimetallic transitions are needed to connect the stainless steel piping to the titanium cavity helium vessel. Explosion bonded stainless steel to titanium transition pieces and bimetallic transition material samples have been tested. A sample transition tube was subjected to tests and x-ray examinations between tests. Samples of the bonded joint material were impact and tensile tested at room temperature as well as liquid helium temperature. The joint has been used successfully in horizontal tests of LCLS-II cavity helium vessels and is planned to be used in LCLS-II cryomodules. Results of material sample and transition tube tests will be presented.

  18. Development of nano/sub-micron grain structures in metastable austenitic stainless steels

    Science.gov (United States)

    Rajasekhara, Shreyas

    2007-12-01

    This dissertation is a part of a collaborative work between the University of Texas, Austin-Texas, the University of Oulu, Oulu-Finland, and Outokumpu Stainless Oy, Tornio-Finland, to develop commercial austenitic stainless steels with high strength and ductility. The idea behind this work involves cold-rolling a commercial metastable austenitic stainless steel - AISI 301LN stainless steel to produce strain-induced martensite, followed by an annealing treatment to generate nano/sub-micron grained austenite. AISI 301LN stainless steel sheets are cold-rolled to 63% reduction and subsequently annealed at 600°C, 700°C, 800°C, 900°C and 1000°C for 1, 10 and 100 seconds. The samples are analyzed by X-Ray diffraction, SQUID, transmission electron microscopy, and tensile testing to fundamentally understand the microstructural evolution, the mechanism for the martensite → austenite reversion, the formation of nano/sub-micron austenite grains, and the relationship between the microstructure and the strength obtained in this stainless steel. The results show that cold-rolled AISI 301LN stainless steel consist of dislocation-cell martensite, heavily deformed lath-martensite and austenite shear bands. Subsequent annealing at 600°C for short durations of 1 and 10 seconds leads to negligible martensite to austenite reversion. These 600°C samples exhibit a similar microstructure to the cold-rolled sample. However, for samples annealed at 600°C for 100 seconds and those annealed at higher temperatures (700°C, 800°C, 900°C and 1000°C) exhibit equiaxed austenitic grains of sizes 0.2mum-10mum and secondary phase precipitates. The microstructural analysis also reveals that the martensite → austenite reversion occurs via a diffusion-type reversion mechanism. In this regard, a generalized form of Avrami's equation is used to model the kinetics of martensite → austenite phase reversion. The results from the model agree reasonably well with the experiments. Furthermore

  19. Fatigue behavior of welded austenitic stainless steel in different environments

    Directory of Open Access Journals (Sweden)

    D.S. Yawas

    2014-01-01

    Full Text Available The fatigue behavior of welded austenitic stainless steel in 0.5 M hydrochloric acid and wet steam corrosive media has been investigated. The immersion time in the corrosive media was 30 days to simulate the effect on stainless steel structures/equipment in offshore and food processing applications and thereafter annealing heat treatment was carried out on the samples. The findings from the fatigue tests show that seawater specimens have a lower fatigue stress of 0.5 × 10−5 N/mm2 for the heat treated sample and 0.1 × 10−5 N/mm2 for the unheat-treated sample compared to the corresponding hydrochloric acid and steam samples. The post-welding heat treatment was found to increase the mechanical properties of the austenitic stainless steel especially tensile strength but it reduces the transformation and thermal stresses of the samples. These findings were further corroborated by the microstructural examination of the stainless steel specimen.

  20. Laves intermetallics in stainless steel-zirconium alloys

    International Nuclear Information System (INIS)

    Abraham, D.P.; McDeavitt, S.M.; Richardson, J.W. Jr.

    1997-01-01

    Laves intermetallics have a significant effect on properties of metal waste forms being developed at Argonne National Laboratory. These waste forms are stainless steel-zirconium alloys that will contain radioactive metal isotopes isolated from spent nuclear fuel by electrometallurgical treatment. The baseline waste form composition for stainless steel-clad fuels is stainless steel-15 wt.% zirconium (SS-15Zr). This article presents results of neutron diffraction measurements, heat-treatment studies and mechanical testing on SS-15Zr alloys. The Laves intermetallics in these alloys, labeled Zr(Fe,Cr,Ni) 2+x , have both C36 and C15 crystal structures. A fraction of these intermetallics transform into (Fe,Cr,Ni) 23 Zr 6 during high-temperature annealing; the authors have proposed a mechanism for this transformation. The SS-15Zr alloys show virtually no elongation in uniaxial tension, but exhibit good strength and ductility in compression tests. This article also presents neutron diffraction and microstructural data for a stainless steel-42 wt.% zirconium (SS-42Zr) alloy

  1. Determination tensile mechanical properties of AISI316 stainless steel implanted with different helium concentrations

    International Nuclear Information System (INIS)

    Abreu, A.S. de; Santos, G.R. dos; Goncalves, Z.C.

    1986-01-01

    Tensile tests in AISI 316 stainless steel samples steel samples implanted with different helium concentration were carried out. The samples were irradiated in Brazilian-CNEN cyclotron. The irradiated samples were submitted to annealing at the temperature of 1000 sup(0)C during 10 minutes. The results are presented. (M.C.K.)

  2. Standard test method for electrochemical critical pitting temperature testing of stainless steels

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1999-01-01

    1.1 This test method covers a procedure for the evaluation of the resistance of stainless steel and related alloys to pitting corrosion based on the concept of the determination of a potential independent critical pitting temperature (CPT). 1.2 This test methods applies to wrought and cast products including but not restricted to plate, sheet, tubing, bar, forgings, and welds, (see Note 1). Note 1—Examples of CPT measurements on sheet, plate, tubing, and welded specimens for various stainless steels can be found in Ref (1). See the research reports (Section 14). 1.3 The standard parameters recommended in this test method are suitable for characterizing the CPT of austenitic stainless steels and other related alloys with a corrosion resistance ranging from that corresponding to solution annealed UNS S31600 (Type 316 stainless steel) to solution annealed UNS S31254 (6 % Mo stainless steel). 1.4 This test method may be extended to stainless steels and other alloys related to stainless steel that have a CPT...

  3. Correlation Between Shear Punch and Tensile Strength for Low-Carbon Steel and Stainless Steel Sheets

    Science.gov (United States)

    Mahmudi, R.; Sadeghi, M.

    2013-02-01

    The deformation behavior of AISI 1015 low-carbon steel, and AISI 304 stainless steel sheets was investigated by uniaxial tension and the shear punch test (SPT). Both materials were cold rolled to an 80% thickness reduction and subsequently annealed in the temperature range 25-850 °C to produce a wide range of yield and ultimate strength levels. The correlations between shear punch and tensile yield and ultimate stresses were established empirically. Different linear relationships having different slopes and intercepts were found for the low-carbon and stainless steel sheets, and the possible parameters affecting the correlation were discussed. It was shown that, within limits, yield and tensile strength of thin steel sheets can be predicted from the shear data obtained by the easy-to-perform SPT.

  4. Ion-nitriding of austenitic stainless steels

    International Nuclear Information System (INIS)

    Pacheco, O.; Hertz, D.; Lebrun, J.P.; Michel, H.

    1995-01-01

    Although ion-nitriding is an extensively industrialized process enabling steel surfaces to be hardened by nitrogen diffusion, with a resulting increase in wear, seizure and fatigue resistance, its direct application to stainless steels, while enhancing their mechanical properties, also causes a marked degradation in their oxidation resistance. However, by adaption of the nitriding process, it is possible to maintain the improved wear resistant properties while retaining the oxidation resistance of the stainless steel. The controlled diffusion permits the growth of a nitrogen supersaturated austenite layer on parts made of stainless steel (AISI 304L and 316L) without chromium nitride precipitation. The diffusion layer remains stable during post heat treatments up to 650 F for 5,000 hrs and maintains a hardness of 900 HV. A very low and stable friction coefficient is achieved which provides good wear resistance against stainless steels under diverse conditions. Electrochemical and chemical tests in various media confirm the preservation of the stainless steel characteristics. An example of the application of this process is the treatment of Reactor Control Rod Cluster Assemblies (RCCAs) for Pressurized Water Nuclear Reactors

  5. Ultrasonic testing of austenitic stainless steel welds

    International Nuclear Information System (INIS)

    Nishino, Shunichi; Hida, Yoshio; Yamamoto, Michio; Ando, Tomozumi; Shirai, Tasuku.

    1982-05-01

    Ultrasonic testing of austenitic stainless steel welds has been considered difficult because of the high noise level and remarkable attenuation of ultrasonic waves. To improve flaw detectability in this kind of steel, various inspection techniques have been studied. A series of tests indicated: (1) The longitudinal angle beam transducers newly developed during this study can detect 4.8 mm dia. side drilled holes in dissimilar metal welds (refraction angle: 55 0 from SUS side, 45 0 from CS side) and in cast stainless steel welds (refraction angle: 45 0 , inspection frequency: 1 MHz). (2) Cracks more than 5% t in depth in the heat affected zones of fine-grain stainless steel pipe welds can be detected by the 45 0 shear wave angle beam method (inspection frequency: 2 MHz). (3) The pattern recognition method using frequency analysis technology was presumed useful for discriminating crack signals from spurious echoes. (author)

  6. Aging degradation of cast stainless steel

    International Nuclear Information System (INIS)

    Chopra, O.K.; Chung, H.M.

    1985-10-01

    A program is being conducted to investigate the significance of in-service embrittlement of cast-duplex stainless steels under light-water reactor operating conditions. Data from room-temperature Charpy-impact tests for several heats of cast stainless steel aged up to 10,000 h at 350, 400, and 450 0 C are presented and compared with results from other studies. Microstructures of cast-duplex stainless steels subjected to long-term aging either in the laboratory or in reactor service have been characterized. The results indicate that at least two processes contribute to the low-temperature embrittleent of duplex stainless steels, viz., weakening of the ferrite/austenite phase boundary by carbide precipitation and embrittlement of ferrite matrix by the formation of additional phases such as G-phase, Type X, or the α' phase. Carbide precipitation has a significant effect on the onset of embrittlement of CF-8 and -8M grades of stainless steels aged at 400 or 450 0 C. The existing correlations do not accurately represent the embrittlement behavior over the temperature range 300 to 450 0 C. 18 refs., 13 figs

  7. HTPro: Low-temperature Surface Hardening of Stainless Steel

    DEFF Research Database (Denmark)

    Christiansen, Thomas Lundin; Somers, Marcel A. J.

    2013-01-01

    Low-temperature surface hardening of stainless steel provides the required performance properties without affecting corrosion resistance.......Low-temperature surface hardening of stainless steel provides the required performance properties without affecting corrosion resistance....

  8. 77 FR 64545 - Drawn Stainless Steel Sinks From China

    Science.gov (United States)

    2012-10-22

    ... merchandise as ``drawn stainless steel sinks with single or multiple drawn bowls, with or without drain boards... finishing the vertical corners to form the bowls. Stainless steel sinks with fabricated bowls may sometimes...

  9. Phosphate coating on stainless steel 304 sensitized

    International Nuclear Information System (INIS)

    Cruz V, J. P.; Vite T, J.; Castillo S, M.; Vite T, M.

    2009-01-01

    The stainless steel 304 can be sensitized when welding processes are applied, that causes the precipitation of chromium carbide in the grain limits, being promoted in this way the formation of galvanic cells and consequently the corrosion process. Using a phosphate coating is possible to retard the physiochemical damages that can to happen in the corrosion process. The stainless steel 304 substrate sensitized it is phosphate to base of Zn-Mn, in a immersion cell very hot. During the process was considered optimization values, for the characterization equipment of X-rays diffraction and scanning electron microscopy was used. The XRD technique confirmed the presence of the phases of manganese phosphate, zinc phosphate, as well as the phase of the stainless steel 304. When increasing the temperature from 60 to 90 C in the immersion process a homogeneous coating is obtained. (Author)

  10. Tensile behavior of irradiated manganese-stabilized stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Klueh, R.L. [Oak Ridge National Lab., TN (United States)

    1996-10-01

    Tensile tests were conducted on seven experimental, high-manganese austenitic stainless steels after irradiation up to 44 dpa in the FFTF. An Fe-20Mn-12Cr-0.25C base composition was used, to which various combinations of Ti, W, V, B, and P were added to improve strength. Nominal amounts added were 0.1% Ti, 1% W, 0.1% V, 0.005% B, and 0.03% P. Irradiation was carried out at 420, 520, and 600{degrees}C on the steels in the solution-annealed and 20% cold-worked conditions. Tensile tests were conducted at the irradiation temperature. Results were compared with type 316 SS. Neutron irradiation hardened all of the solution-annealed steels at 420, 520, and 600{degrees}C, as measured by the increase in yield stress and ultimate tensile strength. The steel to which all five elements were added to the base composition showed the least amount of hardening. It also showed a smaller loss of ductility (uniform and total elongation) than the other steels. The total and uniform elongations of this steel after irradiation at 420{degrees}C was over four times that of the other manganese-stabilized steels and 316 SS. There was much less difference in strength and ductility at the two higher irradiation temperatures, where there was considerably less hardening, and thus, less loss of ductility. In the cold-worked condition, hardening occured only after irradiation at 420{degrees}C, and there was much less difference in the properties of the steels after irradiation. At the 420{degrees}C irradiation temperature, most of the manganese-stabilized steels maintained more ductility than the 316 SS. After irradiation at 420{degrees}C, the temperature of maximum hardening, the steel to which all five of the elements were added had the best uniform elongation.

  11. Robustness of steel joints with stainless steel bolts in fire

    Science.gov (United States)

    Satheeskumar, N.; Davison, J. B.

    2014-12-01

    The robustness of steel joints in fire is important for steel building structures because of the need to prevent progressive collapse. Stainless steel is widely used in building construction mainly because of its corrosion resistance, but it also possesses improved fire resistance compared with conventional non-alloy, fine grain structural steels. Extensive research performed on the robustness of steel joints in fire has revealed that failure at elevated temperature may be controlled by bolt shear for fin plate and web cleat connections. Hence, this study focussed on the use of stainless steel in experimental tests conducted on fin plate and web cleat connections at high temperatures. In addition, this study investigated the use of a component-based model to predict connection performance at elevated temperature.

  12. Effects of high energy nitrogen implantation on stainless steel microstructure

    Science.gov (United States)

    Pelletier, H.; Mille, P.; Cornet, A.; Grob, J. J.; Stoquert, J. P.; Muller, D.

    1999-01-01

    Low energy ion implantation is known to improve chemical and mechanical surface properties of metals. This treatment is often used to enhance wear and corrosion resistance or mechanical life-time of fatigue test of stainless steel or titanium alloys. The aim of this work is to investigate these effects at higher energy, for which deeper (and still not well understood) modifications occur. High fluence (10 18 cm -2) 15N and 14N implantations at 1 MeV have been performed in the 316LL stainless steel and some specimen have been annealed in the 200-500°C temperature range. Nitrogen concentration distribution, structure, morphology and microhardness have been examined with Nuclear Resonance Analysis, Grazing Incidence X-Ray Diffraction and Nanoindentation, respectively. Precipitates of steel and chromium nitride phases and a superficial martensitic transformation can be observed, leading to a significant increase of hardness. The best result is obtained after one hour annealing at 425°C, due to a larger and more homogeneous repartition of nitride species. In this case, a near surface accumulation is observed and explained in terms of diffusion and precipitation mechanisms.

  13. Electrochemical noise measurements of stainless steel in high temperature water

    International Nuclear Information System (INIS)

    Arganis-Juarez, C.R.; Malo, J.M.; Uruchurtu, J.

    2007-01-01

    Corrosion in a high purity aqueous environment simulating a boiling water reactor (BWR) is addressed in this work. This condition necessitates autoclave experiments under high pressure and temperature. Long-term electrochemical noise measurements were explored as a mean to detect and monitor stress corrosion cracking phenomenon. An experimental set up, designed to insulate the working electrode from external interference, made possible to detect and monitor stress corrosion cracking in slow strain rate tests for sensitized and solution annealed 304 stainless steel at 288 o C. Time-series analysis showed variations in the signature of the current density series due to transgranular stress corrosion cracking (TGSCC) and intergranular stress corrosion cracking (IGSCC)

  14. Void swelling behaviour of austenitic stainless steel during electron irradiation

    International Nuclear Information System (INIS)

    Sheng Zhongqi; Xiao Hong; Peng Feng; Ti Zhongxin

    1994-04-01

    The irradiation swelling behaviour of 00Cr17Ni14Mo2 austenitic stainless steel (AISI 316L) was investigated by means of high voltage electron microscope. Results showed that in solution annealed condition almost no swelling incubation period existed, and the swelling shifted from the transition period to the steady-state one when the displacement damage was around 40 dpa. In cold rolled condition there was evidently incubation period, and when the displacement damage was up to 84 dpa the swelling still remained in the transition period. The average size and density of voids in both conditions were measured, and the factors, which influenced the void swelling, were discussed. (3 figs.)

  15. 77 FR 1504 - Stainless Steel Wire Rod From India

    Science.gov (United States)

    2012-01-10

    ... COMMISSION Stainless Steel Wire Rod From India Determination On the basis of the record \\1\\ developed in the... antidumping duty order on stainless steel wire rod From India would be likely to lead to continuation or... contained in USITC Publication 4300 (January 2012), entitled Stainless Steel Wire Rod From India...

  16. 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....

  17. Low temperature gaseous surface hardening of stainless steel

    DEFF Research Database (Denmark)

    Christiansen, Thomas; Somers, Marcel A. J.

    2011-01-01

    The present contribtion 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 expanded austenite "layers" on stainless steel are addressed....

  18. 21 CFR 872.3350 - Gold or stainless steel cusp.

    Science.gov (United States)

    2010-04-01

    ...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3350 Gold or stainless steel cusp. (a) Identification. A gold or stainless steel cusp is a prefabricated device made of austenitic alloys or alloys containing 75 percent or greater gold and metals of the platinum group or stainless steel intended to provide...

  19. 78 FR 21417 - Drawn Stainless Steel Sinks From China

    Science.gov (United States)

    2013-04-10

    ... COMMISSION Drawn Stainless Steel Sinks From China Determinations On the basis of the record \\1\\ developed in... drawn stainless steel sinks from China, provided for in subheading 7324.10.00 of the Harmonized Tariff... notification of a preliminary determinations by Commerce that imports of drawn stainless steel sinks from China...

  20. Void swelling at low displacement rates in annealed 12X18HgT stainless steel at 4-56 dpa and 280-332 deg. C

    International Nuclear Information System (INIS)

    Porollo, S.I.; Konobeev, Yu.V.; Dvoriashin, A.M.; Vorobjev, A.N.; Krigan, V.M.; Garner, F.A.

    2002-01-01

    Water-cooled fusion devices most likely will have austenitic components that operate at temperatures below the inlet temperatures characteristic of high flux fast reactors used to generate majority of data on void swelling. Many of these components will experience displacement rates of 10 -7 -10 -8 dpa/s that are lower than that of most in-core fast reactor experiments. One question of particular interest is how to define the lower limit of the temperature range over which void swelling can occur at such low dpa rates. This question was addressed using a flow restrictor component irradiated at 4-56 dpa and 280-332 deg. C in the low-flux breeder zone of the BN-350 fast reactor in Kazakhstan. This component was constructed of annealed 12X18HgT, an alloy similar to AISI 321. Extensive sectioning to produce 114 separate specimens, followed by examination of the radiation-induced microstructure showed that void swelling in the range of temperatures and dpa rates of interest occurs down to ∼300 deg. C

  1. Evolution of stainless steels in nuclear industry

    International Nuclear Information System (INIS)

    Tavassoli, Farhad

    2010-01-01

    Starting with the stainless steels used in the conventional industry, their adoption and successive evolutions in the nuclear industry, from one generation of nuclear reactors to another, is presented. Specific examples for several steels are given, covering fabrication procedures, qualification methods, property databases and design allowable stresses, to show how the ever-increasing demands for better performance and reliability, in particular under neutron irradiation, have been met. Particular attention is paid to the austenitic stainless steels types 304L, 316L, 316L(N), 316L(N)-IG, titanium stabilized grade 321, precipitation strengthened alloy 800, conventional and low activation ferritic/martensitic steels and their oxygen dispersion strengthening (ODS) derivatives. For each material, the evolution of the associated filler metal and welding techniques are also presented. (author)

  2. HYDROGEN-ASSISTED FRACTURE IN FORGED TYPE 304L AUSTENITIC STAINLESS STEEL

    Energy Technology Data Exchange (ETDEWEB)

    Switzner, Nathan; Neidt, Ted; Hollenbeck, John; Knutson, J.; Everhart, Wes; Hanlin, R. [University of Missouri-Kansas City; Bergen, R. [Precision Metal Products; Balch, D. K. [Sandia Natl Laboratory

    2012-09-06

    Austenitic stainless steels generally have good resistance to hydrogen-assisted fracture; however, structural designs for high-pressure gaseous hydrogen are constrained by the low strength of this class of material. Forging is used to increase the low strength of austenitic stainless steels, thus improving the efficiency of structural designs. Hydrogen-assisted racture, however, depends on microstructural details associated with manufacturing. In this study, hydrogen-assisted fracture of forged type 304L austenitic stainless steel is investigated. Microstructural variation in multi-step forged 304L was achieved by forging at different rates and temperatures, and by process annealing. High internal hydrogen content in forged type 304L austenitic stainless steel is achieved by thermal precharging in gaseous hydrogen and results in as much as 50% reduction of tensile ductility.

  3. Nickel-free austenitic stainless steels for medical applications.

    Science.gov (United States)

    Yang, Ke; Ren, Yibin

    2010-02-01

    The adverse effects of nickel ions being released into the human body have prompted the development of high-nitrogen nickel-free austenitic stainless steels for medical applications. Nitrogen not only replaces nickel for austenitic structure stability but also much improves steel properties. Here we review the harmful effects associated with nickel in medical stainless steels, the advantages of nitrogen in stainless steels, and emphatically, the development of high-nitrogen nickel-free stainless steels for medical applications. By combining the benefits of stable austenitic structure, high strength and good plasticity, better corrosion and wear resistances, and superior biocompatibility compared to the currently used 316L stainless steel, the newly developed high-nitrogen nickel-free stainless steel is a reliable substitute for the conventional medical stainless steels.

  4. Colorimetric values of esthetic stainless steel crowns.

    Science.gov (United States)

    Hosoya, Yumiko; Omachi, Koichi; Staninec, Michal

    2002-01-01

    The colorimetric values of two different kinds of esthetic stainless steel crowns were measured and compared with the colorimetric values of primary anterior teeth in Japanese children. The colorimetric values of resin composite-faced stainless steel crowns (Kinder Krown) and epoxy-coated stainless steel crowns (White Steel Crown) were measured with a color difference meter. The Commission Internationale de Eclairage L*, a*, b*, and delta E*ab values and Munsell value, chroma, and hue were calculated. The data were compared with previously reported colorimetric values of Japanese primary anterior teeth measured with the same color difference meter used in this study. Compared to Japanese primary anterior teeth, Kinder Krown Pedo I and Pedo II showed much higher L* values and lower hue; on the other hand, White Steel Crown showed much higher L*, a*, b* values, much higher value and chroma, and much lower hue. Color analysis revealed that the colors of the White Steel Crown and Kinder Krown Pedo I were substantially different from the color of Japanese primary anterior teeth. The color difference between Pedo II crowns and Japanese primary anterior teeth was relatively high, but the color of Pedo II might be acceptable for clinical use.

  5. Granulate of stainless steel as compensator material

    NARCIS (Netherlands)

    J.P.C. van Santvoort (J. P C)

    1995-01-01

    textabstractCompensators produced with computer controlled milling devices usually consist of a styrofoam mould, filled with an appropriate material. We investigated granulate of stainless steel as filling material. This cheap, easy to use, clean and re-usable material can be obtained with an

  6. Stainless steel forgings for nuclear chemical plants

    International Nuclear Information System (INIS)

    1982-02-01

    This Specification covers detailed requirements for the supply of austenitic stainless steel forgings used in radioactive and corrosive areas within the Nuclear Industry. With the exception of 316S51 the materials specified are all suitable for contact with nitric acid, 316S51 being included as suitable for use in contact with sodium and other alkali metals at elevated temperatures. (author)

  7. Austenitic stainless steels for cryogenic service

    International Nuclear Information System (INIS)

    Dalder, E.N.C.; Juhas, M.C.

    1985-01-01

    Presently available information on austenitic Fe-Cr-Ni stainless steel plate, welds, and castings for service below 77 K are reviewed with the intent (1) of developing systematic relationships between mechanical properties, composition, microstructure, and processing, and (2) of assessing the adequacy of these data bases in the design, fabrication, and operation of engineering systems at 4 K

  8. CASE-HARDENING OF STAINLESS STEEL

    DEFF Research Database (Denmark)

    2004-01-01

    The invention relates to case-hardening of a stainless steel article by means of gas including carbon and/or nitrogen, whereby carbon and/or nitrogen atoms diffuse through the surface into the article. The method includes activating the surface of the article, applying a top layer on the activated...

  9. Microstructure of laser cladded martensitic stainless steel

    CSIR Research Space (South Africa)

    Van Rooyen, C

    2006-08-01

    Full Text Available of austenitic solidification. Table 4 - Chemical composition of the laser cladded martensitic stainless steel in the dendritic and interdendritic areas Material Area C* Cr Ni Mn Si Mo Dendritic 0.3 12.8 0.15 0.7 0.65 0.02 Fe211-1 (420) Off... alloy steels and are shown in Table 4. Ms (ºC) = 550 – 350C – 40Mn - 20Cr – 10Mo – 17Ni – 8W – 35V – 10Cu + 15Co + 30Al (Eq 3) Table 5 - Ms temperatures of laser cladded martensitic stainless steel Material Ms Dendritic area (ºC) Ms...

  10. Protective and non-protective oxide formation on 304 stainless steel

    International Nuclear Information System (INIS)

    Baer, D.R.

    1980-05-01

    Parameters controlling the formation of protective and non-protective oxides on 304 stainless steel were examined by using Auger electron spectroscopy to monitor oxides formed in the vacuum chamber. Variables found to influence the oxide formation include: oxygen partial pressure, the location of the oxide over a grain or grain boundary, sample grain size, and anneal treatments

  11. Monitoring of Fatigue Degradation in Austenitic Stainless Steels

    International Nuclear Information System (INIS)

    Kalkhof, D.; Niffenegger, M.; Leber, H.J.

    2004-01-01

    During cyclic loading of austenitic stainless steel, it was observed that microstructural changes occurred; these affect both the mechanical and physical properties of the material. For certain steels, a strain-induced martensite phase transformation was seen. The investigations showed that, for the given material and loading conditions, the volume fraction of martensite depends on the cycle number, temperature and initial material state. It was also found that the martensite content continuously increased with the cycle number. Therefore, the volume fraction of martensite was used as an indication of fatigue usage. It was noted that the temperature dependence of the martensite formation could be described by a Boltzmann function, and that the martensite content decreased with increasing temperature. Two different heats of the austenitic stainless steel X6CrNiTi18-10 (AISI 321, DIN 1.4541) were investigated. It was found that the martensite formation rate was much higher for the cold-worked than for the solution-annealed material. All applied techniques - neutron diffraction and advanced magnetic methods - were successful in detecting the presence of martensite in the differently fatigued specimens. (author)

  12. Embrittlement in CN3MN Grade Superaustenitic Stainless Steels

    Science.gov (United States)

    Başkan, Mertcan; Chumbley, Scott L.; Kalay, Yunus Eren

    2014-05-01

    Superaustenitic stainless steels (SSS) are widely used in extreme environments such as off-shore oil wells, chemical and food processing equipment, and seawater systems due to their excellent corrosion resistance and superior toughness. The design of the corresponding heat treatment process is crucial to create better mechanical properties. In this respect, the short-term annealing behavior of CN3MN grade SSS was investigated by a combined study of Charpy impact tests, hardness measurements, scanning and transmission electron microscopy. Specimens were heat treated at 1200 K (927 °C) for up to 16 minutes annealing time and their impact strengths and hardnesses were tested. The impact toughness was found to decrease to less than the half of the initial values while hardness stayed the same. Detailed fracture surface analyses revealed a ductile to brittle failure transition for relatively short annealing times. Brittle fracture occurred in both intergranular and transgranular modes. SEM and TEM indicated precipitation of nano-sized intermetallics, accounting for the intergranular embrittlement, along the grain boundaries with respect to annealing time. The transgranular fracture originated from linear defects seen to exist within the grains. Close observation of such defects revealed stacking-fault type imperfections, which lead to step-like cracking observed in microlength scales.

  13. Boronization and Carburization of Superplastic Stainless Steel and Titanium-Based Alloys

    Directory of Open Access Journals (Sweden)

    Masafumi Matsushita

    2011-07-01

    Full Text Available Bronization and carburization of fine-grain superplastic stainless steel is reviewed, and new experimental results for fine grain Ti88.5Al4.5V3Fe2Mo2 are reported. In superplastic duplex stainless steel, the diffusion of carbon and boron is faster than in non-superplastic duplex stainless steel. Further, diffusion is activated by uniaxial compressive stress. Moreover, non-superplastic duplex stainless steel shows typical grain boundary diffusion; however, inner grain diffusion is confirmed in superplastic stainless steel. The presence of Fe and Cr carbides or borides is confirmed by X-ray diffraction, which indicates that the diffused carbon and boron react with the Fe and Cr in superplastic stainless steel. The Vickers hardness of the carburized and boronized layers is similar to that achieved with other surface treatments such as electro-deposition. Diffusion of boron into the superplastic Ti88.5Al4.5V3Fe2Mo2 alloy was investigated. The hardness of the surface exposed to boron powder can be increased by annealing above the superplastic temperature. However, the Vickers hardness is lower than that of Ti boride.

  14. Superplasticity of Annealed H13 Steel

    Directory of Open Access Journals (Sweden)

    Zhenxin Duan

    2017-07-01

    Full Text Available H13 steel is a widely used hot work die material. A new type of hot working method is imperative to develop complex and precise dies. In this paper, the heat treatment of H13 steel (AISI was carried out by annealing, the final structure is a point or spherical pearlite, and the grain size is about 30–40 μm. The tensile properties of the annealed microstructure were investigated at 650, 750, and 850 °C with the strain rates of 1 × 10−3 s−1, 5 × 10−4 s−1, and 1 × 10−4 s−1. The tensile fracture and microstructure were analyzed by SEM and HREM. The results show that the tensile samples reach superplasticity at the strain rate of 1 × 10−4 s−1 in the temperature range of 750–850 °C. When the temperature is 850 °C, the maximum elongation rate reaches 112.5%. This demonstrates the possibility of making superplastic forming molds. During the tensile process, the refined M23C6 and other high hardness carbides which are dispersed uniformly in the matrix, effectively inhibits grain growth and hinders dislocation movement, leading to the improvement of plasticity.

  15. Superplasticity of Annealed H13 Steel.

    Science.gov (United States)

    Duan, Zhenxin; Pei, Wen; Gong, Xuebo; Chen, Hua

    2017-07-28

    H13 steel is a widely used hot work die material. A new type of hot working method is imperative to develop complex and precise dies. In this paper, the heat treatment of H13 steel (AISI) was carried out by annealing, the final structure is a point or spherical pearlite, and the grain size is about 30-40 μm. The tensile properties of the annealed microstructure were investigated at 650, 750, and 850 °C with the strain rates of 1 × 10 -3 s -1 , 5 × 10 -4 s -1 , and 1 × 10 -4 s -1 . The tensile fracture and microstructure were analyzed by SEM and HREM. The results show that the tensile samples reach superplasticity at the strain rate of 1 × 10 -4 s -1 in the temperature range of 750-850 °C. When the temperature is 850 °C, the maximum elongation rate reaches 112.5%. This demonstrates the possibility of making superplastic forming molds. During the tensile process, the refined M 23 C₆ and other high hardness carbides which are dispersed uniformly in the matrix, effectively inhibits grain growth and hinders dislocation movement, leading to the improvement of plasticity.

  16. Studies of stainless steel exposed to sandblasting

    Directory of Open Access Journals (Sweden)

    Horodek Paweł

    2015-12-01

    Full Text Available The influence of sandblasting on surface and subsurface of stainless steel is investigated using variable energy positron beam (VEP, positron annihilation spectroscopy (PAS, scanning electron microscopy (SEM, and atomic force microscopy (AFM. Samples of stainless steel were blasted using 110 μm particles of Al2O3 under different pressure and time duration. In the case of sandblasting for 90 s, the reduction of positron diffusion length depending on the applied pressure was observed. Sandblasting during 30 s leads only to the reduction of positron diffusion length to about 60 nm for all samples. Positron lifetimes close to 170 ps measured using positrons emitted directly from the source point to the presence of vacancies on the dislocation lines. SEM and AFM images show that surface roughness depends rather on pressure of sandblasting than time of exposition.

  17. Plasma spot welding of ferritic stainless steels

    International Nuclear Information System (INIS)

    Lesnjak, A.; Tusek, J.

    2002-01-01

    Plasma spot wedding of ferritic stainless steels studied. The study was focused on welding parameters, plasma and shieldings and the optimum welding equipment. Plasma-spot welded overlap joints on a 0.8 mm thick ferritic stainless steel sheet were subjected to a visual examination and mechanical testing in terms of tension-shear strength. Several macro specimens were prepared Plasma spot welding is suitable to use the same gas as shielding gas and as plasma gas , i. e. a 98% Ar/2% H 2 gas mixture. Tension-shear strength of plasma-spot welded joint was compared to that of resistance sport welded joints. It was found that the resistance welded joints withstand a somewhat stronger load than the plasma welded joints due to a large weld sport diameter of the former. Strength of both types of welded joints is approximately the same. (Author) 32 refs

  18. State on AISI 304 Stainless Steel

    Directory of Open Access Journals (Sweden)

    A. Fattah-alhosseini

    2011-01-01

    Full Text Available The passivity and protective nature of the passive films are essentially related to ionic and electronic transport processes, which are controlled by the optical and electronic properties of passive films. In this study, the electrochemical behavior of passive films anodically formed on AISI 304 stainless steel in sulfuric acid solution has been examined using electrochemical impedance spectroscopy. AISI 304 in sulphuric acid solution is characterized by high interfacial impedance, thereby illustrating its high corrosion resistance. Results showed that the interfacial impedance and the polarization resistance (pol initially increase with applied potential, within the low potential passive. However, at a sufficiently high potential passive (>0.4 V, the interfacial impedance and the polarization resistance decrease with increasing potential. An electrical equivalent circuit based on the impedance analysis, which describes the behavior of the passive film on stainless steel more satisfactorily than the proposed models, is presented.

  19. Diffraction study on aging duplex stainless steel

    International Nuclear Information System (INIS)

    Ishigaki, Toru; Miura, Takayuki; Kuwano, Hisashi; Torii, Syuuki; Kamiyama, Takashi

    2001-01-01

    SUS329J2L duplex stainless steels exhibit high strength and resistance to corrosion, so widely used in piping of industrial plants. However, it is known that they are brought deterioration of strength using for long time. This reason of this deterioration is that ferrite decomposes to Fe-rich α phase and Cr-rich α' phase and, Cr-rich α' phase decreases mechanical properties and resistance for corrosion. In this experiment, we made neutron diffraction experiments on long time aging (625 K, 16000 h) duplex stainless steel to observe the behavior for α phase and α' phase, using Sirius diffractometer at KENS. The result shows, the lattice parameters in α phase were decreased. In contrast to, its in austenite (γ phase) were slightly increased. (author)

  20. Influence of laser shock peening on irradiation defects in austenitic stainless steels

    Science.gov (United States)

    Lu, Qiaofeng; Su, Qing; Wang, Fei; Zhang, Chenfei; Lu, Yongfeng; Nastasi, Michael; Cui, Bai

    2017-06-01

    The laser shock peening process can generate a dislocation network, stacking faults, and deformation twins in the near surface of austenitic stainless steels by the interaction of laser-driven shock waves with metals. In-situ transmission electron microscopy (TEM) irradiation studies suggest that these dislocations and incoherent twin boundaries can serve as effective sinks for the annihilation of irradiation defects. As a result, the irradiation resistance is improved as the density of irradiation defects in laser-peened stainless steels is much lower than that in untreated steels. After heating to 300 °C, a portion of the dislocations and stacking faults are annealed out while the deformation twins remain stable, which still provides improved irradiation resistance. These findings have important implications on the role of laser shock peening on the lifetime extension of austenitic stainless steel components in nuclear reactor environments.

  1. Diamond deposition on siliconized stainless steel

    International Nuclear Information System (INIS)

    Alvarez, F.; Reinoso, M.; Huck, H.; Rosenbusch, M.

    2010-01-01

    Silicon diffusion layers in AISI 304 and AISI 316 type stainless steels were investigated as an alternative to surface barrier coatings for diamond film growth. Uniform 2 μm thick silicon rich interlayers were obtained by coating the surface of the steels with silicon and performing diffusion treatments at 800 deg. C. Adherent diamond films with low sp 2 carbon content were deposited on the diffused silicon layers by a modified hot filament assisted chemical vapor deposition (HFCVD) method. Characterization of as-siliconized layers and diamond coatings was performed by energy dispersive X-ray analysis, scanning electron microscopy, X-ray diffraction and Raman spectroscopy.

  2. STRUCTURAL STRESS RELAXATION IN STAINLESS INSTABILITY STEEL

    Directory of Open Access Journals (Sweden)

    S. Lyabuk

    2017-06-01

    Full Text Available The approach to the description of conditions of martensitic transformation in austenitic steel is advanced. Transformation induced hardening is the result of Le Chatelier principle in instability alloys. The phase transformation in austenitic instability stainless steel is the cause of reduction of grain refining and increase of strength. It was experimentally shown that physical-mechanical characteristics of the prepared materials were defined by the structure and inhomogeneous distribution of the hardening phase within a grain. The reasons for high thermal stability of inverse austenitic were established. The factors determining the inverse austenitic relaxation resistibility and resources for its increasing were revealed.

  3. Pitting corrosion resistant austenite stainless steel

    Science.gov (United States)

    van Rooyen, D.; Bandy, R.

    A pitting corrosion resistant austenite stainless steel comprises 17 to 28 wt. % chromium, 15 to 26 wt. % nickel, 5 to 8 wt. % molybdenum, and 0.3 to 0.5 wt. % nitrogen, the balance being iron, unavoidable impurities, minor additions made in the normal course of melting and casting alloys of this type, and may optionally include up to 10 wt. % of manganese, up to 5 wt. % of silicon, and up to 0.08 wt. % of carbon.

  4. Fatigue fracture modes of a stainless steel

    International Nuclear Information System (INIS)

    Pacheco, D.J.; Souza e Silva, A.S. de; Monteiro, S.N.

    1977-01-01

    The influence of strain hardening and martensite phase transformation on the fatigue fracture regions (pulsative tension) of a Stainless Steel type AISI 316 was investigated. This lead to the conclusion that the greater austenite strain hardening level only favours the occurrence of a brittle fracture. Also, in as much as the static induced martensite is concerned, a direct influence on the failure process was not observed, whereas, apparently, the one transformed under cyclic loading has no contribution to the rupture mechanisms. (author) [pt

  5. Corrosion Properties of Laser Welded Stainless Steel

    DEFF Research Database (Denmark)

    Weldingh, Jakob; Olsen, Flemmming Ove

    1997-01-01

    In this paper the corrosion properties of laser welded AISI 316L stainless steel are examined. A number of different welds has been performed to test the influence of the weld parameters of the resulting corrosion properties. It has been chosen to use the potential independent critical pitting...... temperature (CPT) test as corrosion test. The following welding parameters are varied: Welding speed, lsser power, focus point position and laser operation mode (CW or pulsed)....

  6. Ferritic stainless steels: corrosion resistance + economy

    International Nuclear Information System (INIS)

    Remus, A.L.

    1976-01-01

    Ferritic stainless steels provide corrosion resistance at lower cost. They include Type 409, Type 439, 18SR, 20-Mo (1.6 Mo), 18-2 (2 Mo), 26-1S, E-Brite 26-1, 29 Cr-4 Mo, and 29 Cr-4 Mo-2 Ni. Their corrosion and mechanical properties are examined. Resistance to stress-corrosion cracking is an advantage compared to austenitic types

  7. Estimation of embrittlement during aging of AISI 316 stainless steel ...

    Indian Academy of Sciences (India)

    Unknown

    Nitrogen additions to stainless steels have been found beneficial as it improves austenite stability and thereby ... selected keeping in mind the service conditions in the nuclear reactors where these steels are used. .... increases. δ-Ferrite in austenitic stainless steel weld met- als containing FN4–FN11 decomposes to α + α′ ...

  8. Withdrawal Strength and Bending Yield Strength of Stainless Steel Nails

    Science.gov (United States)

    Douglas R. Rammer; Samuel L. Zelinka

    2015-01-01

    It has been well established that stainless steel nails have superior corrosion performance compared to carbon steel or galvanized nails in treated wood; however, their mechanical fastening behavior is unknown. In this paper, the performance of stainless steel nails is examined with respect to two important properties used in wood connection design: withdrawal strength...

  9. 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 ...

  10. Impact Testing of Stainless Steel Materials

    International Nuclear Information System (INIS)

    R. K. Blandford; D. K. Morton; T. E. Rahl; S. D. Snow

    2005-01-01

    Stainless steels are used for the construction of numerous spent nuclear fuel or radioactive material containers that may be subjected to high strains and moderate strain rates (10 to 200 per second) during accidental drop events. Mechanical characteristics of these materials under dynamic (impact) loads in the strain rate range of concern are not well documented. The goal of the work presented in this paper was to improve understanding of moderate strain rate phenomena on these materials. Utilizing a drop-weight impact test machine and relatively large test specimens (1/2-inch thick), initial test efforts focused on the tensile behavior of specific stainless steel materials during impact loading. Impact tests of 304L and 316L stainless steel test specimens at two different strain rates, 25 per second (304L and 316L material) and 50 per second (304L material) were performed for comparison to their quasi-static tensile test properties. Elevated strain rate stress-strain curves for the two materials were determined using the impact test machine and a ''total impact energy'' approach. This approach considered the deformation energy required to strain the specimens at a given strain rate. The material data developed was then utilized in analytical simulations to validate the final elevated stress-strain curves. The procedures used during testing and the results obtained are described in this paper

  11. Computer simulation of sensitization in stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    Logan, R W

    1983-12-20

    Stainless steel containers are prime candidates for the containment of nuclear waste in tuff rock. The thermal history of a container involves exposure to temperatures of 500 to 600/sup 0/C when it is welded and possibly filled with molten waste glass, followed by hundreds of years exposure in the 100 to 300/sup 0/C range. The problems of short- and long-term sensitization in stainless steels have been addressed by two computer programs. The TTS program uses classical nucleation and growth theory plus experimental input to predict the onset of precipitation or sensitization under complex thermal histories. The FEMGB program uses quadratic finite-element methods to analyze diffusion processes and chromium depletion during precipitate growth. The results of studies using both programs indicate that sensitization should not be a problem in any of the austenitic stainless steels considered. However, more precise information on the process thermal cycles, especially during welding of the container, is needed. Contributions from dislocation pipe diffusion could promote long-term low-temperature sensitization.

  12. Aging degradation of cast stainless steel

    International Nuclear Information System (INIS)

    Chopra, O.K.; Chung, H.M.

    1986-10-01

    A program is being conducted to investigate the significance of in-service embrittlement of cast duplex stainless steels under light-water reactor operating conditions. Microstructures of cast materials subjected to long-term aging either in reactor service or in the laboratory have been characterized by TEM, SANS, and APFIM techniques. Two precipitate phases, i.e., the Cr-rich α' and Ni- and Si-rich G phase, have been identified in the ferrite matrix of the aged steels. The results indicate that the low-temperature embrittlement is primarily caused by α' precipitates which form by spinodal decomposition. The relative contribution of G phase to loss of toughness is now known. Microstructural data also indicate that weakening of ferrite/austenite phase boundary by carbide precipitates has a significant effect on the onset and extent of embrittlement of the high-carbon CF-8 and CF-8M grades of stainless steels, particularly after aging at 400 or 450 0 C. Data from Charpy-impact, tensile, and J-R curve tests for several heats of cast stainless steel aged up to 10,000 h at 350, 400, and 450 0 C are presented and correlated with the microstructural results. Thermal aging of the steels results in an increase in tensile strength and a decrease in impact energy, J/sub IC/, and tearing modulus. The fracture toughness results show good agreement with the Charpy-impact data. The effects of compositional and metallurgical variables on loss of toughness are discussed

  13. Influence Of Heat Treatment On Duplex Stainless Steel To Study The Material Properties

    Directory of Open Access Journals (Sweden)

    Jithin M

    2015-02-01

    Full Text Available Abstract The various heat treatment processes are annealing normalizing hardening tempering spheroidising surface hardening flame and induction hardening nitriding cyaniding carbonitriding carburizing etc Heat treatment on duplex stainless steel is to improve ductility toughness strength hardness and to relieve internal stress developed in the material. Here basically the experiment of hardness test impact test wear test and compression is done to get idea about heat treated duplex stainless steel which has extensive uses in all industries and scientific research and development fields.

  14. Alpha prime effect on mechanical properties and corrosion resistance of UR 52N+ duplex stainless steel

    International Nuclear Information System (INIS)

    Fontes, Talita Filier

    2009-01-01

    Alpha prime phase leads to decreased corrosion resistance and mechanical properties losses of duplex stainless steels. In this work mechanical and electrochemical tests were performed in duplex stainless steel UR 52N+ aged at 475 degree C for various periods in order to determine the sensibility of these tests to alpha prime presence. Hardness tests showed a gradual increase in its values; on the other hand, impact tests revealed that the material aged for 12h losses about 80% of energy absorption capacity of the solution annealed sample. Notwithstanding cyclic polarization tests showed that significant changes are only noted for aging times greater than 96h. (author)

  15. Characterization of thermal aging of duplex stainless steel by SQUID

    International Nuclear Information System (INIS)

    Isobe, Y.; Kamimura, A.; Aoki, K.; Nakayasu, F.

    1995-01-01

    Thermal aging is a growing concern for long-term-aged duplex stainless steel piping in nuclear power plants. Superconducting QUantum Interference Device (SQUID) was used for the detection of thermal aging of SUS329 rolled duplex stainless steel and SCS16 cast duplex stainless steel. It was found that the SQUID output signal pattern in the presence of AC magnetic field applied to the specimen was sensitive to the changes in electromagnetic properties due to thermal aging

  16. The effect of metastability in the process of fatigue of an austenitic stainless steel

    International Nuclear Information System (INIS)

    Pacheco, D.J.

    1977-01-01

    The influence of martensitic phase transformation on the process of pulsating tensile stress is studied in a metastable type AISI 316 stainless steel in the temperature range from 25 to -196 0 C. Annealed as well as previously deformed specimens are tested for the typical microstructural characteristics. It is concluded that the fatigue limit as well as the crack mechanisms depend upon the nature of the slip of crystalographic planes. The martensitic transformation previously induced by plastic deformation shows an undesirable fatigue character, in the annealed state and tested at 25 0 C, the type 316 steel will need a plastic deformation equal to or slightly above 9% for pulsating tension fracture [pt

  17. Tritium distributing in stainless steel determined by chemical etchin

    International Nuclear Information System (INIS)

    Xiong Yifu; Luo Deli; Chen Changan; Chen Shicun; Jing Wenyong

    2009-01-01

    The depth distribution of tritium in stainless steel was measured by chemical etching. The results show that the method can more quantitatively evaluate the tritium distributing in stainless steel. The maximum amount of tritium which distributed in crystal lattice of stainless steel is limitted by its solubility at room temperature. The other form of tritium in stainless steel is gaseous tritium that are trapped by defects, impurities, fractures, etc. within it. The gaseous tritium is several times more than the solid-dissolved tritium. (authors)

  18. Stainless Steel Leaches Nickel and Chromium into Foods During Cooking

    Science.gov (United States)

    Kamerud, Kristin L.; Hobbie, Kevin A.; Anderson, Kim A.

    2014-01-01

    Toxicological studies show that oral doses of nickel and chromium can cause cutaneous adverse reactions such as dermatitis. Additional dietary sources, such as leaching from stainless steel cookware during food preparation, are not well characterized. This study examined stainless steel grades, cooking time, repetitive cooking cycles, and multiple types of tomato sauces for their effects on nickel and chromium leaching. Trials included three types of stainless steels and a stainless steel saucepan; cooking times of 2 to 20 hours, ten consecutive cooking cycles, and four commercial tomato sauces. After a simulated cooking process, samples were analyzed by ICP-MS for Ni and Cr. After six hours of cooking, Ni and Cr concentrations in tomato sauce increased up to 26- and 7-fold respectively, depending on the grade of stainless steel. Longer cooking durations resulted in additional increases in metal leaching, where Ni concentrations increased 34 fold and Cr increased approximately 35 fold from sauces cooked without stainless steel. Cooking with new stainless steel resulted in the largest increases. Metal leaching decreases with sequential cooking cycles and stabilized after the sixth cooking cycle, though significant metal contributions to foods were still observed. The tenth cooking cycle, resulted in an average of 88 μg of Ni and 86 μg of Cr leached per 126 g serving of tomato sauce. Stainless steel cookware can be an overlooked source of nickel and chromium, where the contribution is dependent on stainless steel grade, cooking time, and cookware usage. PMID:23984718

  19. Stainless steels for cryogenic bolts and nuts

    International Nuclear Information System (INIS)

    Leroy, F.; Rabbe, P.; Odin, G.

    1975-01-01

    Stainless steel for cryogenic applications are generally austenitic steels which, under the effect of cold-drawing, can or cannot undergo a partial martensitic transformation according to their composition. It has been shown that very high ductility and endurance characteristics at low temperatures, together with very high yield strength and resistances values, can be attained with grades of nitrogenous steels of types Z2CN18-10N and Z3CMN18-8-6N. Optimum ductility values are obtained by employing to the best possible, the martensitic transformations which develop during cold-drawing. From the plotting of the rational traction curves, it is possible to analyse very simply the influence of the composition on the martensitic transformations [fr

  20. Complex Protection of Vertical Stainless Steel Tanks

    Directory of Open Access Journals (Sweden)

    Fakhrislamov Radik Zakievich

    2014-03-01

    Full Text Available The authors consider the problem of fail-safe oil and oil products storage in stainless steel tanks and present the patented tank inner side protection technology. The latter provides process, ecological and fire safety and reducing soil evaporation of oil products, which is a specific problem. The above-mentioned technology includes corrosion protection and heat insulation protection providing increase of cover durability and RVS service life in general. The offered technological protection scheme is a collaboration of the author, Steel Paint GmbH firm and JSC “Koksokhimmontazhproyekt”. PU foam unicomponent materials of Steel Paint GmbH firm provide the protection of tank inner side and cover.

  1. Effects of metallurgical variables on hydrgen embrittlement in types 316, 321, and 347 stainless steels

    International Nuclear Information System (INIS)

    Rozenak, P.; Eliezer, D.

    1984-01-01

    Hydrogen embrittlement of 316, 321 and 347 types austenitic stainless steels has been studied by charging thin tensile specimens with hydrogen through cathodic polarization. Throughout this study we have compared solution annealed samples having various prior austenitic grain-size with samples given the additional sensitization treatment. The results show that refined grains improves the resistance to hydrogen cracking regardless of the failure mode. The sensitized specimens were predominantly intergranular, while the annealed specimens show massive regions of microvoid coalescence producing ductile rupture. 347 type stainless steel is much more susceptible to hydrogen embrittlement than 321 type steel, and 316 type is the most resistant to hydrogen embrittlement. the practical implication of the experimental conclusions are discussed

  2. Yield stress of duplex stainless steel specimens estimated using a compound Hall–Petch equation

    Directory of Open Access Journals (Sweden)

    Noriaki Hirota, Fuxing Yin, Tsukasa Azuma and Tadanobu Inoue

    2010-01-01

    Full Text Available In this study, the 0.2% yield stress of duplex stainless steel was evaluated using a compound Hall–Petch equation. The compound Hall–Petch equation was derived from four types of duplex stainless steel, which contained 0.2–64.4 wt% δ-ferrite phase, had different chemical compositions and were annealed at different temperatures. Intragranular yield stress was measured with an ultra-microhardness tester and evaluated with the yield stress model proposed by Dao et al. Grain size, volume fraction and texture were monitored by electron backscattering diffraction measurement. The kγ constant in the compound equation for duplex stainless steel agrees well with that for γ-phase SUS316L steel in the temperature range of 1323–1473 K. The derived compound Hall–Petch equation predicts that the yield stress will be in good agreement with the experimental results for the Cr, Mn, Si, Ni and N solid-solution states. We find that the intragranular yield stress of the δ-phase of duplex stainless steel is rather sensitive to the chemical composition and annealing conditions, which is attributed to the size misfit parameter.

  3. Effect of shot peening on metastable austenitic stainless steels

    International Nuclear Information System (INIS)

    Fargas, G.; Roa, J.J.; Mateo, A.

    2015-01-01

    In this work, shot peening was performed in a metastable austenitic stainless steel EN 1.4318 (AISI 301LN) in order to evaluate its effect on austenite to martensite phase transformation and also the influence on the fatigue limit. Two different steel conditions were considered: annealed, i.e., with a fully austenitic microstructure, and cold rolled, consisting of a mixture of austenite and martensite. X-ray diffraction, electron back-scattered diffraction and focus ion beam, as well as nanoindentation techniques, were used to elucidate deformation mechanisms activated during shot peening and correlate with fatigue response. Results pointed out that extensive plastic deformation and phase transformation developed in annealed specimens as a consequence of shot peening. However, the increase of roughness and the generation of microcracks led to a limited fatigue limit improvement. In contrast, shot peened cold rolled specimens exhibited enhanced fatigue limit. In the latter case, the main factor that determined the influence on the fatigue response was the distance from the injector, followed successively by the exit speed of the shots and the coverage factor

  4. Ion nitriding in 316=L stainless steel

    International Nuclear Information System (INIS)

    Rojas-Calderon, E.L.

    1989-01-01

    Ion nitriding is a glow discharge process that is used to induce surface modification in metals. It has been applied to 316-L austenitic stainless steel looking for similar benefits already obtained in other steels. An austenitic stainless steel was selected because is not hardenable by heat treatment and is not easy to nitride by gas nitriding. The samples were plastically deformed to 10, 20, 40, 50 AND 70% of their original thickness in order to obtain bulk hardening and to observe nitrogen penetration dependence on it. The results were: an increase of one to two rockwell hardness number (except in 70% deformed sample because of its thickness); an increase of even several hundreds per cent in microhardness knoop number in nitrided surface. The later surely modifies waste resistance which would be worth to quantify in further studies. Microhardness measured in an internal transversal face to nitrided surface had a gradual diminish in its value with depth. Auger microanalysis showed a higher relative concentration rate C N /C F e near the surface giving evidence of nitrogen presence till 250 microns deep. The color metallography etchant used, produced faster corrosion in nitrited regions. Therefore, corrosion studies have to be done before using ion nitrited 316-L under these chemicals. (Author)

  5. Stress corrosion cracking of duplex stainless steels in caustic solutions

    Science.gov (United States)

    Bhattacharya, Ananya

    Duplex stainless steels (DSS) with roughly equal amount of austenite and ferrite phases are being used in industries such as petrochemical, nuclear, pulp and paper mills, de-salination plants, marine environments, and others. However, many DSS grades have been reported to undergo corrosion and stress corrosion cracking in some aggressive environments such as chlorides and sulfide-containing caustic solutions. Although stress corrosion cracking of duplex stainless steels in chloride solution has been investigated and well documented in the literature but the SCC mechanisms for DSS in caustic solutions were not known. Microstructural changes during fabrication processes affect the overall SCC susceptibility of these steels in caustic solutions. Other environmental factors, like pH of the solution, temperature, and resulting electrochemical potential also influence the SCC susceptibility of duplex stainless steels. In this study, the role of material and environmental parameters on corrosion and stress corrosion cracking of duplex stainless steels in caustic solutions were investigated. Changes in the DSS microstructure by different annealing and aging treatments were characterized in terms of changes in the ratio of austenite and ferrite phases, phase morphology and intermetallic precipitation using optical micrography, SEM, EDS, XRD, nano-indentation and microhardness methods. These samples were then tested for general and localized corrosion susceptibility and SCC to understand the underlying mechanisms of crack initiation and propagation in DSS in the above-mentioned environments. Results showed that the austenite phase in the DSS is more susceptible to crack initiation and propagation in caustic solutions, which is different from that in the low pH chloride environment where the ferrite phase is the more susceptible phase. This study also showed that microstructural changes in duplex stainless steels due to different heat treatments could affect their SCC

  6. Electrochemical noise measurements of stainless steel in high temperature water

    Energy Technology Data Exchange (ETDEWEB)

    Arganis-Juarez, C.R. [Instituto Nacional de Investigaciones Nucleares Km. 36.5, Carretera Federal Mexico-Toluca, Municipio de Ocoyoacac, C.P. 52045, Estado de Mexico (Mexico); Malo, J.M. [Instituto de Investigaciones Electricas Av. Reforma 113, Col. Palmira, C.P. 62490, Cuernavaca, Morelos (Mexico)], E-mail: jmmalo@iie.org.mx; Uruchurtu, J. [Centro de Investigaciones en Ingenieria y Ciencias Aplicadas, Universidad Autonoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, C.P. 62210, Cuernavaca, Morelos (Mexico)

    2007-12-15

    Corrosion in a high purity aqueous environment simulating a boiling water reactor (BWR) is addressed in this work. This condition necessitates autoclave experiments under high pressure and temperature. Long-term electrochemical noise measurements were explored as a mean to detect and monitor stress corrosion cracking phenomenon. An experimental set up, designed to insulate the working electrode from external interference, made possible to detect and monitor stress corrosion cracking in slow strain rate tests for sensitized and solution annealed 304 stainless steel at 288 {sup o}C. Time-series analysis showed variations in the signature of the current density series due to transgranular stress corrosion cracking (TGSCC) and intergranular stress corrosion cracking (IGSCC)

  7. Investigating the Crevice Corrosion Behavior of Coated Stainless Steel in Seawater

    National Research Council Canada - National Science Library

    Kain, Robert

    2000-01-01

    .... austenitic stainless steel. Testing in natural seawater has demonstrated that coatings can protect susceptible stainless steel from barnacle related crevice corrosion and localized corrosion at weldments...

  8. Plasticity of low carbon stainless steels

    International Nuclear Information System (INIS)

    Bulat, S.I.; Fel'dgandler, Eh.G.; Kareva, E.N.

    1975-01-01

    In the temperature range 800-1200 0 C and with strain rates of from 10 -3 to 3 s -1 , austenitic (000Kh18N12) and austenitic-ferrite (000Kh26N6) very low carbon stainless steels containing 0.02-0.03% C exhibit no higher resilience than corresponding ordinary steels containing 0.10-0.12% C. However, the plasticity of such steels (particularly two-phase steels) at 900-1100 0 C is appreciably inferior owing to the development of intergranular brittle fracture. Pressure treatment preceded by partial cooling of the surface to 850 0 C yields rolled and forged products with acceptable indices but is inconvenient technically. At the Zlatoustovsk and Ashin metallurgical plants successful tests have been performed involving the forging and rolling of such steels heated to 1280-1300 0 C without partial cooling; it was necessary to improve the killing conditions, correct the chemical composition (increasing the proportion of ferrite) and take measures against heat loss. (author)

  9. Antimicrobial Cu-bearing stainless steel scaffolds

    International Nuclear Information System (INIS)

    Wang, Qiang; Ren, Ling; Li, Xiaopeng; Zhang, Shuyuan; Sercombe, Timothy B.; Yang, Ke

    2016-01-01

    Copper-bearing stainless steel scaffolds with two different structures (Body Centered Cubic and Gyroid labyrinth) at two solid fractions (25% and 40%) were fabricated from both 316L powder and a mixture of 316L and elemental Cu powder using selective laser melting, and relative 316L scaffolds were served as control group. After processing, the antimicrobial testing demonstrated that the 316L-Cu scaffolds presented excellent antimicrobial activity against Escherichia coli and Staphylococcus aureus, and the cell viability assay indicated that there was no cytotoxic effect of 316L-Cu scaffolds on rat marrow mesenchymal stem cells. As such, these have the potential to reduce implant-associated infections. The Cu was also found to homogeneously distribute within the microstructure by scanning electronic microcopy. The addition of Cu would not significantly affect its strength and stiffness compared to 316L scaffold, and the stiffness of all the scaffolds (3-20GPa) is similar to that of bone and much less than that of bulk stainless steel. Consequently, fabrication of such low stiffness porous structures, especially coupled with the addition of antimicrobial Cu, may provide a new direction for medical stainless steels. - Highlights: • 316L-Cu scaffolds were fabricated by using selective laser melting (SLM). • 316L-Cu scaffolds showed satisfied antimicrobial activities. • 316L-Cu scaffolds have no cytotoxic effect on normal cells. • Other properties of 316L-Cu scaffolds were similar to 316L scaffolds. • 316L-Cu scaffolds have the potential to be used in orthopedic applications.

  10. Benefits of Intercritical Annealing in Quenching and Partitioning Steel

    Science.gov (United States)

    Wang, X.; Liu, L.; Liu, R. D.; Huang, M. X.

    2018-03-01

    Compared to the quenching and partitioning (Q&P) steel produced by full austenization annealing, the Q&P steel produced by the intercritical annealing shows a similar ultimate tensile stress but a larger tensile ductility. This property is attributable to the higher volume fraction and the better mechanical stability of the retained austenite after the intercritical annealing. Moreover, intercritical annealing produces more ferrite and fewer martensite phases in the microstructure, making an additional contribution to a higher work hardening rate and therefore a better tensile ductility.

  11. Static strain aging in austenitic stainless steels

    International Nuclear Information System (INIS)

    Monteiro, S.N.

    1978-07-01

    The static strain aging effects were investigated in austenitic stainless steels by measuring the yield points developed in tensile tests following the arrest of the crosshead for some period of time. The results appear to indicate that the dragging of dislocations in the interval of temperatures from 100 to 300 0 C, where the strain aging is effective, does not apparently depend on the Cottrell's atmosphere. Moreover the influence of the pre-deformation and time on the yield point intensity displayed the existence of stages. The strain aging mechanics and the reasons for the stages were discussed. (Author) [pt

  12. Solidification cracking in austenitic stainless steel welds

    Indian Academy of Sciences (India)

    Solidification cracking is a significant problem during the welding of austenitic stainless steels, particularly in fully austenitic and stabilized compositions. Hot cracking in stainless steel welds is caused by low-melting eutectics containing impurities such as S, P and alloy elements such as Ti, Nb. The WRC-92 diagram can be ...

  13. Stress corrosion cracking of AISI 321 stainless steel in acidic ...

    Indian Academy of Sciences (India)

    Unknown

    The stress corrosion cracking (SCC) of AISI 321 stainless steel in acidic chloride solution was studied by slow strain rate (SSR) ... Stress corrosion cracking; chloride; stainless steel; inhibitor. 1. Introduction. Stress corrosion cracking (SCC) ..... Xi'an Jiaotong University Press) (in Chinese). Huang Y L, Cao C N, Lu M and Lin ...

  14. Analysis of polypyrrole-coated stainless steel electrodes-Estimation ...

    Indian Academy of Sciences (India)

    Analysis of polypyrrole-coated stainless steel electrodes - Estimation of specific capacitances and construction of equivalent circuits. R Ramya M V Sangaranarayanan ... The galvanostatic polymerization of pyrrole is carried out on stainless steel electrodes using -toluene sulphonic acid. The morphology of the film is ...

  15. Stainless steels for seawater desalination plants; Nichtrostende Staehle fuer Meerwasserentsalzungsanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Uhlig, G. [ThyssenKrupp Nirosta GmbH, Krefeld (Germany)

    2007-07-01

    Seawater desalination plants can be used to produce drinking water with low chloride concentrations. Stainless steels are an elementary component of the various process technologies in such plants. Due to growing demand for drinking water - especially in the Arabian states, but also in southern Europe - seawater desalination plants represent a very interesting area of application with increasing economic importance for stainless steels. (orig.)

  16. Cast alumina forming austenitic stainless steels

    Science.gov (United States)

    Muralidharan, Govindarajan; Yamamoto, Yukinori; Brady, Michael P

    2013-04-30

    An austenitic stainless steel alloy consisting essentially of, in terms of weight percent ranges 0.15-0.5C; 8-37Ni; 10-25Cr; 2.5-5Al; greater than 0.6, up to 2.5 total of at least one element selected from the group consisting of Nb and Ta; up to 3Mo; up to 3Co; up to 1W; up to 3Cu; up to 15Mn; up to 2Si; up to 0.15B; up to 0.05P; up to 1 total of at least one element selected from the group consisting of Y, La, Ce, Hf, and Zr; steel alloys is also disclosed.

  17. Segregation effects in welded stainless steels

    International Nuclear Information System (INIS)

    Akhter, J.I.; Shoaid, K.A.; Ahmed, M.; Malik, A.Q.

    1987-01-01

    Welding of steels causes changes in the microstructure and chemical composition which could adversely affect the mechanical and corrosion properties. The report describes the experimental results of an investigation of segregation effects in welded austenitic stainless steels of AISI type 304, 304L, 316 and 316L using the techniques of scanning electron microscopy and electron probe microanalysis. Considerable enhancement of chromium and carbon has been observed in certain well-defined zones on the parent metal and on composition, particularly in the parent metal, in attributed to the formation of (M 23 C 6 ) precipitates. The formation of geometrically well-defined segregation zones is explained on the basis of the time-temperature-precipitation curve of (M 23 C 6 ). (author)

  18. Dependence of corrosion properties of AISI 304L stainless steel on the austenite grain size

    Energy Technology Data Exchange (ETDEWEB)

    Sabooni, Soheil; Rashtchi, Hamed; Eslami, Abdoulmajid; Karimzadeh, Fathallah; Enayati, Mohammad Hossein; Raeissi, Keyvan; Imani, Reihane Faghih [Isfahan Univ. of Technology, Isfahan (Iran, Islamic Republic of). Dept. of Materials Engineering; Ngan, Alfonso Hing Wan [The Univ. of Hong Kong (China). Dept. of Mechanical Engineering

    2017-07-15

    The corrosion resistance of austenitic stainless steels is known to be hampered by the loss of chromium available for passive surface layer formation as a result of chromium carbide precipitation at austenite grain boundaries during annealing treatments. Although high-temperature annealing can promote carbide dissolution leading to better corrosion resistance, grain coarsening also results, which would lead to poorer mechanical properties. Processing methods to achieve both good corrosion resistance and mechanical properties are thus highly desirable for austenitic stainless steels. In the present study, we show that the corrosion resistance of AISI 304L stainless steel can be improved by grain refinement into the ultrafine-grained regime. Specifically, samples with different austenite grain sizes in the range of 0.65-12 μm were studied by potentiodynamic polarization and electrochemical impedance spectroscopy tests in a 3.5 wt.% NaCl solution. All samples showed a typical passive behavior with similar corrosion potential, but the corrosion current density decreased significantly with decreasing grain size. The results show that the sample with the finest grain size had the best corrosion resistance due to a higher resistance of the passive layer to pitting attacks. This study indicates that grain refinement which improves mechanical properties can also significantly improve the corrosion resistance of AISI 304L stainless steel.

  19. Hydrogen assisted fracture of sensitized Type 304L austenitic stainless steel

    International Nuclear Information System (INIS)

    Caskey, G.R. Jr.

    1980-01-01

    Sensitized specimens of Type 304L stainless steel were tensile tested in atmospheres of hydrogen and helium at high pressure, and in air at ambient pressure. Comparison tensile tests were made with solution-annealed specimens of Type 304L stainless steel in the same atmosphere. When both specimens were tested in high-pressure hydrogen, the sensitized specimens had greater loss in ductility and increased tendency to intergranular fracture. For the sensitized specimens, plastic strain to failure (epsilon/sub p/ = 1n A 0 /A/sub f/) in hydrogen at 69 MPa was reduced by 60 to 70% in comparison to similar tests in helium. In addition, a notch with a stress concentration factor of about 3 reduced plastic strain an additional 50 to 60%. In all cases, the nominal tensile strength of Type 304L stainless steel was increased by the notch. There was no evidence of intergranular failure in notched specimens of solution-annealed Type 304L stainless steel tested in high-pressure hydrogen environments

  20. Citric Acid Passivation of Stainless Steel

    Science.gov (United States)

    Yasensky, David; Reali, John; Larson, Chris; Carl, Chad

    2009-01-01

    Passivation is a process for cleaning and providing corrosion protection for stainless steel. Currently, on Kennedy Space Center (KSC), only parts passivated with nitric acid are acceptable for use. KSC disposes of approximately 125gal of concentrated nitric acid per year, and receives many parts from vendors who must also dispose of used nitric acid. Unfortunately, nitric acid presents health and environmental hazards. As a result, several recent industry studies have examined citric acid as an alternative. Implementing a citric acid-based passivation procedure would improve the health and environmental safety aspects of passivation process. However although there is a lack of published studies that conclusively prove citric acid is a technically sound passivation agent. In 2007, NASA's KSC Materials Advisory Working Group requested the evaluation of citric acid in place of nitric acid for passivation of parts at KSC. United Space Alliance Materials & Processes engineers have developed a three-phase test plan to evaluate citric acid as an alternative to nitric acid on three stainless steels commonly used at KSC: UNS S30400, S41000, and S17400. Phases 1 and 2 will produce an optimized citric acid treatment based on results from atmospheric exposure at NASA's Beach Corrosion Facility. Phase 3 will compare the optimized solution(s) with nitric acid treatments. If the results indicate that citric acid passivates as well or better than nitric acid, NASA intends to approve this method for parts used at the Kennedy Space Center.

  1. Carburization of stainless steel furnace tubes

    Energy Technology Data Exchange (ETDEWEB)

    Mirabal, E.; Molina, C. [Refineria Isla, Curazao, S.A., P.O. Box 3843. Curacao, (Netherlands Antilles); Hau, J.L.; Mayorga, A.G. [PDVSA-Intevep. P.O. Box 76343. Caracas 1070A, Venezuela (Venezuela)

    1998-12-31

    Stainless steel containing molybdenum are usually recommended to resist naphtenic acid corrosion in vacuum heaters. In 1993 the original 5Cr-1/2Mo roof tubes of the furnace in a vacuum unit were replaced by stainless steel 316 Ti to minimize tube replacement and increase heater reliability. Unexpectedly, some of the new tubes failed after only three years of service and just one year after undergoing the last inspection. The damage occurred in the form of deep holes and perforations, starting from the outside tube surface on the fireside. Coke build-up occurred due to severe operating conditions, overheating the tubes on the fireside, above 675 Centigrade. Metallographic and Scanning Electron Microscopy (Sem) examination revealed internal and external carburization of the material due to the presence of coke and combustion ashes, respectively. The increase in the skin metal temperature facilitated the diffusion of carbon from these carbon-rich deposits into the low carbon content material (0.023%). Depletion of chromium at the grain boundaries due to the massive formation of chromium carbides, resulted in a severe intergranular corrosion attack by molten salts rich in vanadium and sulfur produced by asphalt burning. Normal operating practice demands the use of steam for the heater tubes to control coke build-up. This practice had been first reduced and then eliminated, during the past two years prior to the failure, because of economic incentives. This paper describes the root cause analysis conducted to account for these premature tube failures. (Author)

  2. Carburization of stainless steel furnace tubes

    International Nuclear Information System (INIS)

    Mirabal, E.; Molina, C.; Hau, J.L.; Mayorga, A.G.

    1998-01-01

    Stainless steel containing molybdenum are usually recommended to resist naphtenic acid corrosion in vacuum heaters. In 1993 the original 5Cr-1/2Mo roof tubes of the furnace in a vacuum unit were replaced by stainless steel 316 Ti to minimize tube replacement and increase heater reliability. Unexpectedly, some of the new tubes failed after only three years of service and just one year after undergoing the last inspection. The damage occurred in the form of deep holes and perforations, starting from the outside tube surface on the fireside. Coke build-up occurred due to severe operating conditions, overheating the tubes on the fireside, above 675 Centigrade. Metallographic and Scanning Electron Microscopy (Sem) examination revealed internal and external carburization of the material due to the presence of coke and combustion ashes, respectively. The increase in the skin metal temperature facilitated the diffusion of carbon from these carbon-rich deposits into the low carbon content material (0.023%). Depletion of chromium at the grain boundaries due to the massive formation of chromium carbides, resulted in a severe intergranular corrosion attack by molten salts rich in vanadium and sulfur produced by asphalt burning. Normal operating practice demands the use of steam for the heater tubes to control coke build-up. This practice had been first reduced and then eliminated, during the past two years prior to the failure, because of economic incentives. This paper describes the root cause analysis conducted to account for these premature tube failures. (Author)

  3. Single pit propagation on austenitic stainless steel

    International Nuclear Information System (INIS)

    Heurtault, Stephane

    2016-01-01

    The electrochemical characterization of metastable events such as pitting corrosion of stainless steel in chloride electrolyte remains complex because many individual processes may occur simultaneously on the alloy surface. To overcome these difficulties, an experimental setup, the flow micro-device, has been developed to achieve the initiation of a single pit and to propagate the single pit in three dimensions. In this work, we take advantage of such a device in order to revisit the pitting process on a 316L stainless steel in a chloride - sulphate bulk. In a first step, the time evolution of the pit geometry (depth, radius) and the chemical evolution of the pit solution investigated using in situ Raman spectroscopy have shown that the pit depth propagation depends on the formation of a metal chloride and sulphate gel in the pit solution, and is controlled by the metallic cations diffusion from the pit bottom to the pit mouth. The pit radius growth is defined by the initial surface de-passivation, by the presence of a pit cover and by the gel development in the solution. all of these phenomena are function of applied potential and chemical composition of the solution. In a last step, it was demonstrated that a critical chloride concentration is needed in order to maintain the pit propagation. This critical concentration slightly increases with the pit depth. From statistical analysis performed on identical experiments, a zone diagram showing the pit stability as a function of the chloride concentration and the pit dimensions was built. (author) [fr

  4. New aspects of sensitization behavior in recent 316 type austenitic stainless steels

    International Nuclear Information System (INIS)

    Magula, V.; Liao, J.; Ikeuchi, Kenji; Kuroda, Toshio; Kikuchi, Yasushi; Matsuda, Fukuhisa.

    1996-01-01

    Intergranular precipitation behavior of 316 and 316L stainless steels after annealing at 600 - 900degC for 5 min - 50 hrs were examined using transmission electron microscopy of carbon extraction replicas and thin foil techniques. Precipitated particles were identified by electron diffraction analysis. Chemical compositions of precipitated particles were measured from EDX - spectra by a semiquantitative method. When 316 steel was annealed at 750 - 850degC for 15 min or longer, only M 23 C 6 carbide was identified at grain boundaries. For 316L steel, however, three kinds of particles, i.e. Laves phase, M 23 C 6 and a quasicrystal, were precipitated at the grain boundaries when annealed at 700 - 800degC for 10 hrs or longer. Most of the precipitated particles at grain boundaries of annealed 316L steel were Laves phase. M 23 C 6 precipitation caused Cr depletion at grain boundaries of the annealed 316 steel, but the formation of Laves phase did not induce the Cr depletion at grain boundaries of annealed 316L steel. Although no Cr depletion occurred, the grain boundaries of annealed 316L steel were attacked in Oxalic acid etch tests and Strauss tests, probably because of electrical potential difference between the Laves phases and matrix, and/or low Cr contents in Laves phases. After single-pass welding with cooling rates higher than 0.07degC/s, the weld HAZs of both 316 and 316L seem to be free of sensitivity to intergranular attack. (author)

  5. Characterization of friction stir welded joint of low nickel austenitic stainless steel and modified ferritic stainless steel

    Science.gov (United States)

    Mondal, Mounarik; Das, Hrishikesh; Ahn, Eun Yeong; Hong, Sung Tae; Kim, Moon-Jo; Han, Heung Nam; Pal, Tapan Kumar

    2017-09-01

    Friction stir welding (FSW) of dissimilar stainless steels, low nickel austenitic stainless steel and 409M ferritic stainless steel, is experimentally investigated. Process responses during FSW and the microstructures of the resultant dissimilar joints are evaluated. Material flow in the stir zone is investigated in detail by elemental mapping. Elemental mapping of the dissimilar joints clearly indicates that the material flow pattern during FSW depends on the process parameter combination. Dynamic recrystallization and recovery are also observed in the dissimilar joints. Among the two different stainless steels selected in the present study, the ferritic stainless steels shows more severe dynamic recrystallization, resulting in a very fine microstructure, probably due to the higher stacking fault energy.

  6. Response of neutron-irradiated RPV steels to thermal annealing

    Energy Technology Data Exchange (ETDEWEB)

    Iskander, S.K.; Sokolov, M.A.; Nanstad, R.K.

    1997-03-01

    One of the options to mitigate the effects of irradiation on reactor pressure vessels (RPVs) is to thermally anneal them to restore the fracture toughness properties that have been degraded by neutron irradiation. This paper summarizes experimental results of work performed at the Oak Ridge National Laboratory (ORNL) to study the annealing response of several irradiated RPV steels.

  7. Comparison of frictional resistance between conventional stainless steel, metal insert ceramic, self ligating stainless steel and self ligating ceramic with stainless steel wire : invitro study

    Directory of Open Access Journals (Sweden)

    Sivaram Subbiah

    2010-01-01

    Full Text Available Friction is an integral part of fixed orthodontic treatment. Several innovations have been made to reduce friction and thereby get predictable and faster tooth movements. Self ligating brackets are one such innovation which is said to offer the possibility of a significant reduction in average treatment times and also in anchorage requirements. Ceramic Self ligating brackets introduce recently have the added advantage of aesthetics. This study was conducted to compare the frictional resistance of conventional stainless steel, metal insert ceramic, Self ligating stainless steel and Self ligating ceramic brackets against a common stainless steel wire. Fifteen premolar in each group (0.022 Roth prescription were tested against 0.019x0.025 stainless steel wire using Lloyd universal testing machine. The conventional stainless steel brackets showed a frictional resistance of 66.47±7.86g metal insert ceramic brackets showed a frictional resistance of 77.52± 8.59g . the Self ligating stainless steel brackets had a frictional resistance of 40.21±7.76g Self ligating ceramic brackets had a frictional resistance of 72.67±5.76 g Self ligating ceramic brackets do have slightly lesser friction than metal insert ceramic brackets but significantly more than metal brackets .

  8. Fireside carburization of stainless steel furnace tubes

    Energy Technology Data Exchange (ETDEWEB)

    Mirabal, E.; Molina, C. [PDVSA-Refineria Isla, Curayao (Netherlands); Mayorga, A.; Hau, J.L. [PDVSA-Intevep, Caracas (Venezuela)

    1999-11-01

    Most heavy Venezuelan crudes are recognized for having a high total acid number (TAN) that is usually associated with a high tendency to produce naphthenic acid corrosion. To resist this type of corrosion in vacuum heaters, 9Cr-1Mo steel and stainless steels containing molybdenum are usually recommended. In 1993 the original 5Cr-1/2Mo roof tubes of the furnace in a vacuum unit were replaced by stainless steel 316Ti to minimize tube replacement and increase heater reliability. Unexpectedly, some of the new tubes failed after only three years of service, and just one year after undergoing the last turnaround inspection. The damage occurred in the form of deep holes and perforations, starting from the outside tube surface on the fireside. Coke build-up occurred due to severe operating conditions, overheating the tubes on the fireside, above 675 C (1250 F). Metallographic and Scanning Electron Microscopic (SEM) examination revealed internal and external carburization of the material due to the presence of coke and combustion ashes, respectively. The increase in the skin metal temperature facilitated the diffusion of carbon from these carbon-rich deposits into the low carbon content material (0.023 O/O).Depletion of chromium at the grain boundaries due to the massive formation of chromium carbides, resulted in a severe intergranular corrosion attack by molten salts rich in vanadium and sulfur due to asphalt burning. Normal operating practice demands the use of steam for the heater tubes to control coke build-up. This practice had been first reduced and then eliminated, during the past two years prior to the failure, because of economic incentives. This paper describes the root cause analysis conducted to account for these premature tube failures.

  9. High cycle fatigue of austenitic stainless steels

    International Nuclear Information System (INIS)

    Gauthier, J.P.; Lehmann, D.; Picker

    1990-01-01

    This study concerns the evaluation of material data to be used in LMFBR design codes. High cycle fatigue properties of three austenitic stainless steels are evaluated: type AISI 316 (UKAEA tests), type AISI 316L (CEA tests) and type AISI 304 (Interatom tests). The data on these steels comprised some 550 data points from 14 casts. This data set covered a wide range of testing parameters: temperature from 20-625 0 C, frequency from 1-20 000 Hz, constant amplitude and random fatigue loading, with and without mean stress, etc. However, the testing conditions chosen by the three partners differed considerably because they had been fixed independently and not harmonized prior to the tests. This created considerable difficulties for the evaluations. Experimental procedures and statistical treatments used for the three subsets of data are described and discussed. Results are presented in tables and graphs. Although it is often difficult to single out the influence of each parameter due to the different testing conditions, several interesting conclusions can be drawn: The HCF properties of the three steels are consistent with the 0.2% proof stress, the fatigue limit being larger than the latter at temperatures above 550 0 C. The type 304 steel has lower tensile properties than the two other steels and hence also lower HCF properties. Parameters which clearly have a significant effect of HCF behaviour are mean stress or R-ratio (less in the non-endurance region than in the endurance region), temperature, cast or product. Other parameters have probably a weak or no effect but it is difficult to conclude due to insufficient data: environment, specimen orientation, frequency, specimen geometry

  10. Development of commercial nitrogen-rich stainless steels

    International Nuclear Information System (INIS)

    Liljas, M.

    1999-01-01

    This paper reviews the development of nitrogen alloyed stainless steels. Nitrogen alloying of austenitic stainless steels started at an early stage and was to a large extent caused by nickel shortage. However, direct technical advantages such as increased strength of the nitrogen alloyed steels made them attractive alternatives to the current steels. It was not until the advent of the AOD (argon oxygen decarburisation) process in the late 1960s that nitrogen alloying could be controlled to such accuracy that it became successful commercially on a broader scale. The paper describes production aspects and how nitrogen addition influences microstructure and the resulting properties of austenitic and duplex stainless steels. For austenitic steels there are several reasons for nitrogen alloying. Apart from increasing strength nitrogen also improves structural stability, work hardening and corrosion resistance. For duplex steels nitrogen also has a decisive effect in controlling the microstructure during thermal cycles such as welding. (orig.)

  11. 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

    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 re...

  12. Compressibility of 304 Stainless Steel Powder Metallurgy Materials Reinforced with 304 Short Stainless Steel Fibers

    Directory of Open Access Journals (Sweden)

    Bibo Yao

    2016-03-01

    Full Text Available Powder metallurgy (P/M technique is usually used for manufacturing porous metal materials. However, some P/M materials are limitedly used in engineering for their performance deficiency. A novel 304 stainless steel P/M material was produced by a solid-state sintering of 304 stainless steel powders and 304 short stainless steel fibers, which were alternately laid in layers according to mass ratio. In this paper, the compressive properties of the P/M materials were characterized by a series of uniaxial compression tests. The effects of fiber content, compaction pressure and high temperature nitriding on compressive properties were investigated. The results indicated that, without nitriding, the samples changed from cuboid to cydariform without damage in the process of compression. The compressive stress was enhanced with increasing fiber content ranging from 0 to 8 wt.%. For compaction pressure from 55 to 75 MPa, greater compaction pressure improved compressive stress. Moreover, high temperature nitriding was able to significantly improve the yield stress, but collapse failure eventually occurred.

  13. Compressibility of 304 Stainless Steel Powder Metallurgy Materials Reinforced with 304 Short Stainless Steel Fibers.

    Science.gov (United States)

    Yao, Bibo; Zhou, Zhaoyao; Duan, Liuyang; Xiao, Zhiyu

    2016-03-04

    Powder metallurgy (P/M) technique is usually used for manufacturing porous metal materials. However, some P/M materials are limitedly used in engineering for their performance deficiency. A novel 304 stainless steel P/M material was produced by a solid-state sintering of 304 stainless steel powders and 304 short stainless steel fibers, which were alternately laid in layers according to mass ratio. In this paper, the compressive properties of the P/M materials were characterized by a series of uniaxial compression tests. The effects of fiber content, compaction pressure and high temperature nitriding on compressive properties were investigated. The results indicated that, without nitriding, the samples changed from cuboid to cydariform without damage in the process of compression. The compressive stress was enhanced with increasing fiber content ranging from 0 to 8 wt.%. For compaction pressure from 55 to 75 MPa, greater compaction pressure improved compressive stress. Moreover, high temperature nitriding was able to significantly improve the yield stress, but collapse failure eventually occurred.

  14. Design and construction of precast piles with stainless reinforcing steel.

    Science.gov (United States)

    2014-02-01

    The service life of prestressed concrete piles is, in part, dictated by the time required to corrode the steel once : chloride ions are at the surface of the steel. Stainless steel materials, although limited in availability in strand : form, have a ...

  15. Nickel release from nickel-plated metals and stainless steels.

    Science.gov (United States)

    Haudrechy, P; Foussereau, J; Mantout, B; Baroux, B

    1994-10-01

    Nickel release from nickel-plated metals often induces allergic contact dermatitis, but, for nickel-containing stainless steels, the effect is not well-known. In this paper, AISI 304, 316L, 303 and 430 type stainless steels, nickel and nickel-plated materials were investigated. 4 tests were performed: patch tests, leaching experiments, dimethylglyoxime (DMG) spot tests and electrochemical tests. Patch tests showed that 96% of the patients were intolerant to Ni-plated samples, and 14% to a high-sulfur stainless steel (303), while nickel-containing stainless steels with a low sulfur content elicited no reactions. Leaching experiments confirmed the patch tests: in acidic artificial sweat, Ni-plated samples released about 100 micrograms/cm2/week of nickel, while low-sulfur stainless steels released less than 0.03 microgram/cm2/week of nickel, and AISI 303 about 1.5 micrograms/cm2/week. Attention is drawn to the irrelevance of the DMG spot test, which reveals Ni present in the metal bulk but not its dissolution rate. Electrochemical experiments showed that 304 and 316 grades remain passive in the environments tested, while Ni-plated steels and AISI 303 can suffer significant cation dissolution. Thus, Ni-containing 304 and 316 steels should not induce contact dermatitis, while 303 should be avoided. A reliable nitric acid spot test is proposed to distinguish this grade from other stainless steels.

  16. Electrochemical decontamination of Pu contaminated stainless steel

    International Nuclear Information System (INIS)

    Turner, A.D.; Pottinger, J.S.; Junkison, A.R.

    1983-08-01

    Electrochemical decontamination has been demonstrated to be very effective in removing plutonium nitrate contamination (0.5 μg cm -2 ) on stainless steels. The amount of metal dissolved to achieve a DF of 10 2 to 10 3 was 2 to 7 μm depending on the electrolyte used. In unstirred electrolytes 1M HNO 3 , 1M HNO 3 /0.1M NaF, 5M HNO 3 perform best. Under stirred electrolyte conditions, there is a general marginal fall in effectiveness except for 5M HNO 3 where there is a slight improvement. The optimum performance is a compromise between maximizing the electrolyte throwing power and minimizing substrate surface roughening during decontamination. (author)

  17. Phase identification in neutron irradiated stainless steels

    International Nuclear Information System (INIS)

    Lee, E.H.; Rowcliffe, A.F.

    1980-01-01

    Techniques used for the identification of phases which develop in AISI 316 stainless steel which has been modified by the addition of Ti are described. Five major phases were identified in the alloy containing 0.2 wt % Ti after irradation by 7 x 10 22 n.cm -2 at temperatures ranging from 400 to 650 0 C. Once identification was established from diffraction pattern measurements, subsequent identification could be made by observation of the characteristic shape of each phase combined with the observation of certain characteristic features of te x-ray spectrum of each phase. This combination permitted rapid identification of large numbers of particles necessary for the elucidation of the role of phase instabilities in void swelling

  18. Structural refinement and property optimization in an Fe-23Cr-8.5Ni duplex stainless steel

    DEFF Research Database (Denmark)

    Xie, L.; Huang, T. L.; Wang, Y. H.

    2017-01-01

    An Fe-23Cr-8.5Ni duplex stainless steel was used to prepare samples with different volume-fraction-weighted grain sizes (d(alpha gamma)), ranging from the nano-scale to the micrometer-scale by cold rolling and subsequent annealing. The cold rolled sample with d(alpha gamma) of 72 nm showed a high...

  19. [Study on biocompatibility of MIM 316L stainless steel].

    Science.gov (United States)

    Wang, Guohui; Zhu, Shaihong; Li, Yiming; Zhao, Yanzhong; Zhou, Kechao; Huang, Boyun

    2007-04-01

    This study was aimed to evaluate the biocompatibility of metal powder injection molding (MIM) 316L stainless steel. The percentage of S-period cells was detected by flow cytometry after L929 cells being incubated with extraction of MIM 316L stainless steel, and titanium implant materials for clinical application were used as control. In addition, both materials were implanted in animals and the histopathological evaluations were carried out. The statistical analyses show that there are no significant differences between the two groups (P > 0.05), which demonstrate that MIM 316L stainless steel has good biocompatibility.

  20. Kinetics of chemical interactions between zirconium alloys and stainless steels

    International Nuclear Information System (INIS)

    Frecska, J.; Maroti, L.; Matus, L.

    1995-01-01

    The chemical interaction kinetics of reactor core component zirconium alloys and stainless steels at high temperatures was examined. Interaction of as-received and preoxidized Zr1%Nb with X18H10T stainless steel used in WWER type nuclear reactors, and also that of Zircaloy-4 and AISI-316 stainless steel, for comparison, were investigated. The reaction rate measurements were supplemented with post-test metallographical examinations. Results are presented and evaluated, and compared with literature data. (author). 14 refs., 31 figs., 8 tabs

  1. Systemic hypersensitivity reaction to endovascular stainless steel stent.

    Science.gov (United States)

    Univers, Junior; Long, Chandler; Tonks, Stephen A; Freeman, Michael B

    2018-02-01

    Endovascular intervention has become the mainstay for treatment of most patients suffering from peripheral vascular disease. We describe a patient with a known nickel allergy who underwent placement of a stainless steel stent for aortoiliac occlusive disease. Despite our attempt to avoid a nickel-containing stent, the patient developed a diffuse rash consistent with a nickel or metal allergy. A review of stainless steel metallurgy revealed that nickel, cobalt, and titanium are frequently used to provide anticorrosive properties to stainless steel. The clinical significance of the use of nickel-alloy stents in the setting of patients with a nickel allergy is discussed. Published by Elsevier Inc.

  2. Structural Analysis of Cavitation for Different Stainless Steels

    Directory of Open Access Journals (Sweden)

    Mădălina-Elena Mânzână

    2011-09-01

    Full Text Available The cavitation phenomenon is currently approaching all areas of technology and modern industry, where are fluid in motion. In this paper cavitational erosion was conducted on different samples of stainless steels. The cavitation were performed in magnetostrictive vibrating apparatus at Cavitation Laboratory (Polytechnic University of Timisoara. The present paper intends to identify specific structural features in stainless steels. Several investigations were done: macrostructural analysis (Olympus SZX57, scaning electron microscope (Philips SEM and X-ray diffraction (D8 ADVANCE. After quantitative and qualitative investigations structural features were put in evidence on experimental stainless steels.

  3. Stainless steel-zirconium alloy waste forms

    International Nuclear Information System (INIS)

    McDeavitt, S.M.; Abraham, D.P.; Keiser, D.D. Jr.; Park, J.Y.

    1996-01-01

    An electrometallurgical treatment process has been developed by Argonne National Laboratory to convert various types of spent nuclear fuels into stable storage forms and waste forms for repository disposal. The first application of this process will be to treat spent fuel alloys from the Experimental Breeder Reactor-II. Three distinct product streams emanate from the electrorefining process: (1) refined uranium; (2) fission products and actinides extracted from the electrolyte salt that are processed into a mineral waste form; and (3) metallic wastes left behind at the completion of the electrorefining step. The third product stream (i.e., the metal waste stream) is the subject of this paper. The metal waste stream contains components of the chopped spent fuel that are unaffected by the electrorefining process because of their electrochemically ''noble'' nature; this includes the cladding hulls, noble metal fission products (NMFP), and, in specific cases, zirconium from metal fuel alloys. The selected method for the consolidation and stabilization of the metal waste stream is melting and casting into a uniform, corrosion-resistant alloy. The waste form casting process will be carried out in a controlled-atmosphere furnace at high temperatures with a molten salt flux. Spent fuels with both stainless steel and Zircaloy cladding are being evaluated for treatment; thus, stainless steel-rich and Zircaloy-rich waste forms are being developed. Although the primary disposition option for the actinides is the mineral waste form, the concept of incorporating the TRU-bearing product into the metal waste form has enough potential to warrant investigation

  4. Influence of post irradiation annealing on the mechanical properties and defect structure of AISI 304 steel

    Science.gov (United States)

    Van Renterghem, W.; Al Mazouzi, A.; Van Dyck, S.

    2011-06-01

    The effect of post irradiation annealing on the mechanical properties and the radiation induced defect structure was investigated on stainless steel, of type AISI 304, that was irradiated up to 24 dpa in the decommissioned Chooz A reactor. The material was investigated both in the as-irradiated state as well as after post irradiation annealing. In the as-irradiated specimen the typical radiation induced defects were found as well as γ'-precipitates (Ni 3Si). Annealing at 400 °C had almost no effect on the radiation induced defects, but annealing at 500 °C resulted in the immediate unfaulting of the Frank loops. As to the mechanical properties, annealing at 400 °C did not strongly affect the yield strength and the ductility of the material, although the fraction of intergranular fracture during slow strain rate tensile tests under pressurised water reactor conditions, was significantly reduced. Annealing at 500 °C did reduce the yield strength and restored substantially the ductility and the strain hardening capability of the material. The microstructure investigated by transmission electron microscopy correlates to the mechanical test results. It was found that the observed defect changes after post irradiation annealing provide a reasonable explanation for the observed changes of the mechanical properties.

  5. Development of nuclear grade stainless steels at KCSSL

    International Nuclear Information System (INIS)

    Balachandran, G.; Dhere, M.; Mahadik, A.; Hinge, N.M.; Balasubramanian, V.

    2011-01-01

    Kalyani Carpenter Special Steels Ltd is an alloy steel plant, where a variety of alloy steel grades are produced for automotive, defence, nuclear and aerospace applications. The plant has developed expertise in processing of several alloy steel grades of superior quality that meets stringent specifications. Primary steel is processed through a combination of electric arc furnace, ladle furnace and vacuum degassing where stringent control over dephosphorisation, desulphurization, deoxidation is effected to get a refined high quality steel. The molten steel is cast through continuous casting of slabs or ingot casting. In grades specific to nuclear application, the primary cast products are further subjected to electroslag remelting to achieve further freedom from inclusions and to achieve a favourable solidification grain structure, which ultimately improve the hot workability of the alloy steel. Appropriate choice of slag and operating parameters are needed for realising the required ingot quality. The present study would examine the processing and quality aspects of some important grades of steels used in nuclear industry namely ferritic 9Cr-1Mo steel, martensitic stainless steels 403, 410, precipitation hardenable 17-4 PH stainless steel and austenitic 321, 316LN stainless steel, which were made and supplied for applications to Indian nuclear industry. The expertise developed in processing the steels in terms of melting, heat treatment and their relationship to structural features and mechanical properties would be highlighted. (author)

  6. Compatibility of 316L stainless steel with the liquid alloy Pb17Li

    International Nuclear Information System (INIS)

    Broc, M.; Fauvet, P.; Flament, T.; Terlain, A.; Sannier, J.

    1988-01-01

    The behavior of 316L austenitic stainless steel in liquid eutectic lead alloy is investigated. The 316L is a possible structural material for fusion reactors. The obtained results are summarized and compared with other experimental data. The mechanisms which control the corrosion process are discussed. The investigation shows that whatever, the hydraulic flow, the corrosion of 316L stainless steel exposed to Pb17Li is characterized by the formation of a porous ferritic layer. The corrosion kinetics is mainly dependent on temperature, hydraulic flow and metallurgical state of the steel. At 400 0 C in turbulent flow, the corrosion rate at steady state of 316L solution annealed is estimated to 27 microns/year to which a depth of 25 microns has to be added to take into account the initial transient period. From overall available results, dissolution and solid state transformation in case of turbulent flow and diffusion in liquid phase for laminar flow, may be suggested

  7. Microscopic observation and statics consideration of tensile fracture of TiC coating on stainless steel

    International Nuclear Information System (INIS)

    Okawa, Akira; Hasiguti, Ryukiti

    1986-01-01

    We have measured the tensile fracture properties of the TiC coated SUS316L stainless steel, applying a stress perpendicular to the plane of interface between the coating and the substrate. The fracture of the as grown or non-annealed specimens occurred partially within the TiC layer. A tensile fracture of the TiC coated specimens after vacuum annealing at about 1373 K (1100 deg C) presented arc-shape curved fracture surfaces which can be understood by statics consideration taking into account the maximum stress plane theory and the residual thermal stress. The strengths of non-annealed and annealed specimens are 34.4 MPa (350 kgf/cm 2 ) and 30.2 MPa (308 kgf/cm 2 ), respectively, expressed in terms of Weibull's 50 % fracture stresses. (author)

  8. Stainless steel anodes for alkaline water electrolysis and methods of making

    Science.gov (United States)

    Soloveichik, Grigorii Lev

    2014-01-21

    The corrosion resistance of stainless steel anodes for use in alkaline water electrolysis was increased by immersion of the stainless steel anode into a caustic solution prior to electrolysis. Also disclosed herein are electrolyzers employing the so-treated stainless steel anodes. The pre-treatment process provides a stainless steel anode that has a higher corrosion resistance than an untreated stainless steel anode of the same composition.

  9. Development of Ultra-Fine-Grained Structure in AISI 321 Austenitic Stainless Steel

    Science.gov (United States)

    Tiamiyu, A. A.; Szpunar, J. A.; Odeshi, A. G.; Oguocha, I.; Eskandari, M.

    2017-12-01

    Ultra-fine-grained (UFG) structure was developed in AISI 321 austenitic stainless steel (ASS) using cryogenic rolling followed by annealing treatments at 923 K, 973 K, 1023 K, and 1073 K (650 °C, 700 °C, 750 °C, and 800 °C) for different lengths of time. The α'-martensite to γ-austenite reversion behavior and the associated texture development were analyzed in the cryo-rolled specimens after annealing. The activation energy, Q, required for the reversion of α'-martensite to γ-austenite in the steel was estimated to be 80 kJ mol-1. TiC precipitates and unreversed triple junction α'-martensite played major roles in the development of UFG structure through the Zener pinning of grain boundaries. The optimum annealing temperature and time for the development of UFG structure in the cryo-rolled AISI 321 steel are (a) 923 K (650 °C) for approximately 28800 seconds and (b) 1023 K (750 °C) for 600 seconds, with average grain sizes of 0.22 and 0.31 µm, respectively. Annealing at 1023 K (750 °C) is considered a better alternative since the volume fraction of precipitated carbides in specimens annealed at 1023 K (750 °C) are less than those annealed at 923 K (650 °C). More so, the energy consumption during prolonged annealing time to achieve an UFG structure at 923 K (650 °C) is higher due to low phase reversion rate. The hardness of the UFG specimens is 195 pct greater than that of the as-received steel. The higher volume fraction of TiC precipitates in the UFG structure may be an additional source of hardening. Micro and macrotexture analysis indicated {110}〈uvw〉 as the major texture component of the austenite grains in the UFG structure. Its intensity is stronger in the specimen annealed at low temperatures.

  10. Nonmetallic inclusions in JBK-75 stainless steel

    International Nuclear Information System (INIS)

    Brewer, A.W.; Krenzer, R.W.; Doyle, J.H.; Riefenberg, D.H.

    1977-01-01

    Stainless steel alloys that are chemically complex, such as A-286 or JBK-75, are designed to improve such high-temperature properties as strength. This is accomplished by precipitating secondary phases during aging. Such multicomponent systems, however, can also produce undesirable phases that are detrimental to forgeability and final mechanical properties. Cast segregation and numerous nonmetallic inclusions can have a degrading influence on the toughness and ductility of the alloy. Several different heats of A-286 and JBK-75 were studied, and titanium carbide and/or molybdenum carbide [(Ti, Mo)C] plus titanium carbide and/or titanium carbonitride Ti(C,N)-type phases were qualitatively identified as the major nonmetallic constituent in these alloys. The common procedure for rating the microcleanliness of steels does not classify such carbide or carbonitride phases and thus does not provide an appropriate means of controlling in-process inspection. The results of this study are discussed in terms of alternative methods for evaluating the microcleanliness of superalloys

  11. Corrosion behaviour of sintered duplex stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    Utrilla, M. Victoria; Urena, Alejandro; Otero, Enrique; Munez, Claudio Jose [Escuela Superior de Ciencias Experimentales y Tecnologia, Universidad Rey Juan Carlos, C/ Tulipan s/n, 28933 Mostoles, Madrid (Spain)

    2004-07-01

    Duplex austenite-ferrite stainless steels were prepared by mixing austenitic (316L) and ferritic (434L) atomized powders. Although different 316L/434L ratios were prepared, present work centred its study on 50% ferrite - 50% austenite sintered steel. The powders were mixed and pressed at 700 MPa and sintered at 1250 deg. C for 30 min in vacuum. The cooling rate was 5 deg. C/min. Solution treatment was carried out to homogenize the microstructure at 1100 deg. C during 20 min. A microstructural study of the material in solution was performed, evaluating the microstructure, proportion and shape of porosity, and ferrite percentage. This last was measured by two methods, quantitative metallography and Fischer ferrito-metry. The materials were heat treated in the range of 700 to 1000 deg. C, for 10, 30 and 60 min and water quenched, to study the microstructural changes and the influence on the intergranular corrosion resistance. The method used to evaluate the sensitization to the intergranular corrosion was the electrochemical potentio-kinetic reactivation procedure (EPR). The test solution was 0.5 M H{sub 2}SO{sub 4} + 0,01 M KSCN at 30 deg. C. The criterion used to evaluate the sensitization was the ratio between the maximum reactivation density (Ir) and the maximum activation density (Ia). The results of the electrochemical tests were discussed in relation with the microstructures observed at the different heat treatments. (authors)

  12. 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...

  13. Phase Transformations in Cast Duplex Stainless Steels

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yoon-Jun [Iowa State Univ., Ames, IA (United States)

    2004-01-01

    Duplex stainless steels (DSS) constitute both ferrite and austenite as a matrix. Such a microstructure confers a high corrosion resistance with favorable mechanical properties. However, intermetallic phases such as σ and χ can also form during casting or high-temperature processing and can degrade the properties of the DSS. This research was initiated to develop time-temperature-transformation (TTT) and continuous-cooling-transformation (CCT) diagrams of two types of cast duplex stainless steels, CD3MN (Fe-22Cr-5Ni-Mo-N) and CD3MWCuN (Fe-25Cr-7Ni-Mo-W-Cu-N), in order to understand the time and temperature ranges for intermetallic phase formation. The alloys were heat treated isothermally or under controlled cooling conditions and then characterized using conventional metallographic methods that included tint etching, and also using electron microscopy (SEM, TEM) and wavelength dispersive spectroscopy (WDS). The kinetics of intermetallic-phase (σ + χ) formation were analyzed using the Johnson-Mehl-Avrami (MA) equation in the case of isothermal transformations and a modified form of this equation in the case of continuous cooling transformations. The rate of intermetallic-phase formation was found to be much faster in CD3MWCuN than CD3MN due mainly to differences in the major alloying contents such as Cr, Ni and Mo. To examine in more detail the effects of these elements of the phase stabilities; a series of eight steel castings was designed with the Cr, Ni and Mo contents systematically varied with respect to the nominal composition of CD3MN. The effects of varying the contents of alloying additions on the formation of intermetallic phases were also studied computationally using the commercial thermodynamic software package, Thermo-Calc. In general, σ was stabilized with increasing Cr addition and χ by increasing Mo addition. However, a delicate balance among Ni and other minor elements such as N and Si also exists. Phase equilibria in DSS can be affected by

  14. Phase transformations in cast duplex stainless steels

    Science.gov (United States)

    Kim, Yoon-Jun

    Duplex stainless steels (DSS) constitute both ferrite and austenite as a matrix. Such a microstructure confers a high corrosion resistance with favorable mechanical properties. However, intermetallic phases such as sigma (sigma) and chi (chi) can also form during casting or high-temperature processing and can degrade the properties of the DSS. This research was initiated to develop time-temperature-transformation (TTT) and continuous-cooling-transformation (CCT) diagrams of two types of cast duplex stainless steels, CD3MN (Fe-22Cr-5Ni-Mo-N) and CD3MWCuN (Fe-25Cr-7Ni-Mo-W-Cu-N), in order to understand the time and temperature ranges for intermetallic phase formation. The alloys were heat treated isothermally or under controlled cooling conditions and then characterized using conventional metallographic methods that included tint etching, and also using electron microscopy (SEM, TEM) and wavelength dispersive spectroscopy (WDS). The kinetics of intermetallic-phase (sigma + chi) formation were analyzed using the Johnson-Mehl-Avrami (JMA) equation in the case of isothermal transformations and a modified form of this equation in the case of continuous cooling transformations. The rate of intermetallic-phase formation was found to be much faster in CD3MWCuN than CD3MN due mainly to differences in the major alloying contents such as Cr, Ni and Mo. To examine in more detail the effects of these elements of the phase stabilities, a series of eight steel castings was designed with the Cr, Ni and Mo contents systematically varied with respect to the nominal composition of CD3MN. The effects of varying the contents of alloying additions on the formation of intermetallic phases were also studied computationally using the commercial thermodynamic software package, Thermo-Calc. In general, a was stabilized with increasing Cr addition and chi by increasing Mo addition. However, a delicate balance among Ni and other minor elements such as N and Si also exists. Phase equilibria in

  15. Metallurgical and acoustical characterization of a hydroformed, 304 stainless steel, Caribbean-style musical pan

    International Nuclear Information System (INIS)

    Murr, L.E.; Gaytan, S.M.; Lopez, M.I.; Bujanda, D.E.; Martinez, E.Y.; Whitmyre, G.; Price, H.

    2008-01-01

    We report herein the metallurgical and acoustical characterization of hydroformed 304 stainless steel, Caribbean pans. These pans were fully tuned to chromatic tones and compared to a manufactured, low-carbon, Caribbean steel pan standard. Hydroformed platforms had a Vickers microindentation hardness of HV 345, which was reduced by annealing during pan fabrication to HV 270. Skirts welded to the hydroformed head had a microindentation hardness of HV 440. Microstructural characterization by light optical metallography and transmission electron microscopy illustrated microstructures (including grain structures) characteristic of these pan microindentation hardnesses

  16. Corrosion-free precast prestressed concrete piles made with stainless steel reinforcement : construction, test and evaluation.

    Science.gov (United States)

    2015-03-01

    The use of duplex high-strength stainless steel (HSSS) grade 2205 prestressing strand and : austenitic stainless steel (SS) grade 304 spiral wire reinforcement is proposed as a replacement of : conventional prestressing steel, in order to provide a 1...

  17. Stress Corrosion Cracking of Type 304 Stainless Steel

    National Research Council Canada - National Science Library

    Louthan, M

    1964-01-01

    Stress corrosion cracking of type 304 stainless steel exposed in dilute chloride solutions is being investigated at the Savannah River Laboratory in attempts to develop a fundamental understanding of the phenomenon...

  18. Enhanced Corrosion Resistance of Stainless Steel Carburized at Low Temperature

    Science.gov (United States)

    Martin, F. J.; Natishan, P. M.; Lemieux, E. J.; Newbauer, T. M.; Rayne, R. J.; Bayles, R. A.; Kahn, H.; Michal, G. M.; Ernst, F.; Heuer, A. H.

    2009-08-01

    The pitting corrosion resistance of surface-modified 316L austenitic stainless steel and N08367 (a “superaustenitic” stainless steel) were evaluated in 0.6 M NaCl solutions and compared to untreated samples of the same materials. The surface modification process used to treat the surfaces was a low-temperature carburization technology termed “low-temperature colossal supersaturation” (LTCSS). The process typically produces surface carbon concentrations of ~15 at. pct without the formation of carbides. The pitting potential of the LTCSS-treated 316L stainless steel in the NaCl solution substantially increased compared to untreated 316L stainless steel, while the pitting behavior of the LTCSS-treated N08367 was unchanged compared to the untreated alloy.

  19. Controlled dissolution of colossal quantities of nitrogen in stainless steel

    DEFF Research Database (Denmark)

    Christiansen, Thomas; Somers, Marcel A. J.

    2006-01-01

    The solubility of nitrogen in austenitic stainless steel was investigated thermogravimetrically by equilibrating thin foils of AISI 304 and AISI 316 in ammonia/hydrogen gas mixtures. Controlled dissolution of colossal amounts of nitrogen under metastable equilibrium conditions was realized...

  20. Strengthening of stainless steel weldment by high temperature precipitation

    Directory of Open Access Journals (Sweden)

    Sergio Neves Monteiro

    2017-10-01

    Full Text Available The mechanical behavior and the strengthening mechanism of stainless steel welded joints at 600 °C have been investigated. The welds were composed of AISI 304 stainless steel, as base metal, and niobium containing AISI 347 stainless steel, as weld metal. The investigation was conducted by means of creep tests. The welded specimens were subjected to both high temperature (600 °C and long periods (up to 2000 h under constant load, and both mechanical properties and microstructural changes in the material were monitored. It was found that the exposure of the material at 600 °C under load contributes to a strengthening effect on the weld. The phenomenon might be correlated with an accelerated process of second phase precipitation hardening. Keywords: Stainless steel, Weld, AISI 304, Precipitation hardening

  1. Stainless steels in power plant and plant construction. Papers

    International Nuclear Information System (INIS)

    1994-01-01

    The conference report comprises 14 papers on the corrosion characteristics of stainless steels in power plant and plant engineering. 9 papers are available as separate records in the ENERGY database. (MM) [de

  2. Stress-Corrosion Cracking in Martensitic PH Stainless Steels

    Science.gov (United States)

    Humphries, T.; Nelson, E.

    1984-01-01

    Precipitation-hardening alloys evaluated in marine environment tests. Report describes marine-environment stress-corrosion cracking (SCC) tests of three martensitic precipitation hardening (PH) stainless-steel alloys.

  3. Development of oxide dispersion strengthened 2205 duplex stainless steel composite

    Directory of Open Access Journals (Sweden)

    Oladayo OLANIRAN

    2015-05-01

    Full Text Available Composites of duplex stainless steel were produced by oxide dispersion strengthening with comparatively improved mechanical properties by hot press sintering of partially stabilized Zirconia (PSZ, 3% yttria, mole fraction dispersion in 2205 duplex stainless steels. Ceramic oxide was added as reinforcement, while chromium (Cr and Nickel (Ni were incorporated to maintain the austenitic/ferritic phase balance of the duplex stainless steel. The powders and sintered were characterized in detail using scanning electron microscopy (SEM and X-ray diffraction (XRD. The microstructural evolution and phase formation during oxide dispersion strengthening of duplex stainless steel composites were investigated. The influence of composition variation of the reinforcements on the microstructural and corrosion behaviour in simulated mine water of the composites were investigated. In this manuscript, it was established that composition has great influence on the structure/properties relationship of the composites developed.

  4. HIP bonding between niobium/copper/stainless steel materials

    International Nuclear Information System (INIS)

    Inoue, Hitoshi; Fujino, Takeo; Hitomi, Nobuteru; Saito, Kenji; Yamada, Masahiro; Shibuya, Junichi; Ota, Tomoko

    2000-01-01

    We have used niobium flanges for the niobium bulk superconducting RF cavities, however, they are expensive. Stainless steel flanges instead of the niobium flanges will be used in the future large scale production of sc cavities like the KEK/JAERI joint project. For a future R and D of the vacuum sealing related to the clean horizontal assembly method or development of cavities welded a helium vessel in the KEK/JAERI joint project, a converter section of niobium material to stainless steel is required. From these requirements we need to develop the converter. We have tried a HIP bonding method between niobium materials and stainless steel or copper material. It was made clear that the technology could offer an enough bonding strength even higher than niobium tensile strength in the joined surface between niobium and stainless steel or copper. (author)

  5. Overlaying of type 316 austenitic stainless steel with type 430 ferritic stainless steel

    International Nuclear Information System (INIS)

    Sujith, S.; Gill, T.P.S.

    1993-01-01

    Overlaying of type 316 austenitic stainless steel vessel with type 430 ferritic stainless is proposed for liquid magnesium service. The interface in this type of bimetallic configuration has been shown to be a cause for concern as it contains a hard and brittle martensite micro constituent which becomes susceptible to cracking under certain conditions. This study was carried out to standardize the welding conditions and characterise the interface in order to obtain sound overlay. Some tests were also conducted to simulate the elevated temperature service. The investigation has shown that the interface hardness approaches 400 VPN when no preheating is employed. However, in the preheated samples, appreciable reduction in the peak hardness was observed. This has been attributed to a decrease in the cooling rate of the clad metal with an increase in the preheating temperature which results in softening of the martensite. The minimum recommended preheat is 473 K. The samples exposed to thermal cycle tests to a peak temperature of 1223 K to simulate the service condition did not show any cracking at the interface after 20 cycles of testing. Therefore, this study has demonstrated the stability of the interface between type 316 and 430 stainless steels at the intended temperature of service. (author)

  6. Stainless steel in contact with food and bevarage

    Directory of Open Access Journals (Sweden)

    Sveto Cvetkovski

    2012-12-01

    Full Text Available Stainless steels are probably the most important materials in the food and beverage industries. The main reason for such broad implementation of stainless steel in contact with food are excellent properties which they possess such as corrosion resistance, resistance to high and low temperatures, very good mechanical and physical properties, aesthetic appeal, inertness of surface, durability, easy cleaning and recycling. Low thermal conductivity of these steels produces steeper temperature coefficient provoking an increased distortion, shrinkage and stresses compared with carbon steel.

  7. A Simple Approach to the Determination of Threshold Stress Intensity for Stress Corrosion Cracking ( K ISCC) and Crack Growth of Sensitized Austenitic Stainless Steel

    Science.gov (United States)

    Singh Raman, R. K.; Pal, Sarvesh

    2011-09-01

    This article discusses the intricacies associated with the determination of threshold stress intensity for stress corrosion cracking ( K ISCC) of narrow regions such as the sensitized microstructure of austenitic stainless steel and presents a simple approach to the accurate determination of K ISCC of a sensitized stainless steel. K ISCC and crack growth rates of solution-annealed and sensitized AISI 304 stainless steel in the 42 wt pct MgCl2 environment at 427 K (154 °C) were determined using the circumferential notch tensile (CNT) technique. The results presented here validate the ability of the CNT technique to overcome some of the fundamental difficulties in determination of the K ISCC of narrow regions, using the traditional techniques. This article also discusses the mechanistic aspects of the difference in fractographic features of the sensitized and solution-annealed stainless steels.

  8. 77 FR 23752 - Drawn Stainless Steel Sinks From China

    Science.gov (United States)

    2012-04-20

    ... COMMISSION Drawn Stainless Steel Sinks From China Determinations On the basis of the record \\1\\ developed in... reason of imports from China of drawn stainless sinks, provided for in subheading 7324.10.00 of the... than fair value (LTFV) and subsidized by the Government of China. \\1\\ The record is defined in sec. 207...

  9. Influence of sodium on the low-cycle fatigue behavior of types 304 and 316 stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Smith, D.L.; Zeman, G.J.; Natesan, K.; Kassner, T.F.

    1976-01-01

    Fatigue tests in sodium were conducted to investigate the influence of a high-temperature sodium environment on the low-cycle fatigue behavior of Types 304 and 316 stainless steel. The effects of testing in a sodium environment as well as long-term sodium exposure were investigated. The fatigue tests were conducted at 600 and 700/sup 0/C in sodium of controlled purity, viz., approximately 1 ppM oxygen and 0.4 ppM carbon, at a strain rate of 4 x 10/sup -3/s/sup -1/. The fatigue life of annealed Type 316 stainless steel is substantially greater in sodium than when tested in air; however, the fatigue life of annealed Type 304 stainless steel is altered much less when tested in sodium. A 1512-h preexposure to sodium had no significant effect on the fatigue life of Type 316 stainless steel tested in sodium. However, a similar exposure substantially increased the fatigue life of Type 304 stainless steel in sodium. 10 fig. (auth)

  10. A Study of Localized Corrosion in Supermartensitic Stainless Steel Weldments

    OpenAIRE

    Enerhaug, Jakob

    2002-01-01

    This doctoral thesis is concerned with pitting corrosion in super martensitic stainless steel (SMSS) weldments in slightly sour service. Thee main objective with the present thesis has been to find out why pitting corrosion occurs in the heat affected zone (HAZ) at ambient rather than at elevated temperatures and how the corrosion mechanism depends on the welding process. The thesis is divided into six parts. Part I gives a general introduction to martensitic stainless steels, focusing on...

  11. Solidification behavior of austenitic stainless steel filler metals

    International Nuclear Information System (INIS)

    David, S.A.; Goodwin, G.M.; Braski, D.N.

    1980-02-01

    Thermal analysis and interrupted solidification experiments on selected austenitic stainless steel filler metals provided an understanding of the solidification behavior of austenitic stainless steel welds. The sequences of phase separations found were for type 308 stainless steel filler metal, L + L + delta + L + delta + γ → γ + delta, and for type 310 stainless steel filler metal, L → L + γ → γ. In type 308 stainless steel filler metal, ferrite at room temperature was identified as either the untransformed primary delta-ferrite formed during the initial stages of solidification or the residual ferrite after Widmanstaetten austenite precipitation. Microprobe and scanning transmission electron microscope microanalyses revealed that solute extensively redistributes during the transformation of primary delta-ferrite to austenite, leading to enrichment and stabilization of ferrite by chromium. The type 310 stainless steel filler metal investigated solidifies by the primary crystallization of austenite, with the transformation going to completion at the solidus temperature. In our samples residual ferrite resulting from solute segregation was absent at the intercellular or interdendritic regions

  12. Wear-corrosion of AISI 316L stainless steel in different concentrations of NaCl solution

    International Nuclear Information System (INIS)

    Quezada, E; Aguilar, W; Angelats, L; De la Cruz, P

    2006-01-01

    AISI 316L austenitic stainless steels have an excellent combination of mechanical and corrosion resistant properties, which means they are used in different fields such as agricultural industry, petrochemistry and marine structures. In this latter area the requirements are more demanding when the offshore structures are exposed to wear-corrosion in the saline environment. This work studied the effect of the concentration of NaCl on the resistance to wear-corrosion of AISI 316L stainless steel submitted to annealing thermal treatment. This resistance was determined by the method for measuring mass loss and the steel's electrochemical parameters from the polarization curves in the different corrosive mediums. The results show that the loss of mass in the stainless steel test pieces and the friction coefficients decrease with the increase in NaCl concentration while the current densities of corrosion increase (CW)

  13. Low-temperature creep of austenitic stainless steels

    Science.gov (United States)

    Reed, R. P.; Walsh, R. P.

    2017-09-01

    Plastic deformation under constant load (creep) in austenitic stainless steels has been measured at temperatures ranging from 4 K to room temperature. Low-temperature creep data taken from past and unreported austenitic stainless steel studies are analyzed and reviewed. Creep at cryogenic temperatures of common austenitic steels, such as AISI 304, 310 316, and nitrogen-strengthened steels, such as 304HN and 3116LN, are included. Analyses suggests that logarithmic creep (creep strain dependent on the log of test time) best describe austenitic stainless steel behavior in the secondary creep stage and that the slope of creep strain versus log time is dependent on the applied stress/yield strength ratio. The role of cold work, strain-induced martensitic transformations, and stacking fault energy on low-temperature creep behavior is discussed. The engineering significance of creep on cryogenic structures is discussed in terms of the total creep strain under constant load over their operational lifetime at allowable stress levels.

  14. 76 FR 34964 - Stainless Steel Bar From India: Partial Rescission of Antidumping Duty Administrative Review

    Science.gov (United States)

    2011-06-15

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-533-810] Stainless Steel Bar From... the antidumping duty order on stainless steel bar from India for the period of review February 1, 2010....; Outokumpu Stainless Bar, Inc.; Universal Stainless & Alloy Products, Inc.; and Valbruna Slater Stainless...

  15. Plasma spot welding of ferritic stainless steels

    Directory of Open Access Journals (Sweden)

    Lešnjak, A.

    2002-06-01

    Full Text Available Plasma spot welding of ferritic stainless steels is studied. The study was focused on welding parameters, plasma and shielding gases and the optimum welding equipment. Plasma-spot welded overlap joints on a 0.8 mm thick ferritic stainless steel sheet were subjected to a visual examination and mechanical testing in terms of tension-shear strength. Several macro specimens were prepared. Plasma spot welding is suitable to use the same gas as shielding gas and as plasma gas, i.e., a 98 % Ar/2 % H 2 gas mixture. Tension-shear strength of plasma-spot welded joints was compared to that of resistance-spot welded joints. It was found that the resistance welded joints withstand a somewhat stronger load than the plasma welded joints due to a larger weld spot diameter of the former. Strength of both types of welded joints is approximately the same.

    El artículo describe el proceso de soldeo de aceros inoxidables ferríticos por puntos con plasma. La investigación se centró en el establecimiento de los parámetros óptimos de la soldadura, la definición del gas de plasma y de protección más adecuado, así como del equipo óptimo para la realización de la soldadura. Las uniones de láminas de aceros inoxidables ferríticos de 0,8 mm de espesor, soldadas a solape por puntos con plasma, se inspeccionaron visualmente y se ensayaron mecánicamente mediante el ensayo de cizalladura por tracción. Se realizaron macro pulidos. Los resultados de la investigación demostraron que la solución más adecuada para el soldeo por puntos con plasma es elegir el mismo gas de plasma que de protección. Es decir, una mezcla de 98 % de argón y 2 % de hidrógeno. La resistencia a la cizalladura por tracción de las uniones soldadas por puntos con plasma fue comparada con la resistencia de las uniones soldadas por resistencia por puntos. Se llegó a la conclusión de que las uniones soldadas por resistencia soportan una carga algo mayor que la uniones

  16. Microstructural characterization of intercritically annealed low alloy PM steels

    International Nuclear Information System (INIS)

    Gueral, A.; Tekeli, S.

    2007-01-01

    In this study, the applicability of intercritical annealing heat treatment, which is usually practiced to high strength low alloy ingot steels (HSLA), to low alloy powder metallurgy (PM) processed steels was investigated. With this heat treatment, it was intended to produce a dual-phase steel structure (ferrite + martensite) in PM steel. The effect of various amount of graphite addition on microstructure was also examined. For these purposes, atomized iron powder (Ancorsteel 1000) was mixed with 0.3 and 0.5 wt% graphite powder. The mixed powders were cold pressed at 700 MPa with single action and sintered at 1120 deg. C for 30 min under pure argon gas atmosphere. Some of the sintered specimens were directly annealed at intercritical heat treatment temperatures of 724, 735 and 760 deg. C and rapidly water quenched. Through these heat treatments, ferrite + martensite microstructure with coarse grain size were produced. The other sintered specimens were first austenitized at 890 deg. C for 12 min before intercritically annealing and then rapidly water quenched to produce fully martensitic structure. These specimens with fully martensitic microstructure were subsequently annealed at intercritical annealing temperatures of 724, 735 and 760 deg. C and rapidly water quenched. Ferrite + martensite microstructure with fine grain size was obtained by this route. The experimental results showed that martensite volume fraction increased with increasing intercritical annealing temperature as well as increasing graphite content. It is thought that mechanical properties of PM steels can be controlled by these heat treatments which are an alternative to traditional heat treatments of quenching + tempering applied usually to PM steels

  17. EFFECT OF INTERMETALLIC PHASES ON CORROSION BEHAVIOR AND MECHANICAL PROPERTIES OF DUPLEX STAINLESS STEEL AND SUPER-DUPLEX STAINLESS STEEL

    OpenAIRE

    Prabhu Paulraj; Rajnish Garg

    2015-01-01

    Duplex Stainless Steels (DSS) and Super Duplex Stainless Steel (SDSS) have excellent integration of mechanical and corrosion properties. However, the formation of intermetallic phases is a major problem in their usage. The mechanical and corrosion properties are deteriorated due to the presence of intermetallic phases. These phases are induced during welding, prolonged exposure to high temperatures, and improper heat treatments. The main emphasis of this review article is on intermetallic pha...

  18. Martensite transformation in antimony implanted stainless steel

    International Nuclear Information System (INIS)

    Johnson, E.; Littmark, U.; Johansen, A.; Christodoulides, C.

    1981-01-01

    The authors have used Rutherford backscattering analysis (RBS) and transmission electron microscopy (TEM) and diffraction to investigate austenitic stainless steel crystals implanted at room temperature with 80 keV Sb + ions to a fluence of 5 x 10 20 ions/m 2 , thus providing implantation with a heavy group V element. RBS channeling spectra from implanted crystals show a damage peak which approaches the height of the random level and therefore indicates a very high degree of disorder in the implanted layers. The distribution of the disorder extends to a depth 3-5 times the depth of the primary radiation damage. The Sb peaks under channeling as well as random conditions are indistinguishable, confirming that substitutionality during implantation is negligible. To establish the nature of the disorder which cannot be assessed from the RBS analysis alone, and in particular to assess whether an amorphous alloy is formed in the implanted layer as indicated from the RBS spectra, samples implanted under similar conditions were investigated in the TEM. Significant extra spots in the patterns can be ascribed to the presence of a radiation induced b.c.c. phase of martensitic origin. The result that a significant amount of martensite can be induced by antimony implantation seems to indicate that the main driving force for the transition is due to damage induced stress concentrations. (Auth.)

  19. Austenitic stainless steel for high temperature applications

    International Nuclear Information System (INIS)

    Johnson, G. D.; Powell, R. W.

    1985-01-01

    This invention describes a composition for an austenitic stainless steel which has been found to exhibit improved high temperature stress rupture properties. The composition of this alloy is about (in wt. %): 12.5 to 14.5 Cr; 14.5 to 16.5 Ni; 1.5 to 2.5 Mo; 1.5 to 2.5 Mn; 0.1 to 0.4 Ti; 0.02 to 0.08 C; 0.5 to 1.0 Si; 0.01 maximum, N; 0.02 to 0.008 P; 0.002 to 0.008 B; 0.004-0.0010 S; 0.02-0.05 Nb; 0.01-0.05 V; 0.005-0.02 Ta; 0.02-0.05 Al; 0.01-0.04 Cu; 0.02-0.05 Co; 0.03 maximum, As; 0.01 maximum, O; 0.01 maximum, Zr; and with the balance of the alloy being essentially iron. The carbon content of the alloy is adjusted such that wt. % Ti/(wt. % C+wt. % N) is between 4 and 6, and most preferably about 5. In addition the sum of the wt. % P+wt. % B+wt. % S is at least 0.03 wt. %. This alloy is believed to be particularly well suited for use as fast breeder reactor fuel element cladding

  20. New Economical 19Cr Duplex Stainless Steels

    Science.gov (United States)

    Li, Jun; Zhang, Zixing; Chen, Hong; Xiao, Xueshan; Zhao, Junliang; Jiang, Laizhu

    2012-02-01

    New economical duplex stainless steels (DSSs) containing 19Cr-6Mn- xNi-1.0Mo-0.5W-0.5Cu-0.2N ( x = 0.5 to 2.0) were developed, and the microstructure, impact property, and corrosion resistance of the alloys were studied. The ferrite content increases with the solution treatment temperature, but decreases with an increase in nickel. The sigma phase is not found precipitating in the alloys treated with solution from 1023 K to 1523 K (750 °C to 1250 °C). The low-temperature impact energy of the experimental alloys increases first and then decreases rapidly with an increase in nickel, which is mainly due to the martensite transformation with an increase in austenite. The alloys have a better mechanical property and pitting corrosion resistance than AISI 304. Among the designed DSS alloys, 19Cr-6Mn-1.3Ni-1.0Mo-0.5W-0.5Cu-0.2N is found to be an optimum alloy with proper phase proportion, a better combination of mechanical strength and elongation, and higher pitting corrosion resistance compared with those of the other alloys.

  1. Fracture toughness of stainless steel welds

    International Nuclear Information System (INIS)

    Mills, W.J.

    1985-11-01

    The effects of temperature, composition and weld-process variations on the fracture toughness behavior for Types 308 and 16-8-2 stainless steel (SS) welds were examined using the multiple-specimen J/sub R/-curve procedure. Fracture characteristics were found to be dependent on temperature and weld process but not on filler material. Gas-tungsten-arc (GTA) welds exhibited the highest fracture toughness, a shielded metal-arc (SMA) weld exhibited an intermediate toughness and submerged-arc (SA) welds yielded the lowest toughness. Minimum-expected fracture properties were defined from lower-bound J/sub c/ and tearing modulus values generated here and in previous studies. Fractographic examination revealed that microvoid coalescence was the operative fracture mechanism for all welds. Second phase particles of manganese silicide were found to be detrimental to the ductile fracture behavior because they separated from the matrix during the initial stages of plastic straining. In SA welds, the high density of inclusions resulting from silicon pickup from the flux promoted premature dimple rupture. The weld produced by the SMA process contained substantially less manganese silicide, while GTA welds contained no silicide inclusions. Delta ferrite particles present in all welds were substantially more resistant to local failure than the silicide phase. In welds containing little or no manganese silicide, delta ferrite particles initiated microvoid coalescence but only after extensive plastic straining

  2. Comparing creep in two stainless steels AISI 316

    International Nuclear Information System (INIS)

    Silveira, T.L. da; Monteiro, S.N.

    1976-07-01

    Two AISI 316 stainless steels, one of Brazilian fabrication (Villares), the other of foreign fabrication (Uddeholm) were submitted to creep tests with temperature ranging from 600 to 800 0 C. Some important differences in the mechanical behaviour of the two steels are pointed out. These differences are due to the particular thermomechanical history of the materials under consideration. (Author) [pt

  3. Damage on 316LN stainless steel transformed by powder metallurgy

    International Nuclear Information System (INIS)

    Couturier, R.; Burlet, H.

    1998-01-01

    This study deals with the 316 LN stainless steel elaboration by powder metallurgy. This method allows the realization of structures in austenitic steel less affected by the thermal aging than the cast austenitic-ferritic components. The components are performed by the method of HIP (Hot Isostatic Pressing). Mechanical tests are provided to control mechanical properties

  4. Stress corrosion cracking of AISI 321 stainless steel in acidic ...

    Indian Academy of Sciences (India)

    Unknown

    seashore facilities showed that an acidic chloride solution film formed on the surface of steel and the stainless steel ... of the specimens was single phase auste- nite. After heat treatment, the specimens were pickled for .... metal at the crack tip reacted with the test solution to generate vacancies and the brittle fracture process ...

  5. Microstructural stability of 21-6-9 stainless steel

    International Nuclear Information System (INIS)

    Krenzer, R.W.; Sanderson, E.C.

    1978-01-01

    Two experiments were designed to better define parameters for thermomechanical processing of 21-6-9 stainless steel. This steel is one of the nitrogen-strengthened chromium, manganese, and nickel austenitic stainless steels having mechanical properties that can be improved by a combination of plastic deformation and heat treatments. By heat-treating coupons, the time-temperature relationship of the precipitate phase, and the solutionizing, recrystallizing, and stress-relieving temperature ranges in 21-6-9 were established. Secondly, mechanical properties and microstructure as a function of percent deformation and stress-relieving temperature are reported

  6. Grain Boundary Assemblies in Dynamically-Recrystallized Austenitic Stainless Steel

    Directory of Open Access Journals (Sweden)

    Marina Tikhonova

    2016-11-01

    Full Text Available The grain boundary misorientation distributions associated with the development of dynamic recrystallization were studied in a high-nitrogen austenitic stainless steel subjected to hot working. Under conditions of discontinuous dynamic recrystallization, the relationships between the grain or subgrain sizes and flow stresses can be expressed by power law functions with different grain/subgrain size exponents of about −0.76 (for grain size or −1.0 (for subgrain size. Therefore, the mean grain size being much larger than the subgrain size under conditions of low flow stress gradually approaches the size of the subgrains with an increase in the flow stress. These dependencies lead to the fraction of high-angle boundaries being a function of the flow stress. Namely, the fraction of ordinary high-angle boundaries in dynamically-recrystallized structures decreases with a decrease in the flow stress. On the other hand, the fraction of special boundaries, which are associated with annealing twins, progressively increases with a decrease of the flow stress.

  7. Neutron irradiation effect of thermally-sensitized stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    Hide, Kouitiro [Central Research Inst. of Electric Power Industry, Komae, Tokyo (Japan). Komae Research Lab.

    1998-03-01

    Intergranular stress corrosion cracking (IGSCC) susceptibility of irradiated thermally-sensitized Type 304 Stainless Steels (SSs) was studied as a function of neutron fluence and correlated with mechanical responses of the materials. Neutron irradiation was carried out to neutron fluences up to 1.1 x 10{sup 24} n/m{sup 2} (E > 1MeV) at the light water reactor temperature in the Japan Material Test Reactor. The irradiated specimens were examined by slow strain rate stress corrosion cracking tests in 290degC pure water of 0.2 ppm dissolved oxygen concentration and microhardness measurements. The IGSCC susceptibility of the irradiated specimens increased with neutron fluence up to 1.1 x 10{sup 24} n/m{sup 2}. From an attempt to correlate the IGSCC susceptibility with the mechanical properties, an excellent correlation was identified between the susceptibility and microhardness increments at the grain boundary relative to the grain center. While intergranular corrosion rate of thermally sensitized SS increased with neutron fluence up to 1.1 x 10{sup 24} n/m{sup 2}, that of solution annealed SS did not change. The incremental grain boundary hardening and degradation of intergranular corrosion resistance may presumably be the major factors affecting IGSCC performance. (author)

  8. Microstructural morphology and stability of rapidly solidified duplex stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Cvijovic, Z.M.; Mihajlovic, D.V.; Knezevic, V.R. [Belgrade Univ. (Yugoslavia). Faculty of Technology and Metallurgy

    1998-10-01

    The microstructure susceptibility of duplex stainless steel alloy with high ratio of Cr{sub eq}/Ni{sub eq} to unequilibrium solidification conditions were studied after rapid solidification. Three methods of locally surface melting were used: stationary gas tungsten arc, plasma arc and electron beam arc melting. Applying relatively high cooling rates in the range from 10{sup 1} to 10{sup 3} Cs{sup -1} and undercooling of 1.5-13 C, the primary ferrite with second-phase austenite (FA) solidification mode was unchanged, but significant changes in microstructure morphology, such as intercellular austenite, very fine microstructural constituents and increase of volume fraction of retained ferrite were observed. At the critical cooling rate of the order of 10{sup 4} Cs{sup -1} and undercooling {Delta}T>75 C a transformation of solidification mode from FA to single-phase ferrite (F) and developing of ferrite grain structure with Widmanstaetten austenite was demonstrated. Based on these results the partitionless solidification of ferrite and undercooling below the ferrite T{sub 0} curve was suggested. The fact that ferritic solidification was favored, was explained by the chemical composition of the alloy. During the subsequent annealing the obtained microstructures were highly unequilibrium and hence unstable. (orig.) 19 refs.

  9. Structure and composition of phases occurring in austenitic stainless steels in thermal and irradiation environments

    International Nuclear Information System (INIS)

    Lee, E.H.; Maziasz, P.J.; Rowcliffe, A.F.

    1980-01-01

    Transmission electron diffraction techniques coupled with quantitative x-ray energy dispersive spectroscopy have been used to characterize the phases which develop in austenitic stainless steels during exposure to thermal and to irradiation environments. In AISI 316 and Ti-modified stainless steels some thirteen phases have been identified and characterized in terms of their crystal structure and chemical composition. Irradiation does not produce any completely new phases. However, as a result of radiation-induced segregation, principally of Ni and Si, and of enhanced diffusion rates, several major changes in phase relationships occur during irradiation. Firstly, phases characteristic of remote regions of the phase diagram appear unexpectedly, and dissolve during postirradiation annealing (radiation-induced phases). Secondly, some phases develop with their compositions significantly altered by the incorporation of Ni or Si (radiation-modified phases). In addition, several phases develop at significantly lower temperaures during neutron irradiation (radiation-enhanced phases). 18 figures, 9 tables

  10. Enhancement of Stainless Steel's Mechanical Properties via Carburizing Process

    Science.gov (United States)

    Ahmad, S.; Alias, S. K.; Abdullah, B.; Hafiz Mohd Bakri, Mohd.; Hafizuddin Jumadin, Muhammad; Mat Shah, Muhammad Amir

    2016-11-01

    Carburizing process is a method to disperse carbon into the steel surface in order to enhance its mechanical properties such as hardness and wear resistance. This paper study investigates the effect of carburizing temperature to the carbon dispersion layer in stainless steel. The standard AISI 304 stainless steel was carburized in two different temperatures which were 900°C and 950°C. The effect of carbon dispersion layers were observed and the results indicated that the increasing value of the average dispersion layer from 1.30 mm to 2.74 mm thickness was found to be related to increment of carburizing holding temperature . The increment of carbon thickness layer also resulted in improvement of hardness and tensile strength of carburized stainless steel.

  11. Corrosion in lithium-stainless steel thermal-convection systems

    International Nuclear Information System (INIS)

    Tortorelli, P.F.; DeVan, J.H.; Selle, J.E.

    1980-01-01

    The corrosion of types 304L and 316 austenitic stainless steel by flowing lithium was studied in thermal-convection loops operated at 500 to 650 0 C. Both weight and compositional changes were measured on specimens distributed throughout each loop and were combined with metallographic examinations to evaluate the corrosion processes. The corrosion rate and mass transfer characteristics did not significantly differ between the two austenitic stainless steels. Addition of 500 or 1700 wt ppM N to purified lithium did not increase the dissolution rate or change the attack mode of type 316 stainless steel. Adding 5 wt % Al to the lithium reduced the weight loss of this steel by a factor of 5 relative to a pure lithium-thermal-convection loop

  12. Mechanical characteristics of welded joints between different stainless steels grades

    Science.gov (United States)

    Topolska, S.; Łabanowski, J.

    2017-08-01

    Investigation of mechanical characteristics of welded joints is one of the most important tasks that allow determining their functional properties. Due to the very high, still rising, cost of some stainless steels it is justified, on economic grounds, welding austenitic stainless steel with steels that are corrosion-resistant like duplex ones. According to forecasts the price of corrosion resistant steels stil can increase by 26 ÷ 30%. For technical reasons welded joints require appropriate mechanical properties such as: tensile strength, bending, ductility, toughness, and resistance to aggressive media. Such joints are applied in the construction of chemical tankers, apparatus and chemical plants and power steam stations. Using the proper binder makes possible the welds directly between the elements of austenitic stainless steels and duplex ones. It causes that such joits behave satisfactorily in service in such areas like maritime constructions and steam and chemical plants. These steels have high mechanical properties such as: the yield strength, the tensile strength and the ductility as well as the resistance to general corrosion media. They are resistant to both pitting and stress corrosions. The relatively low cost of production of duplex steels, in comparison with standard austenitic steels, is inter alia, the result of a reduced amount of scarce and expensive Nickel, which is seen as a further advantage of these steels.

  13. 78 FR 31577 - Diffusion-Annealed, Nickel-Plated Flat-Rolled Steel Products From Japan

    Science.gov (United States)

    2013-05-24

    ...)] Diffusion-Annealed, Nickel-Plated Flat-Rolled Steel Products From Japan Determination On the basis of the... reason of imports from Japan of diffusion-annealed, nickel-plated flat-rolled steel products, provided... diffusion-annealed, nickel-plated flat-rolled steel products from Japan. Accordingly, effective March 27...

  14. The role of martensitic transformation on bimodal grain structure in ultrafine grained AISI 304L stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Sabooni, S., E-mail: s.sabooni@ma.iut.ac.ir [Department of Materials Engineering, Isfahan University of Technology, 84156-83111 Isfahan (Iran, Islamic Republic of); Karimzadeh, F.; Enayati, M.H. [Department of Materials Engineering, Isfahan University of Technology, 84156-83111 Isfahan (Iran, Islamic Republic of); Ngan, A.H.W. [Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong (China)

    2015-06-11

    In the present study, metastable AISI 304L austenitic stainless steel samples were subjected to different cold rolling reductions from 70% to 93%, followed by annealing at 700 °C for 300 min to form ultrafine grained (UFG) austenite with different grain structures. Transmission electron microscopy (TEM) and nanoindentation were used to characterize the martensitic transformation, in order to relate it to the bimodal distribution of the austenite grain size after subsequent annealing. The results showed that the martensite morphology changed from lath type in the 60% rolled sample to a mixture of lath and dislocation-cell types in the higher rolling reductions. Calculation of the Gibbs free energy change during the reversion treatment showed that the reversion mechanism is shear controlled at the annealing temperature and so the morphology of the reverted austenite is completely dependent on the morphology of the deformation induced martensite. It was found that the austenite had a bimodal grain size distribution in the 80% rolled and annealed state and this is related to the existence of different types of martensite. Increasing the rolling reduction to 93% followed by annealing caused changing of the grain structure to a monomodal like structure, which was mostly covered with small grains of around 300 nm. The existence of bimodal austenite grain size in the 80% rolled and annealed 304L stainless steel led to the improvement of ductility while maintaining a high tensile strength in comparison with the 93% rolled and annealed sample.

  15. Compresibility and sinterability of HCx PM steel diluted with stainless steels

    OpenAIRE

    Gordo, Elena; Khattab, Nermein Hamid; Ruiz-Navas, Elisa María

    2003-01-01

    HCx powder metallurgy steel contains in its composition high contents of Cr and C, and significant quantities of alloy elements typical of tool steels (Mo, V, W), to provide the corrosion resistance of stainless steel with wear resistance of tool steels. HCx appears to be a suitable material for applications in aggressive environments, as valve seat inserts in automotive engines. However, this steel presents a low compressibility leading to high production costs. In this work, some results ca...

  16. 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.

  17. Work of adhesion of dairy products on stainless steel surface

    Directory of Open Access Journals (Sweden)

    Patrícia Campos Bernardes

    2012-12-01

    Full Text Available The adhesion of the solids presents in food can difficult the process of surface cleaning and promotes the bacterial adhesion process and can trigger health problems. In our study, we used UHT whole milk, chocolate based milk and infant formula to evaluate the adhesion of Enterobacter sakazakii on stainless steel coupons, and we determine the work of adhesion by measuring the contact angle as well as measured the interfacial tension of the samples. Inaddition we evaluated the hydrophobicity of stainless steel after pre-conditioning with milk samples mentioned. E. sakazakii was able to adhere to stainless steel in large numbers in the presence of dairy products. The chocolate based milk obtained the lower contact angle with stainless steel surface, higher interfacial tension and consequently higher adhesion work. It was verified a tendency of decreasing the interfacial tension as a function of the increasing of protein content. The pre-conditioning of the stainless steel coupons with milk samples changed the hydrophobic characteristics of the surfaces and became them hydrophilic. Therefore, variations in the composition of the milk products affect parameters important that can influence the procedure of hygiene in surface used in food industry.

  18. Optimization of the A-TIG welding for stainless steels

    Science.gov (United States)

    Jurica, M.; Kožuh, Z.; Garašić, I.; Bušić, M.

    2018-03-01

    The paper presents the influence of the activation flux and shielding gas on tungsten inert gas (A-TIG) welding of the stainless steel. In introduction part, duplex stainless steel was analysed. The A-TIG process was explained and the possibility of welding stainless steels using the A-TIG process to maximize productivity and the cost-effectiveness of welded structures was presented. In the experimental part duplex, 7 mm thick stainless steel has been welded in butt joint. The influence of activation flux chemical composition upon the weld penetration has been investigated prior the welding. The welding process was performed by a robot with TIG equipment. With selected A-TIG welding technology preparation of plates and consumption of filler material (containing Cr, Ni and Mn) have been avoided. Specimens sectioned from the produced welds have been subjected to tensile strength test, macrostructure analysis and corrosion resistance analysis. The results have confirmed that this type of stainless steel can be welded without edge preparation and addition of filler material containing critical raw materials as Cr, Ni and Mn when the following welding parameters are set: current 200 A, welding speed 9,1 cm/min, heat input 1,2 kJ/mm and specific activation flux is used.

  19. Growth of MWCNTs on Flexible Stainless Steels without Additional Catalysts

    Directory of Open Access Journals (Sweden)

    Udomdej Pakdee

    2017-01-01

    Full Text Available Multiwalled carbon nanotubes (MWCNTs were synthesized on austenitic stainless steel foils (Type 304 using a home-built thermal chemical vapor deposition (CVD under atmospheric pressure of hydrogen (H2 and acetylene (C2H2. During the growth, the stainless steel substrates were heated at different temperatures of 600, 700, 800, and 900°C. It was found that MWCNTs were grown on the stainless steel substrates heated at 600, 700, and 800°C while amorphous carbon film was grown at 900°C. The diameters of MWCNTs, as identified by scanning electron microscope (SEM images together with ImageJ software program, were found to be 67.7, 43.0, and 33.1 nm, respectively. The crystallinity of MWCNTs was investigated by an X-ray diffractometer. The number of graphitic walled layers and the inner diameter of MWCNTs were investigated using a transmission electron microscope (TEM. The occurrence of Fe3O4 nanoparticles associated with carbon element can be used to reveal the behavior of Fe in stainless steel as catalyst. Raman spectroscopy was used to confirm the growth and quality of MWCNTs. The results obtained in this work showed that the optimum heated stainless steel substrate temperature for the growth of effective MWCNTs is 700°C. Chemical states of MWCNTs were investigated by X-ray photoelectron spectroscopy (XPS using synchrotron light.

  20. Low stress creep of stainless steel

    International Nuclear Information System (INIS)

    Crossland, I.G.; Clay, B.D.; Baker, C.

    1976-06-01

    The creep of 20%Cr, 25%Ni, Nb stainless steel has been examined at temperatures from 675 to 775 0 C at sheer stressed below 13 MPa and grain sizes from 6 to 20μm. The results have indicated that the initial creep rates were linearly dependent upon stress but with a threshold stress below which no creep occurred, i.e. Bingham behaviour; in addition, the creep activation energy at small strains was substantially lower than the lattice self-diffusion value and the initial creep rates were approximately related to the grain size through an inverse cube relation. It has been concluded that at low strains (approaching the initial elastic deflection) the creep mechanism was probably that of grain boundary diffusion creep (Coble, 1963) and this is further supported by the close agreement between the observed and theoretically predicted creep rate values. Steady-state creep rates were not observed; initially the creep rates fell rapidly with strain after which a more gradual decrease occurred. Whilst the creep rate - stress relationship continued to be of a Bingham form, the progressive reduction in creep rate with strain was found to be mainly attributable to an increase in the effective viscosity, threshold stress effects being generally of secondary importance. A model has been proposed which explains the initial creep rates as being due to Cable creep with elastic accommodation at grain boundary particles. At higher strains grain boundary collapse caused by vacancy sinking is accommodated at precipitate particles by plastic deformation of the adjacent matrix material. (author)

  1. Final Report, Volume 1, Metallurgical Evaluation of Cast Duplex Stainless Steels and their Weldments

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Songqing; Lundin, Carl, W.; Batten, Greg, W.

    2005-09-30

    Duplex stainless steels (DSS) are being specified for chloride containing environments due to their enhanced pitting and stress corrosion cracking resistance. They exhibit improved corrosion performance over the austenitic stainless steels. Duplex stainless steels also offer improved strength properties and are available in various wrought and cast forms. Selected grades of duplex stainless steel castings and their welds, in comparison with their wrought counterparts, were evaluated, regarding corrosion performance and mechanical properties and weldability. Multiple heats of cast duplex stainless steel were evaluated in the as-cast, solution annealed (SA) static cast and SA centrifugal cast conditions, while their wrought counterparts were characterized in the SA condition and in the form of as-rolled plate. Welding, including extensive assessment of autogenous welds and a preliminary study of composite welds (shielded metal arc weld (SMAW)), was performed. The evaluations included critical pitting temperature (CPT) testing, intergranular corrosion (IGC) testing, ASTM A923 (Methods A, B and C), Charpy impact testing, weldability testing (ASTM A494), ferrite measurement and microstructural evaluations. In the study, the corrosion performances of DSS castings were characterized and assessed, including the wrought counterparts for comparison. The evaluation filled the pore of lack of data for cast duplex stainless steels compared to wrought materials. A database of the pitting corrosion and IGC behavior of cast and wrought materials was generated for a greater depth of understanding for the behavior of cast duplex stainless steel. In addition, improved evaluation methods for DSS castings were developed according to ASTM A923, A262, G48 and A494. The study revealed that when properly heat treated according to the specification, (1) DSS castings have equal or better pitting and intergranular corrosion resistance than their wrought counterparts; (2) Welding reduces the

  2. Final Report, Volume 1, Metallurgical Evaluation of Cast Duplex Stainless Steels and their Weldments

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Songqing; Lundin, Carl, W.; Batten, Greg, W.

    2005-09-30

    Duplex stainless steels (DSS) are being specified for chloride containing environments due to their enhanced pitting and stress corrosion cracking resistance. They exhibit improved corrosion performance over the austenitic stainless steels. Duplex stainless steels also offer improved strength properties and are available in various wrought and cast forms. Selected grades of duplex stainless steel castings and their welds, in comparison with their wrought counterparts, were evaluated, regarding corrosion performance and mechanical properties and weldability. Multiple heats of cast duplex stainless steel were evaluated in the as-cast, solution annealed (SA) static cast and SA centrifugal cast conditions, while their wrought counterparts were characterized in the SA condition and in the form of as-rolled plate. Welding, including extensive assessment of autogenous welds and a preliminary study of composite welds (shielded metal arc weld (SMAW)), was performed. The evaluations included critical pitting temperature (CPT) testing, intergranular corrosion (IGC) testing, ASTM A923 (Methods A, B and C), Charpy impact testing, weldability testing (ASTM A494), ferrite measurement and microstructural evaluations. In the study, the corrosion performances of DSS castings were characterized and assessed, including the wrought counterparts for comparison. The evaluation filled the pore of lack of data for cast duplex stainless steels compared to wrought materials. A database of the pitting corrosion and IGC behavior of cast and wrought materials was generated for a greater depth of understanding for the behavior of cast duplex stainless steel. In addition, improved evaluation methods for DSS castings were developed according to ASTM A923, A262, G48 and A494. The study revealed that when properly heat treated according to the specification, (1) DSS castings have equal or better pitting and intergranular corrosion resistance than their wrought counterparts; (2) Welding reduces the

  3. Net shape fabrication of stainless-steel micro machine components from metallic powder

    International Nuclear Information System (INIS)

    Imbaby, M; Jiang, K; Chang, I

    2008-01-01

    A fabrication process of the net shape 316-L stainless-steel micro machine components is reported. The fabrication process combines softlithography and powder metallurgy to produce microcomponents of complex geometries of high quality. The process starts with softlithography by producing ultra thick SU-8 master moulds and their negative replicas of polydimethylsiloxane (PDMS). Then stainless-steel slurry is prepared by mixing super fine 316-L steel powder and binder to fill the PDMS moulds. The two binders used in the experiments were Duramax D-3005 and a mixture of B1000 and B1007. The PDMS micro moulds are filled with the metallic slurries and green parts are obtained from de-moulding, before going through de-binding and sintering in forming gas atmosphere. The fabrication steps were repeatedly tested. The resultant micro parts show high quality shape retention which is attributed to the quality of the SU-8 master moulds. The hardness property of the sintered microcomponents was tested with a micro indenter and a 200 g load was applied. The Vickers hardness of the sintered components was found to be about 255, which was higher than 225 of annealed 316L stainless steel and the two binders make little difference on the hardness of the sintered samples

  4. Tensile properties of the modified 13Cr martensitic stainless steels

    International Nuclear Information System (INIS)

    Mabruri, Efendi; Anwar, Moch Syaiful; Prifiharni, Siska; Romijarso, Toni B.; Adjiantoro, Bintang

    2016-01-01

    This paper reports the influence of Mo and Ni on the tensile properties of the modified 13Cr martensitic stainless steels in tempered condition. Four steels with different content of Mo and Ni were prepared by induction melting followed by hot forging, quenching and tempering. The experimental results showed that the addition of about 1% and 3% Mo has a beneficial effect to increase both the tensile strength and the elongation of the steels. On the contrary, the addition of about 3% Ni into the martensitic stainless steel results in decreasing of both the tensile strength and the elongation. Among the alloys investigated the 13Cr3Mo type steel exhibited largest tensile strength of 1348 MPa and largest elongation of 12%. The observation on the tensile fractured surfaces by using scanning electron microscope supported these findings.

  5. Pitting and stress corrosion cracking of stainless steel

    Science.gov (United States)

    Saithala, Janardhan R.

    An investigation has been performed to determine the pitting resistance of stainless steels and stress corrosion cracking of super duplex stainless steels in water containing chloride ions from 25 - 170°C. The steels studied are 12% Cr, FV520B, FV566, 304L, Uranus65, 2205, Ferallium Alloy 255, and Zeron 100. All these commercial materials used in very significant industrial applications and suffer from pitting and stress corrosion failures. The design of a new experimental setup using an autoclave enabled potentiodynamic polarisation experiments and slow strain rate tests in dilute environments to be conducted at elevated temperatures. The corrosion potentials were controlled using a three electrode cell with computer controlled potentiostat.The experimental programme to determine pitting potentials was designed to simulate the service conditions experienced in most industrial plants and develop mathematical model equations to help a design engineer in material selection decision. Stress corrosion resistance of recently developed Zeron100 was evaluated in dilute environments to propose a mechanism in chloride solutions at high' temperatures useful for the nuclear and power generation industry. Results have shown the significance of the composition of alloying elements across a wide range of stainless steels and its influence on pitting. Nitrogen and molybdenum added to modern duplex stainless steels was found to be unstable at higher temperatures. The fractographic results obtained using the scanning electron microscope (SEM) has given insight in the initiation of pitting in modem duplex and super duplex stainless steels. A mathematical model has been proposed to predict pitting in stainless steels based on the effect of environmental factors (temperature, chloride concentration, and chemical composition). An attempt has been made to identify the mechanism of SCC in Zeron100 super duplex stainless steel.The proposed empirical models have shown good correlation

  6. Evaluation of Additive Manufacturing for Stainless Steel Components

    Energy Technology Data Exchange (ETDEWEB)

    Peter, William H [ORNL; Lou, Xiaoyuan [General Electric (GE); List III, Frederick Alyious [ORNL; Webber, David [General Electric (GE)

    2016-09-01

    This collaboration between Oak Ridge National Laboratory and General Electric Company aimed to evaluate the mechanical properties, microstructure, and porosity of the additively manufactured 316L stainless steel by ORNL’s Renishaw AM250 machine for nuclear application. The program also evaluated the stress corrosion cracking and corrosion fatigue crack growth rate of the same material in high temperature water environments. Results show the properties of this material to be similar to the properties of 316L stainless steel fabricated additively with equipment from other manufacturers with slightly higher porosity. The stress corrosion crack growth rate is similar to that for wrought 316L stainless steel for an oxygenated high temperature water environment and slightly higher for a hydrogenated high temperature water environment. Optimized heat treatment of this material is expected to improve performance in high temperature water environments.

  7. Boron effect on stainless steel plasticity under hot deformation

    International Nuclear Information System (INIS)

    Bulat, S.I.; Kardonov, B.A.; Sorokina, N.A.

    1978-01-01

    The effect of boron on plasticity of stainless steels at temperatures of hot deformation has been studied at three levels of alloying, i.e. 0-0.01% (micro-alloying or modifying), 0.01-0.02% (low alloying) and 0.02-2.0% (high alloying). Introduction of 0.001-0.005% of boron increases hot plasticity of both low and high carbon stainless steels due to decrease in grain size and strengthening of grain boundaries. Microalloying by boron has a positive effect at temperatures below 1200-1220 deg C. At higher temperatures, particularly when its content exceeds 0.008%, boron deteriorates plasticity by increasing the size of grains and weakening their boundaries. 0.1-2% boron strengthen the stainless steel and dectease its plasticity

  8. Depth distribution of martensite in xenon implanted stainless steels

    International Nuclear Information System (INIS)

    Johansen, A.; Johnson, E.; Sarholt-Kristensen, L.; Steenstrup, S.; Hayashi, N.; Sakamoto, I.

    1989-01-01

    The amount of stress-induced martensite and its distribution in depth in xenon implanted austenitic stainless steel poly- and single crystals have been measured by Rutherford backscattering and channeling analysis, depth selective conversion electron Moessbauer spectroscopy, cross-sectional transmission electron microscopy and x-ray diffraction analysis. In low nickel 17/7, 304 and 316 commercial stainless steels and in 17:13 single crystals the martensitic transformation starts at the surface and develops towards greater depth with increasing xenon fluence. The implanted layer is nearly completely transformed, and the interface between martensite and austenite is rather sharp and well defined. In high nickel 310 commercial stainless steel and 15:19 and 20:19 single crystals, on the other hand, only insignificant amounts of martensite are observed. (orig.)

  9. Diffusionless bonding of aluminum to type 304 stainless steel

    International Nuclear Information System (INIS)

    Watson, R.D.

    1963-03-01

    High strength diffusionless bonds can be produced between 1S aluminum and oxidized 304 stainless steel by hot pressing and extrusion bonding. Both the hot pressing and extrusion bonding techniques have been developed to a point where consistently good bonds can be obtained. Although the bonding is performed at elevated temperatures (about 510 o C) a protective atmosphere is not required to produce strong bonds. The aluminum-stainless steel bonded specimens can be used to join aluminum and stainless steel by conventional welding. Welding close to the bond zone does not appear to affect the integrity of the bond. The extrusion bonding technique is covered by Canadian patent 702,438 January 26, 1965 and the hot press bonding technique by Canadian patent application 904,548 June 6, 1964. (author)

  10. Characterization of microstructure and texture across dissimilar super duplex/austenitic stainless steel weldment joint by austenitic filler metal

    International Nuclear Information System (INIS)

    Eghlimi, Abbas; Shamanian, Morteza; Eskandarian, Masoomeh; Zabolian, Azam; Szpunar, Jerzy A.

    2015-01-01

    The evolution of microstructure and texture across an as-welded dissimilar UNS S32750 super duplex/UNS S30403 austenitic stainless steel joint welded by UNS S30986 (AWS A5.9 ER309LMo) austenitic stainless steel filler metal using gas tungsten arc welding process was evaluated by optical micrography and EBSD techniques. Due to their fabrication through rolling process, both parent metals had texture components resulted from deformation and recrystallization. The weld metal showed the highest amount of residual strain and had large austenite grain colonies of similar orientations with little amounts of skeletal ferrite, both oriented preferentially in the < 001 > direction with cub-on-cube orientation relationship. While the super duplex stainless steel's heat affected zone contained higher ferrite than its parent metal, an excessive grain growth was observed at the austenitic stainless steel's counterpart. At both heat affected zones, austenite underwent some recrystallization and formed twin boundaries which led to an increase in the fraction of high angle boundaries as compared with the respective base metals. These regions showed the least amount of residual strain and highest amount of recrystallized austenite grains. Due to the static recrystallization, the fraction of low degree of fit (Σ) coincident site lattice boundaries, especially Σ3 boundaries, was increased in the austenitic stainless steel heat affected zone, while the formation of subgrains in the ferrite phase increased the content of < 5° low angle boundaries at that of the super duplex stainless steel. - Graphical abstract: Display Omitted - Highlights: • Extensive grain growth in the HAZ of austenitic stainless steel was observed. • Intensification of < 100 > orientated grains was observed adjacent to both fusion lines. • Annealing twins with Σ3 CSL boundaries were formed in the austenite of both HAZ. • Cub-on-cube OR was observed between austenite and ferrite in the weld

  11. Characterization of microstructure and texture across dissimilar super duplex/austenitic stainless steel weldment joint by austenitic filler metal

    Energy Technology Data Exchange (ETDEWEB)

    Eghlimi, Abbas, E-mail: a.eghlimi@ma.iut.ac.ir [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Shamanian, Morteza [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Eskandarian, Masoomeh [Department of Materials Engineering, Shiraz University, Shiraz 71348-51154 (Iran, Islamic Republic of); Zabolian, Azam [Department of Natural Resources, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Szpunar, Jerzy A. [Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, SK S7N 5A9 (Canada)

    2015-08-15

    The evolution of microstructure and texture across an as-welded dissimilar UNS S32750 super duplex/UNS S30403 austenitic stainless steel joint welded by UNS S30986 (AWS A5.9 ER309LMo) austenitic stainless steel filler metal using gas tungsten arc welding process was evaluated by optical micrography and EBSD techniques. Due to their fabrication through rolling process, both parent metals had texture components resulted from deformation and recrystallization. The weld metal showed the highest amount of residual strain and had large austenite grain colonies of similar orientations with little amounts of skeletal ferrite, both oriented preferentially in the < 001 > direction with cub-on-cube orientation relationship. While the super duplex stainless steel's heat affected zone contained higher ferrite than its parent metal, an excessive grain growth was observed at the austenitic stainless steel's counterpart. At both heat affected zones, austenite underwent some recrystallization and formed twin boundaries which led to an increase in the fraction of high angle boundaries as compared with the respective base metals. These regions showed the least amount of residual strain and highest amount of recrystallized austenite grains. Due to the static recrystallization, the fraction of low degree of fit (Σ) coincident site lattice boundaries, especially Σ3 boundaries, was increased in the austenitic stainless steel heat affected zone, while the formation of subgrains in the ferrite phase increased the content of < 5° low angle boundaries at that of the super duplex stainless steel. - Graphical abstract: Display Omitted - Highlights: • Extensive grain growth in the HAZ of austenitic stainless steel was observed. • Intensification of < 100 > orientated grains was observed adjacent to both fusion lines. • Annealing twins with Σ3 CSL boundaries were formed in the austenite of both HAZ. • Cub-on-cube OR was observed between austenite and ferrite in the weld

  12. Biomaterial Studies on AISI 316L Stainless Steel after Magnetoelectropolishing

    Science.gov (United States)

    Hryniewicz, Tadeusz; Rokosz, Krzysztof; Filippi, Massimiliano

    2009-01-01

    The polarisation characteristics of the electropolishing process in a magnetic field (MEP – magnetoelectropolishing), in comparison with those obtained under standard/conventional process (EP) conditions, have been obtained. The occurrence of an EP plateau has been observed in view of the optimization of MEP process. Up-to-date stainless steel surface studies always indicated some amount of free-metal atoms apart from the detected oxides and hydroxides. Such a morphology of the surface film usually affects the thermodynamic stability and corrosion resistance of surface oxide layer and is one of the most important features of stainless steels. With this new MEP process we can improve metal surface properties by making the stainless steel more resistant to halides encountered in a variety of environments. Furthermore, in this paper the stainless steel surface film study results have been presented. The results of the corrosion research carried out by the authors on the behaviour of the most commonly used material − medical grade AISI 316L stainless steel both in Ringer’s body fluid and in aqueous 3% NaCl solution have been investigated and presented earlier elsewhere, though some of these results, concerning the EIS Nyquist plots and polarization curves are also revealed herein. In this paper an attempt to explain this peculiar performance of 316L stainless steel has been undertaken. The SEM studies, Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS) were performed on 316L samples after three treatments: MP – abrasive polishing (800 grit size), EP – conventional electrolytic polishing, and MEP – magnetoelectropolishing. It has been found that the proposed magnetoelectropolishing (MEP) process considerably modifies the morphology and the composition of the surface film, thus leading to improved corrosion resistance of the studied 316L SS.

  13. Analysis of the Enameled AISI 316LVM Stainless Steel

    Science.gov (United States)

    Bukovec, Mitja; Xhanari, Klodian; Lešer, Tadej; Petovar, Barbara; Finšgar, Matjaž

    2018-03-01

    In this work, four different enamels were coated on AISI 316LVM stainless steel and the corrosion resistance of these samples was tested in 5 wt.% NaCl solution at room temperature. The preparation procedure of the enamels was optimized in terms of firing temperature, time and composition. First the thermal expansion was measured using dilatometry followed by electrochemical analysis using chronopotentiometry, electrochemical impedance spectroscopy and cyclic polarization. The topography of the most resistant sample was obtained by 3D-profilometry. All samples coated with enamel showed significantly higher corrosion and dilatation resistance compared with the uncoated stainless steel material.

  14. Corrosion behaviour of some conventional stainless steels in electrolyzing process

    Directory of Open Access Journals (Sweden)

    Amal NASSAR

    2015-12-01

    Full Text Available In this study, attempts were made to increase the amount of hydrogen generated from the water electrolysis process. Some conventional stainless steels (316; 409; 410 and 430 were used as anode and cathode in electrolysis process. Further study was carried out on the corrosion trend in all the investigated metals. It is observed that the electrode material can effect on the amount of hydrogen generate by electrolyzing process and metal composition of the stainless steels effects on the rate of corrosion.

  15. Analysis of the Enameled AISI 316LVM Stainless Steel

    Science.gov (United States)

    Bukovec, Mitja; Xhanari, Klodian; Lešer, Tadej; Petovar, Barbara; Finšgar, Matjaž

    2018-01-01

    In this work, four different enamels were coated on AISI 316LVM stainless steel and the corrosion resistance of these samples was tested in 5 wt.% NaCl solution at room temperature. The preparation procedure of the enamels was optimized in terms of firing temperature, time and composition. First the thermal expansion was measured using dilatometry followed by electrochemical analysis using chronopotentiometry, electrochemical impedance spectroscopy and cyclic polarization. The topography of the most resistant sample was obtained by 3D-profilometry. All samples coated with enamel showed significantly higher corrosion and dilatation resistance compared with the uncoated stainless steel material.

  16. Ozone decay on stainless steel and sugarcane bagasse surfaces

    Science.gov (United States)

    Souza-Corrêa, Jorge A.; Oliveira, Carlos; Amorim, Jayr

    2013-07-01

    Ozone was generated using dielectric barrier discharges at atmospheric pressure to treat sugarcane bagasse for bioethanol production. It was shown that interaction of ozone molecules with the pretreatment reactor wall (stainless steel) needs to be considered during bagasse oxidation in order to evaluate the pretreatment efficiency. The decomposition coefficients for ozone on both materials were determined to be (3.3 ± 0.2) × 10-8 for stainless steel and (2.0 ± 0.3) × 10-7 for bagasse. The results have indicated that ozone decomposition has occurred more efficiently on the biomass material.

  17. The use of titanium and stainless steel in fracture fixation.

    Science.gov (United States)

    Hayes, J S; Richards, R G

    2010-11-01

    The use of metal in fracture fixation has demonstrated unrivalled success for many years owing to its high stiffness, strength, biological toleration and overall reliable function. The most prominent materials used are electropolished stainless steel and commercially pure titanium, along with the more recent emergence of titanium alloys. Despite the many differences between electropolished stainless steel and titanium, both materials provide a relatively predictable clinical outcome, and offer similar success for fulfilling the main biomechanical and biological requirements of fracture fixation despite distinctive differences in implant properties and biological responses. This article explores these differences by highlighting the limitations and advantages of both materials, and addresses how this translates to clinical success.

  18. Resistance Element Welding of Magnesium Alloy/austenitic Stainless Steel

    Science.gov (United States)

    Manladan, S. M.; Yusof, F.; Ramesh, S.; Zhang, Y.; Luo, Z.; Ling, Z.

    2017-09-01

    Multi-material design is increasingly applied in the automotive and aerospace industries to reduce weight, improve crash-worthiness, and reduce environmental pollution. In the present study, a novel variant of resistance spot welding technique, known as resistance element welding was used to join AZ31 Mg alloy to 316 L austenitic stainless steel. The microstructure and mechanical properties of the joints were evaluated. It was found that the nugget consisted of two zones, including a peripheral fusion zone on the stainless steel side and the main fusion zone. The tensile shear properties of the joints are superior to those obtained by traditional resistance spot welding.

  19. Failure of austenitic stainless steel tubes during steam generator operation

    OpenAIRE

    M. Głowacka; J. Łabanowski; S. Topolska

    2012-01-01

    Purpose: of this study is to analyze the causes of premature failure of steam generator coil made of austenitic stainless steel. Special attention is paid to corrosion damage processes within the welded joints.Design/methodology/approach: Examinations were conducted several segments of the coil made of seamless cold-formed pipes Ø 23x2.3 mm, of austenitic stainless steel grade X6CrNiTi18-10 according to EN 10088-1:2007. The working time of the device was 6 months. The reason for the withdrawa...

  20. Corrosion of 316L stainless steels MAVL wastes containers

    International Nuclear Information System (INIS)

    Helie, M.

    2003-01-01

    The long lived and medium activity wastes are conditioned or could be re-conditioned in primary drums of 316L stainless steels. In the framework of wastes storage, these drums will be placed in concrete containers; each containers would contain one or more drums. This document recalls global information on the corrosion of stainless steels, analyzes specific conditions bond to the drums conditioning in concrete containers and the nature of the wastes, and details the consequences on the possible risks of external and internal corrosion of the drums. (A.L.B.)

  1. Metal-ceramic interfaces: joining silicon nitride-stainless steel

    Science.gov (United States)

    Polanco, R.; De Pablos, A.; Miranzo, P.; Osendi, M. I.

    2004-11-01

    Joining of hot pressed silicon nitride using three types of stainless steel (AISI 304, 316 and 321) as interlayer was done by diffusion bonding at 1100 °C for 120 min. An extensive reaction zone of about 7 μm was formed in the contact region, where Cr2N, FexSiy and α-Fe were observed, outside that region the austenitic phase with precipitates of chromium nitride was observed. In the Mo-containing stainless steel (AISI 316) formation of Mo3Si was also detected. Moderate strengths were measured by shear testing for these joints.

  2. Fatigue crack nucleation of type 316LN stainless steel

    International Nuclear Information System (INIS)

    Kim, Dae Whan; Kim, Woo Gon; Hong, Jun Hwa; Ryu, Woo Seog

    2000-01-01

    Low Cycle Fatigue (LCF) life decreases drastically with increasing temperature but increases with the addition of nitrogen at room and high temperatures. The effect of nitrogen on LCF life may be related to crack nucleation at high temperatures in austenitic stainless steel because the fraction of crack nucleation in LCF life is about 40%. The influence of nitrogen on the crack nucleation of LCF in type 316LN stainless steel is investigated by observations of crack population and crack depth after testing at 40% of fatigue life. Nitrogen increases the number of cycles to nucleate microcracks of 100 μm but decreases the crack population

  3. Intergranular stress corrosion in soldered joints of stainless steel 304

    International Nuclear Information System (INIS)

    Zamora R, L.

    1994-01-01

    The intergranular stress cracking of welded joints of austenitic stainless steel, AISI 304, is a serious problem in BWR type reactors. It is associated with the simultaneous presence of three factors; stress, a critical media and sensibilization (DOS). EPR technique was used in order to verify the sensibilization degree in the base metal, and the zone affected by heat and welding material. The characterization of material was done. The objective of this work is the study of microstructure and the evaluation of EPR technique used for the determination of DOS in a welded plate of austenitic stainless steel AISI 304. (Author)

  4. 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.

  5. SANS and TEM studies of carbide precipitation and creep damage in type 304 stainless steel

    International Nuclear Information System (INIS)

    Yoo, M.H.; Ogle, J.C.; Schneibel, J.H.; Swindeman, R.W.

    1984-01-01

    Small-angle neutron scattering (SANS) and transmission electron microscopy (TEM) studies were performed to characterize the carbide (M 23 C 6 ) precipitation and creep damage induced in type 304 stainless steel in the primary creep stage. The size distribution of matrix carbides evaluated from SANS analyses was consistent with TEM data, and the expected accelerated kinetics of precipitation under applied stress was confirmed. Additional SANS measurements after the postcreep solution annealing were made in order to differentiate cavities from the carbides. Potential advantages and difficulties associated with characterization of creep-induced cavitation by the SANS techniques are discussed

  6. Diffusion of implanted sodium in iron and AISI 316 Ti stainless steel

    International Nuclear Information System (INIS)

    Kehrel, A.; Lieb, K.P.; Scapellato, N.; Uhrmacher, M.

    1990-01-01

    Samples of polycrystalline iron and austenitic stainless steel were implanted with 250 keV Na + ions to a dose of 1.5x10 17 ions/cm 2 . The Na content was depth-profiled with the resonant nuclear reaction 23 Na(p,γ) 24 Mg, after the samples had been isochronally annealed between room temperature and 1060deg C. In both matrices a diffusion process of Na atoms towards the surface was observed which is discussed in the light of results on Na diffusion in other metals (Cr, Ni and Mo). (orig.)

  7. CHOSEN PROPERTIES OF SANDWICH MATERIAL Ti-304 STAINLESS STEEL AFTER EXPLOSIVE WELDING

    Directory of Open Access Journals (Sweden)

    Dmytro Ostroushko

    2011-05-01

    Full Text Available The work deals with evaluation of joint of stainless steel 304 SS (sheet and commercially pure Ti both after welding explosion and followed-up annealing at 600°C/1.5h/air. The bonding line shows sinusoidal character with curls in crest unlike the trough of the sine curve. The heat treatment does not change the character of the interface. In work amplitude, wave length and the interface thickness were measured. Thickness of compressed cladded matrix of Ti was measured in area of crests and troughs. In crest of joint melted zones were studied, where complex oxides and intermetallic phases were revealed.

  8. Microstructural and thermal stability of selective laser melted 316L stainless steel single tracks

    Directory of Open Access Journals (Sweden)

    Krakhmalev, P.

    2017-05-01

    Full Text Available To remove residual stresses, an as-built SLM object is usually post- treated. This treatment can affect the microstructure, changing the final mechanical characteristics. This investigation is focused on the microstructural characterisation of 316L austenitic stainless steel in as-built and annealed conditions. The SLM microstructure was relatively stable up to 900°C, when cell boundaries start to disappear. At higher temperatures, an insignificant grain coarsening was detected. These microstructural changes caused a gradual drop in the hardness. The obtained result is background for the future development of post-treatment regimens to achieve a high level in the final mechanical properties of SLM objects.

  9. Corrosion resistance testing of high-boron-content stainless steels

    International Nuclear Information System (INIS)

    Petrman, I.; Safek, V.

    1994-01-01

    Boron steels, i.e. stainless steels with boron contents of 0.2 to 2.25 wt.%, are employed in nuclear engineering for the manufacture of baskets or wells in which radioactive fissile materials are stored, mostly spent nuclear fuel elements. The resistance of such steels to intergranular corrosion and uniform corrosion was examined in the Strauss solution and in boric acid; the dependence of the corrosion rate of the steels on their chemical composition was investigated, and their resistance was compared with that of AISI 304 type steel. Corrosion resistance tests in actual conditions of ''wet'' compact storage (demineralized water or a weak boric acid solution) gave evidence that boron steels undergo nearly no uniform corrosion and, as electrochemical measurements indicated, match standard corrosion-resistant steels. Corrosion resistance was confirmed to decrease slightly with increasing boron content and to increase somewhat with increasing molybdenum content. (Z.S.). 3 tabs., 4 figs., 7 refs

  10. Accelerated corrosion of stainless steel in thiocyanate-containing solutions

    Energy Technology Data Exchange (ETDEWEB)

    Pistorius, P Chris; Li, Wen

    2012-09-19

    It is known that reduced sulfur compounds (such as thiocyanate and thiosulfate) can accelerate active corrosion of austenitic stainless steel in acid solutions, but before we started this project the mechanism of acceleration was largely unclear. This work combined electrochemical measurements and analysis using scanning electron microscopy (SEM) and X-ray photo-electron spectroscopy (XPS), which provided a comprehensive understanding of the catalytic effect of reduced sulfur species on the active corrosion of stainless steel. Both the behavior of the pure elements and the steel were studied and the work focused on the interaction between the pure elements of the steel, which is the least understood area. Upon completion of this work, several aspects are now much clearer. The main results from this work can be summarized as follows: The presence of low concentrations (around 0.1 mM) of thiocyanate or tetrathionate in dilute sulfuric acid greatly accelerates the anodic dissolution of chromium and nickel, but has an even stronger effect on stainless steels (iron-chromium-nickel alloys). Electrochemical measurements and surface analyses are in agreement with the suggestion that accelerated dissolution really results from suppressed passivation. Even well below the passivation potential, the electrochemical signature of passivation is evident in the electrode impedance; the electrode impedance shows clearly that this pre-passivation is suppressed in the presence of thiocyanate. For the stainless steels, remarkable changes in the morphology of the corroded metal surface and in the surface concentration of chromium support the suggestion that pre-passivation of stainless steels is suppressed because dissolution of chromium is accelerated. Surface analysis confirmed that adsorbed sulfur / sulfide forms on the metal surfaces upon exposure to solutions containing thiocyanate or thiosulfate. For pure nickel, and steels containing nickel (and residual copper), bulk sulfide

  11. A review of hot cracking in austenitic stainless steel weldments

    International Nuclear Information System (INIS)

    Shankar, V.; Gill, T.P.S.; Mannan, S.L.; Rodriguez, P.

    1991-01-01

    The occurrence of hot cracking in austenitic stainless steel weldments is discussed with respect to its origin and metallurgical contributory factors. Of the three types of hot cracking, namely solidification cracking, liquation and ductility dip cracking, solidification cracking occurs in the interdendritic regions in weld metal while liquation and ductility dip cracking occur intergranularly in the heat-affected zone (HAZ). Segregation of impurity and minor elements such as sulphur, phosphorous, silicon, niobium, boron etc to form low melting eutectic phases has been found to be the major cause of hot cracking. Control of HAZ cracking requires minimisation of impurity elements in the base metal. In stabilized stainless steels containing niobium, higher amounts of delta-ferrite have been found necessary to prevent cracking than in unstabilized compositions. Titanium compounds have been found to cause liquation cracking in maraging steels and titanium containing stainless steels and superalloys. In nitrogen added stainless steels, cracking resistance decreases when the solidification mode changes to primary austenitic due to nitrogen addition. A review of the test methods to evaluate hot cracking behaviour showed that several external restraint and semi-self-restraint tests are available. The finger Test, WRC Fissure Bend Test, the PVR test and the Varestraint Test are described along with typical test results. Hot ductility testing to reveal HAZ cracking tendency during welding is described, which is of particular importance to stabilized stainless steels. Based on the literature, recommendations are made for welding stabilized and nitrogen added steels, indicating areas of further work. (author). 81 refs., 30 figs., 1 tab

  12. 76 FR 1599 - Stainless Steel Bar From Brazil: Final Results of Antidumping Duty Administrative Review

    Science.gov (United States)

    2011-01-11

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-351-825] Stainless Steel Bar From... duty order on stainless steel bar from Brazil. The review covers one producer/exporter of the subject... its administrative review of the antidumping duty order on stainless steel bar (SSB) from Brazil. See...

  13. 77 FR 41969 - Stainless Steel Bar From Japan: Rescission of Antidumping Duty Administrative Review

    Science.gov (United States)

    2012-07-17

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-588-833] Stainless Steel Bar From... order on stainless steel bar from Japan (the Order) covering the period February 1, 2010, through... Suruga to the Secretary, ``Stainless Steel Bar--Withdrawal of Request for Administrative Review,'' dated...

  14. 76 FR 76437 - Certain Welded Stainless Steel Pipe From Korea and Taiwan

    Science.gov (United States)

    2011-12-07

    ... COMMISSION Certain Welded Stainless Steel Pipe From Korea and Taiwan Determination On the basis of the record... revocation of the antidumping duty orders on certain welded stainless steel pipe from Korea and Taiwan would... Publication 4280 (December 2011), entitled Certain Welded Stainless Steel Pipe from Korea and Taiwan...

  15. 75 FR 53714 - Stainless Steel Butt-Weld Pipe Fittings From Japan, Korea, and Taiwan

    Science.gov (United States)

    2010-09-01

    ... 564 (Third Review)] Stainless Steel Butt-Weld Pipe Fittings From Japan, Korea, and Taiwan AGENCY... antidumping duty orders on stainless steel butt-weld pipe fittings from Japan, Korea, and Taiwan. SUMMARY: The... stainless steel butt-weld pipe fittings from Japan, Korea, and Taiwan would be likely to lead to...

  16. Quality control of stainless steel pipings for nuclear power generation

    International Nuclear Information System (INIS)

    Miki, Minoru; Kitamura, Ichiro; Ito, Hisao; Sasaki, Ryoichi

    1979-01-01

    The proportion of nuclear power in total power generation is increasing recently in order to avoid the concentrated dependence on petroleum resources, consequently the reliability of operation of nuclear power plants has become important. In order to improve the reliability of plants, the reliability of each machine or equipment must be improved, and for the purpose, the quality control at the time of manufacture is the important factor. The piping systems for BWRs are mostly made of carbon steel, and stainless steel pipings are used for the recirculation system cooling reactors and instrumentation system. Recently, grain boundary type stress corrosion cracking has occurred in the heat-affected zones of welded stainless steel pipings in some BWR plants. In this paper, the quality control of stainless steel pipings is described from the standpoint of preventing stress corrosion cracking in BWR plants. The pipings for nuclear power plants must have sufficient toughness so that the sudden rupture never occurs, and also sufficient corrosion resistance so that corrosion products do not raise the radioactivity level in reactors. The stress corrosion cracking occurred in SUS 304 pipings, the factors affecting the quality of stainless steel pipings, the working method which improves the corrosion resistance and welding control are explained. (Kako, I.)

  17. No genotoxicity of a new nickel-free stainless steel.

    Science.gov (United States)

    Montanaro, L; Cervellati, M; Campoccia, D; Prati, C; Breschi, L; Arciola, C R

    2005-01-01

    Stainless steel is a metallic alloy largely employed in orthopedics, maxillofacial surgery and orthodontic therapy. However, the presence in its composition of a high quantity of nickel, an agent known to trigger toxic, allergic and cancerogenous responses in humans, is cause of some concern. In this study, we have investigated the in vitro mutagenicity and genotoxicity of a new nickel-free stainless steel, namely P558, in comparison to the conventional stainless steel AISI 316L. The cytogenetic effects were evaluated by studying the frequency of Sister Chromatid Exchanges (SCE) and chromosomal aberrations. Ames test was performed to detect the mutagenic activity. Both P558 and AISI 316L did not cause any significant increase in the average number of SCE and in chromosomal aberrations, either with or without metabolic activation. Furthermore, the Ames test showed that the extracts of both P558 and of AISI 316L are not mutagenic. Overall, these findings prove that P558 is devoid of genotoxicity and mutagenicity. The present results, together with other previous interesting observations that P558 promotes osseointegration, suggest that this new nickel-free stainless steel can represent a better alternative to other conventional steel alloys.

  18. Bactericidal behavior of Cu-containing stainless steel surfaces

    Science.gov (United States)

    Zhang, Xiangyu; Huang, Xiaobo; Ma, Yong; Lin, Naiming; Fan, Ailan; Tang, Bin

    2012-10-01

    Stainless steels are one of the most common materials used in health care environments. However, the lack of antibacterial advantage has limited their use in practical application. In this paper, antibacterial stainless steel surfaces with different Cu contents have been prepared by plasma surface alloying technology (PSAT). The steel surface with Cu content 90 wt.% (Cu-SS) exhibits strong bactericidal activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) within 3 h. Although the Cu-containing surface with Cu content 2.5 wt.% (CuNi-SS) can also kill all tested bacteria, this process needs 12 h. SEM observation of the bacterial morphology and an agarose gel electrophoresis were performed to study the antibacterial mechanism of Cu-containing stainless steel surfaces against E. coli. The results indicated that Cu ions are released when the Cu-containing surfaces are in contact with bacterial and disrupt the cell membranes, killing the bacteria. The toxicity of Cu-alloyed surfaces does not cause damage to the bacterial DNA. These results provide a scientific explanation for the antimicrobial applications of Cu-containing stainless steel. The surfaces with different antibacterial abilities could be used as hygienic surfaces in healthcare-associated settings according to the diverse requirement of bactericidal activities.

  19. Liquid Phase Sintering of Highly Alloyed Stainless Steel

    DEFF Research Database (Denmark)

    Mathiesen, Troels

    1996-01-01

    of boride to AISI 316L type steels have previously been studied, but were found to be sensitive to intergranular corrosion due to formation of intermetallic phases rich in chromium and molybdenum. In order to improve this system further, new investigations have focused on the use of higher alloyed stainless......Liquid phase sintering of stainless steel is usually applied to improve corrosion resistance by obtaining a material without an open pore system. The dense structure normally also give a higher strength when compared to conventional sintered steel. Liquid phase sintrering based on addition...... calculations, made by use of the computer programme Thermo-Calc, were also correlated with the observed microstructure. Corrosion measurements by electrochemical techniques show no signs of intergranular corrosion in contrast to the case of AISI 316L based steel. Furthermore most of the material showed...

  20. Ultrasonic Characterization And Micro-Structural Studies On 2205 Duplex Stainless Steel In Thermal Variations

    Directory of Open Access Journals (Sweden)

    Bernice Victoria

    2015-08-01

    Full Text Available Abstract Due to increasing concern on potential impact of materials on human health and environment the materials used in hygienic applications should be durable corrosion resistant clean surface etc. Type 2205 duplex stainless steel is a preferred material for use in biomedical pharmaceutical nuclear pressure vessels chemical tankers etc. it exhibits good mechanical strength and high resistance to corrosion. The strength toughness hardness of such materials are usually determined by destructive tests. However continuous destructive measurements are generally difficult to perform during the productive process which creates a need for a fast and easy nondestructive method of material characterization. Microstructural changes in duplex stainless steel due to changes in annealing temperature are characterized by ultrasonic pulse echo technique and optical microscopy. Type 2205 duplex stainless steel are heat treated at 1000 deg C 1050 deg C 1100 deg C 1150 deg C and 1200 deg C for 15 min and water quenched. There is an appreciable change in the morphology of all the heat treated samples and the ultrasonic velocity is dependent on both ferrite and austenite ratio and the grain size.

  1. Sigma phase morphologies in cast and aged super duplex stainless steel

    International Nuclear Information System (INIS)

    Martins, Marcelo; Casteletti, Luiz Carlos

    2009-01-01

    Solution annealed and water quenched duplex and super duplex stainless steels are thermodynamically metastable systems at room temperature. These systems do not migrate spontaneously to a thermodynamically stable condition because an energy barrier separates the metastable and stable states. However, any heat input they receive, for example through isothermal treatment or through prolonged exposure to a voltaic arc in the welding process, cause them to reach a condition of stable equilibrium which, for super duplex stainless steels, means precipitation of intermetallic and carbide phases. These phases include the sigma phase, which is easily identified from its morphology, and its influence on the material's impact strength. The purpose of this work was to ascertain how 2-hour isothermal heat treatments at 920 deg. C and 980 deg. C affect the microstructure of ASTM A890/A890M GR 6A super duplex stainless steel. The sigma phase morphologies were found to be influenced by these two aging temperatures, with the material showing a predominantly lacy microstructure when heat treated at 920 deg. C and block-shaped when heat treated at 980 deg. C.

  2. Characterization of Electron Beam Free-Form Fabricated 2219 Aluminum and 316 Stainless Steel

    Science.gov (United States)

    Ekrami, Yasamin; Forth, Scott C.; Waid, Michael C.

    2011-01-01

    Researchers at NASA Langley Research Center have developed an additive manufacturing technology for ground and future space based applications. The electron beam free form fabrication (EBF3) is a rapid metal fabrication process that utilizes an electron beam gun in a vacuum environment to replicate a CAD drawing of a part. The electron beam gun creates a molten pool on a metal substrate, and translates with respect to the substrate to deposit metal in designated regions through a layer additive process. Prior to demonstration and certification of a final EBF3 part for space flight, it is imperative to conduct a series of materials validation and verification tests on the ground in order to evaluate mechanical and microstructural properties of the EBF3 manufactured parts. Part geometries of EBF3 2219 aluminum and 316 stainless steel specimens were metallographically inspected, and tested for strength, fatigue crack growth, and fracture toughness. Upon comparing the results to conventionally welded material, 2219 aluminum in the as fabricated condition demonstrated a 30% and 16% decrease in fracture toughness and ductility, respectively. The strength properties of the 316 stainless steel material in the as deposited condition were comparable to annealed stainless steel alloys. Future fatigue crack growth tests will integrate various stress ranges and maximum to minimum stress ratios needed to fully characterize EBF3 manufactured specimens.

  3. Instrumental Neuron Activation Analysis for certification of stainless steel materials

    International Nuclear Information System (INIS)

    Polkowska-Motrenko, H.

    2006-01-01

    The use of Instrumental Neuron Activation Analysis (INAA) may contribute to improve the certification of the materials, especially in the case of minor and trace elements. In presented paper the INAA method of analysis of stainless steel materials has been elaborated. The obtained results were compared with those of common analytical techniques. The presented results show the usefulness of the INAA method for the certification of CRMs for the iron and steel industry

  4. Pitting Corrosion Susceptibility of AISI 301 Stainless Steel in ...

    African Journals Online (AJOL)

    The susceptibility of austenitic (AISI 301) stainless steel to pitting corrosion was evaluated in sodium chloride (NaCl) solutions - 0.1M, 0.2M, 0.3M, 0.5M and 0.7M and 1.0M. Tensile tests and microscopic examinations were performed on samples prepared from the steel after exposure in the various environments.

  5. Characterization of Stainless Steel Welding Fume Particles : Influence of Stainless Steel Grade, Welding Parameters and Particle Size

    OpenAIRE

    Mei, Nanxuan

    2016-01-01

    Welding is a widely used method to join two pieces of stainless steel. Since it produces a large amount of fume during the process, it can cause adverse health effects. The welding fume particles contain many elements. Among them Cr, Mn and Ni are of concern. These three elements can cause diseases if inhaled by humans, especially Cr(VI). In this project, welding fume particles are collected during welding of different stainless steel grades (austenitic AISI 304L and duplex LDX2101). Furtherm...

  6. Properties of super stainless steels for orthodontic applications.

    Science.gov (United States)

    Oh, Keun-Taek; Kim, Young-Sik; Park, Yong-Soo; Kim, Kyoung-Nam

    2004-05-15

    Orthodontic stainless-steel appliances are considered to be corrosion resistant, but localized corrosion can occur in the oral cavity. This study was undertaken to evaluate the properties of super stainless steels in orthodontic applications. Accordingly, the metallurgical properties, mechanical properties, corrosion resistance, amount of the released nickel, cytotoxicity, and characteristics of the passive film were investigated. Corrosion resistances of the specimens were high and in the following order: super austenitic stainless steel (SR-50A) > super ferritic stainless steel (SFSS) = super duplex stainless steel (SR-6DX) > 316L SS > super martensitic stainless steel (SR-3Mo) in artificial saliva, 37 degrees C. At 500 mV (SCE), current densities of SR-50A, SFSS, SR-6DX, 316L SS, and SR-3Mo were 5.96 microA/cm(2), 20.3 microA/cm(2), 31.9 microA/cm(2), 805 microA/cm(2), and 5.36 mA/cm(2), respectively. Open circuit potentials of SR-50A, 316L SS, SR-6DX, SR-3Mo, and SFSS were - 0.2, - 0.22, - 0.24, - 0.43, and - 0.46 V (SCE), respectively. SR-50A, SFSS, and SR-6DX released below 3 ng/ml nickel for 8 weeks, and increased a little with immersion time, and 316L SS released about 3.5 ng/ml nickel, but SR-3Mo released a large amount of nickel, which increased with immersion time. The study demonstrated that SR-50A, SR-6DX, and SFSS have high corrosion resistance and mild or no cytotoxicity, due to the passive film enhanced by synergistic effect of Mo + N or by high addition effect of Cr + W. All super stainless steels showed very low cytotoxicity regardless of their nickel contents, although SR-3Mo was found to be relatively cytotoxic. From these studies, these steels are considered suitable for orthodontic applications. Copyright 2004 Wiley Periodicals, Inc.

  7. Accumulative Roll Bonding of Aluminum/Stainless Steel Sheets

    Directory of Open Access Journals (Sweden)

    Navid Mohammad Nejad Fard

    2017-06-01

    Full Text Available An Al/Stainless Steel/Al lamellar composite was produced by roll bonding of the starting sheets at 400 °C. Afterward, the roll bonded sheet was cut in half and the accumulative roll bonding (ARB process at room temperature was applied seven times. As a result, the central steel layer fractured and distributed in the Al matrix among different layers introduced by the repetition of roll bonding process. The tensile results showed that the roll bonded sheet has much higher strength and strength to weight ratio compared with the initial aluminum sheet as a result of the presence of continuous steel core. However, poor ductility properties were observed during tensile test, which were ascribed to the increasing deformation resistance and localized thinning of the central stainless steel sheet during the roll bonding process. The ARBed sample exhibited lower strength compared with the roll bonded sheet due to the breakup of stainless steel layer into many small segments. Anyway, an ultrafine grained microstructure with average grain size of 400 nm in the aluminum matrix and 71% strain-induced martensite in the steel segments were detected by the electron backscattered diffraction (EBSD technique, which were found to be responsible for the enhancement of mechanical properties compared with the initial aluminum sheet.

  8. Role of the carbon on the kinetics of grain growth in stainless steel 18-10 after deformation by rolling

    International Nuclear Information System (INIS)

    Nguyen Du; Guiraldenq, P.

    1976-01-01

    Kinetics of grain growth in some 18-10 stainless steels after deformation by rolling have been studied: from experimental results obtained after two series of heat treatments: in air and in primary vacuum, one attempts to show specific influence of carbon on grain growth, and the respective activation energies are determined. Several curves showing evolution of grain size versus annealing time and temperature for the two treatments are given [fr

  9. Immobilization of mesoporous silica particles on stainless steel plates

    Energy Technology Data Exchange (ETDEWEB)

    Pasqua, Luigi, E-mail: luigi.pasqua@unical.it [University of Calabria, Department of Environmental and Chemical Engineering (Italy); Morra, Marco, E-mail: mmorra@nobilbio.com [Via Valcastellana 26 (Italy)

    2017-03-15

    A preliminary study aimed to the nano-engineering of stainless steel surface is presented. Aminopropyl-functionalized mesoporous silica is covalently and electrostatically anchored on the surface of stainless steel plates. The anchoring is carried out through the use of a nanometric spacer, and two different spacers are proposed (both below 2 nm in size). The first sample is obtained by anchoring to the stainless steel amino functionalized, a glutaryl dichloride spacer. This specie forms an amide linkage with the amino group while the unreacted acyl groups undergo hydrolysis giving a free carboxylic group. The so-obtained functionalized stainless steel plate is used as substrate for anchoring derivatized mesoporous silica particles. The second sample is prepared using 2-bromo-methyl propionic acid as spacer (BMPA). Successively, the carboxylic group of propionic acid is condensed to the aminopropyl derivatization on the external surface of the mesoporous silica particle through covalent bond. In both cases, a continuous deposition (coating thickness is around 10 μm) is obtained, in fact, XPS data do not reveal the metal elements constituting the plate. The nano-engineering of metal surfaces can represent an intriguing opportunity for producing long-term drug release or biomimetic surface.

  10. Lithium wetting of stainless steel for plasma facing components

    Science.gov (United States)

    Skinner, C. H.; Capece, A. M.; Roszell, J. P.; Koel, B. E.

    2014-10-01

    Ensuring continuous wetting of a solid container by the liquid metal is a critical issue in the design of liquid metal plasma facing components foreseen for NSTX-U and FNSF. Ultrathin wetting layers may form on metallic surfaces under ultrahigh vacuum (UHV) conditions if material reservoirs are present from which spreading and wetting can start. The combined scanning electron microscopy (SEM), Auger electron spectroscopy (AES) and ion beam etching capabilities of a Scanning Auger Microprobe (SAM) have been used to study the spreading of lithium films on stainless steel substrates. A small (mm-scale) amount of metallic lithium was applied to a stainless steel surface in an argon glove box and transferred to the SAM. Native impurities on the stainless steel and lithium surfaces were removed by Ar+ ion sputtering. Elemental mapping of Li and Li-O showed that surface diffusion of Li had taken place at room temperature, well below the 181°C Li melting temperature. The influence of temperature and surface oxidation on the rate of Li spreading on stainless steel will be reported. Support was provided through DOE Contract Number DE-AC02-09CH11466.

  11. Resistance microwelding of 316L stainless steel wire to block

    DEFF Research Database (Denmark)

    Friis, Kasper Storgaard; Khan, M.I.; Bay, Niels

    2011-01-01

    The excellent corrosion resistance of low carbon vacuum melted 316 stainless steel coupled with its non-magnetic properties makes it ideal for biomedical applications. The typical joint geometry for microcomponents, such as medical implants, includes joining of fine wire to a larger block. However...

  12. Pitting corrosion protection of low nickel stainless steel by ...

    Indian Academy of Sciences (India)

    Pitting corrosion protection of low nickel stainless steel by electropolymerized conducting polymer coating in 0·5 M NaCl solution. T DHANABAL, G AMIRTHAGANESAN. ∗ and J RAVICHANDRAN. Post Graduate and Research Department of Chemistry, Sri Ramakrishna Mission Vidyalaya College of Arts and Science,.

  13. Analysis of polypyrrole-coated stainless steel electrodes ...

    Indian Academy of Sciences (India)

    WINTEC

    The galvanostatic polymerization of pyrrole is carried out on stainless steel electrodes using .... polymerization. Figure 3b indicates that the essential peaks anticipated for SS substrates are noticed. 3.2 Characterization of Ppy coated SS. In order to test the feasibility ..... Jesus Lopez-Palacios 2006 Polymer degradation and.

  14. Behavior of stainless steels in pressurized water reactor primary circuits

    International Nuclear Information System (INIS)

    Féron, D.; Herms, E.; Tanguy, B.

    2012-01-01

    Stainless steels are widely used in primary circuits of pressurized water reactors (PWRs). Operating experience with the various grades of stainless steels over several decades of years has generally been excellent. Nevertheless, stress corrosion failures have been reported in few cases. Two main factors contributing to SCC susceptibility enhancement are investigated in this study: cold work and irradiation. Irradiation is involved in the stress corrosion cracking and corrosion of in-core reactor components in PWR environment. Irradiated assisted stress corrosion cracking (IASCC) is a complex and multi-physics phenomenon for which a predictive modeling able to describe initiation and/or propagation is not yet achieved. Experimentally, development of initiation smart tests and of in situ instrumentation, also in nuclear reactors, is an important axis in order to gain a better understanding of IASCC kinetics. A strong susceptibility for SCC of heavily cold worked austenitic stainless steels is evidenced in hydrogenated primary water typical of PWRs. It is shown that for a given cold-working procedure, SCC susceptibility of austenitic stainless steels materials increases with increasing cold-work. Results have shown also strong influences of the cold work on the oxide layer composition and of the maximum stress on the time to fracture.

  15. 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 ...

  16. Monitoring of occupational exposure in manufacturing of stainless steel constructions

    Czech Academy of Sciences Publication Activity Database

    Kučera, Jan; Bencko, V.; Pápayová, A.; Šaligová, D.; Tejral, J.; Borská, L.

    2001-01-01

    Roč. 9, - (2001), s. 171-175 ISSN 1210-7778 R&D Projects: GA ČR GV202/97/K038 Institutional research plan: CEZ:AV0Z1048901 Keywords : occupational exposure * stainless steel construction industry * instrumental neutron activation analysis Subject RIV: FP - Other Medical Disciplines

  17. Chemical coloring on stainless steel by ultrasonic irradiation.

    Science.gov (United States)

    Cheng, Zuohui; Xue, Yongqiang; Ju, Hongbin

    2018-01-01

    To solve the problems of high temperature and non-uniformity of coloring on stainless steel, a new chemical coloring process, applying ultrasonic irradiation to the traditional chemical coloring process, was developed in this paper. The effects of ultrasonic frequency and power density (sound intensity) on chemical coloring on stainless steel were studied. The uniformity of morphology and colors was observed with the help of polarizing microscope and scanning electron microscopy (SEM), and the surface compositions were characterized by X-ray photoelectric spectroscopy (XPS), meanwhile, the wear resistance and the corrosion resistance were investigated, and the effect mechanism of ultrasonic irradiation on chemical coloring was discussed. These results show that in the process of chemical coloring on stainless steel by ultrasonic irradiation, the film composition is the same as the traditional chemical coloring, and this method can significantly enhance the uniformity, the wear and corrosion resistances of the color film and accelerate the coloring rate which makes the coloring temperature reduced to 40°C. The effects of ultrasonic irradiation on the chemical coloring can be attributed to the coloring rate accelerated and the coloring temperature reduced by thermal-effect, the uniformity of coloring film improved by dispersion-effect, and the wear and corrosion resistances of coloring film enhanced by cavitation-effect. Ultrasonic irradiation not only has an extensive application prospect for chemical coloring on stainless steel but also provides an valuable reference for other chemical coloring. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Pitting corrosion of low-Cr austenitic stainless steels

    International Nuclear Information System (INIS)

    Bullard, S.J.; Covino, B.S. Jr.

    1996-01-01

    The Albany Research Center has investigated the pitting corrosion resistance of experimental low-Cr stainless steels and several commercial stainless steels in chloride-containing aqueous and atmospheric environments. Previous research had shown the experimental alloys to be as corrosion resistant as commercial stainless steels in chloride-free acid environments. The alloys studied were Fe-8Cr-16Ni-5.5Si-1Cu-(0-1)Mo, 304 SS, and 316 SS. These alloys were examined by immersion and electrochemical tests in 3.5 wt. pct. NaCl and 6 wt.pct.FeCl 3 . Results of these tests showed that the addition of one weight percent Mo improved the pitting resistance of the low-Cr alloy and that the Mo-containing experimental alloy was as resistant to pitting as the commercial alloys. Electrochemical tests did, however, show the experimental alloys to be slightly less resistant to pitting than the commercial alloys. Because of these results, the low-Cr alloy with one weight percent Mo and 304 SS were exposed for one year to a marine atmospheric environment on the coast of Oregon. The marine atmospheric corrosion resistance of the low-Cr alloy was found to be comparable to that for type 304 stainless steel

  19. 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 present...

  20. Microstructural Characterization of Low Temperature Gas Nitrided Martensitic Stainless Steel

    DEFF Research Database (Denmark)

    Fernandes, Frederico Augusto Pires; Christiansen, Thomas Lundin; Somers, Marcel A. J.

    2015-01-01

    The present work presents microstructural investigations of the surface zone of low temperature gas nitrided precipitation hardening martensitic stainless steel AISI 630. Grazing incidence X-ray diffraction was applied to investigate the present phases after successive removal of very thin sections...

  1. Controlled dissolution of colossal quantities of nitrogen in stainless steel

    DEFF Research Database (Denmark)

    Christiansen, Thomas; Somers, Marcel A. J.

    2006-01-01

    The solubility of nitrogen in austenitic stainless steel was investigated thermogravimetrically by equilibrating thin foils of AISI 304 and AISI 316 in ammonia/hydrogen gas mixtures. Controlled dissolution of colossal amounts of nitrogen under metastable equilibrium conditions was realized, with ...

  2. Methane formation in tritium gas exposed to stainless steel

    International Nuclear Information System (INIS)

    Morris, G.A.

    1977-01-01

    Tests were performed to determine the effect cleanliness of a surface exposed to tritium gas had on methane formation. These tests performed on 304 stainless steel vessels, cleaned in various ways, showed that the methane formation was reduced by the use of various cleaning procedures

  3. Anomalous kinetics of lath martensite formation in stainless steel

    DEFF Research Database (Denmark)

    Villa, Matteo; Hansen, Mikkel Fougt; Pantleon, Karen

    2015-01-01

    The kinetics of lath martensite formation in Fe-17.3 wt-%Cr-7.1 wt-%Ni-1.1 wt-%Al-0.08 wt-%C stainless steel was investigated with magnetometry and microscopy. Lath martensite forms during cooling, heating and isothermally. For the first time, it is shown by magnetometry during extremely slow...

  4. Pitting corrosion protection of low nickel stainless steel by ...

    Indian Academy of Sciences (India)

    corrosive medium. The low value of Rct for uncoated speci- men is due to the easy penetration of the corrosive chloride ions through stainless steel surface. The double layer capacitance (Cdl) of PoPD decreases to a lower value than that of PANi and uncoated specimen, indi- cating the thickening of the PoPD polymer film.

  5. Bending Behavior of Porous Sintered Stainless Steel Fiber Honeycombs

    Science.gov (United States)

    Zou, Shuiping; Wan, Zhenping; Lu, Longsheng; Tang, Yong

    2017-02-01

    A novel porous honeycomb-type substrate has been developed using solid-state sintering stainless steel fibers. The porous sintered stainless steel fiber honeycombs (PSSSFH) are composed of a skeleton of sintered stainless steel fibers, three-dimensionally interconnected porous structures and multiple parallel microchannels. The bending behavior of the PSSSFH is investigated using three-point bending tests. Four stages, including an elastic stage, a yielding stage with a plateau, a hardening stage and a failure stage, are observed during the bending process of the PSSSFH. In the initial yielding stage, the bending forces increase slowly with displacement increasing, and then a yielding plateau follows, which is unique compared with other porous materials. Moreover, the structure parameters of the PSSSFH are varied to investigate the influence on the bending strength. It is determined that the multiple parallel microchannels can enhance the bending strength of porous stainless steel fiber sintered substrates (PSSFSS) and do not influence the variation trend of bending strength of PSSFSS with porosity increasing. The open ratio is conducive to increasing the bending strength, and the microchannel diameters ranging from 0.5 mm to 1.5 mm have little influence on the bending strength. In addition, both the increasing of sintering temperature and sintering time can strengthen the PSSSFH.

  6. Electroless nickel plating on stainless steels and aluminum

    Science.gov (United States)

    1966-01-01

    Procedures for applying an adherent electroless nickel plating on 303 SE, 304, and 17-7 PH stainless steels, and 7075 aluminum alloy was developed. When heat treated, the electroless nickel plating provides a hard surface coating on a high strength, corrosion resistant substrate.

  7. Analysis of polypyrrole-coated stainless steel electrodes

    Indian Academy of Sciences (India)

    The galvanostatic polymerization of pyrrole is carried out on stainless steel electrodes using -toluene sulphonic acid. The morphology of the film is studied from Scanning Electron Microscopy (SEM) measurements while the nature of the substrate is analysed using Energy Dispersive X-ray Spectroscopy (EDAX) technique.

  8. Static friction of stainless steel wire rope–rubber contacts.

    NARCIS (Netherlands)

    Loeve, A.J.; Krijger, T.; Mugge, W.; Breedveld, P.; Dodou, D.; Dankelman, J.

    2014-01-01

    Little is known about static friction of stainless-steel wire ropes ('cables') in contact with soft rubbers, an interface of potential importance for rigidifiable medical instruments. Although friction theories imply that the size and profile of the cables affect static friction, there are no

  9. Towards commercialization of fast gaseous nitrocarburising stainless steel

    DEFF Research Database (Denmark)

    Hummelshøj, Thomas Strabo; Christiansen, Thomas; Somers, Marcel A. J.

    2010-01-01

    A novel method for fast and versatile low temperature nitrocarburising of stainless steel has recently been invented by the present authors. Selected results obtained with this new surface hardening process are presented. It is shown that it is possible to obtain a case thickness of 20 μm...

  10. Assessment of Hot Crack Properties of Laser Welded Stainless Steel

    DEFF Research Database (Denmark)

    Juhl, Thomas Winther; Olsen, Flemming Ove

    2003-01-01

    Crack testing concerning small and fast solidifying laser welds in austenitic stainless steel has been studied. A set of methods has been applied to investigate alloy properties, including (1) Application of known information to predict solidification phases, (2) Weld metal solidification rate me...

  11. Welding Characteristics of Nitrogen Added Stainless Steels for Nuclear Application

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Y. D. [Pohang Iron and Steel Co., Ltd, Pohang (Korea, Republic of)

    1997-07-01

    Characteristics of properties and manufacturing process was evaluated in development of high strength and corrosion resistant stainless steel. The continuous cast structure of STS 316L was similar to that of STS 304. The most of residual {delta}-ferrite of STS 316L was vermicular type. The residual {delta}-ferrite content increased from the surface towards the center of the slab and after reaching a maximum value at about 50mm distance from surface and steeply decreased towards the center itself. Hot ductility of STS 304L and STS 316L stainless steels containing below 1000 ppm N was appeared to be reasonably good in the range of hot rolling temperature. In case of the steels containing over 1000 ppm N, the hot ductility was decreased rapidly when sulfur content of the steel was above 20 ppm. Therefore, to achieve good hot ductility of the high nitrogen containing steel, reduction of sulfur contents is required as low as possible. The inter granular corrosion resistance and impact toughness of STS 316L were increased with increasing the nitrogen contents. Yield strength and tensile strength of 304 and 316 stainless steels are increased linearly with increasing the nitrogen contents but their elongations are decreased with increasing the nitrogen contents. Therefore, the mechanical properties of these stainless steels could be controlled with variation of nitrogen. The effects of nitrogen on the resistance of stress corrosion cracking (SCC) can be explained by improvement of the load bearing capacity with increasing tensile strength rather than inhibition of trans granular SCC crack generation and propagation. 101 refs., 17 tabs., 105 figs. (author)

  12. Thermal fatigue cracking of austenitic stainless steels

    International Nuclear Information System (INIS)

    Fissolo, A.

    2001-01-01

    This report deals with the thermal fatigue cracking of austenitic stainless steels as AISI 316 LN and 304 L. Such damage has been clearly observed for some components used in Fast Breeder reactors (FBR) and Pressure Water Reactor (PWR). In order to investigate thermal fatigue, quasi-structural specimen have been used. In this frame, facilities enforcing temperature variations similar to those found under the operation conditions have been progressively developed. As for components, loading results from impeded dilatation. In the SPLASH facility, the purpose was to establish accurate crack initiation conditions in order to check the relevance of the usual component design methodology. The tested specimen is continuously heated by the passage of an electrical DC current, and submitted to cyclic thermal down shock (up to 1000 deg C/s) by means of periodical spraying of water on two opposite specimen faces. The number of cycles to crack initiation N i is deduced from periodic examinations of the quenched surfaces, by means of optical microscopy. It is considered that initiation occurs when at least one 50μm to 150□m long crack is observed. Additional SPLASH tests were performed for N >> N i , with a view to investigate the evolution of a surface multiple cracking network with the number of cycles N. The CYTHIA test was mainly developed for the purpose of assessing crack growth dynamics of one isolated crack in thermal fatigue conditions. Specimens consist of thick walled tubes with a 1 mm circular groove is spark-machined at the specimen centre. During the test, the external wall of the tube is periodically heated by using a HF induction coil (1 MHz), while its internal wall is permanently cooled by flowing water. Total crack growth is derived from post-mortem examinations, whereby the thermal fatigue final rupture surface is oxidized at the end of the test. The specimen is broken afterwards under mechanical fatigue at room temperature. All the tests confirm that

  13. The role of nitrogen in the preferential chromium segregation on the ferritic stainless steel (1 1 1) surface

    International Nuclear Information System (INIS)

    Yuhara, J.; Matsui, T.

    2010-01-01

    The temperature dependence on the segregation behavior of the ferritic stainless steel single crystal (1 1 1) surface morphology has been examined by scanning tunneling microscopy (STM), Auger electron spectroscopy (AES), and low energy electron diffraction (LEED). AES clearly showed the surface segregations of chromium and nitrogen upon annealing. Nanoscale triangular chromium nitride clusters were formed around 650 deg. C and were regularly aligned in a hexagonal configuration. In contrast, for the ferritic stainless steel (1 1 1) surface with low-nitrogen content, chromium and carbon were found to segregate on the surface upon annealing and Auger spectra of carbon displayed the characteristic carbide peak. For the low-nitrogen surface, LEED identified a facetted surface with (2 x 2) superstructure at 650 deg. C. High-resolution STM identified a chromium carbide film with segregated carbon atoms randomly located on the surface. The facetted (2 x 2) superstructure changed into a (3 x 3) superstructure with no faceting upon annealing at 750 deg. C. Also, segregated sulfur seems to contribute to the reconstruction or interfacial relaxation between the ferritic stainless steel (1 1 1) substrate and chromium carbide film.

  14. Austenite stability in the high strength metastable stainless steels

    OpenAIRE

    S.J. Pawlak

    2007-01-01

    Purpose: The aim of the present paper was to study the peculiarities of the austenite to martensite phase transformation (A-M), which is an essential step in the production technology of the high strength metastable stainless steels.Design/methodology/approach: The desired control over A-M transformation have been achieved by proper design of the steel chemistry, cold working and heat treatment.Findings: For a range of steel compositions, it was shown that severe cold working leads to fully m...

  15. Compatibility of stainless steel with Pb-17 AT. % Li

    International Nuclear Information System (INIS)

    Tortorelli, P.F.; DeVan, J.H.

    1982-01-01

    The corrosion of type 316 stainless steel and Sandvik HT9 by static Pb-17 at. % Li between 300 and 500 0 C was studied. The resulting weight losses were significantly greater than those of these steels in lithium. The corrosive attack was very uniform, and the room-temperature tensile properties of the steels were unaffected by the exposure. The application of molten Pb-17 at. % Li as a tritium-breeding fluid in conjunction with ferrous alloys in a fusion reactor may be limited to 400 0 C or below

  16. Study to define NDE research for inspection of stainless steels

    International Nuclear Information System (INIS)

    Reinhart, E.R.

    1978-08-01

    After the boiling water reactor (BWR) stress corrosion cracking incidents on 4- and 10-inch stainless steel piping, the Electric Power Research Institute (EPRI) organized a round-robin ultrasonic examination of piping removed from service (TPS-75-609). Five inspection teams participated in this program, using both a standard procedure and the individual team procedure. The original intent was to section the piping after the program to evaluate the effectiveness of state-of-the-art ultrasonics in finding stress corrosion cracking. The sectioning was delayed, however, to allow research and development (R and D) groups time to perform basic measurements aimed at determining optimum search unit and instrument characteristics for the ultrasonic examination of stainless steel piping and to study the applicability of various advanced inspection methods. This additional effort was funded as part of an EPRI technical planning study (TPS-75-620), A Study to Define NDE Research for Inspection of Stainless Steels. Inspection methods evaluated in this study included (1) processing of manual scan data using a miniature programmable calculator (Aerojet Nuclear); (2) investigation into the performance characteristics of three experimental ultrasonic transducers (Battelle-Columbus Laboratories); (3) analysis of fundamental ultrasonic response data from intergranular stress corrosion cracks in stainless steels (Southwest Research Institute); and (4) a feasibility study of advanced signal processing and pattern recognition for analyzing flaws in stainless steel piping (Ultrasonics International). The results of the studies compiled in the report have indicated the direction for future research and development and have formed the basis for the recently initiated EPRI Research Project 892, Ultrasonic System Optimization

  17. Stress corrosion cracking (SCC) susceptibility of various stainless steels in oxygenated high temperature water

    International Nuclear Information System (INIS)

    Akashi, Masatsune; Kawamoto, Teruaki

    1978-01-01

    In order to evaluate new plant materials for their future applications to boiling water reactors (BWRs), the creviced bent beam SCC tests (CBB tests) were conducted on various sensitized stainless steels in oxygenated high temperature water. The results obtained are as follows. 1. Field SCC can be easily reproduced by the CBB test using the specimens taken from the 304 stainless steel pipe weld joints. 2. The SCC susceptibility of 18Cr-11Ni stainless steel in oxygenated high temperature water decreases markedly with the reduction of the carbon content. 3. The SCC susceptibility of low carbon stainless steels (304L, 316L) and stabilized stainless steels (321, 347) is significantly lower than that of the 304 and 316 stainless steels. 4. The addition of molybdenum causes the sensitization of stainless steels to delay at lower temperatures, improving the SCC resistance of the weld joints of BWR pipe materials. (auth.)

  18. 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

  19. 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

    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......: - 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...

  20. Study on Thermal Physical Properties of 304 Stainless Steel

    Science.gov (United States)

    Fang, Dong; Jun-mao, Qie; Hao-hua, Deng

    The DIL402C thermal dilatometer and STA449C thermal analyzer were employed to test the linear expansion and contraction coefficient, CP and DSC curve of 304 stainless steel. The result showed that the linear expansion coefficient range was 20.9700×10-6˜21.5712×10-6 and the linear contraction coefficient range was 21.2528×10-6˜21.9471×10-6. The linear expansion and contraction coefficient were higher than other steel grade, so the 304 stainless steel belonged to the crack sensitive steel. Because of the crystal phase transformation occurred during the 1000˜1400 °C,the curve of CP fluctuated obviously and the defects of casting blank occurred easily. Chosen 1414°C as the liquidus temperature of 304 stainless steel based on the analysis results of DSC. The curve of DSC was unsmooth during 1450˜1100°C, the crystal phase transformation occurs and thermal stability of slab was inferior.When the initial solidified shell formed in this temperature range,the thickness of the shell would be nonuniform and the surface defects occurred more easily.

  1. Inorganic coatings on stainless steel for protection against crevice corrosion

    International Nuclear Information System (INIS)

    Henrikson, Sture

    1989-12-01

    In order to create protection against crevice corrosion stainless steel test specimens of type 316 steel with various inorganic coatings applied on crevice surfaces were tested for 3-50 months at 25 and 30 degree C in natural seawater containing 0.2-1.5 ppm free chlorine. Various metallic coatings, Ni base alloys with Cr and Mo, Ni with W, pure Ag and pure Mo, as well as ceramic coatings - Cr 2 O 3 , TiO 2 and Al 2 O 3 - were studied. All the coatings tested, except pure Molybdenum applied by plasma spraying in a max 0.1 mm thick layer were found to promote crevice corrosion of the stainless steel. A significant reduction of the crevice corrosion susceptibility was obtained with Molybdenum. The result is considered promising enough to justify full scale tests in seawater on flange joints of pipes, valves or pumps. (author)

  2. Stainless steel valves with enhanced performance through microstructure optimization

    Science.gov (United States)

    Barani, A. A.; Boukhattam, M.; Haggeney, M.; Güler, S.

    2017-08-01

    Compressor valves are made of hardened and tempered martensitic steels. The main design criterion for the material selection is the fatigue performance of the material under bending loads. In some cases impact loads and corrosive atmospheres additionally act on the part. For the first time, the microstructure of the most commonly used stainless steel and its influence on the properties relevant for flapper valves is presented and described in this paper. It is demonstrated how the tensile properties of a martensitic stainless steel can be enhanced by tailoring the microstructure. Electron back scatter diffraction method is carried out to explain the changes in monotonic mechanical properties. Through a modified heat treatment the martensite microstructure is refined resulting in an increase of yield and ultimate tensile strength and at the same time a significant increase of elongation.

  3. Microstructural and Mechanical Characterization of Solidified Austenitic Stainless Steels

    Directory of Open Access Journals (Sweden)

    Aktaş Çelik G.

    2017-09-01

    Full Text Available Among the family of stainless steels, cast austenitic stainless steels (CASSs are preferably used due to their high mechanical properties and corrosion resistance. These steels owe their properties to their microstructural features consisting of an austenitic matrix and skeletal or lathy type δ-ferrite depending on the cooling rate. In this study, the solidification behavior of CASSs (304L and 316L grades was studied using ThermoCalc software in order to determine the solidification sequence and final microstructure during cooling. Theoretical findings were supported by the microstructural examinations. For the mechanical characterization, not only hardness measurements but also tribological studies were carried out under dry sliding conditions and worn surfaces were examined by microscopy and 3D profilometric analysis. Results were discussed according to the type and amount of microstructural features.

  4. Electrochemical evaluation of crevice corrosion in stainless steels

    International Nuclear Information System (INIS)

    Flyg, J.; Jargelius-Pettersson, R.F.A.

    1998-01-01

    An electrochemical method for the evaluation of crevice corrosion in stainless steels is described. Specimens are carefully abraded in order to give a large number of microcrevices when the specimen is placed in contact with a rubber o-ring. Twelve specimens are tested simultaneously in a purpose-built electrochemical cell. A constant potential is applied to the specimens and the temperature automatically raised at intervals until a current increase indicates the onset of crevice corrosion and thereby defines the critical crevice corrosion temperature (CCT). Testing has been performed on a wide range of stainless steels in 3.5% NaCl at +700 mV SCE. The temperature was raised by 5 C every 70 minutes. Results show good reproducibility with a typical standard deviation of below 5 C. There is also excellent agreement with the ranking of crevice corrosion resistance for different steel grades which is obtained by immersion testing in 6% FeCl 3 solution. (orig.)

  5. Torque resistance of different stainless steel wires commonly used for fixed retainers in orthodontics.

    Science.gov (United States)

    Arnold, Dario T; Dalstra, Michel; Verna, Carlalberta

    2016-06-01

    Movements of teeth splinted by fixed retention wires after orthodontic treatment have been observed. The aetiological factors for these movements are unknown. The aim of this in vitro study was to compare the resistance to torque of different stainless steel wires commonly used for fixed retainers in orthodontics. Torquing moments acting on a retainer wire were measured in a mechanical force testing system by applying buccal crown torque to an upper lateral incisor in both a 3-teeth and in a 2-teeth setup. Seven stainless steel wires with different shape, type (plain, braided, coaxial, or chain) and dimensions were selected for this study. For a torquing angle of 16.2° in the 3-teeth setup torsion moments can vary between 390 cNmm and 3299 cNmm depending on the retainer wire. For the 2-teeth setup the torsion moments are much smaller. Exposure to the flame of a butane-gas torch for 10 seconds to anneal the wire reduces the stiffness of the retainer wire. Clinicians must select wires for fixed retainers very carefully since the difference in resistance to torque is large. A high level of torque control can be achieved with a plain 0.016 × 0.016-inch or a braided 0.016 × 0.022-inch stainless steel wire. A tooth attached by a retainer wire to only one neighbouring tooth is less resistant to torque than a tooth connected to two neighbouring teeth. Annealing a retainer wire with a flame reduces the stiffness of the wire markedly and can lead to a non-uniform and non-reproducible effect.

  6. Effect of Plastic Pre-straining on Residual Stress and Composition Profiles in Low-Temperature Surface-Hardened Austenitic Stainless Steel

    DEFF Research Database (Denmark)

    Bottoli, Federico; Christiansen, Thomas Lundin; Winther, Grethe

    2016-01-01

    The present work deals with the evaluation of the residual stress profiles in expanded austenite by applying grazing incidence X-ray diffraction (GI-XRD) combined with successive sublayer removal. Annealed and deformed (εeq=0.5) samples of stable stainless steel EN 1.4369 were nitrided...

  7. Mass transfer behavior of a modified austenitic stainless steel in lithium

    International Nuclear Information System (INIS)

    Tortorelli, P.F.; DeVan, J.H.

    1983-01-01

    An austenitic stainless steel that was developed to resist neutron damage was exposed to lithium in the high-temperature part of a thermal convection loop for 6700 h. Specimens of this Prime Candidate Alloy (PCA) composed of 65.0 Fe-15.9 Ni-13.0 Cr-1.9 Mo-1.9 Mn-1.7 Si-0.5 Ti-0.05 C (wt %) were exposed at 600 and 570 0 C in both solution annealed and cold worked forms. The dissolution process was found to be similar to other austenitic alloys in flowing lithium: weight losses of PCA eventually became linearly proportional to exposure time with the specimen surfaces exhibiting porous layers depleted in nickel and chromium. However, the measured weight losses and dissolution rates of these PCA specimens were higher than those of type 316 stainless steel exposed under similar conditions and can be attributed to the higher nickel concentration of the former alloy. The effect of cold work on dissolution rates was less definitive, particularly at 570 0 C. At longer exposure times, the annealed PCA specimen exposed at 600 0 C suffered greater dissolution than the cold worked material, while no effect of prior deformation was observed by analysis of the respective surfaces

  8. Effect of hydrogen on the fracture toughness of 17-4 PH stainless steel

    International Nuclear Information System (INIS)

    Capeletti, T.L.

    1976-01-01

    Fracture toughness (K/sub c/) of 17-4 PH stainless steel decreased significantly with increased hydrogen test pressure for a variety of heat treatment conditions: solution annealed, underaged, peak-aged, and overaged. Minimum toughness (13 MPa√m) was obtained with peak-aged samples tested in 69.5-MPa hydrogen; toughness was maximum (100 MPa√m) for samples tested in helium. Aging treatments increased the hardness from 28 R/sub c/ for solution-annealed material to 42 R/c/ for peak-aged material and correspondingly decreased the fracture toughness in high-pressure hydrogen (K/sub H/) from 31 to 13 MPa√m. However, increased hardness had no substantial effect on the K/sub c/ in helium. Fracture mechanism changed from predominantly ductile rupture in helium to cleavage in 69.5-MPa hydrogen, with mixed-mode fractures at lower hydrogen pressure (3.5-MPa). On the basis of these data, 17-4 PH stainless steel is not recommended for hydrogen service

  9. Preparation and characterization of 304 stainless steel/Q235 carbon steel composite material

    Directory of Open Access Journals (Sweden)

    Wenning Shen

    Full Text Available The composite material of 304 stainless steel reinforced Q235 carbon steel has been prepared by modified hot-rolling process. The resulted material was characterized by scanning electron microscope, three-electrode method, fault current impact method, electrochemical potentiodynamic polarization curve measurement and electrochemical impedance spectroscopy. The results showed that metallurgical bond between the stainless steel layer and carbon steel substrate has been formed. The composite material exhibited good electrical conductivity and thermal stability. The average grounding resistance of the composite material was about 13/20 of dip galvanized steel. There has no surface crack and bubbling formed after fault current impact. The composite material led to a significant decrease in the corrosion current density in soil solution, compared with that of hot dip galvanized steel and bare carbon steel. On the basis polarization curve and EIS analyses, it can be concluded that the composite material showed improved anti-corrosion property than hot-dip galvanized steel. Keywords: Stainless steel, Carbon steel, Anti-corrosion, Conductivity, Electrochemical, EIS

  10. Behaviour of steels in natural environments: focus on stainless steels in natural sea water

    International Nuclear Information System (INIS)

    Feron, D.

    2005-01-01

    Corrosion behaviour of steels and alloys in natural environments is not only dependent to material parameters and environmental chemistry, but also to micro-organisms which may be there. The global approach used to investigate the behaviour of alloys in natural environments is illustrated by the work done on stainless steels in seawater. In aerated seawater, studies led to the proposal of an 'enzymatic model' based on the enzymatic catalyze of the cathodic reaction and which allows reproducing the electrochemical behaviour of stainless steels in natural seawater and the crevice corrosion phenomena observed in natural sea waters. Coupling areas under aerobic and anaerobic conditions leads to the worst situation for stainless steel behaviour: the catalysis of the cathodic reaction on aerobic exposed surfaces and the decrease of the corrosion resistance of anaerobic surfaces due to sulphides. These results lead to the concept of electro-active bio-films. (author)

  11. Stainless Steel Cladding Of Structural Steels By CO2 Laser Welding Techniques

    Science.gov (United States)

    Ludovico, A.; Daurelio, G.; Arcamone, O.

    1989-01-01

    Steel cladding processes are usually performed in different ways: hot roll cladding, strip cladding, weld cladding, explosion forming. For the first time, a medium power (2 KW c.w.) CO2 laser was used to clad structural steels (Fe 37C), 3 and 5 mm thick, with austenitic stainless steels (AISI 304 and AISI 316), 0.5 and 1.5 mm thick. The cladding technique we have developed uses the laser penetration welding process.

  12. Structure and Properties of High-Temperature Multilayer Hybrid Material Based on Vanadium Alloy and Stainless Steel

    Science.gov (United States)

    Nechaykina, Tatyana A.; Nikulin, Sergey A.; Rozhnov, Andrey B.; Khatkevich, Vladimir M.; Rogachev, Stanislav O.

    2017-03-01

    The present work is devoted to the development of new structural composite material having the unique complex of properties for operating in ultrahard conditions that combine high temperatures, radiation, and aggressive environments. A new three-layer composite tube material based on vanadium alloy (V-4Ti-4Cr) protected by stainless steel (Fe-0.2C-13Cr) has been obtained by co-extrusion. Mechanism and kinetics of formation as well as structure, composition, and mechanical properties of "transition" area between vanadium alloy and stainless steel have been studied. The transition area (13- to 22- µm thick) of the diffusion interaction between vanadium alloy and steel was formed after co-extrusion. The microstructure in the transition area was rather complicated comprising different grain sizes in components, but having no defects or brittle phases. Tensile strength of the composite was an average 493 ± 22 MPa, and the elongation was 26 ± 3 pct. Annealing at 1073 K (800 °C) increased the thickness of transition area up to 1.2 times, homogenized microstructure, and slightly changed mechanical properties. Annealing at 1273 K (1000 °C) further increased the thickness of transition area and also lead to intensive grain growth in steel and sometimes to separation between composite components during tensile tests. Annealing at 1073 K (800 °C) is proposed as appropriate heat treatment after co-extrusion of composite providing balance between diffusion interaction thickness and microstructure and monolithic-like behavior of composite during tensile tests.

  13. Correlation Between Microstructure and Mechanical Properties Before and After Reversion of Metastable Austenitic Stainless Steels

    Science.gov (United States)

    Fargas, Gemma; Zapata, Ana; Roa, Joan Josep; Sapezanskaia, Ina; Mateo, Antonio

    2015-12-01

    Reversion treatments are a way to improve the mechanical response of metastable austenitic stainless steels by means of grain refinement. To effectively apply those treatments, the steel must be previously deformed to induce a significant amount of martensitic transformation. In this work, the effect of reversion treatments was studied on a commercial AISI 301LN grade subjected to an industrial cold rolling process, with thickness reductions not higher than 40 pct. Microstructural changes and evolution of both monotonic and cyclic mechanical properties were investigated after cold rolling and upon reversion treatments. Results revealed that the finer austenitic microstructure obtained after reversion leads to an interesting combination of properties, with strong increments in hardness and yield strength, and also fatigue limit improvement, as compared to the initial annealed condition.

  14. Influence o the microstructure of duplex stainless steels on their failure characteristics during hot deformation

    Directory of Open Access Journals (Sweden)

    Reis G.S.

    2000-01-01

    Full Text Available Two types of duplex stainless steels were deformed by torsion at a temperature range of 900 to 1200 °C and strain rate of 1.0 s-1 and their final microstructures were observed. The austenite volume fraction of steel A (26.5Cr - 4.9Ni - 1.6Mo is approximately 25% at room temperature, after conventional annealing, while that of steel B (24Cr - 7.5Ni - 2.3Mo is around 55%. Experimental data show that steel A is ductile at high temperatures and displays low ductility at low temperatures, while steel B has low ductility in the entire range of temperatures studied. At high temperatures, steel A is essentially ferritic and shows dynamic recrystallized grains after deformation. When steel A is strained at low temperatures and displays low austenite volume fraction, microstructural observations indicate that failure is triggered by grain boundary sliding due to the formation of an austenite net structure at the ferrite grain boundaries. At intermediate volume fraction, when austenite forms a dispersed second-phase in steels A and B, failure begins at the ferrite/ferrite boundaries since some of the new ferrite grains may become immobilized by the austenite particles. When steel B is strained at volume fraction of around 50% of austenite and both phases percolate the microstructure, failure occurs after low straining as a consequence of the different plastic behaviors of each of the phases. The failure characteristics of both steels are correlated not only with the volume fraction of austenite but also with its distribution within the ferrite matrix, which limits attainable strain without failure.

  15. Strain-Induced Martensite Formation and Recrystallization Behavior in 304 Stainless Steel

    Science.gov (United States)

    Al-Fadhalah, Khaled J.

    2015-04-01

    The effect of recrystallization on the evolution of microstructure, texture, and mechanical properties has been examined in an AISI 304 stainless steel, subjected to strain-induced α '-martensite transformation and subsequent annealing. Samples were processed by cold rolling and subzero rolling to induce different amounts of α '-martensite, using three reductions of 20, 40, and 60%, and later solution annealed to ensure complete recrystallization. Large transformation to α '-martensite occurred for subzero-rolled samples at low reduction (20%), while only a gradual increase of α '-martensite in cold-rolled samples took place with the increasing rolling reduction. Results from electron back-scattered diffraction indicate that annealing of cold-rolled samples produces finer recrystallized grains with increasing rolling reduction, while the predominant formation of α '-martensite in subzero-rolled microstructures is believed to have strong effect on the production of similar grain size upon annealing. Twin-related Σ3 boundaries were formed during annealing with maximum fraction of 53%. These boundaries become longer, straighter, and less incorporated into grain boundary network with the increasing rolling reduction and/or using subzero rolling, demonstrating an indirect mechanism of grain boundary engineering. Also, annealing caused scattering around the rolling texture components (Brass, Goss, S, and Copper) and the recrystallization textures become more random with the increasing rolling reduction and/or using subzero rolling. Nevertheless, recrystallization textures of samples reduced by 60% show formation of Cube and Dillamore orientations and strengthening of Brass orientation. This is thought to contribute to the enhancement of the tensile strength and microhardness of annealed samples.

  16. High specialty stainless steels and nickel alloys for FGD dampers

    Energy Technology Data Exchange (ETDEWEB)

    Herda, W.R.; Rockel, M.B.; Grossmann, G.K. [Krupp VDM GmbH, Werdohl (Germany); Starke, K. [Mannesmann-Seiffert GmbH, Beckum (Germany)

    1997-08-01

    Because of process design and construction, FGD installations normally have bypass ducts, which necessitates use of dampers. Due to corrosion from acid dew resulting from interaction of hot acidic flue gases and colder outside environments, carbon steel cannot be used as construction material under these specific conditions. In the past, commercial stainless steels have suffered by pitting and crevice corrosion and occasionally failed by stress corrosion cracking. Only high alloy specialty super-austenitic stainless steels with 6.5% Mo should be used and considered for this application. Experience in Germany and Europe has shown that with regard to safety and life cycle cost analysis as well as providing a long time warranty, a new specialty stainless steel, alloy 31--UNS N08031--(31 Ni, 27 Cr, 6.5 Mo, 0.2 N) has proven to be the best and most economical choice. Hundreds of tons in forms of sheet, rod and bar, as well as strip (for damper seals) have been used and installed in many FGD installations throughout Europe. Under extremely corrosive conditions, the new advanced Ni-Cr-Mo alloy 59--UNS N06059--(59 Ni, 23 Cr, 16 Mo) should be used. This paper describes qualification and workability of these alloys as pertains to damper applications. Some case histories are also provided.

  17. Modelling of composition and stress profiles in low temperature surface engineered stainless steel

    DEFF Research Database (Denmark)

    Jespersen, Freja Nygaard; Hattel, Jesper Henri; Somers, Marcel A. J.

    2015-01-01

    Thermochemical surface engineering by nitriding/carburizing of stainless steel causes a surface zone of 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 residual ...

  18. Residual stresses and fatigue in a duplex stainless steel

    International Nuclear Information System (INIS)

    Johansson, Johan

    1999-01-01

    Duplex stainless steels, consisting of approximately equal amounts of austenite and ferrite, often combine the best features of austenitic and ferritic stainless steels. They generally have good mechanical properties, including high strength and ductility, and the corrosion resistance is often better than conventional austenitic grades. This has lead to a growing use of duplex stainless steels as a material in mechanically loaded constructions. However, detailed knowledge regarding its mechanical properties and deformation mechanisms are still lacking. In this thesis special emphasis has been placed on the residual stresses and their influence on mechanical behaviour of duplex stainless steels. Due to the difference in coefficient of thermal expansion between the two phases, tensile microstresses are found in the austenitic phase and balancing compressive microstresses in the ferritic phase. The first part of this thesis is a literature survey, which will give an introduction to duplex stainless steels and review the fatigue properties of duplex stainless steels and the influence of residual stresses in two-phase material. The second part concerns the evolution of the residual stress state during uniaxial loading. Initial residual stresses were found to be almost two times higher in the transverse direction compared to the rolling direction. During loading the absolute value of the microstresses increased in the macroscopic elastic regime but started to decrease with increasing load in the macroscopic plastic regime. A significant increase of the microstresses was also found to occur during unloading. Finite element simulations also show stress variation within one phase and a strong influence of both the elastic and plastic anisotropy of the individual phases on the simulated stress state. In the third part, the load sharing between the phases during cyclic loading is studied. X-ray diffraction stress analysis and transmission electron microscopy show that even if

  19. Residual stresses and fatigue in a duplex stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, Johan

    1999-05-01

    Duplex stainless steels, consisting of approximately equal amounts of austenite and ferrite, often combine the best features of austenitic and ferritic stainless steels. They generally have good mechanical properties, including high strength and ductility, and the corrosion resistance is often better than conventional austenitic grades. This has lead to a growing use of duplex stainless steels as a material in mechanically loaded constructions. However, detailed knowledge regarding its mechanical properties and deformation mechanisms are still lacking. In this thesis special emphasis has been placed on the residual stresses and their influence on mechanical behaviour of duplex stainless steels. Due to the difference in coefficient of thermal expansion between the two phases, tensile microstresses are found in the austenitic phase and balancing compressive microstresses in the ferritic phase. The first part of this thesis is a literature survey, which will give an introduction to duplex stainless steels and review the fatigue properties of duplex stainless steels and the influence of residual stresses in two-phase material. The second part concerns the evolution of the residual stress state during uniaxial loading. Initial residual stresses were found to be almost two times higher in the transverse direction compared to the rolling direction. During loading the absolute value of the microstresses increased in the macroscopic elastic regime but started to decrease with increasing load in the macroscopic plastic regime. A significant increase of the microstresses was also found to occur during unloading. Finite element simulations also show stress variation within one phase and a strong influence of both the elastic and plastic anisotropy of the individual phases on the simulated stress state. In the third part, the load sharing between the phases during cyclic loading is studied. X-ray diffraction stress analysis and transmission electron microscopy show that even if

  20. Market Opportunities for Austenitic Stainless Steels in SO2 Scrubbers

    Science.gov (United States)

    Michels, Harold T.

    1980-10-01

    Recent U.S. federal legislation has created new opportunities for SO2 scrubbers because all coals, even low-sulfur western coals, will probably require scrubbing to remove SO2 from gaseous combustion products. Scrubbing, the chemical absorption of SO2 by vigorous contact with a slurry—usually lime or limestone—creates an aggressive acid-chloride solution. This presents a promising market for pitting-resistant austenitic stainless steels, but there is active competition from rubber and fiberglass-lined carbon steel. Since the latter are favored on a first-cost basis, stainless steels must be justified on a cost/performance or life-cost basis. Nickel-containing austenitic alloys are favored because of superior field fabricability. Ferritic stainless steels have little utility in this application because of limitations in weldability and resulting poor corrosion resistance. Inco corrosion test spools indicate that molybdenum-containing austenitic alloys are needed. The leanest alloys for this application are 316L and 317L. Low-carbon grades of stainless steel are specified to minimize corrosion in the vicinity of welds. More highly alloyed materials may be required in critical areas. At present, 16,000 MW of scrubber capacity is operational and 17,000 MW is under construction. Another 29,000 MW is planned, bringing the total to 62,000 MW. Some 160,000 MW of scrubber capacity is expected to be placed in service over the next 10 years. This could translate into a total potential market of 80,000 tons of alloy plate for new power industry construction in the next decade. Retrofitting of existing power plants plus scrubbers for other applications such as inert gas generators for oil tankers, smelters, municipal incinerators, coke ovens, the pulp and paper industry, sulfuric acid plants, and fluoride control in phosphoric acid plants will add to this large market.

  1. Nucleation and swelling in electron irradiated austenitic stainless steels in temperature range 400∼720 degree C

    International Nuclear Information System (INIS)

    Qian Jiapu; Lu Liping; Chen Jiming; Sun Jiguang; Zhao Zhuoyong

    1994-10-01

    A study of the influence of temperature on swelling behavior in electron irradiated austenitic stainless steels has been performed with a high voltage electron microscope (HVEM) in the temperature range 400 to 720 degree C. The specimen materials were solution annealed (SA) 316 stainless steel (SS), cold worked (CW) 316 SS and Ti-modified austenitic stainless steel (Ti-mod. SS). The electron energy in HVEM was 1 MeV. The results of mean void density, mean void diameter, void swelling, swelling rate and incubation dose vs. dose and temperature are presented. It is suggested that the irradiation temperature influenced the microstructure, overall sink strength and relative strength of neutral sinks to that of biased sinks in the specimens and so made the void nucleation, void growth and swelling behavior differently in 316 SA, 316 CW and Ti-mod. SS. The influence of He pre-implantation on void nucleation in electron irradiated austenitic stainless steels has also been studied. The experiments indicated that the helium was active void nucleus but had no direct impact on void growth

  2. Hydrogen induced plastic deformation of stainless steel

    NARCIS (Netherlands)

    Gadgil, V.J.; Keim, Enrico G.; Geijselaers, Hubertus J.M.

    1998-01-01

    Hydrogen can influence the behaviour of materials significantly. The effects of hydrogen are specially pronounced in high fugacities of hydrogen which can occur at the surface of steels in contact with certain aqueous environments. In this investigation the effect of high fugacity hydrogen on the

  3. Infrared electro-thermal NDE of stainless steel

    International Nuclear Information System (INIS)

    Green, D.R.; Hassberger, J.A.

    1975-01-01

    Electro-thermal examination, a branch of thermal testing, is a promising method being developed for nondestructive examination of stainless steel welds. This paper describes the first phase of development; i.e., preliminary demonstration and laboratory evaluation of the method's sensitivity to notches in Type 304 stainless steel plate specimens. It also includes a description of the basic principles, together with a description of the hardware and experimental results showing that electrical discharge machined notches down to 0.16 cm long x 0.08 cm deep were detected. A qualitative technique for interpreting the test results to determine whether defects are at the surface or deeper within the material is demonstrated

  4. Aging degradation of cast stainless steel: status and program

    International Nuclear Information System (INIS)

    Chopra, O.K.; Ayrault, G.

    1983-10-01

    A program has been initiated to investigate the significance of in-service embrittlement of cast duplex stainless steels under light-water reactor operating conditions. The existing data are reviewed to determine the critical parameters that control the aging behavior and to define the objectives and scope of the investigation. The test matrices for microstructural studies and mechanical property measurements are presented. The initial experimental effort is focussed on characterizing the microstructure of long-term, low-temperature aged material. Specimens from three heats of cast CF-8 and CF-8M stainless steel aged for up to 70,000 h at 300, 350, and 400 0 C were obtained from George Fisher Ltd., of Switzerland. Initial analyses reveal the formation of three different types of precipitates which are not α'. An FCC phase, similar to the M 23 C 6 precipitates, was present in all the long-term aged material. 15 references, 10 figures, 2 tables

  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. Hydrogen transport through stainless steel under plasma irradiation

    Science.gov (United States)

    Airapetov, A. A.; Begrambekov, L. B.; Kaplevsky, A. S.; Sadovskiy, Ya A.

    2016-01-01

    The paper presents the results of investigation of gas exchange through stainless steel surface of the plasma chamber under irradiation with hydrogen atoms in oxygen atmosphere or oxygen contaminated hydrogen plasma. Dependence of this process on various irradiation parameters, such as the metal temperature, energy of irradiating ions, gas composition of plasma are studied. It is shown, that desorption from stainless steel is activated with the increase of the plasma chamber walls temperature and energy of irradiating ions. Hydrogen release occurs also under irradiation of the walls by helium and argon plasmas added with oxygen, however the amount of released hydrogen is several times lower than in the case of irradiation with oxygen contaminated deuterium plasma.

  7. Multilayer modelling of stainless steel with a nanocrystallised superficial layer

    Energy Technology Data Exchange (ETDEWEB)

    Petit, J. [Laboratoire Energetique Mecanique Electromagnetisme (LEME), EA4416, Universite Paris Ouest, 92410 Ville d' Avray (France); Waltz, L., E-mail: laurent.waltz@univ-montp2.fr [Laboratoire de Mecanique et Genie Civil de Montpellier (LMGC), University of Montpellier II, Place Eugene Bataillon, 34000 Montpellier (France); Montay, G.; Retraint, D.; Roos, A.; Francois, M. [Institut Charles Delaunay - LASMIS, UMR CNRS 6279, University of Technology of Troyes, 10010 Troyes (France)

    2012-02-28

    Highlights: Black-Right-Pointing-Pointer SMAT has been used for nanocrystallisation of an austenitic stainless steel. Black-Right-Pointing-Pointer The mechanical response of the nano-phase has been obtained by an indirect method. Black-Right-Pointing-Pointer Minimisation of a stress formulated objective function. Black-Right-Pointing-Pointer The model predicts the strain at which diffuse necking occurs. - Abstract: In order to obtain the macroscopic mechanical response of a 316L stainless steel, nanocrystallised by Surface Mechanical Attrition Treatment (SMAT), a multilayer model is proposed. The constitutive behaviour of each layer is determined from tensile tests or by an inverse method and its thickness is evaluated from Scanning and Transmission Electron Microscopy (SEM and TEM) analyses and local hardness measurements. The consistency of the model is verified by its ability to predict the strain at which diffuse necking occurs.

  8. Failure Assessment of Stainless Steel and Titanium Brazed Joints

    Science.gov (United States)

    Flom, Yury A.

    2012-01-01

    Following successful application of Coulomb-Mohr and interaction equations for evaluation of safety margins in Albemet 162 brazed joints, two additional base metal/filler metal systems were investigated. Specimens consisting of stainless steel brazed with silver-base filler metal and titanium brazed with 1100 Al alloy were tested to failure under combined action of tensile, shear, bending and torsion loads. Finite Element Analysis (FEA), hand calculations and digital image comparison (DIC) techniques were used to estimate failure stresses and construct Failure Assessment Diagrams (FAD). This study confirms that interaction equation R(sub sigma) + R(sub tau) = 1, where R(sub sigma) and R(sub t u) are normal and shear stress ratios, can be used as conservative lower bound estimate of the failure criterion in stainless steel and titanium brazed joints.

  9. Magnetic properties of the austenitic stainless steels at cryogenic temperatures

    International Nuclear Information System (INIS)

    Kobayashi, T.; Tsuchiya, K.; Itoh, K.; Kobayashi, S.

    2002-01-01

    The magnetization was measured for the austenitic stainless steel of SUS304, SUS304L, SUS316, and SUS316L with the temperature from 5K to 300K and the magnetic field from 0T to 10T. The field dependences of the magnetizations changed at about 0.7T and 4T. The dependence was analyzed with ranges of 0-0.5T, 1-3T, and 5-10T. There was not so much difference between those stainless steels for the usage at small fields and 300 K. The SUS316 and SUS316L samples showed large non-linearity at high fields and 5K. Therefore, SUS304 was recommended for usage at high fields and low temperatures to design superconducting magnets with the linear approximation of the field dependence of magnetization

  10. Laser composite surfacing of stainless steel with SiC

    Science.gov (United States)

    Dutta Majumdar, J.; Chandra, B. Ramesh; Nath, A. K.; Manna, I.

    2006-07-01

    In the present study, an attempt has been made to improve wear resistance of AISI 304 stainless steel by laser composite surfacing with SiC. Laser processing has been carried out by pre-deposition of Fe + SiC powders (in the ratio of 85:15 and thickness of 100 m) on AISI 304 stainless steel substrate and subsequently, melting it using a 2 kW continuous wave CO2 laser. Following laser processing, a detailed characterization and evaluation of mechanical/electrochemical properties of the composite layer were undertaken to study the influence of laser processing on the characteristics and properties of the composite layer. Microstructure of the composite layer consisted of uniformly dispersed SiC particles in grain refined -Fe dendrites. Laser composite surfacing led to a significant improvement in microhardness and wear resistance as compared to as-received substrate. However, pitting corrosion property was marginally deteriorated due to laser composite surfacing.

  11. Finite Element Modelling of Cold Formed Stainless Steel Columns

    Directory of Open Access Journals (Sweden)

    M. Macdonald

    2005-01-01

    Full Text Available This paper describes the results obtained from a finite element investigation into the load capacity of column members of lipped channel cross-section, cold formed from Type 304 stainless steel, subjected to concentric and eccentric compression loading. The main aims of this investigation were to determine the effects which the non-linearity of the stress-strain behaviour of the material would have on the column behaviour under concentric or eccentric loading. Stress-strain curves derived from tests and design codes are incorporated into non-linear finite element analyses of eccentrically loaded columns and the results obtained are compared with those obtained on the basis of experiments on stainless steel channel columns with the same properties and dimensions. Comparisons of the finite element results and the test results are also made with existing design specifications and conclusions are drawn on the basis of the comparisons. 

  12. SCC-induced failure of a 304 stainless steel pipe

    International Nuclear Information System (INIS)

    Tapping, R.L.; Disney, D.J.; Szostak, F.J.

    1993-01-01

    On 1991 January 12, a 304 Stainless Steel (SS) suction line in the AECL-Research NRU reactor failed, shutting down the reactor for approximately 12 months. The pipe, a 32 mm schedule 40 304 stainless steel line exposed to D 2 O at temperatures ≤35 degrees C had been in service for approximately 20 years, although no manufacturing data or composition specifications were available. The failure and resultant leak resulted in a small loss of D 2 O moderator from the reactor vessel. The pipe cracked approximately 180 degrees C around the circumference of a weld. This failure was unexpected and hense a thorough metallographic examination was carried out on the failed section, on the rest of the line (Line 1212), and on representative samples from the rest of the reactor in order to assess the integrity of the remaining piping

  13. Investigation of Laser Peening Effects on Hydrogen Charged Stainless Steels

    Energy Technology Data Exchange (ETDEWEB)

    Zaleski, Tania M. [San Jose State Univ., CA (United States)

    2008-10-30

    Hydrogen-rich environments such as fuel cell reactors can exhibit damage caused by hydrogen permeation in the form of corrosion cracking by lowering tensile strength and decreasing material ductility. Coatings and liners have been investigated, but there were few shot-peening or laser peening studies referenced in the literature with respect to preventing hydrogen embrittlement. The surface compressive residual stress induced by laser peening had shown success in preventing stress corrosion cracking (SCC) for stainless steels in power plants. The question arose if the residual stresses induced by laser peening could delay the effects of hydrogen in a material. This study investigated the effect of laser peening on hydrogen penetration into metal alloys. Three areas were studied: laser peening, hydrogenation, and hydrogen detection. This study demonstrated that laser peening does not reduce the hydrogen permeation into a stainless steel surface nor does it prevent hydrogen embrittlement. The effect of laser peening to reduce hydrogen-assisted fatigue was unclear.

  14. High temperature damage of a re-sulfurized stainless steel

    International Nuclear Information System (INIS)

    Tinet, Hougo

    2002-01-01

    After having evoked the industrial problem raised by high-temperature damage in the 303 stainless steel, and outlined that the experimental study of high-temperature damage implies the study of the sane (or non damaged) material, the study of micro-voids germination, growth and coalescence, and the study of the material failure process, the author of this research thesis reports a bibliographical study on the behaviour of sane re-sulfurized stainless steel and different damage models. He presents experimental techniques (thermal-mechanical compression and tensile tests, image analysis in optical microscopy) which have been used in this work, and describes and comments results obtained on axisymmetric samples for micro-void germination, growth and coalescence in case of a damage under low and medium stress triaxiality. The last part addresses the study of the damage of strongly notched samples (stress triaxialities close to those existing at the crack bottom) [fr

  15. Electroless Plated Nanodiamond Coating for Stainless Steel Passivation

    Energy Technology Data Exchange (ETDEWEB)

    Li, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Korinko, P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Spencer, W. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Stein, E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-09-15

    Tritium gas sample bottles and manifold components require passivation surface treatments to minimize the interaction of the hydrogen isotopes with surface contamination on the stainless steel containment materials. This document summarizes the effort to evaluate electroless plated nanodiamond coatings as a passivation layer for stainless steel. In this work, we developed an electroless nanodiamond (ND)-copper (Cu) coating process to deposit ND on stainless steel parts with the diamond loadings of 0%, 25% and 50% v/v in a Cu matrix. The coated Conflat Flanged Vessel Assemblies (CFVAs) were evaluated on surface morphology, composition, ND distribution, residual hydrogen release, and surface reactivity with deuterium. For as-received Cu and ND-Cu coated CFVAs, hydrogen off-gassing is rapid, and the off-gas rates of H2 was one to two orders of magnitude higher than that for both untreated and electropolished stainless steel CFVAs, and hydrogen and deuterium reacted to form HD as well. These results indicated that residual H2 was entrapped in the Cu and ND-Cu coated CFVAs during the coating process, and moisture was adsorbed on the surface, and ND and/or Cu might facilitate catalytic isotope exchange reaction for HD formation. However, hydrocarbons (i.e., CH3) did not form, and did not appear to be an issue for the Cu and ND-Cu coated CFVAs. After vacuum heating, residual H2 and adsorbed H2O in the Cu and ND-Cu coated CFVAs were dramatically reduced. The H2 off-gassing rate after the vacuum treatment of Cu and 50% ND-Cu coated CFVAs was on the level of 10-14 l mbar/s cm2, while H2O off-gas rate was on the level of 10-15 l mbar/s cm2, consistent with the untreated or electropolished stainless steel CFVA, but the HD formation remained. The Restek EP bottle was used as a reference for this work. The Restek Electro-Polished (EP) bottle and their Sil

  16. Inhibition of Sodium Benzoate on Stainless Steel in Tropical Seawater

    International Nuclear Information System (INIS)

    Seoh, S. Y.; Senin, H. B.; Nik, W. N. Wan; Amin, M. M.

    2007-01-01

    The inhibition of sodium benzoate for stainless steel controlling corrosion was studied in seawater at room temperature. Three sets of sample have been immersed in seawater containing sodium benzoate with the concentrations of 0.3M, 0.6M and 1.0M respectively. One set of sample has been immersed in seawater without adding any sodium benzoate. It was found that the highest corrosion rate was observed for the stainless steel with no inhibitor was added to the seawater. As the concentration of sodium benzoate being increased, the corrosion rate is decreases. Results show that by the addition of 1.0M of sodium benzoate in seawater samples, it giving ≥ 90% efficiencies

  17. Evaluation of Cutting Fluids in Multiple Reaming of Stainless Steel

    DEFF Research Database (Denmark)

    Belluco, Walter; Zeng, Z.; De Chiffre, Leonardo

    2001-01-01

    An investigation on the effect of different cutting fluids in reaming is presented. The performance of three water based cutting fluids and one cutting oil was compared to that of a reference water based commercial product by measurement of cutting forces, surface roughness and part accuracy. Three...... subsequent reaming operations were carried out on austenitic stainless steel using high-speed-steel and solid carbide tools. The tested fluids were all significantly different from the reference fluid in at least some of the tested conditions. Significant differences down to 2 percent in cutting forces and 6...

  18. Cryogenic properties of austenitic stainless steels for superconducting magnet

    International Nuclear Information System (INIS)

    Nohara, K.; Kato, T.; Ono, Y.; Sasaki, T.; Suzuki, S.

    1983-01-01

    The present study examines the magnetic and mechanical properties of a variety of austenitic stainless steels and high maganese steel which are candidate materials for the superconducting magnet attached to high energy particle accelerators. The effect of a specified heat treatment for the precipitation of intermetallic compound Nb3Sn to be used as superconductor on ductility and toughness are especially examined. It is found that nitrogen-strengthened austenitic stainless steels have high strength and good ductility and toughness, but that these are destroyed by precipitation treatment. The poor ductility and toughness after precipitation are caused by a weakening of the grain boundaries due to the agglomerated chromium carbide percipitates. The addition of vanadium suppresses this effect by refining the grain. Austenitic steels are found to have low magnetic permeabilities and Neel temperatures, and show serrated flow in traction test due to strained martensitic transformation. High manganese steel has extremely low permeability, a Neel temperature about room temperature, and has a serrated flow in traction test due to adiabatic deformation at liquid helium temperature

  19. Surface nanocrystallization of stainless steel for reduced biofilm adherence

    Energy Technology Data Exchange (ETDEWEB)

    Yu Bin; Li, D Y [Department of Biomedical Engineering, University of Alberta, Edmonton, AB (Canada); Davis, Elisabeth M; Irvin, Randall T [Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB, T6G 2H7 (Canada); Hodges, Robert S [Department of Biochemistry and Molecular Genetics, University of Colorado Health Sciences Center at Fitzsimons, RC1 South Tower, Room 9121, PO Box 6511 MS 8101, Aurora, CO 80045 (United States)], E-mail: dongyang@ualberta.ca

    2008-08-20

    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.

  20. Attack polish for nickel-base alloys and stainless steels

    Science.gov (United States)

    Not Available

    1980-05-28

    A chemical attack polish and polishing procedure for use on metal surfaces such as nickel base alloys and stainless steels is described. The chemical attack polich comprises FeNO/sub 3/, concentrated CH/sub 3/COOH, concentrated H/sub 2/SO/sub 4/ and H/sub 2/O. The polishing procedure includes saturating a polishing cloth with the chemical attack polish and submicron abrasive particles and buffing the metal surface.

  1. Method of polishing nickel-base alloys and stainless steels

    Science.gov (United States)

    Steeves, Arthur F.; Buono, Donald P.

    1981-01-01

    A chemical attack polish and polishing procedure for use on metal surfaces such as nickel base alloys and stainless steels. The chemical attack polish comprises Fe(NO.sub.3).sub.3, concentrated CH.sub.3 COOH, concentrated H.sub.2 SO.sub.4 and H.sub.2 O. The polishing procedure includes saturating a polishing cloth with the chemical attack polish and submicron abrasive particles and buffing the metal surface.

  2. Martensite transformations influence in austenite stainless steel fractures

    International Nuclear Information System (INIS)

    Fonseca, H.; Monteiro, S.N.

    1976-07-01

    The influence of martensitic transformation on the fracture of tensile specimens of type AISI 310, and type 302, stainless steels was studied in the temperature interval from 25 0 C to -196 0 C. The influence of the metastability through the amount and rate of martensite transformation leading to high stresses and work hardening, apparently explains the brittle characteristics observed in the fracture of type 302 alloy as well as its ductile nature at -196 0 C [pt

  3. EXAFS investigation of low temperature nitrided stainless steel

    DEFF Research Database (Denmark)

    Oddershede, Jette; Christiansen, Thomas; Ståhl, Kenny

    2008-01-01

    contents: (1) nitriding in pure NH3 and (2)nitriding in pure NH3 followed by reduction in H2. The majority of the Cr atoms in the stainless steel after treatment 1 and 2 was associated with a nitrogen–chromium bond distance comparable to that of the chemical compound CrN. The possibility of the occurrence...... of mixed substitutional– interstitial atom clusters or coherent nitride platelets in nitrogen-expanded austenite is discussed....

  4. Versatility of superaustenitic stainless steels in marine applications

    International Nuclear Information System (INIS)

    Latha, G.; Rajeswari, S.

    1996-01-01

    Corrosion of construction materials in marine applications is a major problem. The frequent variations in chloride ion concentration and temperature experienced by a system pose a serious threat. This investigation evaluated the performance of superaustenitic stainless steels in marine applications by potentiodynamic anodic polarization studies. The concentrations of metal ions such as iron, chromium, and nickel at different impressed potentials were analyzed by inductively coupled plasma spectrometry, which revealed little tendency for leaching of metal ions

  5. Corrosion Testing of Stainless Steel Fuel Cell Hardware

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, M.S.; Zawodzinski, C.; Gottesfeld, S.

    1998-11-01

    Metal hardware is gaining increasing interest in polymer electrolyte fuel cell (PEFC) development as a possible alternative to machined graphite hardware because of its potential for low-cost manufacturing combined with its intrinsic high conductivity, minimal permeability and advantageous mechanical properties. A major barrier to more widespread use of metal hardware has been the susceptibility of various metals to corrosion. Few pure metals can withstand the relatively aggressive environment of a fuel cell and thus the choices for hardware are quite limited. Precious metals such as platinum or gold are prohibitively expensive and so tend to be utilized as coatings on inexpensive substrates such as aluminum or stainless steel. The main challenge with coatings has been to achieve pin-hole free surfaces that will remain so after years of use. Titanium has been used to some extent and though it is very corrosion-resistant, it is also relatively expensive and often still requires some manner of surface coating to prevent the formation of a poorly conducting oxide layer. In contrast, metal alloys may hold promise as potentially low-cost, corrosion-resistant materials for bipolar plates. The dozens of commercially available stainless steel and nickel based alloys have been specifically formulated to offer a particular advantage depending upon their application. In the case of austenitic stainless steels, for example, 316 SS contains molybdenum and a higher chromium content than its more common counterpart, 304 SS, that makes it more noble and increases its corrosion resistance. Likewise, 316L SS contains less carbon than 316 SS to make it easier to weld. A number of promising corrosion-resistant, highly noble alloys such as Hastelloy{trademark} or Duplex{trademark} (a stainless steel developed for seawater service) are available commercially, but are expensive and difficult to obtain in various forms (i.e. wire screen, foil, etc.) or in small amounts for R and D

  6. Internal frictions of austenitic stainless steels at low temperature

    Science.gov (United States)

    Tsubono, K.; Owa, S.; Mio, N.; Akasaka, N.; Hirakawa, H.

    Internal frictions were measured for three types of austenitic stainless steel, AISI 304, 310S and 316, in the temperature range 4-300 K. The intrinsic friction is presented in terms of the quality factor of a 20 kHz eigenmode vibration of discs made from each material. Temperature dependence is also given for the resonant frequency of each disc. These mechanical properties show some peculiarities at low temperature.

  7. Electrochemical reduction of hydrogen peroxide on stainless steel

    Indian Academy of Sciences (India)

    Administrator

    commercial 304 grade stainless steel (SS) foil. (thickness: 0⋅2 mm) was used as the substrate for. H2O2 reduction. A solution of 0⋅5 M NaClO4. (pH = 5⋅8) was .... oxide layers, unlike mediation of the reduction by. CuO present on Cu. A mechanism involving decomposition (or dis- proportionation) of H2O2 leading to the ...

  8. Corrosion Behavior of Austenitic and Duplex Stainless Steels in Lithium Bromide

    Directory of Open Access Journals (Sweden)

    Ayo Samuel AFOLABI

    2009-07-01

    Full Text Available The corrosion behavior of austenitic and duplex stainless steels in various concentrations of lithium, bromide solution was investigated by using the conventional weight loss measurement method. The results obtained show that corrosion of these steels occurred due to the aggressive bromide ion in the medium. Duplex stainless steel shows a greater resistance to corrosion than austenitic stainless steel in the medium. This was attributed to equal volume proportion of ferrite and austenite in the structure of duplex stainless steel coupled with higher content of chromium in its composition. Both steels produced electrochemical noise at increased concentrations of lithium bromide due to continuous film breakdown and repair caused by reduction in medium concentration by the alkaline corrosion product while surface passivity observed in duplex stainless steel is attributed to film stability on this steel.

  9. 77 FR 60673 - Drawn Stainless Steel Sinks From the People's Republic of China: Antidumping Duty Investigation

    Science.gov (United States)

    2012-10-04

    ... without drain boards, whether finished or unfinished, regardless of type of finish, gauge, or grade of... the stainless steel, and then welding and finishing the vertical corners to form the bowls. Stainless...

  10. Corrosion of austenitic and martensitic stainless steels in flowing 17Li-83Pb alloy

    International Nuclear Information System (INIS)

    Broc, M.; Flament, T.; Fauvet, P.; Sannier, J.

    1988-01-01

    With regard to the behaviour of 316 L stainless steel at 400 0 C in flowing anisothermal 17Li-83Pb the mass transfer suffered by this steel appears to be quite important without noticeable influence of constant or cyclic stress. Evaluation made from solution-annealed specimens leads to a corrosion rate of approximately 30 μm yr -1 at steady state to which a depth of 25 μm has to be added to take into account the initial period phenomena. On the other hand, with semi-stagnant 17Li-83Pb at 400 0 C, the mass transfer of 316 L steel appears to be lower and more acceptable after a 3000-h exposure; but long-time kinetics data have to be achieved in order to see if that better behaviour is persistent and does not correspond to a longer incubation period. As for the martensitic steels their corrosion rate at 450 0 C in the thermal convection loop TULIP is constant up to 3000 h and five times lower than that observed for 316 L steel in the same conditions. (orig.)

  11. 75 FR 81966 - Top of the Stove Stainless Steel Cooking Ware From the Republic of Korea: Final Results of Sunset...

    Science.gov (United States)

    2010-12-29

    ... Stainless Steel Cooking Ware From the Republic of Korea: Final Results of Sunset Reviews and Revocation of... reviews of the antidumping and countervailing duty orders on top of the stove stainless steel cooking ware... the stove stainless steel cooking ware from Korea includes all non-electric cooking ware of stainless...

  12. 78 FR 7395 - Stainless Steel Bar From India: Preliminary Results of Antidumping Duty Administrative Review...

    Science.gov (United States)

    2013-02-01

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-533-810] Stainless Steel Bar From... steel bar (SSB) from India. The period of review (POR) is February 1, 2011, through January 31, 2012... Preliminary Results of Antidumping Duty Administrative Review: Stainless Steel Bar from India'' dated...

  13. 78 FR 4383 - Stainless Steel Bar From Brazil: Preliminary Results of Antidumping Duty Administrative Review...

    Science.gov (United States)

    2013-01-22

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-351-825] Stainless Steel Bar From... steel bar (SSB) from Brazil. The period of review (POR) is February 1, 2011, through January 31, 2012... Review: Stainless Steel Bar from Brazil'' dated concurrently with this notice (``Preliminary Decision...

  14. Corrosion produced failures in valves made of micro-melted stainless steel. Valve disk

    International Nuclear Information System (INIS)

    Abuin, G.; Alanis, I.; Berardo, L.

    1991-01-01

    Cast stainless steels show different metallographic structure than equivalent laminated steels where the former presents good resistance in media containing chlorides. In the present work, an analysis is made of the causes for the fracture of an AISI 316 micro-melted stainless steel disk for a valve in a cleaning agents feeding circuit in a food processing plant. (Author) [es

  15. 78 FR 63517 - Control of Ferrite Content in Stainless Steel Weld Metal

    Science.gov (United States)

    2013-10-24

    ... steel welds, the original version of this guide, Safety Guide 31, ``Control of Stainless Steel Welding... NUCLEAR REGULATORY COMMISSION [NRC-2012-0231] Control of Ferrite Content in Stainless Steel Weld.... Nuclear Regulatory Commission (NRC) is issuing a revision to Regulatory Guide (RG) 1.31, ``Control of...

  16. Simulation of Friction Stir Processing in 304L Stainless Steel

    Directory of Open Access Journals (Sweden)

    Miles M.P.

    2016-01-01

    Full Text Available A major dilemma facing the nuclear industry is repair or replacement of stainless steel reactor components that have been exposed to neutron irradiation. When conventional fusion welding is used for weld repair, the high temperatures and thermal stresses inherent in the process enhance the growth of helium bubbles, causing intergranular cracking in the heat-affected zone (HAZ. Friction stir processing (FSP has potential as a weld repair technique for irradiated stainless steel, because it operates at much lower temperatures than fusion welding, and is therefore less likely to cause cracking in the HAZ. Numerical simulation of the FSP process in 304L stainless steel was performed using an Eulerian finite element approach. Model input required flow stresses for the large range of strain rates and temperatures inherent in the FSP process. Temperature predictions in three locations adjacent to the stir zone were accurate to within 4% of experimentally measure values. Prediction of recrystallized grain size at a location about 6mm behind the tool center was less accurate, because the empirical model employed for the prediction did not account for grain growth that occurred after deformation in the experiment was halted.

  17. Biomonitoring of genotoxic exposure among stainless steel welders

    DEFF Research Database (Denmark)

    Knudsen, Lisbeth E.; Boisen, T; Christensen, J M

    1992-01-01

    A biosurvey in the Danish metal industry measured the genotoxic exposure from stainless steel welding. The study comprised measurements of chromosomal aberrations (CA), sister-chromatid exchanges (SCE), unscheduled DNA synthesis (UDS) in peripheral lymphocytes and serum immunoglobulin G. Environm......A biosurvey in the Danish metal industry measured the genotoxic exposure from stainless steel welding. The study comprised measurements of chromosomal aberrations (CA), sister-chromatid exchanges (SCE), unscheduled DNA synthesis (UDS) in peripheral lymphocytes and serum immunoglobulin G....... Environmental monitoring of welding fumes and selected metal oxides, biomonitoring of chromium and nickel in serum and urine and mutagenic activity in urine, and evaluation of semen quality were also done. Manual metal arc (MMA) welding and tungsten inert gas (TIG) welding were the dominant welding processes...... lymphocytes in exposed persons compared with non-exposed are suggested. MMA welding gave the highest exposure to chromium, an increased number of chromosomal aberrations and a decrease in SCE when compared with TIG welding. Consequently improvements in the occupational practice of stainless steel welding...

  18. Stainless steel and polyethylene surfaces functionalized with silver nanoparticles.

    Science.gov (United States)

    Fialho, José Fq; Naves, Emiliane Aa; Bernardes, Patrícia C; Ferreira, Deusmaque C; Dos Anjos, Letícia D; Gelamo, Rogério V; de Sá, João Pn; de Andrade, Nélio J

    2018-01-01

    The antimicrobial effects of a stainless steel surface and a polyethylene surface functionalized with silver nanoparticles on the adhesion of different bacteria and the changes in physical and chemical characteristics of these surfaces that influence biofilm formation were evaluated. The functionalized surfaces of polyethylene and stainless steel were more hydrophobic than the control ones. The bacterial surfaces were hydrophilic. The adhesion of all bacteria was thermodynamically favorable (ΔG adhesion functionalized and control. The numbers of adhered cells of Staphylococcus aureus, Escherichia coli, and Pseudomonas fluorescens were not significantly different (p > 0.05) between the control and functionalized surfaces, reaching values compatible with biofilm formation. Analysis of atomic absorption spectrometry using water and reconstituted skim milk as simulants showed no release of Ag from the functionalized surfaces. In conclusion, the surfaces that were functionalized with silver nanoparticles were modified in hydrophobicity, roughness, and did not avoid bacterial adhesion. Additional studies of surfaces functionalized with silver nanoparticles should be conducted addressing the adsorption technique of silver nanoparticles on the stainless steel surface as well as in the preparation of the polyethylene surface to allow the contact of microorganism with the antimicrobial agent.

  19. Effect of dual torch technique on duplex stainless steel welds

    International Nuclear Information System (INIS)

    Sun, Z.; Kuo, M.; Annergren, I.; Pan, D.

    2003-01-01

    Duplex stainless steels are characterized by balanced ferrite/austenite microstructures and are well known for their superior corrosion resistance and higher strength compared with the common austenitic stainless steels. One major concern, however, is that welding might degrade the corrosion resistance by producing unbalanced phase content, detrimental precipitates, and possible embrittlement of the weldment. In this paper, a dual-torch arc welding technique (plasma torch followed by a gas tungsten arc (GTA) torch) was proposed. Effects of the dual-torch technique on the microstructural changes and corrosion properties were investigated. The preliminary study indicated that a correlation between the welding parameters and the microstructural changes and corrosion resistance existed. It was found that the corrosion rate increases with increasing torch pitch and/or decreasing GTA welding current. By adjusting the distance between the torches, modification of weld microstructure may be realized. Although further studies are required to fine-tune the technique, the present study demonstrated the potential of using dual torch technique to improve weldability of duplex stainless steels

  20. Mechanical Properties of Austenitic Stainless Steel Made by Additive Manufacturing

    Science.gov (United States)

    Luecke, William E; Slotwinski, John A

    2014-01-01

    Using uniaxial tensile and hardness testing, we evaluated the variability and anisotropy of the mechanical properties of an austenitic stainless steel, UNS S17400, manufactured by an additive process, selective laser melting. Like wrought materials, the mechanical properties depend on the orientation introduced by the processing. The recommended stress-relief heat treatment increases the tensile strength, reduces the yield strength, and decreases the extent of the discontinuous yielding. The mechanical properties, assessed by hardness, are very uniform across the build plate, but the stress-relief heat treatment introduced a small non-uniformity that had no correlation to position on the build plate. Analysis of the mechanical property behavior resulted in four conclusions. (1) The within-build and build-to-build tensile properties of the UNS S17400 stainless steel are less repeatable than mature engineering structural alloys, but similar to other structural alloys made by additive manufacturing. (2) The anisotropy of the mechanical properties of the UNS S17400 material of this study is larger than that of mature structural alloys, but is similar to other structural alloys made by additive manufacturing. (3) The tensile mechanical properties of the UNS S17400 material fabricated by selective laser melting are very different from those of wrought, heat-treated 17-4PH stainless steel. (4) The large discontinuous yielding strain in all tests resulted from the formation and propagation of Lüders bands. PMID:26601037

  1. Corrosion Performance of Stainless Steels in a Simulated Launch Environment

    Science.gov (United States)

    Calle, Luz Marina; Vinje, Rubiela D.; MacDowell, Louis

    2004-01-01

    At the Kennedy Space Center, NASA relies on stainless steel (SS) tubing to supply the gases and fluids required to launch the Space Shuttle. 300 series SS tubing has been used for decades but the highly corrosive environment at the launch pad has proven to be detrimental to these alloys. An upgrade with higher alloy content materials has become necessary in order to provide a safer and long lasting launch facility. In the effort to find the most suitable material to replace the existing AISI 304L SS ([iNS S30403) and AISI 316L SS (UNS S31603) shuttle tubing, a study involving atmospheric exposure at the corrosion test site near the launch pads and electrochemical measurements is being conducted. This paper presents the results of an investigation in which stainless steels of the 300 series, 304L, 316L, and AISI 317L SS (UNS S31703) as well as highly alloyed stainless steels 254-SMO (UNS S32154), AL-6XN (N08367) and AL29-4C ([iNS S44735) were evaluated using direct current (DC) electrochemical techniques under conditions designed to simulate those found at the Space Shuttle Launch pad. The electrochemical results were compared to the atmospheric exposure data and evaluated for their ability to predict the long-term corrosion performance of the alloys.

  2. Stress corrosion cracking evaluation of martensitic precipitation hardening stainless steels

    Science.gov (United States)

    Humphries, T. S.; Nelson, E. E.

    1980-01-01

    The resistance of the martensitic precipitation hardening stainless steels PH13-8Mo, 15-5PH, and 17-4PH to stress corrosion cracking was investigated. Round tensile and c-ring type specimens taken from several heats of the three alloys were stressed up to 100 percent of their yield strengths and exposed to alternate immersion in salt water, to salt spray, and to a seacoast environment. The results indicate that 15-5PH is highly resistant to stress corrosion cracking in conditions H1000 and H1050 and is moderately resistant in condition H900. The stress corrosion cracking resistance of PH13-8Mo and 17-4PH stainless steels in conditions H1000 and H1050 was sensitive to mill heats and ranged from low to high among the several heats included in the tests. Based on a comparison with data from seacoast environmental tests, it is apparent that alternate immersion in 3.5 percent salt water is not a suitable medium for accelerated stress corrosion testing of these pH stainless steels.

  3. The repair of preveneered posterior stainless steel crowns.

    Science.gov (United States)

    Yilmaz, Yucel; Gurbuz, Taskin; Eyuboglu, Ozge; Belduz, Nihal

    2008-01-01

    This study's purposes were to determine the shear bond strength (SBS) for and to perform dye penetration (microleakage) and scanning electron microscopy (SEM) evaluations of preveneered posterior stainless steel crowns (SSCs) that were repaired using 2 different materials. Twenty-two crowns were used. They were stored in artificial saliva for 30 days and then thermocycled. A force was applied on the crowns' occlusal surfaces until the original veneer material appeared to be fractured. The fracture types and S8S values were recorded. The crowns were then repaired using Panavia opaque cement and Tetric Flow or Monoopaque and Tetric Flow. Twenty of the repaired crowns were subjected to dye penetration and SBS tests, and the remaining 2 were evaluated using SEM. Statistical analysis revealed no statistically significant differences in the results of either the S8S or the dye penetration test (P = .58 and P = 38, respectively). A statistically significant difference was found between original and repaired crowns regarding fracture extent (P = .02), but not failure type (P = .08). SEM evaluation showed that there was no observable gap at the interface of the original or repaired materials and the stainless steel base. Preveneered posterior stainless steel crowns may be repaired using either repair material types tested here.

  4. Mechanical Properties of Austenitic Stainless Steel Made by Additive Manufacturing.

    Science.gov (United States)

    Luecke, William E; Slotwinski, John A

    2014-01-01

    Using uniaxial tensile and hardness testing, we evaluated the variability and anisotropy of the mechanical properties of an austenitic stainless steel, UNS S17400, manufactured by an additive process, selective laser melting. Like wrought materials, the mechanical properties depend on the orientation introduced by the processing. The recommended stress-relief heat treatment increases the tensile strength, reduces the yield strength, and decreases the extent of the discontinuous yielding. The mechanical properties, assessed by hardness, are very uniform across the build plate, but the stress-relief heat treatment introduced a small non-uniformity that had no correlation to position on the build plate. Analysis of the mechanical property behavior resulted in four conclusions. (1) The within-build and build-to-build tensile properties of the UNS S17400 stainless steel are less repeatable than mature engineering structural alloys, but similar to other structural alloys made by additive manufacturing. (2) The anisotropy of the mechanical properties of the UNS S17400 material of this study is larger than that of mature structural alloys, but is similar to other structural alloys made by additive manufacturing. (3) The tensile mechanical properties of the UNS S17400 material fabricated by selective laser melting are very different from those of wrought, heat-treated 17-4PH stainless steel. (4) The large discontinuous yielding strain in all tests resulted from the formation and propagation of Lüders bands.

  5. 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

  6. Photocatalytic activity of ferric oxide/titanium dioxide nanocomposite films on stainless steel fabricated by anodization and ion implantation

    Science.gov (United States)

    Zhan, Wei-ting; Ni, Hong-wei; Chen, Rong-sheng; Yue, Gao; Tai, Jun-kai; Wang, Zi-yang

    2013-08-01

    A simple surface treatment was used to develop photocatalytic activity for stainless steel. AISI 304 stainless steel specimens after anodization were implanted by Ti ions at an extracting voltage of 50 kV with an implantation dose of 3 × 1015 atoms·cm-2 and then annealed in air at 450°C for 2 h. The morphology was observed by scanning electron microscopy. The microstructure was characterized by X-ray diffraction and X-ray photoelectron spectroscopy. The photocatalytic degradation of methylene blue solution was carried out under ultraviolet light. The corrosion resistance of the stainless steel was evaluated in NaCl solution (3.5 wt%) by electrochemical polarization curves. It is found that the Ti ions depth profile resembles a Gaussian distribution in the implanted layer. The nanostructured Fe2O3/TiO2 composite film exhibits a remarkable enhancement in photocatalytic activity referenced to the mechanically polished specimen and anodized specimen. Meanwhile, the annealed Ti-implanted specimen remains good corrosion resistance.

  7. EFFECT OF INTERMETALLIC PHASES ON CORROSION BEHAVIOR AND MECHANICAL PROPERTIES OF DUPLEX STAINLESS STEEL AND SUPER-DUPLEX STAINLESS STEEL

    Directory of Open Access Journals (Sweden)

    Prabhu Paulraj

    2015-08-01

    Full Text Available Duplex Stainless Steels (DSS and Super Duplex Stainless Steel (SDSS have excellent integration of mechanical and corrosion properties. However, the formation of intermetallic phases is a major problem in their usage. The mechanical and corrosion properties are deteriorated due to the presence of intermetallic phases. These phases are induced during welding, prolonged exposure to high temperatures, and improper heat treatments. The main emphasis of this review article is on intermetallic phases and their effects on corrosion and mechanical properties. First the effect of various alloying elements on DSS and SDSS has been discussed followed by formation of various intermetallic phases. The intermetallic phases affect impact toughness and corrosion resistance significantly. Their deleterious effect on weldments has also been reviewed.

  8. Blast and Fragment Protective Sandwich Panel Concepts for Stainless Steel Monohull Designs

    Science.gov (United States)

    2008-10-21

    and Johnson-Cook parameters for AISI 304 stainless steel used in the numerical analyses. 3. Experimental results 3.1. Honeycomb panels. 3.1.1...20Cr-2Mn-lSi (wt%). The material proper- ties for AISI 304 stainless steel are reported in Table 2. A slotted metal sheet assembly approach was used...Figure 3. AISI 304 stainless steel panel with square honeycomb core, (a) Solid-ring spacers were employed to prevent core crushing while fastening the

  9. Corrosion And Thermal Processing In Cold Gas Dynamic Spray Deposited Austenitic Stainless Steel Coatings

    Science.gov (United States)

    2016-06-01

    testing (ASTM G5) of low pressure cold spray austenitic stainless steel coatings. Several different powders and heat treatments will be applied to...diffusion eliminating the local low chromium region. The low carbon type stainless steel alloys as used here are generally considered to be...maximum 200words) This thesis presents research on the corrosion properties and effects of heat treatment on austenitic stainless steel coatings

  10. Particle Impact Ignition Test Data on a Stainless Steel Hand Valve

    Science.gov (United States)

    Peralta, Stephen

    2010-01-01

    This slide presentation reviews the particle impact ignition test of a stainless steel hand valve. The impact of particles is a real fire hazard with stainless steel hand valves, however 100 mg of particulate can be tolerated. Since it is unlikely that 100 mg of stainless steel contaminant particles can be simultaneously released into this type of valve in the WSTF configuration, this is acceptable and within statistical confidence as demonstrated by testing.

  11. Impact of the nanostructuration on the corrosion resistance and hardness of irradiated 316 austenitic stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    Hug, E., E-mail: eric.hug@ensicaen.fr [Laboratoire de Cristallographie et Sciences des Matériaux, Normandie Université, CNRS UMR 6508, 6 Bd Maréchal Juin, 14050 Caen (France); Prasath Babu, R. [School of Materials, University of Manchester, M13 9PL (United Kingdom); Groupe de Physique des Matériaux, UMR CNRS 6634, Université et INSA de Rouen, Normandie Université, Saint-Etienne du Rouvray Cedex (France); Monnet, I. [Centre de recherches sur les Ions, les Matériaux et la Photonique CEA-CNRS, Normandie Université, 6 Bd Maréchal Juin, 14050 Caen (France); Etienne, A. [Groupe de Physique des Matériaux, UMR CNRS 6634, Université et INSA de Rouen, Normandie Université, Saint-Etienne du Rouvray Cedex (France); Moisy, F. [Centre de recherches sur les Ions, les Matériaux et la Photonique CEA-CNRS, Normandie Université, 6 Bd Maréchal Juin, 14050 Caen (France); Pralong, V. [Laboratoire de Cristallographie et Sciences des Matériaux, Normandie Université, CNRS UMR 6508, 6 Bd Maréchal Juin, 14050 Caen (France); Enikeev, N. [Institute of Physics of Advanced Materials, Ufa (Russian Federation); Saint Petersburg State University, Laboratory of the Mechanics of Bulk Nanostructured Materials, 198504 St. Petersburg (Russian Federation); Abramova, M. [Institute of Physics of Advanced Materials, Ufa (Russian Federation); and others

    2017-01-15

    Highlights: • Impacts of nanostructuration and irradiation on the properties of 316 stainless steels are reported. • Irradiation of nanostructured samples implies chromium depletion as than depicted in coarse grain specimens. • Hardness of nanocrystalline steels is only weakly affected by irradiation. • Corrosion resistance of the nanostructured and irradiated samples is less affected by the chromium depletion. - Abstract: The influence of grain size and irradiation defects on the mechanical behavior and the corrosion resistance of a 316 stainless steel have been investigated. Nanostructured samples were obtained by severe plastic deformation using high pressure torsion. Both coarse grain and nanostructured samples were irradiated with 10 MeV {sup 56}Fe{sup 5+} ions. Microstructures were characterized using transmission electron microscopy and atom probe tomography. Surface mechanical properties were evaluated thanks to hardness measurements and the corrosion resistance was studied in chloride environment. Nanostructuration by high pressure torsion followed by annealing leads to enrichment in chromium at grain boundaries. However, irradiation of nanostructured samples implies a chromium depletion of the same order than depicted in coarse grain specimens but without metallurgical damage like segregated dislocation loops or clusters. Potentiodynamic polarization tests highlight a definitive deterioration of the corrosion resistance of coarse grain steel with irradiation. Downsizing the grain to a few hundred of nanometers enhances the corrosion resistance of irradiated samples, despite the fact that the hardness of nanocrystalline austenitic steel is only weakly affected by irradiation. These new experimental results are discussed in the basis of couplings between mechanical and electrical properties of the passivated layer thanks to impedance spectroscopy measurements, hardness properties of the surfaces and local microstructure evolutions.

  12. Controlling radiation induced segregation in austenitic stainless steels

    International Nuclear Information System (INIS)

    Ahmedabadi, Parag M.; Kain, Vivekanand

    2011-01-01

    In-core components of austenitic stainless steels in light water reactors (LWRs) are susceptible to irradiation assisted stress corrosion cracking (IASCC) in high temperature and high pressure oxygenated water at temperature around 300 deg C . Though, the exact mechanism for IASCC is not fully understood, radiation-induced segregation (RIS) is considered to be a part of a complex process that leads to IASCC. Therefore, controlling RIS in austenitic stainless steels may lead to improvement in resistance to IASCC. RIS is non-equilibrium segregation/depletion of alloying elements in austenitic stainless steels at LWR operating temperatures. RIS occurs due to adsorption of point defects at grain boundaries and leads to segregation of Si and P and depletion of Cr at grain boundaries. Thus by controlling point defect flux towards grain boundaries, the extent of RIS at grain boundaries can be controlled. An extensive study was carried out to simulate and control RIS in austenitic stainless steels using proton irradiation at 300 deg C . The primary aim of this study was to reduce point defect flux towards grain boundaries. Various approaches viz. grain boundary engineering, addition of oversized alloying element, residual strain within matrix and presence of fine precipitates within the grains and at grain boundaries were employed to control RIS in austenitic stainless steels. A novel approach involving combination of electrochemical technique followed by atomic force microscopic (AFM) examination has been used to examine the nature and the extent of RIS. Type 304, 316 and 347 stainless steels were irradiated at 300 deg C (in FOTIA and PELLETRON) in the range of 0.2 to 1.0 dpa using proton beam. The results obtained so far have indicated that a small amount of pre-strain within the grains is very effective in reducing the flux of point defects towards grain boundaries and reducing the extent of RIS at grain boundaries. The presence of NbC precipitates within the grains is

  13. Electrochemical and passivation behavior investigation of ferritic stainless steel in simulated concrete pore media.

    Science.gov (United States)

    Luo, Hong; Su, Huaizhi; Dong, Chaofang; Xiao, Kui; Li, Xiaogang

    2015-12-01

    The applications of stainless steel are one of the most reliable solutions in concrete structures to reduce chloride-induced corrosion problems and increase the structures service life, however, due to high prices of nickel, especially in many civil engineering projects, the austenitic stainless steel is replaced by the ferritic stainless steels. Compared with austenite stainless steel, the ferritic stainless steel is known to be extremely resistant of stress corrosion cracking and other properties. The good corrosion resistance of the stainless steel is due to the formation of passive film. While, there is little literature about the electrochemical and passive behavior of ferritic stainless steel in the concrete environments. So, here, we present the several corrosion testing methods, such as the potentiodynamic measurements, EIS and Mott-Schottky approach, and the surface analysis methods like XPS and AES to display the passivation behavior of 430 ferritic stainless steel in alkaline solution with the presence of chloride ions. These research results illustrated a simple and facile approach for studying the electrochemical and passivation behavior of stainless steel in the concrete pore environments.

  14. Effects of Thermal Aging on Type 316H Stainless Steel for Reactor Vessel

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Ji Hyun; Hong, Seok Min; Lee, Bong Sang; Koo, Gyeong Hoi [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    Type 316H stainless steel is a prime candidate for reactor vessel material of sodium-cooled fast reactor (SFR) which has been developed as one of the Gen IV nuclear reactors in Korea. The reactor vessel steel will be exposed to higher temperature for an extended design life time. It is known that austenitic stainless steel such as Type 316H stainless steel shows excellent toughness and adequate strength at a moderate temperature. However, the previous researches reported the mechanical properties of Type 316H stainless weld would be deteriorated by the aging at the elevated temperature range.

  15. Corrosion study of stainless steels in a dissolver off-gas environment

    International Nuclear Information System (INIS)

    Suzuki, K.; Tsukaue, Y.; Yoshida, K.; Hirose, Y.

    1991-01-01

    Iodine induced corrosion characteristics of stainless steels have been studied under various case of simulated dissolver off-gas environment. No corrosion of any kind of stainless steel so far tested was observed under typical dissolver off-gas environment, containing HNO 3 and NOx as well as I 2 . Pitting corrosion was observed, however, in humid air containing I 2 but no HNO 3 nor NOx, depending upon I 2 concentration on certain types of stainless steel. The higher content of Mo in stainless steels, the less depth of pitting was measured. A mechanism based on iodine concentration in water film on metal surface, was proposed to explain above phenomena. (author)

  16. NDE of explosion welded copper stainless steel first wall mock-up

    International Nuclear Information System (INIS)

    Taehtinen, S.; Kauppinen, P.; Jeskanen, H.; Lahdenperae, K.; Ehrnsten, U.

    1997-04-01

    The study showed that reflection type C-mode scanning acoustic microscope (C-SAM) and internal ultrasonic inspection (IRIS) equipment can be applied for ultrasonic examination of copper stainless steel compound structures of ITER first wall mock-ups. Explosive welding can be applied to manufacture fully bonded copper stainless steel compound plates. However, explosives can be applied only for mechanical tightening of stainless steel cooling tubes within copper plate. If metallurgical bonding between stainless steel tubes and copper plate is required Hot Isostatic Pressing (HIP) method can be applied. (orig.)

  17. HIP bonding for the different material between Niobium and Stainless steel

    International Nuclear Information System (INIS)

    Inoue, H.; Saito, K.; Abe, K.; Fujino, T.; Hitomi, N.; Kobayashi, Y.

    2000-01-01

    In the future advanced cryomodule for superconducting RF cavities, a helium vessel made from titanium or stainless steel has to be welded directly to the niobium cavity wall in order to be simple structure. For that, we need a transformer from niobium to titanium or stainless steel. Stainless steel will have many benefits if the reliable bonding to the niobium is developed. We have tested the niobium/stainless steel bonding by HIP (Hot Isostatic Pressing) with the heat shock between 1023K and 2K. The bonding interface was also observed by SEM. These test results will be presented. (author)

  18. Austenitic stainless steel-to-ferritic steel transition joint welding for elevated temperature service

    International Nuclear Information System (INIS)

    King, J.F.; Goodwin, G.M.; Slaughter, G.M.

    1978-01-01

    Transition weld joints between ferritic steels and austenitic stainless steels are required for fossil-fired power plants and proposed nuclear plants. The experience with these dissimilar-metal transition joints has been generally satisfactory, but an increasing number of failures of these joints is occurring prematurely in service. These concerns with transition joint service history prompted a program to develop more reliable joints for application in proposed nuclear power plants

  19. Quick corrosion cracking test methods for high strength stainless steels

    International Nuclear Information System (INIS)

    Gurnich, L.Ya.; Shubadeeva, L.I.; Erofeeva, V.L.; Lashchevskij, V.B.

    1994-01-01

    Quicks method for testing high strength stainless steels during 10h under atmospheric and sea conditions has been developed. It is shown that (NH 4 ) 2 Se 2 O 8 - 13.5+-1 g/l, NaCl - 40+-2g/l, H 2 SO 4 -5g/l solution at 50+-2 C temperature is recommended for quick tests for tendency to corrosion cracking during. Development of steels and technologies of their treatment. Tests of steels of 08Kh15N5D2T, 07Kh16N6, 20Kh13, 40Kh13, 13Kh15N4AMD and other types can be performed in boiling solutions: H 2 SO 4 (55 ml/l)+CuSO 4 (110 g/l) or MgCl 2 (200 g/l hexahydrate)

  20. Additively manufactured hierarchical stainless steels with high strength and ductility

    Science.gov (United States)

    Wang, Y. Morris; Voisin, Thomas; McKeown, Joseph T.; Ye, Jianchao; Calta, Nicholas P.; Li, Zan; Zeng, Zhi; Zhang, Yin; Chen, Wen; Roehling, Tien Tran; Ott, Ryan T.; Santala, Melissa K.; Depond, Philip J.; Matthews, Manyalibo J.; Hamza, Alex V.; Zhu, Ting

    2018-01-01

    Many traditional approaches for strengthening steels typically come at the expense of useful ductility, a dilemma known as strength-ductility trade-off. New metallurgical processing might offer the possibility of overcoming this. Here we report that austenitic 316L stainless steels additively manufactured via a laser powder-bed-fusion technique exhibit a combination of yield strength and tensile ductility that surpasses that of conventional 316L steels. High strength is attributed to solidification-enabled cellular structures, low-angle grain boundaries, and dislocations formed during manufacturing, while high uniform elongation correlates to a steady and progressive work-hardening mechanism regulated by a hierarchically heterogeneous microstructure, with length scales spanning nearly six orders of magnitude. In addition, solute segregation along cellular walls and low-angle grain boundaries can enhance dislocation pinning and promote twinning. This work demonstrates the potential of additive manufacturing to create alloys with unique microstructures and high performance for structural applications.

  1. Effect of sodium environment on the creep-rupture and low-cycle fatigue behavior of austenitic stainless steels

    International Nuclear Information System (INIS)

    Natesan, K.; Chopra, D.K.; Zeman, G.J.; Smith, D.L.; Kassner, T.F.

    1977-01-01

    Austenitic stainless steels used for in-core structural components, piping, valves, and the intermediate heat exchanger in Liquid-Metal Fast-Breeder Reactors (LMFBRs) are subjected to sodium at elevated temperatures and to complex stress conditions. As a result, the materials can undergo compositional and microstructural changes as well as mechanical deformation by creep and cyclic fatigue processes. In the present paper, information is presented on the creep-rupture and low-cycle fatigue behavior of Types 304 and 316 stainless steel in the solution-annealed condition and after long-term exposure to flowing sodium. The nonmetallic impurity-element concentrations in the sodium were controlled at levels similar to those in EBR-II primary sodium. Strain-time relationships developed from the experimental creep data were used to generate isochronous stress-creep strain curves as functions of sodium-exposure time and temperature. The low-cycle fatigue data were used to obtain relationships between plastic strain range and cycles-to-failure based on the Coffin-Manson formalism and a damage-rate approach developed at ANL. An analysis of the cyclic stress-strain behavior of the materials showed that the strain-hardening rates for the sodium-exposed steels were larger than those for the annealed material. However, the sodium-exposed specimens showed significant softening, as evidenced by the lower stress at half the fatigue life. Microstructural information obtained from the different specimens suggests that crack initiation is more difficult in the long-term sodium-exposed specimens when compared with the solution-annealed material. Based on the expected carbon concentrations in LMFBR primary system sodium, moderate carburization of the austenitic stainless steels will not degrade the mechanical properties to a significant extent, and therefore, will not limit the performance of out-of-core components. (author)

  2. Arc brazing of austenitic stainless steel to similar and dissimilar metals

    Science.gov (United States)

    Moschini, Jamie Ian

    There is a desire within both the stainless steel and automotive industries to introduce stainless steel into safety critical areas such as the crumple zone of modem cars as a replacement for low carbon mild steel. The two main reasons for this are stainless steel's corrosion resistance and its higher strength compared with mild steel. It has been anticipated that the easiest way to introduce stainless steel into the automotive industry would be to incorporate it into the existing design. The main obstacle to be overcome before this can take place is therefore how to join the stainless steel to the rest of the car body. In recent times arc brazil g has been suggested as a joining technique which will eliminate many of the problems associated with fusion welding of zinc coated mild steel to stainless steel.Similar and dissimilar parent material arc brazed joints were manufactured using three copper based filler materials and three shielding gases. The joints were tested in terms of tensile strength, impact toughness and fatigue properties. It was found that similar parent material stainless steel joints could be produced with a 0.2% proof stress in excess of the parent material and associated problems such as Liquid Metal Embrittlement were not experienced. Dissimilar parent material joints were manufactured with an ultimate tensile strength in excess of that of mild steel although during fatigue testing evidence of Liquid Metal Embrittlement was seen lowering the mean fatigue load.At the interface of the braze and stainless steel in the similar material butt joints manufactured using short circuit transfer, copper appeared to penetrate the grain boundaries of the stainless steel without embrittling the parent material. Further microscopic investigation of the interface showed that the penetration could be described by the model proposed by Mullins. However, when dissimilar metal butt joints were manufactured using spray arc transfer, penetration of copper into the

  3. Synergistic Computational and Microstructural Design of Next- Generation High-Temperature Austenitic Stainless Steels

    Energy Technology Data Exchange (ETDEWEB)

    Karaman, Ibrahim [Texas A& M Engineering Experiment Station, College Station, TX (United States); Arroyave, Raymundo [Texas A& M Engineering Experiment Station, College Station, TX (United States)

    2015-07-31

    The purpose of this project was to: 1) study deformation twinning, its evolution, thermal stability, and the contribution on mechanical response of the new advanced stainless steels, especially at elevated temperatures; 2) study alumina-scale formation on the surface, as an alternative for conventional chromium oxide, that shows better oxidation resistance, through alloy design; and 3) design new generation of high temperature stainless steels that form alumina scale and have thermally stable nano-twins. The work involved few baseline alloys for investigating the twin formation under tensile loading, thermal stability of these twins, and the role of deformation twins on the mechanical response of the alloys. These baseline alloys included Hadfield Steel (Fe-13Mn-1C), 316, 316L and 316N stainless steels. Another baseline alloy was studied for alumina-scale formation investigations. Hadfield steel showed twinning but undesired second phases formed at higher temperatures. 316N stainless steel did not show signs of deformation twinning. Conventional 316 stainless steel demonstrated extensive deformation twinning at room temperature. Investigations on this alloy, both in single crystalline and polycrystalline forms, showed that deformation twins evolve in a hierarchical manner, consisting of micron–sized bundles of nano-twins. The width of nano-twins stays almost constant as the extent of strain increases, but the width and number of the bundles increase with increasing strain. A systematic thermomechanical cycling study showed that the twins were stable at temperatures as high as 900°C, after the dislocations are annealed out. Using such cycles, volume fraction of the thermally stable deformation twins were increased up to 40% in 316 stainless steel. Using computational thermodynamics and kinetics calculations, we designed two generations of advanced austenitic stainless steels. In the first generation, Alloy 1, which had been proposed as an alumina

  4. Characterisation of microstructure and its effect on the strength and toughness of 17-4PH stainless steel

    DEFF Research Database (Denmark)

    Das, C. R.; Bhaduri, A. K.; Albert, S. K.

    2009-01-01

    The influence of microstructure on the strength and toughness of 17-4 Precipitation-Hardened (PH) Stainless Steel (SS) was studied as a function of duration of ageing at 783 K. Lath martensite is formed in this steel in its solution-annealed condition. X-ray diffraction studies detected the forma......The influence of microstructure on the strength and toughness of 17-4 Precipitation-Hardened (PH) Stainless Steel (SS) was studied as a function of duration of ageing at 783 K. Lath martensite is formed in this steel in its solution-annealed condition. X-ray diffraction studies detected...... copper-rich body centred cubic (b.c.c.) phase to the incoherent copper rich face centred cubic (f.c.c.) phase. Further ageing for 4 h led to a dip in hardness and strength and an increase in toughness. The dip in hardness upon long-term ageing could be attributed to the formation of coarse copper......-rich precipitates, which also led to an improvement in the toughness of the material. Copyright © 2009, Inderscience Publishers....

  5. Joining dissimilar stainless steels for pressure vessel components

    International Nuclear Information System (INIS)

    Zheng Sun; Huai-Yue Han

    1994-01-01

    A series of studies was carried out to examine the weldability and properties of dissimilar steel joints between martensitic and austenitic stainless steels - F6NM (OCrl3Ni4Mo) and AISI 347, respectively. The weldability tests included weld thermal simulation of the martensitic steel for investigating the influence of weld thermal cycles and post-weld heat treatment (PWHT) on the mechanical properties of the heat-affected zone (HAZ); implant testing for examining the tendency for cold cracking of martensitic steel; rigid restraint testing for determining hot crack susceptibility of the multi-pass dissimilar steel joints. The joints were subjected to various mechanical tests including a tensile test, bending test and impact test at various temperatures, as well as slow strain-rate test for examining the stress corrosion cracking tendency in the simulated environment of a primary circuit of a PWR. Based on the weldability tests, a welding procedure - tungsten inert gas (TIG) welding for root passes with HNiCrMo-2B wire followed by manual metal arc (MMA) welding using coated electrode ENiCrFe-3B - was developed and a PWHT at 600 deg C/2h was recommended. Furthermore, the welding of tube/tube joints between these dissimilar steels is described. (21 refs., 11 figs., 14 tabs.)

  6. Physical characterization of steel and stainless steel metal powders

    International Nuclear Information System (INIS)

    Lavilla, A.O.; Lucchesi, C.G.; Sandin, O.O.

    1991-01-01

    A methodology has been developed for the physical characterization of steel powders (obtained by atomization) for later sintering and for the construction of porous sheets and filtrating tubes, capable of operating at temperatures between 600 deg C and 800 deg C in corrosive atmospheres. This methodology was based on the equipment and methods used for the physical characterization of uranium oxide powders. (Author) [es

  7. Microstructure and Mechanical Properties of 21-6-9 Stainless Steel Electron Beam Welds

    Science.gov (United States)

    Elmer, John W.; Ellsworth, G. Fred; Florando, Jeffrey N.; Golosker, Ilya V.; Mulay, Rupalee P.

    2017-04-01

    Welds can either be stronger or weaker than the base metals that they join depending on the microstructures that form in the fusion and heat-affected zones of the weld. In this paper, weld strengthening in the fusion zone of annealed 21-6-9 stainless steel is investigated using cross-weld tensile samples, hardness testing, and microstructural characterization. Due to the stronger nature of the weld, the cross-weld tensile tests failed in the base metal and were not able to generate true fusion zone mechanical properties. Nanoindentation with a spherical indenter was instead used to predict the tensile behavior for the weld metal. Extrapolation of the nanoindentation results to higher strains was performed using the Steinberg-Guinan and Johnson-Cook strength models, and the results can be used for weld strength modeling purposes. The results illustrate how microstructural refinement and residual ferrite formation in the weld fusion zone can be an effective strengthener for 21-6-9 stainless steel.

  8. Evaluation of radiation-induced sensitization using electrochemical potentiokinetic reactivation technique for austenitic stainless steels

    International Nuclear Information System (INIS)

    Inazumi, T.; Bell, G.E.C.; Hishinuma, A.

    1990-01-01

    The electrochemical potentiokinetic reactivation (EPR) test technique was applied to the determination of sensitization in a neutron-irradiated (420 degree C, 10 dpa) titanium-modified austenitic stainless steel. Miniaturized specimens (3 mm diam by 0.25 mm thick) in solution-annealed and 25% cold-worked conditions were tested. The degree of sensitization (DOS) was calculated in terms of the reactivation charge (Pa). Results indicated the occurrence of radiation-induced sensitization when compared to control specimens thermally aged at the irradiation temperature. Post-EPR examination of the specimen surfaces showed etching across the face of each grain as well as at grain boundaries. This indicates that the Pa value normalized by the total grain boundary area, which is an accepted EPR-DOS criterion, cannot be directly used as an indicator of the DOS to determine the susceptibility of this irradiated material to intergranular stress corrosion cracking (IGSCC). Further investigations are necessary to correlate the results in this study to the IGSCC susceptibility of the irradiated stainless steel. 26 refs., 7 figs., 3 tabs

  9. 78 FR 21596 - Drawn Stainless Steel Sinks From the People's Republic of China: Countervailing Duty Order

    Science.gov (United States)

    2013-04-11

    ... single or multiple drawn bowls, with or without drain boards, whether finished or unfinished, regardless... steel, and then welding and finishing the vertical corners to form the bowls. Stainless steel sinks with...

  10. 75 FR 973 - Certain Welded Stainless Steel Pipes From the Republic of Korea: Preliminary Results of...

    Science.gov (United States)

    2010-01-07

    ... and transport lines, general food processing lines, automotive paint lines, and paper process machines... purchased hot-rolled stainless steel coil from a Korean affiliate, Pohang Iron and Steel Company (POSCO...

  11. In situ 3D monitoring of corrosion on carbon steel and ferritic stainless steel embedded in cement paste

    KAUST Repository

    Itty, Pierre-Adrien

    2014-06-01

    In a X-ray microcomputed tomography study, active corrosion was induced by galvanostatically corroding steel embedded in cement paste. The results give insight into corrosion product build up, crack formation, leaching of products into the cracks and voids, and differences in morphology of corrosion attack in the case of carbon steel or stainless steel reinforcement. Carbon steel was homogeneously etched away with a homogeneous layer of corrosion products forming at the steel/cement paste interface. For ferritic stainless steel, pits were forming, concentrating the corrosion products locally, which led to more extensive damage on the cement paste cover. © 2014 Elsevier Ltd.

  12. Stoichiometric titanium dioxide ion implantation in AISI 304 stainless steel for corrosion protection

    Science.gov (United States)

    Hartwig, A.; Decker, M.; Klein, O.; Karl, H.

    2015-12-01

    The aim of this study is to evaluate the applicability of highly chemically inert titanium dioxide synthesized by ion beam implantation for corrosion protection of AISI 304 stainless steel in sodium chloride solution. More specifically, the prevention of galvanic corrosion between carbon-fiber reinforced plastic (CFRP) and AISI 304 was investigated. Corrosion performance of TiO2 implanted AISI 304 - examined for different implantation and annealing parameters - is strongly influenced by implantation fluence. Experimental results show that a fluence of 5 × 1016 cm-2 (Ti+) and 1 × 1017 cm-2 (O+) is sufficient to prevent pitting corrosion significantly, while galvanic corrosion with CFRP can already be noticeably reduced by an implantation fluence of 5 × 1015 cm-2 (Ti+) and 1 × 1016 cm-2 (O+). Surface roughness, implantation energy and annealing at 200 °C and 400 °C show only little influence on the corrosion behavior. TEM analysis indicates the existence of stoichiometric TiO2 inside the steel matrix for medium fluences and the formation of a separated metal oxide layer for high fluences.

  13. Stoichiometric titanium dioxide ion implantation in AISI 304 stainless steel for corrosion protection

    International Nuclear Information System (INIS)

    Hartwig, A.; Decker, M.; Klein, O.; Karl, H.

    2015-01-01

    The aim of this study is to evaluate the applicability of highly chemically inert titanium dioxide synthesized by ion beam implantation for corrosion protection of AISI 304 stainless steel in sodium chloride solution. More specifically, the prevention of galvanic corrosion between carbon-fiber reinforced plastic (CFRP) and AISI 304 was investigated. Corrosion performance of TiO 2 implanted AISI 304 – examined for different implantation and annealing parameters – is strongly influenced by implantation fluence. Experimental results show that a fluence of 5 × 10 16 cm −2 (Ti + ) and 1 × 10 17 cm −2 (O + ) is sufficient to prevent pitting corrosion significantly, while galvanic corrosion with CFRP can already be noticeably reduced by an implantation fluence of 5 × 10 15 cm −2 (Ti + ) and 1 × 10 16 cm −2 (O + ). Surface roughness, implantation energy and annealing at 200 °C and 400 °C show only little influence on the corrosion behavior. TEM analysis indicates the existence of stoichiometric TiO 2 inside the steel matrix for medium fluences and the formation of a separated metal oxide layer for high fluences.

  14. Stoichiometric titanium dioxide ion implantation in AISI 304 stainless steel for corrosion protection

    Energy Technology Data Exchange (ETDEWEB)

    Hartwig, A.; Decker, M.; Klein, O.; Karl, H., E-mail: helmut.karl@physik.uni-augsburg.de

    2015-12-15

    The aim of this study is to evaluate the applicability of highly chemically inert titanium dioxide synthesized by ion beam implantation for corrosion protection of AISI 304 stainless steel in sodium chloride solution. More specifically, the prevention of galvanic corrosion between carbon-fiber reinforced plastic (CFRP) and AISI 304 was investigated. Corrosion performance of TiO{sub 2} implanted AISI 304 – examined for different implantation and annealing parameters – is strongly influenced by implantation fluence. Experimental results show that a fluence of 5 × 10{sup 16} cm{sup −2} (Ti{sup +}) and 1 × 10{sup 17} cm{sup −2} (O{sup +}) is sufficient to prevent pitting corrosion significantly, while galvanic corrosion with CFRP can already be noticeably reduced by an implantation fluence of 5 × 10{sup 15} cm{sup −2} (Ti{sup +}) and 1 × 10{sup 16} cm{sup −2} (O{sup +}). Surface roughness, implantation energy and annealing at 200 °C and 400 °C show only little influence on the corrosion behavior. TEM analysis indicates the existence of stoichiometric TiO{sub 2} inside the steel matrix for medium fluences and the formation of a separated metal oxide layer for high fluences.

  15. Neutron fluence effect on the IASCC susceptibility of AISI 304 stainless steel under simulated BWR conditions

    International Nuclear Information System (INIS)

    Navas, M.; Castano, M.L; Gomez-Briceno, D.; Karlsen, T.

    2004-01-01

    Full text: Neutron irradiation modifies the stress corrosion cracking (SCC) resistance of AISI 304 stainless steel in high temperature water. The microstructure and the microchemistry of materials change with the increasing of dose, inducing Radiation Hardening and Radiation Induced Segregation (RIS). SCC behaviour of irradiated material is influenced by these changes, leading to a value of threshold neutron fluence which could depend on different variables. Therefore, fully understanding of the IASCC material susceptibility implies the study of the effect of critical parameters like accumulated neutron fluence, material composition and water chemistry. Experimental work is being carried out in collaboration with the Halden Reactor Project and it includes the performance of Constant Extension Rate Tests (CERT) at CIEMAT laboratories in out-of-pile loops that simulate BWR operating conditions. The main objective is to determine the influence of neutron fluence on the SCC susceptibility of austenitic steels. A test matrix was defined to test unirradiated and irradiated specimens fabricated from tubes used previously in the Crack Initiation Test (IFA 618) performed at the Halden Reactor Project. According to the irradiation periods of IFA 618, three materials (Annealed and thermally-sensitised AISI 304 and AISI 316L) with three different accumulated neutron fluences are available. This paper presents the results obtained with annealed and thermally sensitised AISI 304 SS tested in different environments. (Author)

  16. Mechanical Properties of Super Duplex Stainless Steel 2507 after Gas Phase Thermal Precharging with Hydrogen

    Science.gov (United States)

    San Marchi, C.; Somerday, B. P.; Zelinski, J.; Tang, X.; Schiroky, G. H.

    2007-11-01

    Thermal precharging of super duplex stainless steel 2507 with 125 wppm hydrogen significantly reduced tensile ductility and fracture toughness. Strain-hardened 2507 exhibited more severe ductility loss compared to the annealed microstructure. The reduction of area (RA) was between 80 and 85 pct for both microstructures in the noncharged condition, while reductions of area were 25 and 46 pct for the strain-hardened and annealed microstructures, respectively, after hydrogen precharging. Similar to the effect of internal hydrogen on tensile ductility, fracture toughness of strain-hardened 2507 was lowered from nearly 300 MPa m1/2 in the noncharged condition to less than 60 MPa m1/2 in the hydrogen-precharged condition. While precharging 2507 with hydrogen results in a considerable reduction in ductility and toughness, the absolute values are similar to high-strength austenitic steels that have been tested under the same conditions, and which are generally considered acceptable for high-pressure hydrogen gas systems. The fracture mode in hydrogen-precharged 2507 involved cleavage cracking of the ferrite phase and ductile fracture along oblique planes in the austenite phase, compared to 100 pct microvoid coalescence in the absence of hydrogen. Predictions from a strain-based micromechanical fracture toughness model were in good agreement with the measured fracture toughness of hydrogen-precharged 2507, implying a governing role of austenite for resistance to hydrogen-assisted fracture.

  17. The influence of cold work on the oxidation behaviour of stainless steel

    International Nuclear Information System (INIS)

    Langevoort, J.C.

    1985-01-01

    In this thesis the study of the interaction of oxygen gas with stainless steel surfaces is described. Thermogravimetry, microscopy and ellipsometry have been used to follow the oxidation in situ, while EDX, AES and XPS have been used to determine the oxide compositions. The aim of this thesis is to reveal the influence on the oxidation behaviour of stainless steel of i) cold work (rolling, drawing, milling, polishing and Ar ion bombardment) ii) the initially formed oxide and iii) the experimental conditions. Two types of stainless steels have been used (AISI 304 (a 18/8 Cr/Ni steel) and Incoloy 800 H (a 20/30 Cr/Ni steel)). (Auth.)

  18. Prevention of Crevice Corrosion of STS 304 Stainless Steel by a Mg-alloy Galvanic Anode

    International Nuclear Information System (INIS)

    Lim, U. J.; Yun, B. D.; Kim, J. J.

    2006-01-01

    Prevention of crevice corrosion was studied for STS 304 stainless steel using a Mg-alloy galvanic anode in solutions with various specific resistivity. The crevice corrosion and corrosion protection characteristics of the steel was investigated by the electrochemical polarization and galvanic corrosion tests. Experimental results show that the crevice corrosion of STS 304 stainless steel does not occur in solutions of high specific resistivity, but it occurs in solutions of low specific resistivity like in solutions with resistivities of 30, 60 and 115 Ω · m. With decreasing specific resistivity of the solution, the electrode potential of STS 304 stainless steel in the crevice is lowered. The potential of STS 304 stainless steel in the crevice after coupling is cathodically polarized more by decreasing specific resistivity indicating that the crevice corrosion of STS 304 stainless steel is prevented by the Mg-alloy galvanic anode

  19. Separation by transportation in vapor phase of stainless steels components

    International Nuclear Information System (INIS)

    Allibert, M.; Gibon, G.; Kurka, G.; Tanis, G.

    1987-01-01

    A procedure for separating cobalt from other constituents of radioactive stainless steel is proposed in order to condition material originating from dismantling of reactor pressure vessels. The procedure is based on the transport in the vapour phase, under the presence of an appropriate carrier gas and a thermal gradient in a sealed device. By calculation, iodine was found to be the most appropriate carrier gas. Tests carried out at 50 mg to 2 g scale in quartz ampoules permitted to determine parameters, i.e. temperature range and gradient, pressure, and the effectiveness. It was shown that steel turnings may be treated efficiently. The procedure achieves well a partition of stainless steel into two metal masses: one containing the bulk of cobalt and radioactivity, the other depleted of cobalt and suitable for recycling. There is few or no secondary waste created, but the costs of the procedure are estimated to be high, i.e. between 100 and 1,000 ECU/kg [fr

  20. Barnacle cement: an etchant for stainless steel 316L?

    Science.gov (United States)

    Sangeetha, R; Kumar, R; Doble, M; Venkatesan, R

    2010-09-01

    Localized corrosion of stainless steel beneath the barnacle-base is an unsolved issue for the marine industry. In this work, we clearly bring out for the first time the role of the barnacle cement in acting as an etchant, preferentially etching the grain boundaries, and initiating the corrosion process in stainless steel 316L. The investigations include structural characterization of the cement and corroded region, and also chemical characterization of the corrosion products generated beneath the barnacle-base. Structural characterization studies using scanning electron microscopy (SEM) reveals the morphological changes in the cement structure across the interface of the base-plate and the substrate, modification of the steel surface by the cement and the corrosion pattern beneath the barnacle-base. Fourier transform infrared spectroscopy (FTIR) of the corrosion products show that they are composed of mainly oxides of iron thereby implying that the corrosion is aerobic in nature. A model for the etching and corrosion mechanism is proposed based on our observations.

  1. A review on nickel-free nitrogen containing austenitic stainless steels for biomedical applications.

    Science.gov (United States)

    Talha, Mohd; Behera, C K; Sinha, O P

    2013-10-01

    The field of biomaterials has become a vital area, as these materials can enhance the quality and longevity of human life. Metallic materials are often used as biomaterials to replace structural components of the human body. Stainless steels, cobalt-chromium alloys, commercially pure titanium and its alloys are typical metallic biomaterials that are being used for implant devices. Stainless steels have been widely used as biomaterials because of their very low cost as compared to other metallic materials, good mechanical and corrosion resistant properties and adequate biocompatibility. However, the adverse effects of nickel ions being released into the human body have promoted the development of "nickel-free nitrogen containing austenitic stainless steels" for medical applications. Nitrogen not only replaces nickel for austenitic structure stability but also much improves steel properties. Here we review the harmful effects associated with nickel and emphatically the advantages of nitrogen in stainless steel, as well as the development of nickel-free nitrogen containing stainless steels for medical applications. By combining the benefits of stable austenitic structure, high strength, better corrosion and wear resistance and superior biocompatibility in comparison to the currently used austenitic stainless steel (e.g. 316L), the newly developed nickel-free high nitrogen austenitic stainless steel is a reliable substitute for the conventionally used medical stainless steels. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Temperature dependence of the deformation behavior of 316 stainless steel after low temperature neutron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Pawel-Robertson, J.E.; Rowcliffe, A.F.; Grossbeck, M.L. [Oak Ridge National Lab., TN (United States)] [and others

    1996-10-01

    The effects of low temperature neutron irradiation on the tensile behavior of 316 stainless steel have been investigated. A single heat of solution annealed 316 was irradiated to 7 and 18 dpa at 60, 200, 330, and 400{degrees}C. The tensile properties as a function of dose and as a function of temperature were examined. Large changes in yield strength, deformation mode, strain to necking, and strain hardening capacity were seen in this irradiation experiment. The magnitudes of the changes are dependent on both irradiation temperature and neutron dose. Irradiation can more than triple the yield strength over the unirradiated value and decrease the strain to necking (STN) to less than 0.5% under certain conditions. A maximum increase in yield strength and a minimum in the STN occur after irradiation at 330{degrees}C but the failure mode remains ductile.

  3. Effect of Continuous Cooling on Secondary Phase Precipitation in the Super Duplex Stainless Steel ZERON-100

    Science.gov (United States)

    Calliari, Irene; Bassani, Paola; Brunelli, Katya; Breda, Marco; Ramous, Emilio

    2013-12-01

    The precipitation of secondary phases in super duplex stainless steels (SDSS) is a subject of great relevance owing to their dangerous effects on both mechanical and corrosion-resistance properties. This paper examines the effect of continuous cooling after solution annealing treatment on secondary phase precipitation in the ZERON-100 SDSS. It considers the influence of cooling rate on volume fraction, morphology and chemical composition. It has been found that the formation of sigma and chi phases can be avoided only at cooling rates higher than 0.7 °C/s. In addition, at the lowest cooling rate the sigma phase amount approaches the equilibrium value, but the chi phase amount remains significantly low.

  4. The Localized Corrosion Behavior Associated with Microstructure of F53 Super Duplex Stainless Steel

    International Nuclear Information System (INIS)

    Kim, Soon-Tae; Lee, In-Sung; Kong, Kyeong-Ho; Park, Yong-Soo; Lee, Jong-Hoon; Yang, Won-Jon

    2015-01-01

    The localized corrosion behavior associated with microstructure of F53 super duplex stainless steel (SDSS) was investigated using a potentiodynamic polarization test, a critical crevice temperature test, an electron probe micro-analyzer analysis, and scanning electron microscopy-energy dispersive spectroscopy analyses. Crevice corrosion was initiated at the α/γ phase boundaries, MO x inclusions (where M is Cr, Mn, Al, Fe, or Ti), as well as Cr and Mo depleted areas adjacent to the σ-phases precipitated in the F53 SDSS alloy. This alloy had been annealed at 1050 ℃ followed by improper water-cooling, and the corrosion was propagated into the α-phases because the pitting resistance equivalent number (PREN) of the α-phase was smaller than that of the γ-phase. As cooling rate increased, the variation of the α-phases decreased, and the content of the Cr and Mo rich σ-phases decreased, thereby increasing the corrosion resistance.

  5. Temperature dependence of {sigma} phase formation in surface melted duplex stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Knezevic, V.; Cvijovic, Z.; Mihajlovic, D. [Faculty of Technology and Metallurgy, Univ. of Belgrade, Belgrade (Yugoslavia)

    2000-07-01

    The {sigma} phase formation in GTA surface melted 22/7/2 copper-bearing duplex stainless steel was investigated in the range of 800 C to 1150 C. Annealing at 1050 C and below resulted in {sigma} phase formation, which was preceded by the {delta}{yields}{gamma}{sub 2} transformation. At 800 C and 900 C, the {sigma} phase forms by the in situ transformation and via the eutectoid reaction {delta}{yields}{sigma}+{gamma}{sub 2}, while at 1050 C it precipitates directly from the {delta} ferrite. This observation is supported by the Johnson-Mehl analysis. From a C shaped TTT diagram, the precipitation is most rapid at about 950 C. At 1150 C, total {sigma} dissolution occurs. (orig.)

  6. 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...... to welding fume particulates. METHODS: Male metal workers employed at least 1 year at one or more Danish stainless or mild steel industrial companies from 1964 through 1984 were enrolled in a cohort. Data on occupational and smoking history were obtained by questionnaire in 1986. Welders in the cohort who.......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...

  7. Overview of Intergranular Fracture of Neutron Irradiated Austenitic Stainless Steels

    Directory of Open Access Journals (Sweden)

    Anna Hojná

    2017-09-01

    Full Text Available Austenitic stainless steels are normally ductile and exhibit deep dimples on fracture surfaces. These steels can, however, exhibit brittle intergranular fracture under some circumstances. The occurrence of intergranular fracture in the irradiated steels is briefly reviewed based on limited literature data. The data are sorted according to the irradiation temperature. Intergranular fracture may occur in association with a high irradiation temperature and void swelling. At low irradiation temperature, the steels can exhibit intergranular fracture at low or even at room temperatures during loading in air and in high temperature water (~300 °C. This paper deals with the similarities and differences for IG fractures and discusses the mechanisms involved. The intergranular fracture occurrence at low temperatures might be correlated with decohesion or twinning and strain martensite transformation in local narrow areas around grain boundaries. The possibility of a ductile-to-brittle transition is also discussed. In case of void swelling higher than 3%, quasi-cleavage at low temperature might be expected as a consequence of ductile-to-brittle fracture changes with temperature. Any existence of the change in fracture behavior in the steels of present thermal reactor internals with increasing irradiation dose should be clearly proven or disproven. Further studies to clarify the mechanism are recommended.

  8. Aging and Embrittlement of High Fluence Stainless Steels

    Energy Technology Data Exchange (ETDEWEB)

    Was, gary; Jiao, Zhijie; der ven, Anton Van; Bruemmer, Stephen; Edwards, Dan

    2012-12-31

    Irradiation of austenitic stainless steels results in the formation of dislocation loops, stacking fault tetrahedral, Ni-Si clusters and radiation-induced segregation (RIS). Of these features, it is the formation of precipitates which is most likely to impact the mechanical integrity at high dose. Unlike dislocation loops and RIS, precipitates exhibit an incubation period that can extend from 10 to 46 dpa, above which the cluster composition changes and a separate phase, (G-phase) forms. Both neutron and heavy ion irradiation showed that these clusters develop slowly and continue to evolve beyond 100 dpa. Overall, this work shows that the irradiated microstructure features produced by heavy ion irradiation are remarkably comparable in nature to those produced by neutron irradiation at much lower dose rates. The use of a temperature shift to account for the higher damage rate in heavy ion irradiation results in a fairly good match in the dislocation loop microstructure and the precipitate microstructure in austenitic stainless steels. Both irradiations also show segregation of the same elements and in the same directions, but to achieve comparable magnitudes, heavy ion irradiation must be conducted at a much higher temperature than that which produces a match with loops and precipitates. First-principles modeling has confirmed that the formation of Ni-Si precipitates under irradiation is likely caused by supersaturation of solute to defect sinks caused by highly correlated diffusion of Ni and Si. Thus, the formation and evolution of Ni-Si precipitates at high dose in austenitic stainless steels containing Si is inevitable.

  9. The role of duplex stainless steels for downhole tubulars

    International Nuclear Information System (INIS)

    Francis, R.

    1993-01-01

    In sour conditions there is an increasing trend to turn to corrosion resistant alloys for downhole tubulars. The most commonly used CRA tubular is 13Cr, and there are thousands of feet in service. However, there are limits to the use of 13Cr, ie., the risk of sulphide stress corrosion cracking at high H 2 S levels, and the possibility of pitting or high corrosion rates in waters with high chloride contents. Where the service conditions are felt to be too severe for 13Cr alloys it has been traditional to switch to nickel base alloys such as alloys 825 and C-276 (UNS N08825 and N10276). The alloys are much more expensive than 13Cr, and in recent years the duplex stainless steels have been selected as alloys with superior corrosion and SSCC resistance compared with 13Cr, and having lower cost than nickel alloys. Originally the 22Cr duplex alloy (UNS 31803) was used, but more recently the 25Cr super duplex alloys (UNS S32760 and S32750) have become more available. The present paper reviews the data available for 13Cr and the limits of applicability. Data is also presented for laboratory tests for both the 22Cr and 25Cr super duplex alloys. There is extensive service experience with both 22Cr and 25Cr super duplex in the North Sea, covering both downhole tubulars, manifold and post wellhead equipment. Data is presented showing some of the sour condition being experienced in the North Sea by super duplex alloys. These results show that there is a substantial gap between the limits of use for 13Cr and the 25Cr super duplex stainless steel alloys. This means that in many sour environments super duplex stainless steel provides a cost effective alternative to nickel-base alloys

  10. Creep rupture properties of oxidised 20%Cr austenitic stainless steels

    International Nuclear Information System (INIS)

    Lobb, R.C.; Ecob, R.C.

    1989-02-01

    Sheet specimens of stabilised 20%Cr/25%Ni/Nb and nitrided 20%Cr/25%Ni/Ti stainless steels, both used as fuel cladding materials in CAGRs, have been oxidised in simulated reactor gas (Co 2 /1-2%CO) for up to l.9kh at 850 0 C, including intermediate thermal cycles to room temperature. The oxidised specimens have been creep tested subsequently at 750 0 C, under conditions of constant stress. The creep rupture properties are affected differently for the two materials. For 20%Cr/25%Ni/Nb stainless steel, there was no effect of oxidation on the intrinsic microstructure, when compared with thermally aged, non-oxidised material. Any differences in creep ductility were ascribed to geometric effects in specimens of this alloy. Lower ductilities were associated with an increased incidence of pitting attack (higher oxide spallation) and it was concluded that the extent of local, rather than general, loss of section controlled the ductility. For nitrided 20%Cr/25%Ni/Ti stainless steel, the intrinsic microstructure was affected by oxidation, such that increased grain boundary precipitation of M 23 C 6 occurred. The resultant effect was for a greater tendency for intergranular failure at lower ductility than for the thermally aged material. The magnitude of this reduction could not be quantified because the specimen geometry was also changed by oxidation. In this instance, the oxidation mode that produced the most severe loss of section was grain boundary, rather than pitting, attack. This mode of attack was not linked directly to oxide fracture/spallation, but to the period of oxidation. (author)

  11. Cytotoxicity study of plasma-sprayed hydroxyapatite coating on high nitrogen austenitic stainless steels.

    Science.gov (United States)

    Ossa, C P O; Rogero, S O; Tschiptschin, A P

    2006-11-01

    Stainless steel has been frequently used for temporary implants but its use as permanent implants is restricted due to its low pitting corrosion resistance. Nitrogen additions to these steels improve both mechanical properties and corrosion resistance, particularly the pitting and crevice corrosion resistance. Many reports concerning allergic reactions caused by nickel led to the development of nickel free stainless steel; it has excellent mechanical properties and very high corrosion resistance. On the other hand, stainless steels are biologically tolerated and no chemical bonds are formed between the steel and the bone tissue. Hydroxyapatite coatings deposited on stainless steels improve osseointegration, due their capacity to form chemical bonds (bioactive fixation) with the bone tissue. In this work hydroxyapatite coatings were plasma-sprayed on three austenitic stainless steels: ASTM-F138, ASTM-F1586 and the nickel-free Böhler-P558. The coatings were analyzed by SEM and XDR. The cytotoxicity of the coatings/steels was studied using the neutral red uptake method by quantitative evaluation of cell viability. The three uncoated stainless steels and the hydroxyapatite coated Böhler-P558 did not have any toxic effect on the cell culture. The hydroxyapatite coated ASTM-F138 and ASTM-F1586 stainless steels presented cytotoxicity indexes (IC50%) lower than 50% and high nickel contents in the extracts.

  12. Development of nuclear grade type 316 stainless steel for BWR pipings

    International Nuclear Information System (INIS)

    Kowaka, Masamichi; Nagano, Hiroo; Yoshikawa, Kunihiko; Miura, Minoru; Ota, Kunio.

    1981-01-01

    The countermeasures were established against the grain boundary stress corrosion cracking in the heat-affected zone of 304 stainless steel pipings used for recirculating system and others of BWRs. Sumitomo Metal Industries, Ltd. has engaged in the development of the stainless steel having excellent resistance to stress corrosion cracking, substituting for 304 stainless steel. In order to prevent stainless steel from becoming sensitive to the grain boundary stress corrosion cracking, the reduction of carbon content, or the addition of the elements stabilizing carbon in steel are conceivable. 316 L stainless steel was selected as the base for development, because it is a low carbon steel (C <= 0.03%) and contains Mo effective for improving the pitting corrosion resistance and restricting the steel to become sensitive. The requirements for the piping materials for BWRs are the resistance to stress corrosion cracking in high temperature, high pressure water, excellent strength and weldability, and the possibility of the commercial production of pipes. For the purpose of developing 316 stainless steel pipes, the effects of Mo and trace elements on the stress corrosion cracking resistance, the effects of C, N and grain size on the strength, and the effect of N on the weldability were examined, and the composition design of 316 stainless steel for atomic energy use was carried out. The result is given. (Kako, I.)

  13. Experimental Study Of Fog Water Harvesting By Stainless Steel Mesh

    OpenAIRE

    Nikhil R. Pawar; Suman S. Jain; Smitha R. God

    2017-01-01

    The collection of fog water is a simple and sustainable technology to get hold of fresh water for various purposes. In areas where a substantial amount of fog can be obtained it is feasible to set up a stainless steel as well as black double layer plastic mesh structure for fog water harvesting. The mesh structure is directly exposed to the weather and the fog containing air is pushed through the active mesh surface by the wind. Afterward fog droplets are deposited on the active mesh area whi...

  14. High cycle fatigue of Type 422 stainless steel

    International Nuclear Information System (INIS)

    Soo, P.; Chow, J.G.Y.; Sabatini, R.L.

    1978-01-01

    High cycle fatigue testing has been carried out on Type 422 stainless steel to determine the performance of cyclically stressed disks and blades in the main and auxiliary HTGR helium circulators. Tests were performed at 316, 482, and 538 0 C (600, 900, and 1000 0 F) in air for the fully reversible and mean load conditions. Goodman's analysis is shown to be valid in predicting failure at 316 0 C (600 0 F), marginally valid at 482 0 C (900 0 F), and probably invalid at 538 0 C (1000 0 F). Metallographic analyses were conducted to characterize the nature of failure for the temperatures and loading conditions investigated

  15. Cutting of Stainless Steel With Fiber and Disk Laser

    DEFF Research Database (Denmark)

    Wandera, Catherine; Salminen, Antti; Olsen, Flemming Ove

    2006-01-01

    role also in cutting applications. This has not happened mainly due to the fact that beam quality has not been sufficient. The introduction of new generation of solid state lasers has raised the interest of use of them in cutting application. This study was concentrated on use of fiber and disk lasers......, the new laser types with a high beam quality, in cutting of austenitic stainless steel. The performance of these new lasers at power level of 4 kW was compared with CO2-laser in respect of cutting speed, kerf width, kerf edge roughness and perpendicularity (squarness) in order to validate the potential...

  16. Physical properties of the AISI 348 L* austenitic stainless steel

    International Nuclear Information System (INIS)

    Teodoro, Celso Antonio; Lucki, Georgi; Silva, Jose Eduardo Rosa da; Terremoto, Luis Antanio Albiac; Castanheira, Myrthes; Damy, Margaret de Almeida

    2005-01-01

    The study of radiation damage in metals and alloys, used as structural materials of nuclear reactors has a strategic meaning in nuclear technology, because it allows the performance evaluation of these materials in working conditions of PWR. For this sake it is necessary to know the detrimental structural changes that occur during fast neutron irradiation. The aim of the present work is to show some strain-stress results of the AISI 348 L * stainless steel utilized as a structural material of the fuel elements of PWR, in comparison with the AISI 304. (author)

  17. Recycled hydroxyapatite coatings on 316L stainless steel substrates

    International Nuclear Information System (INIS)

    Mendes Filho, Antonio Alves; Pereira, Renato Alves; Araujo, Fernando Gabriel da Silva; Sousa, Camila Mateus de

    2010-01-01

    In this work were evaluated recycled hydroxyapatite coatings on 316L stainless steel substrates by plasma thermal aspersion. The hydroxyapatite used was obtained from bovine bone by the hydrothermal method. The samples of hydroxyapatite powders were divided according to their particle size distribution. The adhesion of the powders coating to the substrate was evaluated by assay scratch. The X-ray diffraction techniques and scanning electron microscopy were also used. The results of scratch resistance were between 46N and 63N. Analysis by scanning electron microscopy and x-ray diffraction showed no cracks coatings, single-phase and with few fused particles. (author)

  18. Corrosion Resistance of Some Stainless Steels in Chloride Solutions

    Directory of Open Access Journals (Sweden)

    Kasprzyk D.

    2017-06-01

    Full Text Available The present work compares corrosion behaviour of four types of S30403, S31603, S32615 austenitic and S32404 austenitic-ferritic stainless steels in chloride solutions (1%, 3% NaCl and in Ringer solution, at 37°C temperature. Corrosion resistance was determined by potentiodynamic polarization measurements and a thirty day immersion test conducted in Ringer solution. The immersion test was performed in term of biomedical application. These alloy were spontaneously passivated in all electrolytes, wherein S30403, S31603 and S32404 undergo pitting corrosion. Only S32615 containing 5.5% Si shows resistance to pitting corrosion.

  19. Stress relaxation characteristics of type 304 stainless steel

    International Nuclear Information System (INIS)

    Manjoine, M.J.

    1975-01-01

    The stress relaxation of type 304 stainless steel below 900 0 F (482 0 C) is practically time independent after 100 h and has a maximum of about 18 per cent. The per cent relaxation decreases with increasing degree of cold work and with decreasing stress. Above 900 0 F the per cent relaxation increases with time, temperature, and cold work. The initial stress can also be increased for cold work materials so that the remaining stress can be maintained at a higher value even up to 1200 0 F (649 0 C). Time-temperature parameters are practical to correlate and extrapolate the data in the higher temperature range. (author)

  20. On femtosecond laser shock peening of stainless steel AISI 316

    Science.gov (United States)

    Hoppius, Jan S.; Kukreja, Lalit M.; Knyazeva, Marina; Pöhl, Fabian; Walther, Frank; Ostendorf, Andreas; Gurevich, Evgeny L.

    2018-03-01

    In this paper we report on the competition in metal surface hardening between the femtosecond shock peening on the one hand, and formation of laser-induced periodic surface structures (LIPSS) and surface oxidation on the other hand. Peening of the stainless steel AISI 316 due to shock loading induced by femtosecond laser ablation was successfully demonstrated. However, for some range of processing parameters, surface erosion due to LIPSS and oxidation seems to dominate over the peening effect. Strategies to increase the peening efficiency are discussed.

  1. Biomonitoring of genotoxic exposure among stainless steel welders

    DEFF Research Database (Denmark)

    Knudsen, Lisbeth E.; Boisen, T; Christensen, J M

    1992-01-01

    . Environmental monitoring of welding fumes and selected metal oxides, biomonitoring of chromium and nickel in serum and urine and mutagenic activity in urine, and evaluation of semen quality were also done. Manual metal arc (MMA) welding and tungsten inert gas (TIG) welding were the dominant welding processes....... A higher frequency of chromosomal aberrations, classified as translocations, double minutes, exchanges and rings, was observed in stainless steel welders than in non-welders. SCE was lower in welders working with both MMA and TIG welding than in reference persons. N-Acetoxy-N-acetylaminofluorene (NA...

  2. Mechanical properties of austenitic stainless steels in sodium

    International Nuclear Information System (INIS)

    Lloyd, G.J.

    1978-03-01

    A detailed review of the mechanical properties of austenitic stainless steels in liquid sodium is presented. Consideration has been given to the influence of the of the impurities in reactor sodium and metallurgical variables upon the stress rupture life, the low cycle fatigue and combined creep/fatigue resistance, elastic-plastic crack propagation rates, the high cycle fatigue life, tensile properties and fracture toughness. The effects of exposure to contaminated sodium prior to testing are also discussed. Examples of the success of mechanistic interpretations of materials behaviour in sodium are given and additionally, the extent to which mechanical properties in sodium may be predicted with the use of appropriate data. (author)

  3. Elastic interaction between defects during dynamic aging of stainless steels

    International Nuclear Information System (INIS)

    Journaux, J.; Monteiro, S.N.

    1977-01-01

    The study of the mechanical properties through traction tests, at temperatures above room temperature in 316 type stainless steel emphasizes the existence of the dynamic aging phenomenon (Portevin-Lechantelier effect). The present paper explains in a general way the fundamental causes of this effect by examining the elastic interactions that occur between the solute atoms in solid solution and the crystal dislocations. These interactions, which are present only at a certain temperature range, are responsible for the improvement of the mechanical properties always noticed in the alloys showing this phenomenon. (F.R.) [pt

  4. Weld failure analysis of 2205 duplex stainless steel nozzle

    Directory of Open Access Journals (Sweden)

    Jingqiang Yang

    2014-10-01

    Full Text Available Failure analyses of weld joint between the nozzle and the head of the reactor made of 2205 duplex stainless steel was performed by optical microscopy (OM and scanning electron microscopy (SEM. Cracks were found in HAZ of the weld. The depth of the cracks is equal to the thickness of the inner weld. Localized uneven distribution of ferrite/austenite with 80–90% ferrite in weld is found. Results show that the cracks occurred along columnar granular with cleavage fracture. Poor weld process probably results in these cracks.

  5. Weld failure analysis of 2205 duplex stainless steel nozzle

    OpenAIRE

    Jingqiang Yang; Qiongqi Wang; Zhongkun Wei; Kaishu Guan

    2014-01-01

    Failure analyses of weld joint between the nozzle and the head of the reactor made of 2205 duplex stainless steel was performed by optical microscopy (OM) and scanning electron microscopy (SEM). Cracks were found in HAZ of the weld. The depth of the cracks is equal to the thickness of the inner weld. Localized uneven distribution of ferrite/austenite with 80–90% ferrite in weld is found. Results show that the cracks occurred along columnar granular with cleavage fracture. Poor weld process pr...

  6. Electropolishing of Stainless Steel Implants for Stable Functional Osteosynthesis

    Directory of Open Access Journals (Sweden)

    Omel’chuk, A.О.

    2016-01-01

    Full Text Available A new method for the electropolishing stainless steel for stable functional osteosynthesis has been developed. The polishing of implants was carried out in solutions, based on the ternary system H2SO4—H3PO4—H2O with stepwise decreasing the current density and increasing the orthophosphoric acid concentration. The optimal polishing conditions (current density, solution composition, temperature and duration have been determined. The developed method improves the quality and mechanical properties of the surface.

  7. Deformation modes of proton and neutron irradiated stainless steels

    Science.gov (United States)

    Bailat, C.; Gröschel, F.; Victoria, M.

    2000-01-01

    AISI 304 and 316 stainless steels of two purity levels that have been irradiated with high energy protons up to 0.3 dpa and neutrons in a high flux reactor up to 7.5 dpa were investigated in terms of irradiation induced mechanical properties and microstructural changes. The stress-strain relationships were obtained at room temperature. The deformation, grain, twinning and irradiation defect microstructures were investigated using both transmission and scanning electron microscopy. The results are discussed in terms of deformation mechanisms linked with the radiation induced defect microstructure.

  8. Low temperature gaseous nitriding and carburising of stainless steel

    DEFF Research Database (Denmark)

    Christiansen, Thomas; Somers, Marcel A.J.

    2005-01-01

    The response of various austenitic and duplex stainless steel grades to low temperature gaseous nitriding and carburising was investigated. Gaseous nitriding was performed in ammonia/hydrogen mixtures at temperatures ,723 K; gaseous carburising was carried out in carbon monoxide/hydrogen mixtures...... for temperatures (783 K. The case developed by thermochemical treatment was examined using reflected light microscopy, X-ray diffraction analysis and microhardness testing. Both nitriding and carburising led to the development of expanded austenite in the surface adjacent zone, irrespective of the phase...... constitution of the substrate. A two step process, consisting of carburising followed by nitriding, provides great flexibility with regard to adjusting the hardness–depth profile....

  9. Microchemical evolution of neutron-irradiated stainless steel

    International Nuclear Information System (INIS)

    Brager, H.R.; Garner, F.A.

    1980-04-01

    The precipitates that develop in AISI 316 stainless steel during irradiation play a dominant role in determining the dimensional and mechanical property changes of this alloy. This role is expressed primarily in a large change in matrix composition that alters the diffusional properties of the alloy matrix and also appears to alter the rate of acceptance of point defects at dislocations and voids. The major elemental participants in the evolution have been identified as nickel, silicon, and carbon. The exceptional sensitivity of this evolution to many variables accounts for much of the variability of response exhibited by this alloy in nominally similar irradiations

  10. Simulasi Proses Deep Drawing Stainless Steel dengan Software Abaqus

    Directory of Open Access Journals (Sweden)

    Tri Widodo Besar Riyadi

    2016-08-01

    Full Text Available Tujuan dari penelitian ini adalah untuk mengetahui hasil simulasi proses deep drawing terhadap bahan stainless steel pada proses pembentukan komponen end cup hub body. Penelitian dilakukan dengan paket software Abaqus 6.5-1 yang diawali dengan pengujian uji tarik, kemudian mengkonversi data tegangan-regangan nominal ke dalam tegangan-regangan sebenarnya, dan menghitung sifat plastisitas bahan dengan persamaan Holomon. Hasil simulasi menunjukkan bentuk produk dan distribusi tegangan pada pelat setelah mengalami proses deep drawing. Hubungan antara tegangan dan fenomena kerutan juga diketahui. Perbandingan hasil menunjukkan bahwa bentuk produk pelat hasil simulasi mendekati hasil yang diperoleh dengan eksperimen.

  11. Oxidation resistant high creep strength austenitic stainless steel

    Science.gov (United States)

    Brady, Michael P.; Pint, Bruce A.; Liu, Chain-Tsuan; Maziasz, Philip J.; Yamamoto, Yukinori; Lu, Zhao P.

    2010-06-29

    An austenitic stainless steel displaying high temperature oxidation and creep resistance has a composition that includes in weight percent 15 to 21 Ni, 10 to 15 Cr, 2 to 3.5 Al, 0.1 to 1 Nb, and 0.05 to 0.15 C, and that is free of or has very low levels of N, Ti and V. The alloy forms an external continuous alumina protective scale to provide a high oxidation resistance at temperatures of 700 to 800.degree. C. and forms NbC nanocarbides and a stable essentially single phase fcc austenitic matrix microstructure to give high strength and high creep resistance at these temperatures.

  12. High nitrogen-dosed austenitic-stainless steels and duplex steels

    International Nuclear Information System (INIS)

    Harzenmoser, M.A.E.

    1990-01-01

    The austenitic grades represent the most important group in the family of stainless steels. Nitrogen addition to austenitic stainless steels provides much higher yield strength. It was the goal of the present work to develop new high strength austenitic and duplex stainless steels and to investigate the beneficial influence of nitrogen. More than 40 small ingots up to a weight of 1.5 kg were melted in a specially developed high pressure induction furnace. In addition 20 more alloys produced by a pressurized electro slag remelting facility were included in this investigation. The nitrogen content was varied between 0.37 and 1.47 wt.%. New coefficients are proposed for the nickel equivalent in the Schaeffler diagram; these are from 0.12 to 0.24 for manganese and 18 for nitrogen. The increase in yield strength by interstitially dissolved nitrogen is due to solid solution hardening and to increased grain boundary hardening. The addition of 1% nitrogen gives a yield strength of more than 759 MPa. The toughness remains very good. At room temperature nitrogen alloyed Fe-Cr-Mn austenitic steels give the highest product of strength and toughness. Nitrogen containing austenitic stainless steels show a substantial increase in strength at low temperature. From room temperature to 4K the yield strength is more than tripled. Nitrogen alloyed Fe-Cr-Mn austenitic stainless steels exhibit a ductile to brittle transition as the temperature is lowered. This is due to a planar deformation mode which could be caused by low stacking fault energy. Nickel improves the low temperature toughness and also raises the stacking fault energy. In the temperature range from 600 to 900 o C, Cr 2 N precipitate. The minimal time for precipitation is longer by a factor of 10 than in Fe-Cr-Ni grade. Nitrogen decreases the corrosion rate in austenitic and duplex stainless steels. The resistance to pitting corrosion can be described by the equation W L = %Cr + 3.3 %Mo + 30 %N. (author) figs., tabs., refs

  13. Thermal stability study for candidate stainless steels of GEN IV reactors

    Energy Technology Data Exchange (ETDEWEB)

    Simeg Veternikova, J., E-mail: jana.veternikova@stuba.sk [Institute of Nuclear and Physical Engineering, Faculty of Electrical and Information Technology, Slovak University of Technology, Ilkovicova 3, 812 19 Bratislava (Slovakia); Degmova, J. [Institute of Nuclear and Physical Engineering, Faculty of Electrical and Information Technology, Slovak University of Technology, Ilkovicova 3, 812 19 Bratislava (Slovakia); Pekarcikova, M. [Institute of Materials Science, Faculty of Materials Science and Technology, Slovak University of Technology, Paulinska 16, 917 24 Trnava (Slovakia); Simko, F. [Department of Molten Salts, Institute of Inorganic Chemistry, Slovak Academy of Sciences, Dubravska cesta 9, 845 36 Bratislava (Slovakia); Petriska, M. [Institute of Nuclear and Physical Engineering, Faculty of Electrical and Information Technology, Slovak University of Technology, Ilkovicova 3, 812 19 Bratislava (Slovakia); Skarba, M. [Slovak University of Technology, Vazovova 5, 812 43 Bratislava (Slovakia); Mikula, P. [Institute of Nuclear and Physical Engineering, Faculty of Electrical and Information Technology, Slovak University of Technology, Ilkovicova 3, 812 19 Bratislava (Slovakia); Pupala, M. [Department of Molten Salts, Institute of Inorganic Chemistry, Slovak Academy of Sciences, Dubravska cesta 9, 845 36 Bratislava (Slovakia)

    2016-11-30

    Highlights: • Thermal resistance of advanced stainless steels were observed at 1000 °C. • GEN IV candidate steels were confronted to classic AISI steels. • ODS AISI 316 has weaker thermal resistance than classic AISI steel. • Ferritic ODS steels and NF 709 has better thermal resistance than AISI steels. - Abstract: Candidate stainless steels for GEN IV reactors were investigated in term of thermal and corrosion stability at high temperatures. New austenitic steel (NF 709), austenitic ODS steel (ODS 316) and two ferritic ODS steels (MA 956 and MA 957) were exposed to around 1000 °C in inert argon atmosphere at pressure of ∼8 MPa. The steels were further studied in a light of vacancy defects presence by positron annihilation spectroscopy and their thermal resistance was confronted to classic AISI steels. The thermal strain supported a creation of oxide layers observed by scanning electron microscopy (SEM).

  14. General and Localized corrosion of Austenitic and Borated Stainless Steels in Simulated Concentrated Ground Waters

    International Nuclear Information System (INIS)

    Fix, D.; Estill, J.; Wong, L.; Rebak, R.

    2004-01-01

    Boron containing stainless steels are used in the nuclear industry for applications such as spent fuel storage, control rods and shielding. It was of interest to compare the corrosion resistance of three borated stainless steels with standard austenitic alloy materials such as type 304 and 316 stainless steels. Tests were conducted in three simulated concentrated ground waters at 90 C. Results show that the borated stainless were less resistant to corrosion than the witness austenitic materials. An acidic concentrated ground water was more aggressive than an alkaline concentrated ground water

  15. Stress Corrosion Cracking Behaviour of Dissimilar Welding of AISI 310S Austenitic Stainless Steel to 2304 Duplex Stainless Steel

    Directory of Open Access Journals (Sweden)

    Thiago AmaroVicente

    2018-03-01

    Full Text Available The influence of the weld metal chemistry on the stress corrosion cracking (SCC susceptibility of dissimilar weldments between 310S austenitic stainless steel and 2304 duplex steels was investigated by constant load tests and microstructural examination. Two filler metals (E309L and E2209 were used to produce fusion zones of different chemical compositions. The SCC results showed that the heat affected zone (HAZ on the 2304 base metal side of the weldments was the most susceptible region to SCC for both filler metals tested. The SCC results also showed that the weldments with 2209 duplex steel filler metal presented the best SCC resistance when compared to the weldments with E309L filler metal. The lower SCC resistance of the dissimilar joint with 309L austenitic steel filler metal may be attributed to (1 the presence of brittle chi/sigma phase in the HAZ on the 2304 base metal, which produced SC cracks in this region and (2 the presence of a semi-continuous delta-ferrite network in the fusion zone which favored the nucleation and propagation of SC cracks from the fusion zone to HAZ of the 2304 stainless steel. Thus, the SC cracks from the fusion zone associated with the SC cracks of 2304 HAZ decreased considerably the time-of-fracture on this region, where the fracture occurred. Although the dissimilar weldment with E2209 filler metal also presented SC cracks in the HAZ on the 2304 side, it did not present the delta ferrite network in the fusion zone due to its chemical composition. Fractography analyses showed that the mixed fracture mode was predominant for both filler metals used.

  16. Toughness and other mechanical properties of the duplex stainless steel 2205

    International Nuclear Information System (INIS)

    Sieurin, H.; Sandstroem, R.

    2003-01-01

    The use and range of potential applications of duplex stainless steel continuously increase. An overview of the mechanical properties of duplex stainless steel 2205 is presented with focus on toughness properties. Impact and fracture toughness as well as strength results from the European research project, EcoPress, are presented. (orig.)

  17. 77 FR 39467 - Stainless Steel Bar From India: Final Results of the Antidumping Duty Administrative Review

    Science.gov (United States)

    2012-07-03

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-533-810] Stainless Steel Bar From... duty order on stainless steel bar from India. The review covers shipments of subject merchandise to the... Bar From India: Preliminary Results and Partial Rescission of the Antidumping Duty Administrative...

  18. Microstructure and wear resistance of spray-formed supermartensitic stainless steel

    Directory of Open Access Journals (Sweden)

    Guilherme Zepon

    2013-06-01

    Full Text Available Since the early 90's the oil industry has been encouraging the development of corrosion and wear resistant alloys for onshore and offshore pipeline applications. In this context supermartensitic stainless steel was introduced to replace the more expensive duplex stainless steel for tubing applications. Despite the outstanding corrosion resistance of stainless steels, their wear resistance is of concern. Some authors reported obtaining material processed by spray forming, such as ferritic stainless steel, superduplex stainless steel modified with boron, and iron-based amorphous alloys, which presented high wear resistance while maintaining the corrosion performance1,2. The addition of boron to iron-based alloys promotes the formation of hard boride particles (M2B type which improve their wear resistances3-9. This work aimed to study the microstructure and wear resistance of supermartensitic stainless steel modified with 0.3 wt. (% and 0.7 wt. (% processed by spray forming (SF-SMSS 0.3%B and SF-SMSS 0.7%B, respectively. These boron contents were selected in order to improve the wear resistance of supermartensitic stainless steel through the formation of uniformly distributed borides maintaining the characteristics of the corrosion resistant matrix. SF-SMSS 0.7%B presents an abrasive wear resistance considerably higher than spray-formed supermartensitic stainless steel without boron addition (SF-SMSS.

  19. 77 FR 60478 - Control of Ferrite Content in Stainless Steel Weld Metal

    Science.gov (United States)

    2012-10-03

    ... Metal AGENCY: Nuclear Regulatory Commission. ACTION: Draft regulatory guide; request for comment... draft regulatory guide (DG), DG-1279, ``Control of Ferrite Content in Stainless Steel Weld Metal.'' This... stainless steel weld metal. Revision 4 updates the guide to remove references to outdated standards and to...

  20. 78 FR 45271 - Welded Stainless Steel Pressure Pipe From Malaysia, Thailand, and Vietnam

    Science.gov (United States)

    2013-07-26

    ... Stainless Steel Pressure Pipe From Malaysia, Thailand, and Vietnam Determination On the basis of the record... reason of imports from Malaysia, Thailand, and Vietnam of welded stainless steel pressure pipe, provided... appear as parties in Commission antidumping and countervailing duty investigations. The Secretary will...

  1. Discontinuous precipitation in a nickel-free high nitrogen austenitic stainless steel on solution nitriding

    DEFF Research Database (Denmark)

    Mohammadzadeh, Roghayeh; Akbari, Alireza; Grumsen, Flemming Bjerg

    2017-01-01

    Chromium-rich nitride precipitates in production of nickel-free austenitic stainless steel plates via pressurised solution nitriding of Fe–22.7Cr–2.4Mo ferritic stainless steel at 1473 K (1200 °C) under a nitrogen gas atmosphere was investigated. The microstructure, chemical and phase composition...

  2. Microstructural development during laser cladding of low-C martensitic stainless steel.

    CSIR Research Space (South Africa)

    Van Rooyen, C

    2007-07-01

    Full Text Available Heat input plays an important role in the microstructural development of 12%Cr martensitic stainless steel. The microstructure of low-C 12%Cr martensitic stainless steel resulting from laser cladding was investigated. For 410L a ferritic...

  3. 75 FR 76025 - Stainless Steel Butt-Weld Pipe Fittings From Japan, Korea, and Taiwan

    Science.gov (United States)

    2010-12-07

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Stainless Steel Butt-Weld Pipe Fittings From Japan, Korea, and Taiwan AGENCY: United States... stainless steel butt-weld pipe fittings from Japan, Korea, and Taiwan would be likely to lead to...

  4. 75 FR 67110 - Forged Stainless Steel Flanges From India and Taiwan

    Science.gov (United States)

    2010-11-01

    ... COMMISSION Forged Stainless Steel Flanges From India and Taiwan AGENCY: United States International Trade... stainless steel flanges from India and Taiwan. SUMMARY: The Commission hereby gives notice that it has... Taiwan would be likely to lead to continuation or recurrence of material injury. Pursuant to section 751...

  5. 75 FR 59744 - Stainless Steel Plate From Belgium, Italy, Korea, South Africa, and Taiwan

    Science.gov (United States)

    2010-09-28

    ... Plate From Belgium, Italy, Korea, South Africa, and Taiwan AGENCY: United States International Trade... on stainless steel plate from Belgium, Italy, Korea, South Africa, and Taiwan. SUMMARY: The... stainless steel plate from Belgium, Italy, Korea, South Africa, and Taiwan would be likely to lead to...

  6. Austenitic Reversion of Cryo-rolled Ti-Stabilized Austenitic Stainless Steel: High-Resolution EBSD Investigation

    Science.gov (United States)

    Tiamiyu, A. A.; Odeshi, A. G.; Szpunar, J. A.

    2018-02-01

    In this study, AISI 321 austenitic stainless steel (ASS) was cryo-rolled and subsequently annealed at 650 and 800 °C to reverse BCC α'-martensite to FCC γ-austenite. The texture evolution associated with the reversion at the selected temperatures was investigated using high-resolution EBSD. After the reversion, TiC precipitates were observed to be more stable in 650 °C-annealed specimens than those reversed at 800 °C. {110} texture was mainly developed in specimens subjected to both annealing temperatures. However, specimens reversed at 650 °C have stronger texture than those annealed at 800 °C, even at the higher annealing time. The strong intensity of {110} texture component is attributed to the ability of AISI 321 ASS to memorize the crystallographic orientation of the deformed austenite, a phenomenon termed texture memory. The development of weaker texture in 800 °C-annealed specimens is attributed to the residual strain relief in grains, dissolution of grain boundary precipitates, and an increase in atomic migration along the grain boundaries. Based on the observed features of the reversed austenite grains and estimation from an existing model, it is suspected that the austenite reversion at 650 and 800 °C undergone diffusional and martensitic shear reversion, respectively.

  7. Beneficially reusing LLRW the Savannah River Site Stainless Steel Program

    International Nuclear Information System (INIS)

    Boettinger, W.L.

    1993-01-01

    With 68 radioactively contaminated excess Process Water Heat Exchangers the Savannah River Site launched its program to turn potential LLRW metal liabilities into assets. Each Heat Exchanger contains approximately 100 tons of 304 Stainless Steel and could be disposed as LLRW by land burial. Instead the 7000 tons of metal will be recycled into LLRW, HLW, and TRU waste containers thereby eliminating the need for near term land disposal and also eliminating the need to add more clean metal to the waste stream. Aspects of the partnership between DOE and Private Industry necessary to accomplish this new mission are described. A life cycle cost analysis associated with past practices of using carbon steel containers to indefinitely store material (contributing to the creation of today's legacy waste problems) is presented. The avoided cost calculations needed to support the economics of the ''Indifference'' decision process in assessing the Beneficial Reuse option relative to the Burial option are described

  8. Characteristic of Low Temperature Carburized Austenitic Stainless Steel

    Science.gov (United States)

    Istiroyah; Pamungkas, M. A.; Saroja, G.; Ghufron, M.; Juwono, A. M.

    2018-01-01

    Low temperature carburizing process has been carried out on austenitic stainless steel (ASS) type AISI 316L, that contain chromium in above 12 at%. Therefore, conventional heat treatment processes that are usually carried out at high temperatures are not applicable. The sensitization process due to chromium migration from the grain boundary will lead to stress corrosion crack and decrease the corrosion resistance of the steel. In this study, the carburizing process was carried out at low temperatures below 500 °C. Surface morphology and mechanical properties of carburized specimens were investigated using optical microscopy, non destructive profilometer, and Vicker microhardness. The surface roughness analysis show the carburising process improves the roughness of ASS surface. This improvement is due to the adsorption of carbon atoms on the surface of the specimen. Likewise, the hardness test results indicate the carburising process increases the hardness of ASS.

  9. Corrosion of AISI 304 stainless steel in polluted seawater

    International Nuclear Information System (INIS)

    Brankevich, G.; Guiamet, P.; Videla, H.A.

    1987-01-01

    The sequence of microbiofouling settlement on AISI 304 stain steel samples exposed to polluted harbor sea water of a power cooling water intake is studied. The firts sates of bacterial colonization are followed by means of scanning electron microscopy during two weeks of exposure. The relation between microbiofouling and corrosion is also followed by scanning electron microscopy and evaluated through electrochemical polarization experiments. The results obtained show that microbial colonization and extracellular polimeric substances forming the biofilms have a marked influence on the electrochemical behaviour of stainless steel in sea water. Laboratory experiments using inorganic chloride solutions or artificial sea water show a considerably lesser attack of the metal than those performed 'in situ' with natural sea water. Passivity breadown is highly facilitated when complex biological and inorganic deposits (fouling) have settled on the metal surface. (Author) [pt

  10. Improvement of the stainless steel electropolishing process by organic additives

    Directory of Open Access Journals (Sweden)

    Lochynski Pawel

    2016-12-01

    Full Text Available The influence of organic additives on the process of surface electropolishing of AISI 304 type steel was determined. Additives were selected in initial potentiodynamic tests pursuant to the plateau analysis on the current/potential curves. The assessment of the operational effectiveness of additives consisted in determining the relationship between surface gloss after electropolishing and the mass loss of the sample and in determining surface roughness. The applied electropolishing bath consisted of a mixture of concentrated acids: H3PO4 and H2SO4, and the following organic additives were used: triethylamine, ethanolamine, diethanolamine, triethanolamine, diethylene glycol monobutyl ether and glycerol. The best electropolishing result, i.e. low roughness and high gloss of stainless steel surface with a relatively low mass loss of the sample at the same time were obtained for baths containing triethanolamine.

  11. The retention of iodine in stainless steel sample lines

    Energy Technology Data Exchange (ETDEWEB)

    Evans, G.J.; Deir, C. [Univ. of Toronto (Canada); Ball, J.M. [Whiteshell Laboratories, Pinawa (Canada)

    1995-02-01

    Following an accident in a multi-unit CANDU nuclear generating station, decontamination of air vented from containment would play a critical role in minimizing the release of iodine to the environment. The concentration of gas phase iodine in containment air would be measured using the post accident radiation monitoring system, requiring that air samples be passed through a considerable length of tubing to a remote location where the desired measurements could safely be made. A significant loss of iodine, due to adsorption on the sample line surfaces, could greatly distort the measurement. In this study, the retention of I{sub 2}(g) on stainless steel was evaluated in bench scale experiments in order to evaluate, and if possible minimise, the extent of any such line losses. Experiments at the University of Toronto were performed using 6 inch lengths of 1/4 inch stainless steel tubing. Air, containing I-131 labelled I{sub 2}(g), ranging in concentration from 10{sup {minus}10} to 10{sup {minus}6} mol/dm{sup 3} and relative humidity (:RH) from 20 to 90 %, was passed through tubing samples maintained at temperatures ranging from 25 to 90{degrees}C. Adsorption at low gas phase iodine concentrations differed substantially from that at higher concentrations. The rate of deposition was proportional to the gas phase concentration, giving support to the concept of a first order deposition velocity. The surface loading increased with increasing relative humidity, particularly at low RH values, while the deposition rate decreased with increasing temperature. Surface water on the steel may play an important role in the deposition process. The chemisorbed iodine was located primarily in areas of corrosion. Furthermore, water used to wash the steel contained Fe, Mn and iodine in the form of iodide, suggesting that I{sub 2} reacted to form metal iodides. The deposition of I{sub 2} was also found to depend on the initial surface condition.

  12. Mechanical evaluation of hip cement spacer reinforcement with stainless steel Kirschner wires, titanium and carbon rods, and stainless steel mesh.

    Science.gov (United States)

    Kaku, Nobuhiro; Tabata, Tomonori; Tsumura, Hiroshi

    2015-04-01

    In two-stage treatments for infections after total hip arthroplasty, antibiotic-loaded cement spacers help treat the infection by antibiotic elution and prevent contraction. However, such spacers are weak and may fracture while awaiting replacement, impairing functionality. We evaluated whether a Kirschner wire (K-wire) mounted into the spacer reinforced its strength along with the effects of the reinforcing material, position, and intensity. Spacers without reinforcing materials constituted the control group. As reinforcing materials, stainless steel K-wires (diameters 3 and 6 mm), titanium alloy and carbon fibers (diameter 3.175 mm), and stainless steel meshes (inner and outer diameters, 6 and 9 mm, respectively) were inserted into the spacer mold before filling with cement. The spacers complied with ISO 7206-4; a compressive load was applied using a testing machine with a velocity of 25.4 mm/min, and the maximum load was recorded. We used 1-3 K-wires positioned on the medial side, lateral side, neck only, and stem only and tested 3 specimens for each condition. The control group withstood the highest load. Stainless steel was the strongest material; 3-mm K-wires in the neck and lateral side withstood a higher load. The computed tomography (CT) imaging revealed a cavity between the K-wires and cement. When K-wires were inserted along the whole length, despite cement fractures, continuity was maintained because of the reinforcing materials. It is difficult to improve the reinforcing strength of spacers using K-wires; however, K-wires prevented dislocation of cement spacer fragments, which can help prevent contraction and facilitate spacer removal during replacement.

  13. The influence of the martensitic transformation on the fatigue of an AISI type 316 metastable stainless steel

    International Nuclear Information System (INIS)

    Pacheco, D.J; Sousa e Silva, A.S. de; Monteiro, S.N.

    The influence of the martensitic transformation on the process of pulse tension fatigue of a AISI type 316 metastable stainless steel was studied at 25 0 and 196 0 c. The fatigue tests were performed on annealed and cold worked specimens in order to separate the effects of static transformation, dynamic transformation and work hardening. The fatigue limits obtained from the corresponding Wohler curves were compared for the different test conditions. The results showed that the fatigue is not affected by the dynamically induced martensite. On the other hand the static martensite, previously induced, appears to decrease the resistance to fatigue. The reasons for these effects are discussed. (Author) [pt

  14. Phase transformations evaluation on a UNS S31803 duplex stainless steel based on nondestructive testing

    Energy Technology Data Exchange (ETDEWEB)

    Macedo Silva, Edgard de, E-mail: edgard@cefetpb.edu.br [Centro federal de Educacao Tecnologica da Paraiba (CEFET PB), Area da Industria, Avenida 1o de Maio, 720 - 58015-430 - Joao Pessoa/PB (Brazil); Costa de Albuquerque, Victor Hugo, E-mail: victor.albuquerque@fe.up.pt [Universidade Federal da Paraiba (UFPB), Departamento de Engenharia Mecanica (DEM), Cidade Universitaria, S/N - 58059-900 - Joao Pessoa/PB (Brazil); Pereira Leite, Josinaldo, E-mail: josinaldo@ct.ufpb.br [Universidade Federal da Paraiba (UFPB), Departamento de Engenharia Mecanica (DEM), Cidade Universitaria, S/N - 58059-900 - Joao Pessoa/PB (Brazil); Gomes Varela, Antonio Carlos, E-mail: varela@cefetpb.edu.br [Universidade Federal da Paraiba (UFPB), Departamento de Engenharia Mecanica (DEM), Cidade Universitaria, S/N - 58059-900 - Joao Pessoa/PB (Brazil); Pinho de Moura, Elineudo, E-mail: elineudo@pq.cnpq.br [Universidade Federal do Ceara (UFC), Departamento de Engenharia Metalurgica e de Materiais, Campus do Pici, Bloco 715, 60455-760 - Fortaleza/CE (Brazil); Tavares, Joao Manuel R.S., E-mail: tavares@fe.up.pt [Faculdade de Engenharia da Universidade do Porto (FEUP), Departamento de Engenharia Mecanica e Gestao Industrial (DEMEGI)/Instituto de Engenharia Mecanica e Gestao Industrial - INEGI, Rua Dr. Roberto Frias, s/n, 4200-465 Porto (Portugal)

    2009-08-15

    Duplex stainless steel presents special mechanical properties such as, for example, mechanical and corrosion strength, becoming competitive in relation to the other types of stainless steel. One of the great problems of duplex stainless steel microstructural changes study is related to embrittlement above 300 deg. C, with the precipitation of the {alpha}' phase occurring over the ferritic microstructure. Aiming to characterise embrittlement of duplex stainless steel, hardening kinetics, from 425 to 475 deg. C, was analysed through the speed of sound, Charpy impact energy, X-ray diffraction, hardness and microscopy parameters. The presence of two hardening stages, detected through the speed of sound, was observed, one being of brittle characteristic and the other ductile. Moreover, the speed of sound showed a direct correlation with the material's hardness. Thus, it is concluded that the speed of sound is a promising nondestructive parameter to follow-up embrittlement in duplex stainless steel.

  15. Phase transformations evaluation on a UNS S31803 duplex stainless steel based on nondestructive testing

    International Nuclear Information System (INIS)

    Macedo Silva, Edgard de; Costa de Albuquerque, Victor Hugo; Pereira Leite, Josinaldo; Gomes Varela, Antonio Carlos; Pinho de Moura, Elineudo; Tavares, Joao Manuel R.S.

    2009-01-01

    Duplex stainless steel presents special mechanical properties such as, for example, mechanical and corrosion strength, becoming competitive in relation to the other types of stainless steel. One of the great problems of duplex stainless steel microstructural changes study is related to embrittlement above 300 deg. C, with the precipitation of the α' phase occurring over the ferritic microstructure. Aiming to characterise embrittlement of duplex stainless steel, hardening kinetics, from 425 to 475 deg. C, was analysed through the speed of sound, Charpy impact energy, X-ray diffraction, hardness and microscopy parameters. The presence of two hardening stages, detected through the speed of sound, was observed, one being of brittle characteristic and the other ductile. Moreover, the speed of sound showed a direct correlation with the material's hardness. Thus, it is concluded that the speed of sound is a promising nondestructive parameter to follow-up embrittlement in duplex stainless steel.

  16. Compresibility and sinterability of HCx PM steel diluted with stainless steels

    Directory of Open Access Journals (Sweden)

    Elena Gordo

    2003-12-01

    Full Text Available HCx powder metallurgy steel contains in its composition high contents of Cr and C, and significant quantities of alloy elements typical of tool steels (Mo, V, W, to provide the corrosion resistance of stainless steel with wear resistance of tool steels. HCx appears to be a suitable material for applications in aggressive environments, as valve seat inserts in automotive engines. However, this steel presents a low compressibility leading to high production costs. In this work, some results carried out to improve the compressibility of HCx are presented. The way to attempt this improvement is the dilution of base material with two stainless steels, the ferritic 430LHC and the austenitic 316L. The powder mixes prepared were uniaxially pressed to study the compressibility. The sinterability was study by determining of density, hardness, transverse rupture strength (TRS and microstructural evolution after vacuum sintering at different temperatures. As a result, better compressibility is observed in the mixes although not all of them present the properties required.

  17. 76 FR 64105 - Stainless Steel Wire Rod From India; Scheduling of an Expedited Five-Year Review Concerning the...

    Science.gov (United States)

    2011-10-17

    ... COMMISSION Stainless Steel Wire Rod From India; Scheduling of an Expedited Five-Year Review Concerning the Antidumping Duty Order on Stainless Steel Wire Rod From India AGENCY: United States International Trade... determine whether revocation of the antidumping duty order on stainless steel wire rod from India would be...

  18. 78 FR 22227 - Stainless Steel Bar From Brazil: Final Results of Antidumping Duty Administrative Review; 2011-2012

    Science.gov (United States)

    2013-04-15

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-351-825] Stainless Steel Bar From... duty order on stainless steel bar (SSB) from Brazil. For these final results, we continue to find that....\\1\\ The period of review is February 1, 2011, through January 31, 2012. \\1\\ See Stainless Steel Bar...

  19. 77 FR 47595 - Stainless Steel Bar From Brazil, India, Japan, and Spain: Continuation of Antidumping Duty Orders

    Science.gov (United States)

    2012-08-09

    ...-805] Stainless Steel Bar From Brazil, India, Japan, and Spain: Continuation of Antidumping Duty Orders... International Trade Commission (ITC) that revocation of the antidumping duty orders on stainless steel bar from... Department initiated the third sunset reviews of the antidumping duty orders \\1\\ on stainless steel bar from...

  20. 76 FR 74807 - Stainless Steel Bar From Brazil, India, Japan, and Spain; Institution of Five-Year Reviews

    Science.gov (United States)

    2011-12-01

    ...)] Stainless Steel Bar From Brazil, India, Japan, and Spain; Institution of Five-Year Reviews AGENCY: United...)) (the Act) to determine whether revocation of the antidumping duty orders on stainless steel bar from... Department of Commerce issued antidumping duty orders on imports of stainless steel bar from Brazil, India...

  1. 77 FR 16207 - Stainless Steel Bar From Brazil, India, Japan, and Spain: Final Results of the Expedited Third...

    Science.gov (United States)

    2012-03-20

    ...-805] Stainless Steel Bar From Brazil, India, Japan, and Spain: Final Results of the Expedited Third...) initiated the third sunset reviews of the antidumping duty orders on stainless steel bar from Brazil, India... stainless steel bar from Brazil, India, Japan, and Spain\\1\\ pursuant to section 751(c) of the Act. See...

  2. 77 FR 5486 - Stainless Steel Bar From India: Extension of Time Limit for the Preliminary Results of the 2010...

    Science.gov (United States)

    2012-02-03

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-533-810] Stainless Steel Bar From... administrative review of the antidumping duty order on stainless steel bar from India, covering the period... results for this review extending the deadline to January 30, 2012. See Stainless Steel Bar From India...

  3. 78 FR 34337 - Stainless Steel Bar From India: Final Results of Antidumping Duty Administrative Review; 2011-2012

    Science.gov (United States)

    2013-06-07

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-533-810] Stainless Steel Bar From... duty order on stainless steel bar from India (Preliminary Results).\\1\\ The review covers shipments of... than normal value. \\1\\ See Stainless Steel Bar from India: Preliminary Results of the Antidumping Duty...

  4. 76 FR 78614 - Welded ASTM A-312 Stainless Steel Pipe From South Korea and Taiwan: Continuation of Antidumping...

    Science.gov (United States)

    2011-12-19

    ... International Trade Administration Welded ASTM A-312 Stainless Steel Pipe From South Korea and Taiwan... welded ASTM A-312 stainless steel pipe from South Korea (Korea) and Taiwan would likely lead to.... See Welded ASTM A-312 Stainless Steel Pipe From South Korea and Taiwan: Final Results of Expedited...

  5. Effect of stress during neutron irradiation on the microstructure of type 316 stainless steel

    International Nuclear Information System (INIS)

    Brager, H.R.; Garner, F.A.; Guthrie, G.L.

    1976-04-01

    A transmission electron microscopy (TEM) examination was performed on solution annealed and 20 percent cold-worked Type 316 stainless steel specimens stressed during irradiation at 500 0 C in EBR-II. Hoop stress levels ranged from 0 to 327 MN/m 2 (47,300 psi) and fluences between 2.0 and 3.0 x 10 22 n/cm 2 (E greater than 0.1 MeV). Data confirm that applied tensile stresses enhance swelling in the solution annealed steel. The number densities of both voids and Frank loops were sensitive to the stress environment. Total swelling in the annealed material increased with stress, but not in direct proportion to the increased void nucleation. While the effect of cold working was to suppress swelling, the nucleation and growth of Frank loops was unaffected by the cold worked microstructure. The individual planar loop densities within any one specimen were quite sensitive to the magnitude of the stress component normal to the loop plane, while the total loop number density was sensitive to a smaller degree of the magnitude of the hydrostatic stress level. The number and size distribution of the loop populations were unaffected by the planar shear stress components, but the mean loop sizes were found to be limited by the probability of loop intersection with dislocations and loops. The stress dependence of void and loop densities allowed determination of the critical nuclei sizes, approximately sixteen vacancies for voids and six atoms for loops. Many observations were made on the probable creep mechanisms. Both dislocation and void microstructures evolved in a consistent stress-dependent manner, giving support to models which predict a coupling of the swelling and irradiation creep phenomena through the stress environment. 13 figures, 3 tables

  6. Effect of prior cold work on creep properties of a titanium modified austenitic stainless steel

    International Nuclear Information System (INIS)

    Vijayanand, V.D.; Parameswaran, P.; Nandagopal, M.; Panneer Selvi, S.; Laha, K.; Mathew, M.D.

    2013-01-01

    Prior cold worked (PCW) titanium-modified 14Cr–15Ni austenitic stainless steel (SS) is used as a core-structural material in fast breeder reactor because of its superior creep strength and resistance to void swelling. In this study, the influence of PCW in the range of 16–24% on creep properties of IFAC-1 SS, a titanium modified 14Cr–15Ni austenitic SS, at 923 K and 973 K has been investigated. It was found that PCW has no appreciable effect on the creep deformation rate of the steel at both the test temperatures; creep rupture life increased with PCW at 923 K and remained rather unaffected at 973 K. The dislocation structure along with precipitation in the PCW steel was found to change appreciably depending on creep testing conditions. A well-defined dislocation substructure was observed on creep testing at 923 K; a well-annealed microstructure with evidences of recrystallization was observed on creep testing at 973 K

  7. Dynamic Recrystallization and Hot Workability of 316LN Stainless Steel

    Directory of Open Access Journals (Sweden)

    Chaoyang Sun

    2016-07-01

    Full Text Available To identify the optimal deformation parameters for 316LN austenitic stainless steel, it is necessary to study the macroscopic deformation and the microstructural evolution behavior simultaneously in order to ascertain the relationship between the two. Isothermal uniaxial compression tests of 316LN were conducted over the temperature range of 950–1150 °C and for the strain rate range of 0.001–10 s−1 using a Gleeble-1500 thermal-mechanical simulator. The microstructural evolution during deformation processes was investigated by studying the constitutive law and dynamic recrystallization behaviors. Dynamic recrystallization volume fraction was introduced to reveal the power dissipation during the microstructural evolution. Processing maps were developed based on the effects of various temperatures, strain rates, and strains, which suggests that power dissipation efficiency increases gradually with increasing temperature and decreasing stain rate. Optimum regimes for the hot deformation of 316LN stainless steel were revealed on conventional hot processing maps and verified effectively through the examination of the microstructure. In addition, the regimes for defects of the product were also interpreted on the conventional hot processing maps. The developed power dissipation efficiency maps allow optimized processing routes to be selected, thus enabling industry producers to effectively control forming variables to enhance practical production process efficiency.

  8. Posterior preveneered stainless steel crowns: clinical performance after three years.

    Science.gov (United States)

    O'Connell, Anne C; Kratunova, Evelina; Leith, Rona

    2014-01-01

    The purpose of this study was to evaluate the clinical performance of posterior preveneered stainless steel crowns after three years. NuSmile crowns and Kinder Krowns were randomly allocated on paired molars using a split-mouth design. Variables such as fracture, wear, gingival health, and esthetics were recorded. (Pcrowns in 14 children. After three years, 53 percent of crowns were fracture free compared to 81 percent at one year. There was minimal esthetic impact for most fractures due to the location of the veneer fracture, but five crowns had extensive fracture. No difference was reported in the clinical performance between the two crown types. Fracture was more likely to occur where the adjacent tooth was missing. Parents reported a satisfaction rating of 8.3 out of 10. Clinical performance of both crown types was similar and successful for three years. Facing fracture occurred in 47 percent of crowns but had minimal impact on the esthetic value or parental satisfaction in the majority of cases. These crowns offer an esthetic alternative to the traditional stainless steel crown, but parents should be alerted to the possibility of veneer loss over time.

  9. Processing fine stainless-steel slag using spiral concentration.

    Science.gov (United States)

    Wolfe, Eric R; Klima, Mark S

    2008-04-01

    In this study, the effectiveness of spiral concentration to process a fine (-1 mm) stainless-steel slag was evaluated. Specifically, testing was conducted to determine the feasibility of producing a high metal content stainless steel product and a low metal content aggregate product. This involved investigating a key operating variable for both five-and seven-turn spiral concentrators. The raw slag and spiral products were characterized to determine their respective size and metal distributions. Separation testing was carried out using the two full-scale spiral concentrators to evaluate the effects of feed solids concentration on spiral performance at solids feed rates ranging from 15 to 30 kg/min. The results indicated that under certain conditions, a high-quality metal fraction could be produced. For example, using the five-turn spiral, a product containing 95% metal was obtained at a low metal recovery. Both spirals were ineffective at concentrating the aggregate fraction. Overall, the feed solids concentration did not significantly affect the quality or recoveries of the products, particularly for feed solids concentrations less than 35% by weight. In order to improve the metal recoveries and to produce a low-metal aggregate material, reprocessing of the product streams and/or additional liberation of the raw slag would be required.

  10. Deuterium retention in ITER-grade austenitic stainless steel

    Science.gov (United States)

    Nemanič, Vincenc; Žumer, Marko; Zajec, Bojan

    2008-11-01

    In view of the construction of ITER, it is essential to confirm that the retention of tritium by the large interior surface area of stainless steel will not become an issue for safety or operating inventory reasons. Retention of deuterium in ITER-grade austenitic stainless steel samples was studied during t = 24 h exposures to pure gaseous deuterium at p = 0.01 mbar and 0.1 mbar and T = 100 °C, 250 °C and 400 °C, respectively. The required high sensitivity for distinguishing hydrogen isotopes involved in the process (H2, HD and D2) was gained after suppression of the native hydrogen concentration by a thermal treatment at T = 400 °C for t = 200 h. The quantity of retained deuterium was determined by measuring the absolute pressure change during the deuterium exposure and subsequent mass spectrometry revealing an intense isotope exchange reaction. The retained amount of 2.6 × 1016 D cm-2 was the highest at T = 400 °C and p = 0.1 mbar and noticeably less at lower deuterium pressure and temperature. Our results, when compared with similar tritium exposures, do not exceed the limits set in the generic safety analysis for the ITER. They manifest that an extremely high sensitivity for deuterium absorption and release can be gained with a precise pressure measuring technique, otherwise attributed exclusively to tritium scintillation methods.

  11. Determination of delta ferrite volumetric fraction in austenitic stainless steel

    International Nuclear Information System (INIS)

    Almeida Macedo, W.A. de.

    1983-01-01

    Measurements of delta ferrite volumetric fraction in AISI 304 austenitic stainless steels were done by X-ray diffraction, quantitative metallography (point count) and by means of one specific commercial apparatus whose operational principle is magnetic-inductive: The Ferrite Content Meter 1053 / Institut Dr. Foerster. The results obtained were comparated with point count, the reference method. It was also investigated in these measurements the influence of the martensite induced by mechanical deformation. Determinations by X-ray diffraction, by the ratio between integrated intensities of the ferrite (211) and austenite (311) lines, are in excelent agreement with those taken by point count. One correction curve for the lectures of the commercial equipment in focus was obtained, for the range between zero and 20% of delta ferrite in 18/8 stainless steels. It is demonstrated that, depending on the employed measurement method and surface finishing of the material to be analysed, the presence of martensite produced by mechanical deformation of the austenitic matrix is one problem to be considered. (Author) [pt

  12. Determination of delta ferrite volumetric fraction in austenitic stainless steels

    International Nuclear Information System (INIS)

    Almeida Macedo, W.A. de.

    1983-01-01

    Measurements of delta ferrite volumetric fraction in AISI 304 austenitic stainless steels were done by X-ray difraction, quantitative metallography (point count) and by means of one specific commercial apparatus whose operational principle is magnetic-inductive: The Ferrite Content Meter 1053 / Institut Dr. Forster. The results obtained were comparated with point count, the reference method. It was also investigated in these measurements the influence of the martensite induced by mechanical deformation. Determinations by X-ray diffraction, by the ratio between integrated intensities of the ferrite (211) and austenite (311) lines, are in excelent agreement with those taken by point count. One correction curve for the lectures of the commercial equipment in focus was obtained, for the range between zero and 20% of delta ferrite in 18/8 stainless steels. It is demonstrated that, depending on the employed measurement method and surface finishing of the material to be analysed, the presence of martensite produced by mechanical deformation of the austenitic matrix is one problem to be considered. (Author) [pt

  13. Assessment of nickel release from stainless steel crowns.

    Directory of Open Access Journals (Sweden)

    Nahid Ramazani

    2014-06-01

    Full Text Available Adverse effects of dental materials, especially metals, have been an important issue in recent decades.The purpose of this study was to determine the amount of nickel released from stainless steel crowns in artificial saliva.In this in-vitro study, 270 stainless steel crowns were divided into five groups, each with nine subgroups. Each group (I to V was comprised of four, five, six, seven and eight crowns, respectively. Each subgroup was placed in a polyethylene jar containing artificial saliva and held in an incubator at 37°C for four weeks. The amount of released nickel was determined on days 1, 7, 14, 21 and 28, using an atomic absorption spectrophotometer. Wilcoxon Signed-Rank and Kruskal-Wallis with Dunn's post hoc tests (SPSS software, v. 18 were used for statistical analysis at a significance level of 0.05.The mean level of nickel on day 1 was more than that of day 7; this difference was statistically significant for all groups (P < 0.05, except for group II (P = 0.086. Also, the mean difference of released nickel between the groups was significant on day 1 (P = 0.006 and was insignificant on day 7 (P = 0.620. The nickel levels were zero on days 14, 21, and 28.The amount of nickel was below the toxic level and did not exceed the dietary intake.

  14. Aging degradation of cast stainless steel: status and program

    Energy Technology Data Exchange (ETDEWEB)

    Chopra, O.K.; Ayrault, G.

    1983-10-01

    A program has been initiated to investigate the significance of in-service embrittlement of cast duplex stainless steels under light-water reactor operating conditions. The existing data are reviewed to determine the critical parameters that control the aging behavior and to define the objectives and scope of the investigation. The test matrices for microstructural studies and mechanical property measurements are presented. The initial experimental effort is focussed on characterizing the microstructure of long-term, low-temperature aged material. Specimens from three heats of cast CF-8 and CF-8M stainless steel aged for up to 70,000 h at 300, 350, and 400/sup 0/C were obtained from George Fisher Ltd., of Switzerland. Initial analyses reveal the formation of three different types of precipitates which are not ..cap alpha..'. An FCC phase, similar to the M/sub 23/C/sub 6/ precipitates, was present in all the long-term aged material. 15 references, 10 figures, 2 tables.

  15. 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

  16. Multiregion analysis of creep rupture data of 316 stainless steel

    International Nuclear Information System (INIS)

    Maruyama, Kouichi; Armaki, Hassan Ghassemi; Yoshimi, Kyosuke

    2007-01-01

    A creep rupture data set of 316 stainless steel containing 319 data points at nine heats was subjected to a conventional single-region analysis and a multiregion analysis. In the former, the conventional Larson-Miller analysis was applied to the whole data set. In the latter, a data set of a single heat is divided into several data sets, so that the Orr-Sherby-Dorn (OSD) constant Q takes a unique value in each data set, and the conventional OSD analysis was applied to each divided data set. A region with a low value of Q appears in long-term creep of eight heats. Predicted values of the 10 5 h creep rupture stress of three heats were lower than the 99% confidence limit evaluated by the single-region analysis, suggesting that the single-region analysis is error prone. The multiregion analysis is necessary for the correct evaluation of the long-term creep properties of 316 stainless steel

  17. Magnetic anisotropy of ultrafine 316L stainless steel fibers

    Energy Technology Data Exchange (ETDEWEB)

    Shyr, Tien-Wei, E-mail: twshyr@fcu.edu.tw [Department of Fiber and Composite Materials, Feng Chia University, No. 100, Wenhwa Road, Seatwen, Taichung 40724, Taiwan, ROC (China); Huang, Shih-Ju [Department of Fiber and Composite Materials, Feng Chia University, No. 100, Wenhwa Road, Seatwen, Taichung 40724, Taiwan, ROC (China); Wur, Ching-Shuei [Department of Physics, National Cheng Kung University, No. 1, University Road, Tainan 70101, Taiwan, ROC (China)

    2016-12-01

    An as-received 316L stainless steel fiber with a diameter of 20 μm was drawn using a bundle drawing process at room temperature to form ultrafine stainless steel fibers with diameters of 12, 8, and 6 μm. The crystalline phases of the fibers were analyzed using the X-ray diffraction (XRD) profile fitting technique. The grain sizes of γ-austenite and α′-martensite were reduced to nanoscale sizes after the drawing process. XRD analysis and focused ion beam-scanning electron microscope observations showed that the newly formed α′-martensitic grains were closely arrayed in the drawing direction. The magnetic property was measured using a superconducting quantum interference device vibrating sample magnetometer. The magnetic anisotropy of the fibers was observed by applying a magnetic field parallel and perpendicular to the fiber axis. The results showed that the microstructure anisotropy including the shape anisotropy, magnetocrystalline anisotropy, and the orientation of the crystalline phases strongly contributed to the magnetic anisotropy. - Highlights: • The martensitic transformation of the 316L SS fiber occurred during the cold drawn. • The grain sizes of γ-austenite and α′-martensite were reduced to the nanoscale. • The newly formed martensitic grains were closely arrayed in the drawing direction. • The drawing process caused the magnetic easy axis to be aligned with the fiber axis. • The microstructure anisotropy strongly contributed to the magnetic anisotropy.

  18. Stainless Steel RSM Beneficial Reuse technical feasibility to business reality

    International Nuclear Information System (INIS)

    Boettinger, W.L.; Mishra, G.

    1997-08-01

    The Stainless Steel Beneficial Reuse Program began in 1994 as a demonstration funded by the DOE Office of Science and Technology. The purpose was to assess the practicality of stainless steel radioactive scrap metal (RSM) recycle. Technical feasibility has been demonstrated through the production of a number of products made from recycled RSM. A solid business foundation is yet to be achieved. However, a business environment is beginning to develop as multiple markets and applications for RSM are surfacing around the Complex. The criteria for a successful business reality includes: - affordable programs, - a continuing production base from which to expand, - real products needs, -adequate RSM supply, and - a multi-year program This program currently sponsored by SRS and DOE-ORO to fabricate Defense Waste Processing Facility (DWPF) canisters from RSM provides an activity that satisfies these criteria. The program status is discussed. A comparison of the cost of DWPF canisters fabricated from recycled RSM and virgin metal is presented. The comparison is a function of several factors: disposal costs, the fabrication cost of virgin metal canisters, the fabrication cost of recycled RSM canisters, free release decontamination costs, and the cost to accumulate the RSM. These variables are analyzed and the relationship established to show the break-even point for various values of each parameter

  19. Evaluation of stainless steel pipe cracking: causes and fixes

    International Nuclear Information System (INIS)

    Shack, W.J.; Kassner, T.F.; Maiya, P.S.; Nichols, F.A.; Park, J.Y.; Ruther, W.; Rybicki, E.F.

    1985-01-01

    This paper discusses (1) studies of impurity effects on susceptibility to intergranular stress corrosion cracking (IGSCC), (2) intergranular crack growth rate measurements, (3) finite-element studies of the residual stresses produced by induction heating stress improvement (IHSI) and the addition of weld overlays to flawed piping, (4) leak-before-break analyses of piping with 360 deg part-through cracks, and (5) parametric studies on the effect of through-wall residual stresses on intergranular crack growth behavior in large diameter piping weldments. The studies on the effect of impurities on IGSCC of Type 304 stainless steel show a strong synergistic interaction between dissolved oxygen and impurity concentration of the water. Low carbon stainless steels (Type 316NG) appear resistant to IGSCC even in impurity environments. However, they can become susceptible to transgranular SCC with low levels of sulfate or chloride present in the environment. The finite-element calculations show that IHSI and the weld overlay produce compressive residual stresses on the inner surface, and that the stresses at the crack tip remain compressive under design loads at least for shallow cracks. (author)

  20. Benchmark experiments to test plutonium and stainless steel cross sections

    International Nuclear Information System (INIS)

    Jenquin, U.P.; Bierman, S.R.

    1978-06-01

    Neutronics calculations of physical systems containing fissionable material in various configurations are often necessary to assess criticality safety and economic parameters. Criticality safety of the material must be assured for all configurations in the fuel fabrication, spent fuel reprocessing, and transportation processes. Integral criticality experiments are utilized to evaluate neutron cross sections, test theoretical methods, and validate calculational procedures. The Nuclear Regulatory Commission (NRC) commissioned Battelle, Pacific Northwest Laboratory (PNL) to ascertain the accuracy of the neutron cross sections for the isotopes of plutonium and the constituents of stainless steel and determine if improvements can be made in application to criticality safety analysis. NRC's particular area of interest is in the transportation of light--water reactor spent fuel assemblies. The project was divided into two tasks. The first task was to define a set of integral experimental measurements (benchmarks). The second task is to use these benchmarks in neutronics calculations such that the accuracy of ENDF/B-IV plutonium and stainless steel cross sections can be assessed. The results of the second task should help to identify deficiencies in the neutron cross sections. The results of the first task are given

  1. Dynamical recrystallization of high purity austenitic stainless steels

    International Nuclear Information System (INIS)

    Gavard, L.

    2001-01-01

    The aim of this work is to optimize the performance of structural materials. The elementary mechanisms (strain hardening and dynamical regeneration, germination and growth of new grains) occurring during the hot working of metals and low pile defect energy alloys have been studied for austenitic stainless steels. In particular, the influence of the main experimental parameters (temperature, deformation velocity, initial grain size, impurities amount, deformation way) on the process of discontinuous dynamical recrystallization has been studied. Alloys with composition equal to those of the industrial stainless steel-304L have been fabricated from ultra-pure iron, chromium and nickel. Tests carried out in hot compression and torsion in order to cover a wide range of deformations, deformation velocities and temperatures for two very different deformation ways have allowed to determine the rheological characteristics (sensitivity to the deformation velocity, apparent activation energy) of materials as well as to characterize their microstructural deformations by optical metallography and electron back-scattered diffraction. The influence of the initial grain size and the influence of the purity of the material on the dynamical recrystallization kinetics have been determined. An analytical model for the determination of the apparent mobility of grain boundaries, a semi-analytical model for the dynamical recrystallization and at last an analytical model for the stationary state of dynamical recrystallization are proposed as well as a new criteria for the transition between the refinement state and the state of grain growth. (O.M.)

  2. Water Lubrication of Stainless Steel using Reduced Graphene Oxide Coating

    Science.gov (United States)

    Kim, Hae-Jin; Kim, Dae-Eun

    2015-01-01

    Lubrication of mechanical systems using water instead of conventional oil lubricants is extremely attractive from the view of resource conservation and environmental protection. However, insufficient film thickness of water due to low viscosity and chemical reaction of water with metallic materials have been a great obstacle in utilization of water as an effective lubricant. Herein, the friction between a 440 C stainless steel (SS) ball and a 440 C stainless steel (SS) plate in water lubrication could be reduced by as much as 6-times by coating the ball with reduced graphene oxide (rGO). The friction coefficient with rGO coated ball in water lubrication was comparable to the value obtained with the uncoated ball in oil lubrication. Moreover, the wear rate of the SS plate slid against the rGO coated ball in water lubrication was 3-times lower than that of the SS plate slid against the uncoated ball in oil lubrication. These results clearly demonstrated that water can be effectively utilized as a lubricant instead of oil to lower the friction and wear of SS components by coating one side with rGO. Implementation of this technology in mechanical systems is expected to aid in significant reduction of environmental pollution caused by the extensive use of oil lubricants. PMID:26593645

  3. Deformation in type 304 austenitic stainless steel. Final report

    International Nuclear Information System (INIS)

    Kumar, V.; Mukherjee, S.; Huang, F.H.; Li, C.Y.

    1979-12-01

    Extensive experimental and theoretical work on Type 304 stainless steel to demonstrate the applicability of a state variable approach in materials testing and in stress analysis are reported. The state variable approach adopted has been shown recently to be able to describe the deformation properties of a variety of materials accurately with constitutive equations in the form of mechanical equation of state. It has been shown that the effort required in materials testing to determine the parameters of the constitutive equations is considerably less compared to that required for equations based on the traditional approach. During the course of the work a set of constitutive equations based on state variables for Type 304 stainless steel were established with all the required parameters determined experimentally. Numerical codes for uniaxial deformation and for bending of a beam were developed and used to predict the results of component testing. The code predictions were found to agree well with experimental data. The same constitutive equations were also incorporated into two versions of NONFIN, a finite element stress analysis code; one for Honeywell Computers and the other for IBM Computers. Both versions ran successfully and economically

  4. EBSD study of a hot deformed austenitic stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Mirzadeh, H., E-mail: h-m@gmx.com [Departamento de Ciencia de los Materiales e Ingenieria Metalurgica, ETSEIB, Universitat Politecnica de Catalunya, Av. Diagonal 647, 08028 Barcelona (Spain); Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Cabrera, J.M. [Departamento de Ciencia de los Materiales e Ingenieria Metalurgica, ETSEIB, Universitat Politecnica de Catalunya, Av. Diagonal 647, 08028 Barcelona (Spain); Fundacio CTM Centre Tecnologic, Av. Bases de Manresa 1, 08242 Manresa (Spain); Najafizadeh, A. [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Calvillo, P.R. [Departamento de Ciencia de los Materiales e Ingenieria Metalurgica, ETSEIB, Universitat Politecnica de Catalunya, Av. Diagonal 647, 08028 Barcelona (Spain); Fundacio CTM Centre Tecnologic, Av. Bases de Manresa 1, 08242 Manresa (Spain)

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer Microstructural characterization of an austenitic stainless steel by EBSD. Black-Right-Pointing-Pointer The role of twins in the nucleation and growth of dynamic recrystallization. Black-Right-Pointing-Pointer Grain refinement through the discontinuous dynamic recrystallization. Black-Right-Pointing-Pointer Determination of recrystallized fraction using the grain average misorientation. Black-Right-Pointing-Pointer Relationship between recrystallization and the frequency of high angle boundaries. - Abstract: The microstructural evolution of a 304 H austenitic stainless steel subjected to hot compression was studied by the electron backscattered diffraction (EBSD) technique. Detailed data about the boundaries, coincidence site lattice (CSL) relationships and grain size were acquired from the orientation imaging microscopy (OIM) maps. It was found that twins play an important role in the nucleation and growth of dynamic recrystallization (DRX) during hot deformation. Moreover, the conventional discontinuous DRX (DDRX) was found to be in charge of grain refinement reached under the testing conditions studied. Furthermore, the recrystallized fraction (X) was determined from the grain average misorientation (GAM) distribution based on the threshold value of 1.55 Degree-Sign . The frequency of high angle boundaries showed a direct relationship with X. A time exponent of 1.11 was determined from Avrami analysis, which was related to the observed single-peak behavior in the stress-strain flow curves.

  5. A Study on Structural, Corrosion, and Sensitization Behavior of Ultrafine and Coarse Grain 316 Stainless Steel Processed by Multiaxial Forging and Heat Treatment

    Science.gov (United States)

    Kiahosseini, Seyed Rahim; Mohammadi Baygi, Seyyed Javad; Khalaj, Gholamreza; Khoshakhlagh, Ali; Samadipour, Razieh

    2018-01-01

    Cubic specimens from AISI 316 stainless steel were multiaxially forged to 15 passes and annealed at 1200 °C for 1, 2, and 3 h and finally sensitized at 700 °C for 24 h. Examination of samples indicated that the hardness of the annealed samples was reduced from 153 to 110, 81, and 74 HV for as-received sample and under 1, 2, and 3 h of annealing, and increased from 245 to 288 HV for samples forged at 3 and 7 passes. However, no significant changes were observed in a large number of passes and at about 300 HV. Degree of sensitization of samples was increased to approximately 27.3% at 3-h annealing but reduced to 1.23% by 15 passes of MF. The potentiodynamic polarization test shows that the breakdown potentials decreased with annealing time from 0.6 to - 102 (mV/SCE) for as-received and 3-h annealed specimen. These potentials increased to approximately - 16.5 mV with the increase in MF passes to 15. These observations indicated that the chromium carbide deposition affects Cr-depleted zone, which can subsequently affect the degree of sensitization and pitting corrosion resistance of AISI 316 austenitic stainless steel.

  6. Development of stainless steels for nuclear power plant - Advanced nuclear materials development -

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Jun Hwa; Ryu, Woo Seog; Chi, Se Hwan; Lee, Bong Sang; Oh, Yong Jun; Byun, Thak Sang; Oh, Jong Myung [Korea Atomic Energy Res. Inst., Taejon (Korea, Republic of)

    1994-07-01

    This report reviews the status of R and D and the material specifications of nuclear components in order to develop the stainless steels for nuclear applications, and the technology of computer-assisted alloy design is developed to establish the thermodynamic data of Fe-Cr-Ni-Mo-Si-C-N system which is the basic stainless steel systems. High strength and corrosion resistant stainless steels, 316LN and super clean 347, are developed, and the manufacturing processes and heat treatment conditions are determined. In addition, a martensitic steel is produced as a model alloy for turbine blade, and characterized. The material properties showed a good performance for nuclear applications. (Author).

  7. Development of stainless steels for nuclear power plant - Advanced nuclear materials development -

    International Nuclear Information System (INIS)

    Hong, Jun Hwa; Ryu, Woo Seog; Chi, Se Hwan; Lee, Bong Sang; Oh, Yong Jun; Byun, Thak Sang; Oh, Jong Myung

    1994-07-01

    This report reviews the status of R and D and the material specifications of nuclear components in order to develop the stainless steels for nuclear applications, and the technology of computer-assisted alloy design is developed to establish the thermodynamic data of Fe-Cr-Ni-Mo-Si-C-N system which is the basic stainless steel systems. High strength and corrosion resistant stainless steels, 316LN and super clean 347, are developed, and the manufacturing processes and heat treatment conditions are determined. In addition, a martensitic steel is produced as a model alloy for turbine blade, and characterized. The material properties showed a good performance for nuclear applications. (Author)

  8. Effect of Titanium on the Microstructure and Mechanical Properties of High-Carbon Martensitic Stainless Steel 8Cr13MoV

    Directory of Open Access Journals (Sweden)

    Wen-Tao Yu

    2016-08-01

    Full Text Available The effect of titanium on the carbides and mechanical properties of martensitic stainless steel 8Cr13MoV was studied. The results showed that TiCs not only acted as nucleation sites for δ-Fe and eutectic carbides, leading to the refinement of the microstructure, but also inhibited the formation of eutectic carbides M7C3. The addition of titanium in steel also promoted the transformation of M7C3-type to M23C6-type carbides, and consequently more carbides could be dissolved into the matrix during hot processing as demonstrated by the determination of extracted carbides from the steel matrix. Meanwhile, titanium suppressed the precipitation of secondary carbides during annealing. The appropriate amount of titanium addition decreased the size and fraction of primary carbides in the as-cast ingot, and improved the mechanical properties of the annealed steel.

  9. Microstructure Refinement and Mechanical Properties of 304 Stainless Steel by Repetitive Thermomechanical Processing

    Science.gov (United States)

    Al-Fadhalah, Khaled; Aleem, Muhammad

    2018-01-01

    Repetitive thermomechanical processing (TMP) was applied for evaluating the effect of strain-induced α'-martensite transformation and reversion annealing on microstructure refinement and mechanical properties of 304 austenitic stainless steel. The first TMP scheme consisted of four cycles of tensile deformation to strain of 0.4, while the second TMP scheme applied two cycles of tensile straining to 0.6. For both schemes, tensile tests were conducted at 173 K (- 100 °C) followed by 5-minute annealing at 1073 K (800 °C). The volume fraction of α'-martensite in deformed samples increased with increasing cycles, reaching a maximum of 98 vol pct. Examination of annealed microstructure by electron backscattered diffraction indicated that increasing strain and/or number of cycles resulted in stronger reversion to austenite with finer grain size of 1 μm. Yet, increasing strain reduced the formation of Σ3 boundaries. The annealing textures generally show reversion of α'-martensite texture components to the austenite texture of brass and copper orientations. The increase in strain and/or number of cycles resulted in stronger intensity of copper orientation, accompanied by the formation of recrystallization texture components of Goss, cube, and rotated cube. The reduction in grain size with increasing cycles caused an increase in yield strength. It also resulted in an increase in strain hardening rate during deformation due to the increase in the formation of α'-martensite. The increase in strain hardening rate occurred in two consecutive stages, marked as stages II and III. The strain hardening in stage II is due to the formation of α'-martensite from either austenite or ɛ-martensite, while the stage-III strain hardening is attributed to the necessity to break the α'-martensite-banded structure for forming block-type martensite at high strains.

  10. Influence of hydrogen on the corrosion behavior of stainless steels in lithium

    Science.gov (United States)

    Shulga, A. V.

    2008-02-01

    Corrosion behavior of several stainless steels in lithium and lithium with 0.05%H has been examined. Corrosion tests were performed under static conditions at 600 and 700 °C in the austenitic stainless steel of the type AISI 304 containers. Intensive formation of σ-phase of the composition Fe 50Cr 43Mo 3Ni 4 on the surface of austenitic stainless steels of the type AISI 316 at 700 °C for 1000 h was established as a result of isothermal mass transfer. Addition of 0.05%H in the form of LiH to lithium resulted in an increase in the quantity of the σ-phase. After corrosion tests of ferritic/martensitic steel in lithium at 700 °C for 1000 h the formation of the γ-phase was observed. In Li + 0.05%H besides the γ-phase was also formed the σ-phase. The features of decarburization of investigated stainless steels were examined using the direct method of activation autoradiography on carbon. Addition of 0.05%H in lithium significantly decreased the carbon content in the decarburization zone of austenitic stainless steel Fe-18Cr-15Ni-0.15C-0.23B without a noticeable change in the thickness of the decarburization zone. Decarburization of ferritic/martensitic stainless steel was less than of austenitic stainless steel using the same corrosion tests.

  11. Attenuation of shock waves in copper and stainless steel

    International Nuclear Information System (INIS)

    Harvey, W.B.

    1986-06-01

    By using shock pins, data were gathered on the trajectories of shock waves in stainless steel (SS-304L) and oxygen-free-high-conductivity copper (OFHC-Cu). Shock pressures were generated in these materials by impacting the appropriate target with thin (approx.1.5 mm) flying plates. The flying plates in these experiments were accelerated to high velocities (approx.4 km/s) by high explosives. Six experiments were conducted, three using SS-304L as the target material and three experiments using OFHC-Cu as the target material. Peak shock pressures generated in the steel experiments were approximately 109, 130, and 147 GPa and in the copper experiments, the peak shock pressures were approximately 111, 132, and 143 GPa. In each experiment, an attenuation of the shock wave by a following release wave was clearly observed. An extensive effort using two characteristic codes (described in this work) to theoretically calculate the attenuation of the shock waves was made. The efficacy of several different constitutive equations to successfully model the experiments was studied by comparing the calculated shock trajectories to the experimental data. Based on such comparisons, the conclusion can be drawn that OFHC-Cu enters a melt phase at about 130 GPa on the principal Hugoniot. There was no sign of phase changes in the stainless-steel experiments. In order to match the observed attenuation of the shock waves in the SS-304L experiments, it was necessary to include strength effects in the calculations. It was found that the values for the parameters in the strength equations were dependent on the equation of state used in the modeling of the experiments. 66 refs., 194 figs., 77 tabs

  12. Attenuation of shock waves in copper and stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Harvey, W.B.

    1986-06-01

    By using shock pins, data were gathered on the trajectories of shock waves in stainless steel (SS-304L) and oxygen-free-high-conductivity copper (OFHC-Cu). Shock pressures were generated in these materials by impacting the appropriate target with thin (approx.1.5 mm) flying plates. The flying plates in these experiments were accelerated to high velocities (approx.4 km/s) by high explosives. Six experiments were conducted, three using SS-304L as the target material and three experiments using OFHC-Cu as the target material. Peak shock pressures generated in the steel experiments were approximately 109, 130, and 147 GPa and in the copper experiments, the peak shock pressures were approximately 111, 132, and 143 GPa. In each experiment, an attenuation of the shock wave by a following release wave was clearly observed. An extensive effort using two characteristic codes (described in this work) to theoretically calculate the attenuation of the shock waves was made. The efficacy of several different constitutive equations to successfully model the experiments was studied by comparing the calculated shock trajectories to the experimental data. Based on such comparisons, the conclusion can be drawn that OFHC-Cu enters a melt phase at about 130 GPa on the principal Hugoniot. There was no sign of phase changes in the stainless-steel experiments. In order to match the observed attenuation of the shock waves in the SS-304L experiments, it was necessary to include strength effects in the calculations. It was found that the values for the parameters in the strength equations were dependent on the equation of state used in the modeling of the experiments. 66 refs., 194 figs., 77 tabs.

  13. Significance of stainless steel wire reinforcement on the mechanical properties of GFRP composites

    OpenAIRE

    K. Pazhanivel; G.B. Bhaskar; A.Elayaperumal

    2014-01-01

    Investigations on flexural and tensile properties of GFRP laminates influenced by stainless steel wire reinforcement were carried out as a novel approach. Plain GFRP laminates and GFRP laminates reinforced with stainless steel wires at different depth with various pitch distances were fabricated by hand layup method. The composite specimens reinforced with steel wires were exposed to low frequency high amplitude cyclic load by using a cam arrangement. Three point bend test was carried out on ...

  14. Effects of nitrogen on corrosion of stainless steels in a liquid sodium environment

    International Nuclear Information System (INIS)

    Suzuki, Tadashi; Mutoh, Isao

    1990-01-01

    The corrosion of ferritic stainless steels using sodium at 650degC in a maximum isothermal region contained in a non-isothermal sodium loop constructed of a Type 316 stainless steel has been examined. Also, previous results on corrosion of austenitic stainless steels in sodium at 700degC in the same loop have been reproduced. The selective dissolution and absorption of nickel, the selective dissolution of chromium, and the resultant increase in iron in the surface of stainless steels in the loop mainly determine the corrosion loss of the stainless steel specimens. The austenitic steels hardly decarburize, but denitride. The ferritic steels decarburize and denitride and the denitriding is more remarkable than the decarburizing. The vanadium and niobium, carbide and nitride formers, in the ferritic steels inhibit the decarburizing to some extent, but barely inhibit the denitriding. The nitrogen in the steels rapidly diffuses to the grain boundaries, and rapidly dissolves into sodium, which will lower surface energy of the steels to enhance the dissolution of other elements. The dissolved N in sodium would then be transported to the free surface of the sodium adjacent to the argon cover gas of sodium and easily be released into the cover gas. This mechanism would cause the rapid dissolution of nitrogen into sodium and the enhancement of the corrosion rate of the steels containing nitrogen. (orig.)

  15. Influence of silver additions to type 316 stainless steels on bacterial inhibition, mechanical properties, and corrosion resistance

    DEFF Research Database (Denmark)

    Chiang, Wen-Chi; Tseng, I-Sheng; Møller, Per

    2010-01-01

    techniques. The microstructure of these 316 stainless steels was examined, and the influences of silver additions to 316 stainless steels on bacterial inhibition, mechanical properties, and corrosion resistance were investigated. This study suggested that silver-bearing 316 stainless steels could be used......Bacterial contamination is a major concern in many areas. In this study, silver was added to type 316 stainless steels in order to obtain an expected bacteria inhibiting property to reduce the occurrence of bacterial contamination. Silver-bearing 316 stainless steels were prepared by vacuum melting...

  16. Texture Analysis using The Neutron Diffraction Method on The Non Standardized Austenitic Steel Process by Machining,Annealing, and Rolling

    Directory of Open Access Journals (Sweden)

    Tri Hardi Priyanto

    2016-04-01

    Full Text Available Austenitic steel is one type of stainless steel which is widely used in the industry. Many studies on  austenitic stainless steel have been performed to determine the physicalproperties using various types of equipment and methods. In this study, the neutron diffraction method is used to characterize the materials which have been made from  minerals extracted from the mines in Indonesia. The materials consist of a granular ferro-scrap, nickel, ferro-chrome, ferro-manganese, and ferro-silicon added with a little titanium. Characterization of the materials was carried out in threeprocesses, namely: machining, annealing, and rolling. Experimental results obtained from the machining process generally produces a texture in the 〈100〉direction. From the machining to annealing process, the texture index decreases from 3.0164 to 2.434.Texture strength in the machining process (BA2N sample is  8.13 mrd and it then decreases to 6.99 in the annealing process (A2DO sample. In the annealing process the three-component texture appears, cube-on-edge type texture{110}〈001〉, cube-type texture {001}〈100〉, and brass-type {110}〈112〉. The texture is very strong leading to the direction of orientation {100}〈001〉, while the {011}〈100〉is weaker than that of the {001}, and texture withorientation {110}〈112〉is weak. In the annealing process stress release occurred, and this was shown by more randomly pole compared to stress release by the machining process. In the rolling process a brass-type texture{110}〈112〉with a spread towards the goss-type texture {110}〈001〉 appeared,  and  the  brass  component  is markedly  reinforced  compared  to  the undeformed state (before rolling. Moreover, the presence of an additional {110} component was observed at the center of the (110 pole figure. The pole density of three components increases withthe increasing degree of thickness reduction. By increasing degrees

  17. Characterization of microstructure and texture across dissimilar super duplex/austenitic stainless steel weldment joint by super duplex filler metal

    Energy Technology Data Exchange (ETDEWEB)

    Eghlimi, Abbas, E-mail: a.eghlimi@ma.iut.ac.ir [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Shamanian, Morteza [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Eskandarian, Masoomeh [Department of Materials Engineering, Shiraz University, Shiraz 71348-51154 (Iran, Islamic Republic of); Zabolian, Azam [Department of Natural Resources, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Szpunar, Jerzy A. [Department of Mechanical Engineering, University of Saskatchewan, Saskatoon SK S7N 5A9 (Canada)

    2015-08-15

    In the present paper, microstructural changes across an as-welded dissimilar austenitic/duplex stainless steel couple welded by a super duplex stainless steel filler metal using gas tungsten arc welding process is characterized with optical microscopy and electron back-scattered diffraction techniques. Accordingly, variations of microstructure, texture, and grain boundary character distribution of base metals, heat affected zones, and weld metal were investigated. The results showed that the weld metal, which was composed of Widmanstätten austenite side-plates and allotriomorphic grain boundary austenite morphologies, had the weakest texture and was dominated by low angle boundaries. The welding process increased the ferrite content but decreased the texture intensity at the heat affected zone of the super duplex stainless steel base metal. In addition, through partial ferritization, it changed the morphology of elongated grains of the rolled microstructure to twinned partially transformed austenite plateaus scattered between ferrite textured colonies. However, the texture of the austenitic stainless steel heat affected zone was strengthened via encouraging recrystallization and formation of annealing twins. At both interfaces, an increase in the special character coincident site lattice boundaries of the primary phase as well as a strong texture with <100> orientation, mainly of Goss component, was observed. - Graphical abstract: Display Omitted - Highlights: • Weld metal showed local orientation at microscale but random texture at macroscale. • Intensification of <100> orientated grains was observed adjacent to the fusion lines. • The austenite texture was weaker than that of the ferrite in all duplex regions. • Welding caused twinned partially transformed austenites to form at SDSS HAZ. • At both interfaces, the ratio of special CSL boundaries of the primary phase increased.

  18. Special Features of Induction Annealing of Friction Stir Welded Joints of Medium-Alloy Steels

    Science.gov (United States)

    Priymak, E. Yu.; Stepanchukova, A. V.; Bashirova, E. V.; Fot, A. P.; Firsova, N. V.

    2018-01-01

    Welded joints of medium-alloy steels XJY750 and 40KhN2MA are studied in the initial condition and after different variants of annealing. Special features of the phase transformations occurring in the welded steels are determined. Optimum modes of annealing are recommended for the studied welded joints of drill pipes, which provide a high level of mechanical properties including the case of impact loading.

  19. Positron beam and RBS studies of thermally grown oxide films on stainless steel grade 304

    Science.gov (United States)

    Horodek, P.; Siemek, K.; Kobets, A. G.; Kulik, M.; Meshkov, I. N.

    2015-04-01

    The formation of oxide films on surfaces of stainless steel 304 AISI annealed at 800 °C in vacuum, air and in flow N2 atmospheres was studied using variable energy positron beam technique (VEP) and Rutherford backscattering/nuclear reaction (RBS/NR) methods. In frame of these studies, Doppler broadening of annihilation line (DB) measurements were performed. For a sample heated in vacuum the oxide film ca. 8 nm is observed. For specimens oxidized in air and N2 the multi-layered oxide films of about a few hundred nanometers are recognized. The RBS/NR measurements have shown that the sample annealed in vacuum contains a lower quantity of oxygen while for samples heated in the air and N2 non-linear and rather linear time-dependency are observed, respectively. The thicknesses of total oxide films obtained from RBS/NR tests are in good agreement with the VEP results. Time evolution of the oxide growing was studied as well.

  20. Effect of Plastic Deformation on the Corrosion Behavior of a Super-Duplex Stainless Steel

    Science.gov (United States)

    Renton, Neill C.; Elhoud, Abdu M.; Deans, William F.

    2011-04-01

    The role of plastic deformation on the corrosion behavior of a 25Cr-7Ni super-duplex stainless steel (SDSS) in a 3.5 wt.% sodium chloride solution at 90 °C was investigated. Different levels of plastic strain between 4 and 16% were applied to solution annealed tensile specimens and the effect on the pitting potential measured using potentiodynamic electrochemical techniques. A nonlinear relationship between the pitting potential and the plastic strain was recorded, with 8 and 16% causing a significant reduction in average E p, but 4 and 12% causing no significant change when compared with the solution-annealed specimens. The corrosion morphology revealed galvanic interaction between the anodic ferrite and the cathodic austenite causing preferential dissolution of the ferrite. Mixed potential theory and the changing surface areas of the two phases caused by the plastic deformation structures explain the reductions in pitting potential at certain critical plastic strain levels. End-users and manufacturers should evaluate the corrosion behavior of specific cold-worked duplex and SDSSs using their as-produced surface finishes assessing in-service corrosion performance.