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Sample records for fabricate ratcheting stainless-steel

  1. Experimental Study on Uniaxial and Multiaxial Strain Cyclic Characteristics and Ratcheting of 316L Stainless Steel

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    An experimental study was carried out on the strain cycliccharacteristics and ratcheting of 316Lstainless steel subjected to uniaxial and multiaxial cyclic loading. The strain cyclic characteristics were researched under the strain-controlled uniaxial tension-compression and multiaxial circular paths of loading. The ratcheting tests were conducted for the stress-controlled uniaxial tensioncompression and multiaxial circular, rhombic and linear paths of loading with different mean stresses, stress amplitudes and histories. The experiment results show that 316L stainless steel features the cyclic hardening, and its strain cyclic characteristics depend on the strain amplitude and its history apparently. The ratcheting of 316L stainless steel depends greatly on the values of mean stress, stress amplitude and their histories. In the meantime, the shape of load path and its history also apparently influence the ratcheting.

  2. Ratcheting Behavior of a Non-conventional Stainless Steel and Associated Microstructural Variations

    Science.gov (United States)

    Sahu, Lopamudra; Mishra, Awanish Kumar; Dutta, Krishna

    2014-11-01

    Ratcheting fatigue behavior of a non-conventional stainless steel X12CrMnNiN17-7-5 has been investigated with varying combinations of mean stress (σm) and stress amplitude (σa) at room temperature using a servo-hydraulic universal testing machine. X-ray diffraction profile analysis has been carried out for assessing possible martensitic phase transformation in the steel subjected to ratcheting deformation. The results indicate that ratcheting strain as well as volume fraction of martensite increases with increasing σm and/or σa; the phenomenon of strain accumulation is considered to be governed by the associated mechanics of cyclic loading, increased plastic damage as well as martensitic transformation. A correlation between strain produced by ratcheting deformation and martensitic transformation has been established.

  3. Uniaxial Time-Dependent Ratcheting of SS304 Stainless Steel at High Temperatures

    Institute of Scientific and Technical Information of China (English)

    KANG Guo-zheng; ZHANG Juan; SUN Ya-fang; KAN Qian-hua

    2007-01-01

    The uniaxial time-dependent strain cyclic behaviors and ratcheting of SS304 stainless steel were studied at high temperatures (350 ℃ and 700 ℃). The effects of straining and stressing rates, holding time at the peak and/or valley of each cycle in addition to ambient temperature on the cyclic softening/hardening behavior and ratcheting of the material were discussed. It can be seen from experimental results that the material presents remarkable time dependence at 700 ℃, and the ratcheting strain depends greatly on the stressing rate, holding time and ambient temperature. Some significant conclusions are obtained, which are useful to build a constitutive model describing the time-dependent cyclic deformation of the material.

  4. Predicting the ratcheting strain of 304 stainless steel by considering yield surface distortion and using a viscoplastic model

    Energy Technology Data Exchange (ETDEWEB)

    Ahmadi, Nabi; Nayebi, Ali [Shiraz University, Shiraz (Iran, Islamic Republic of)

    2015-07-15

    Yield surface distortion and its center movement were employed in a unified viscoplastic model to predict the ratcheting behavior of the 304 stainless steel. A combination of the Ohno-Wang model and the yield surface distortion model of Baltov and Sawczuk was used in uniaxial loading. Stress amplitude and the mean stress were varied in the tests to verify the model. Uniaxial loadings were simulated with and without consideration of yield surface distortion. Results from both simulations were compared. Yield surface distortion showed a significant effect on the simulation of the ratcheting responses.

  5. Fabrication of stainless steel foil utilizing chromized steel strip

    Science.gov (United States)

    Loria, Edward A.

    1980-10-01

    Stainless steel foil has properties which are, in many respects, unmatched by alternative thin films. The high strength to weight ratio and resistance to corrosion and oxidation at elevated temperatures are generally advantageous. The aerospace and automotive industries have used Type 430 and 304 foil in turbine engine applications. Foil around 2 mils (5.1 × 10-3 cm) thick has been appropriate for the recuperator or heat exchanger and this product has also been used in honeycomb and truss-core structures. Further, such foil has been employed as a wrap to protect tool steel parts from contamination during heat treating. A large part of the high cost of producing stainless steel foil by rolling is due to the complicated and expensive rolling mill and annealing equipment involved. A method will be described which produces (solid) stainless steel foil from chromized (coated) steel which can be cheaper than the conventional processing stainless steel, such as Type 430, from ingot to foil. Also, the material is more ductile and less work hardenable during processing to foil and consequently intermediate annealing treatments are eliminated and scrap losses minimized.

  6. Superhydrophobic surfaces fabricated by microstructuring of stainless steel using a femtosecond laser

    Energy Technology Data Exchange (ETDEWEB)

    Wu Bo [Center for Photon Manufacturing Science and Technology, Jiangsu University, Zhenjiang, Jiangsu 212013 (China); School of Mechanical Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013 (China); Zhou Ming, E-mail: zm_laser@126.com [Center for Photon Manufacturing Science and Technology, Jiangsu University, Zhenjiang, Jiangsu 212013 (China); Li Jian; Ye Xia; Li Gang; Cai Lan [Center for Photon Manufacturing Science and Technology, Jiangsu University, Zhenjiang, Jiangsu 212013 (China)

    2009-10-15

    Fabrication of superhydrophobic surfaces induced by femtosecond laser is a research hotspot of superhydrophobic surface studies nowadays. We present a simple and easily-controlled method for fabricating stainless steel-based superhydrophobic surfaces. The method consists of microstructuring stainless steel surfaces by irradiating samples with femtosecond laser pulses and silanizing the surfaces. By low laser fluence, we fabricated typical laser-induced periodic surface structures (LIPSS) on the submicron level. The apparent contact angle (CA) on the surface is 150.3 deg. With laser fluence increasing, we fabricated periodic ripples and periodic cone-shaped spikes on the micron scale, both covered with LIPSS. The stainless steel-based surfaces with micro- and submicron double-scale structure have higher apparent CAs. On the surface of double-scale structure, the maximal apparent CA is 166.3 deg. and at the same time, the sliding angle (SA) is 4.2 deg.

  7. Fabrication of High Strength and Ductile Stainless Steel Fiber Felts by Sintering

    Science.gov (United States)

    Wang, J. Z.; Tang, H. P.; Qian, M.; Li, A. J.; Ma, J.; Xu, Z. G.; Li, C. L.; Liu, Y.; Wang, Y.

    2016-03-01

    Stainless steel fiber felts are important porous stainless steel products for a variety of industry applications. A systematic study of the sintering of 28- µm stainless steel fibers has been conducted for the first time, assisted with synchrotron radiation experiments to understand the evolution of the sintered joints. The critical sintering conditions for the formation of bamboo-like grain structures in the fiber ligaments were identified. The evolution of the number density of the sintered joints and the average sintered neck radius during sintering was assessed based on synchrotron radiation experiments. The optimum sintering condition for the fabrication of high strength and ductile 28- µm-diameter stainless steel fiber felts was determined to be sintering at 1000°C for 900 s. Sintering under this optimum condition increased the tensile strength of the as-sintered stainless steel fiber felts by 50% compared to conventional sintering (1200°C for 7200 s), in addition to much reduced sintering cycle and energy consumption.

  8. Fabrication of stainless steel clad tubing. [gas pressure bonding

    Science.gov (United States)

    Kovach, C. W.

    1978-01-01

    The feasibility of producing stainless steel clad carbon steel tubing by a gas pressure bonding process was evaluated. Such a tube product could provide substantial chromium savings over monolithic stainless tubing in the event of a serious chromium shortage. The process consists of the initial assembly of three component tubesets from conventionally produced tubing, the formation of a strong metallurgical bond between the three components by gas pressure bonding, and conventional cold draw and anneal processing to final size. The quality of the tubes produced was excellent from the standpoint of bond strength, mechanical, and forming properties. The only significant quality problem encountered was carburization of the stainless clad by the carbon steel core which can be overcome by further refinement through at least three different approaches. The estimated cost of clad tubing produced by this process is greater than that for monolithic stainless tubing, but not so high as to make the process impractical as a chromium conservation method.

  9. 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.

  10. Solution Fabrication of a Superconducting MgB2 Coated Conductor on Stainless Steel

    Institute of Scientific and Technical Information of China (English)

    WANG Yin-Bo; CHEN Li-Ping; ZHANG Chen; WANG Yue; GUO Zheng-Shan; CHEN Yi-Ling; FENG Qing-Rong; GAN Zi-Zhao

    2012-01-01

    We report the solution fabrication of a MgB2 coated conductor on a stainless steel substrate. The precursor solution of Mg(BH4)2 diethyl ether is initially synthesized by refluxing the milled mixture of NaBH4 and MgCl2 in diethyl ether. Then the Mg(BH4)2 diethyl ether is spin coated on a stainless steel substrate and annealed in Mg vapor, which yields a homogeneous MgB2 coated conductor. X-ray diffraction indicates that the grown MgB2 coated conductor is polycrystalline. It has a superconducting transition temperature of 34-37K. The slope of the upper critical field Hc2 increases with decreasing temperature, and the extrapolated value of Hc2 (0) reaches ~28T. The critical current density estimated by the Bean model is Jc (25K, 0T)~106 A·cm-2. These parameters indicate that the solution method is potentially able to produce MgB2 coated conductors that can satisfy application purposes.%We report the solution fabrication of a MgB2 coated conductor on a stainless steel substrate.The precursor solution of Mg(BH4 )2 diethyl ether is initially synthesized by refluxing the milled mixture of NaBH4 and MgCl2 in diethyl ether.Then the Mg(BH4)2 diethyl ether is spin coated on a stainless steel substrate and annealed in Mg vapor,which yields a homogeneous MgB2 coated conductor.X-ray diffraction indicates that the grown MgB2 coated conductor is polycrystalline.It has a superconducting transition temperature of 34-37K.The slope of the upper critical field HC2 increases with decreasing temperature,and the extrapolated value of Hc2 (0)reaches ~28 T.The critical current density estimated by the Bean model is JC (25K,0 T)~1 06 A.cm-2.These parameters indicate that the solution method is potentially able to produce MgB2 coated conductors that can satisfy application purposes.

  11. Fabrication of a stainless steel microchannel microcombustor using a lamination process

    Science.gov (United States)

    Matson, Dean W.; Martin, Peter M.; Tonkovich, Anna Lee Y.; Roberts, Gary L.

    1998-09-01

    Microscale chemical devices have potential application as fuel processors to produce high purity hydrogen for PEM fuel cells from hydrocarbon fuels such as methane, methanol, ethanol, or gasoline. The fabrication of a novel stainless steel catalytic microcombustor/reactor suitable for use to high temperatures is described. The device consisted of three parts to accommodate catalyst loading: a laminated reactor body, a laminated combustor, and a solid cover plate. The laminated components were produced using stacks of photochemically machined stainless steel shims. When formed into solid leak-tight components using a diffusion bonding process, the laminated parts were designed to contain a complex series of internal gas-flow microchannels that could not be produced in a solid metal block by other fabrication methods. Included within the reactor body was an array of heat exchanger microchannels 250 microns wide and 5000 microns deep that were designed to extract heat from the catalytic reaction region and pre-heat the reactant gases. Catalytic combustion of hydrogen or hydrocarbon fuel occurred in a separate laminated combustor plate. The laminated combustor/reactor design has potential for use in a variety of chemical processing and heat exchanger applications.

  12. Solution Fabrication of a Superconducting MgB2 Coated Conductor on Stainless Steel

    Science.gov (United States)

    Wang, Yin-Bo; Chen, Li-Ping; Zhang, Chen; Wang, Yue; Guo, Zheng-Shan; Chen, Yi-Ling; Feng, Qing-Rong; Gan, Zi-Zhao

    2012-04-01

    We report the solution fabrication of a MgB2 coated conductor on a stainless steel substrate. The precursor solution of Mg(BH4)2 diethyl ether is initially synthesized by refluxing the milled mixture of NaBH4 and MgCl2 in diethyl ether. Then the Mg(BH4)2 diethyl ether is spin coated on a stainless steel substrate and annealed in Mg vapor, which yields a homogeneous MgB2 coated conductor. X-ray diffraction indicates that the grown MgB2 coated conductor is polycrystalline. It has a superconducting transition temperature of 34-37 K. The slope of the upper critical field HC2 increases with decreasing temperature, and the extrapolated value of HC2(0) reaches ~28 T. The critical current density estimated by the Bean model is JC(25K, 0T)~106 A·cm-2. These parameters indicate that the solution method is potentially able to produce MgB2 coated conductors that can satisfy application purposes.

  13. Heat Treatment Optimization and Fabrication of a 440C Stainless Steel Knife

    Science.gov (United States)

    Bush, Ralph; Gill, Jacob; Teakell, Jarred

    2016-12-01

    There is ample evidence in the literature that the austenitization temperature and a post-quench liquid nitrogen soak play a significant role in the hardness/strength of martensitic stainless steels typically used in the fabrication of knives. However, there is a lack of quantitative data documenting the role these parameters have on the microstructure of these steels. A systematic study quantifies the volume fraction and composition of the microstructural constituents and hardness of 440C as a function of austenitization temperature and liquid nitrogen soak. Chromium carbide composition is independent of austenitization temperature. However, composition of the martensite matrix, and volume fractions of tempered martensite and carbides change with austenitization temperature. The liquid nitrogen soak is effective only at high temperatures that result in retained austenite. The results are used to rationalize and select an optimum heat-treat process for a knife fabricated in anticipation of the 2017 TMS Bladesmithing competition.

  14. Investigation on Porosity and Microhardness of 316L Stainless Steel Fabricated by Selective Laser Melting

    Directory of Open Access Journals (Sweden)

    Shahir Mohd Yusuf

    2017-02-01

    Full Text Available This study investigates the porosity and microhardness of 316L stainless steel samples fabricated by selective laser melting (SLM. The porosity content was measured using the Archimedes method and the advanced X-ray computed tomography (XCT scan. High densification level (≥99% with a low average porosity content (~0.82% were obtained from the Archimedes method. The highest porosity content in the XCT-scanned sample was ~0.61. However, the pores in the SLM samples for both cases (optical microscopy and XCT were not uniformly distributed. The higher average microhardness values in the SLM samples compared to the wrought manufactured counterpart are attributed to the fine microstructures from the localised melting and rapid solidification rate of the SLM process.

  15. FABRICATION OF GD CONTAINING DUPLEX STAINLESS STEEL SHEET FOR NEUTRON ABSORBING STRUCTURAL MATERIALS

    Directory of Open Access Journals (Sweden)

    YONG CHOI

    2013-10-01

    Full Text Available A duplex stainless steel sheet with 1 wt.% gadolinium was fabricated for a neutron absorbing material with high strength, excellent corrosion resistance, and low cost as well as high neutron absorption capability. The microstructure of the as-cast specimen has typical duplex phases including 31% ferrite and 69% austenite. Main alloy elements like chromium (Cr, nickel (Ni, and gadolinium (Gd are relatively uniformly distributed in the matrix. Gadolinium rich precipitates were present in the grains and at the grain boundaries. The solution treatment at 1070 °C for 50 minutes followed by the hot-rolling above 950 °C after keeping the sheet at 1200 °C for 1.5 hours are important points of the optimum condition to produce a 6 mm-thick plate without cracking.

  16. Preliminary Investigation of Keyhole Phenomena during Single Layer Fabrication in Laser Additive Manufacturing of Stainless Steel

    Science.gov (United States)

    Matilainen, Ville-Pekka; Piili, Heidi; Salminen, Antti; Nyrhilä, Olli

    Laser additive manufacturing (LAM) is a fabrication technology that enables production of complex parts from metallic materials with mechanical properties comparable to conventionally manufactured parts. In the LAM process, parts are manufactured by melting metallic powder layer-by-layer with a laser beam. This manufacturing technology is nowadays called powder bed fusion (PBF) according to the ASTM F2792-12a standard. This strategy involves several different independent and dependent thermal cycles, all of which have an influence on the final properties of the manufactured part. The quality of PBF parts depends strongly on the characteristics of each single laser-melted track and each single layer. This study consequently concentrates on investigating the effects of process parameters such as laser power on single track and layer formation and laser-material interaction phenomena occurring during the PBF process. Experimental tests were done with two different machines: a modified research machine based on an EOS EOSINT M-series system and an EOS EOSINT M280 system. The material used was EOS stainless steel 17-4 PH. Process monitoring was done with an active illuminated high speed camera system. After microscopy analysis, it was concluded that a keyhole can form during laser additive manufacturing of stainless steel. It was noted that heat input has an important effect on the likelihood of keyhole formation. The threshold intensity value for keyhole formation of 106 W/cm2 was exceeded in all manufactured single tracks. Laser interaction time was found to have an effect on penetration depth and keyhole formation, since the penetration depth increased with increased laser interaction time. It was also concluded that active illuminated high speed camera systems are suitable for monitoring of the manufacturing process and facilitate process control.

  17. MATHEMATICAL MODELLING OF THE SHIELDING EFFECTIVENESS FOR PES/STAINLESS STEEL FABRICS

    Directory of Open Access Journals (Sweden)

    RADULESCU Ion Razvan

    2017-05-01

    Full Text Available Textile screens for electromagnetic radiation represent a modern solution, due to their flexibility, lightweight and good mechanical resistance. Electromagnetic shielding is a must in various applications, while strict regulations are set for electromagnetic compatibility. Conductive fabrics are widely used for electronic equipment covers, RF suits or EMI protection tents. This paper aims to investigate the shielding effectiveness of conductive woven fabrics with stainless steel yarns at different weft distances [2,3,4,5 mm]. These conductive fabrics were investigated for their physical-mechanical properties (mass per surface unit, density on warp and weft direction and thickness, within the INCDTP accredited laboratories. The conductive fabrics as well as combinations thereof where tested for their shielding effectiveness accordingly to the standard ASTM ES 07, within the EMC laboratories of ICPE-CA. A signal generator, an amplifier, a TEM Cell and a spectrum analyser were used were used for this purpose. Graphs in logarithmic scale were issued for the shielding effectiveness analysis. Moreover, an experimental factorial plan was conceived for obtaining a mathematical model for the studied fabrics in relation to the weft distance between the conductive yarns. The coefficients of the mathematical model were obtained through the least squares regression method in Excel, while the response curve was designed in Matlab. The response curve enables the computation of intermediate values of the shielding effectiveness in relation to the distance between conductive yarns.

  18. Fabrication of low-cost, cementless femoral stem 316L stainless steel using investment casting technique.

    Science.gov (United States)

    Baharuddin, Mohd Yusof; Salleh, Sh-Hussain; Suhasril, Andril Arafat; Zulkifly, Ahmad Hafiz; Lee, Muhammad Hisyam; Omar, Mohd Afian; Abd Kader, Ab Saman; Mohd Noor, Alias; A Harris, Arief Ruhullah; Abdul Majid, Norazman

    2014-07-01

    Total hip arthroplasty is a flourishing orthopedic surgery, generating billions of dollars of revenue. The cost associated with the fabrication of implants has been increasing year by year, and this phenomenon has burdened the patient with extra charges. Consequently, this study will focus on designing an accurate implant via implementing the reverse engineering of three-dimensional morphological study based on a particular population. By using finite element analysis, this study will assist to predict the outcome and could become a useful tool for preclinical testing of newly designed implants. A prototype is then fabricated using 316L stainless steel by applying investment casting techniques that reduce manufacturing cost without jeopardizing implant quality. The finite element analysis showed that the maximum von Mises stress was 66.88 MPa proximally with a safety factor of 2.39 against endosteal fracture, and micromotion was 4.73 μm, which promotes osseointegration. This method offers a fabrication process of cementless femoral stems with lower cost, subsequently helping patients, particularly those from nondeveloped countries.

  19. Fabrication of high nitrogen austenitic stainless steels with excellent mechanical and pitting corrosion properties

    Institute of Scientific and Technical Information of China (English)

    Hua-bing Li; Zhou-hua Jiang; Yang Cao; Zu-rui Zhang

    2009-01-01

    18Cr18Mn2Mo0.9N high nitrogen austenitic stainless steel exhibits high strength and good ductility at room temperature. The steel shows typical duc-tile-brittle transition behavior and excellent pitting corrosion resistance properties.

  20. Femtosecond laser fabrication of highly hydrophobic stainless steel surface with hierarchical structures fabricated by combining ordered microstructures and LIPSS

    Science.gov (United States)

    Martínez-Calderon, M.; Rodríguez, A.; Dias-Ponte, A.; Morant-Miñana, M. C.; Gómez-Aranzadi, M.; Olaizola, S. M.

    2016-06-01

    In this work we have developed hierarchical structures that consist of micro-patterned surfaces covered by nanostructures with a femtosecond laser. The first part of this work is a study to determine the microscale modifications produced on a stainless steel alloy (AISI304) surface at high pulse energy, different velocities, and number of overscans in order to obtain microstructures with a selected depth of around 10 μm and line widths of 20 μm. The second part of the work is focused on finding the optimal irradiation parameters to obtain the nanostructure pattern. Nanostructures have been defined by means of Laser Induced Periodical Surface Structures (LIPSS) around 250 nm high and a period of 580 nm, which constitute the nanostructure pattern. Finally, dual scale gratings of 50 mm2 were fabricated with different geometries and their effect on the measured contact angle. Combining the micro-pattern with the LIPSS nano-pattern, highly hydrophobic surfaces have been developed with measured static contact angles higher than 150° on a stainless steel alloy.

  1. Stainless Steel NaK-Cooled Circuit (SNaKC) Fabrication and Assembly

    Science.gov (United States)

    Godfroy, Thomas J.

    2007-01-01

    An actively pumped Stainless Steel NaK Circuit (SNaKC) has been designed and fabricated by the Early Flight Fission Test Facility (EFF-TF) team at NASA's Marshall Space Flight Center. This circuit uses the eutectic mixture of sodium and potassium (NaK) as the working fluid building upon the experience and accomplishments of the SNAP reactor program from the late 1960's The SNaKC enables valuable experience and liquid metal test capability to be gained toward the goal of designing and building an affordable surface power reactor. The basic circuit components include a simulated reactor core a NaK to gas heat exchanger, an electromagnetic (EM) liquid metal pump, a liquid metal flow meter, an expansion reservoir and a drain/fill reservoir To maintain an oxygen free environment in the presence of NaK, an argon system is utilized. A helium and nitrogen system are utilized for core, pump, and heat exchanger operation. An additional rest section is available to enable special component testing m an elevated temperature actively pumped liquid metal environment. This paper summarizes the physical build of the SNaKC the gas and pressurization systems, vacuum systems, as well as instrumentation and control methods.

  2. Fabrication of antibacterial and hydrophilic electroless Ni-B coating on 316L stainless steel

    Science.gov (United States)

    Bülbül, Ferhat; Bülbül, Leman Elif

    2016-01-01

    Biomaterial-associated bacterial infection is one of the most common complications with medical vehicles and implants made of stainless steel. A surface coating treatment like electroless Ni-B deposition, a new candidate to be used in a broad range of engineering applications owing to many advantages such as low cost, thickness uniformity, good wear resistance, may improve the antibacterial activity and physical properties of biomedical devices made of stainless steel. In this study, the antibacterial property of the electroless Ni-B film coated on AISI 316L (UNS S31603) stainless steel is basically investigated. Inhibition halo diameter measurement after incubation at 37 °C and 24 h demonstrates the existence of antimicrobial activity of the electroless Ni-B coating deposited on 316L stainless steel over the Escherichia coli test bacteria. The results of X-ray diffraction, scanning electron microscopy, atomic force microscopy and microhardness measurement studies confirms that the coating deposited on the substrate has an uniform amorphous and a harder structure. Besides, the wettability property of the uncoated substrate and the coating was measured as the contact angle of water. The water contact angle reduced about from 97.7 to 69.25°.

  3. Tensile and Impact Properties of Shielded Metal Arc Welded AISI 409M Ferritic Stainless Steel Joints

    Institute of Scientific and Technical Information of China (English)

    K.Shanmugam; A.K.Lakshminarayanan; V.Balasubramanian

    2009-01-01

    The present study is concerned with the effect of filler metals such as austenitic stainless steel, ferritic stainless steel and duplex stainless steel on tensile and impact properties of the ferritic stainless steel conforming to AISI 409M grade. Rolled plates of 4 mm thickness were used as the base material for preparing single pass butt welded joints. Tensile and impact properties, microhardness, microstructure and fracture surface morphology of the joints fabricated by austenitic stainless steel, ferritic stainless steel and duplex stainless steel filler metals were evaluated and the results were reported. From this investigation, it is found that the joints fabricated by duplex stainless steel filler metal showed higher tensile strength and hardness compared to the joints fabricated by austenitic and ferritic stainless steel filler metals. Joints fabricated by austenitic stainless steel filler metal exhibited higher ductility and impact toughness compared with the joints fabricated by ferritic stainless steel and duplex stainless steel filler metals.

  4. Integration of Heat Treatment with Shot Peening of 17-4 Stainless Steel Fabricated by Direct Metal Laser Sintering

    Science.gov (United States)

    AlMangour, Bandar; Yang, Jenn-Ming

    2017-08-01

    Direct metal laser sintering (DMLS) is a promising powder-based additive manufacturing process for fabrication of near-net-shape parts. However, the typically poor fatigue performance of DMLS parts must be addressed for use in demanding industrial applications. Post-treatment can be applied to enhance the performance of such components. Earlier attempts at inducing grain refinement through severe plastic deformation of part surfaces using shot peening improved the physical and mechanical properties of metals without chemical alteration. However, heat treatment can modify the surface-hardening effects attained by shot peening. Hence, we examined the feasibility of applying shot peening combined with heat treatment to improve the performance of DMLS-fabricated 17-4 stainless steel parts through microstructural evolution studies and hardness measurements. Compared to a specimen treated only by shot peening, the sample exposed to additional heat treatment showed increased hardness due to aging of the dominant phase.

  5. Micro solid oxide fuel cell fabricated on porous stainless steel: a new strategy for enhanced thermal cycling ability

    Science.gov (United States)

    Kim, Kun Joong; Park, Byung Hyun; Kim, Sun Jae; Lee, Younki; Bae, Hongyeul; Choi, Gyeong Man

    2016-03-01

    Miniaturized solid oxide fuel cells (micro-SOFCs) are being extensively studied as a promising alternative to Li batteries for next generation portable power. A new micro-SOFC is designed and fabricated which shows enhanced thermal robustness by employing oxide-based thin-film electrode and porous stainless steel (STS) substrate. To deposit gas-tight thin-film electrolyte on STS, nano-porous composite oxide is proposed and applied as a new contact layer on STS. The micro-SOFC fabricated on composite oxide- STS dual layer substrate shows the peak power density of 560 mW cm-2 at 550 °C and maintains this power density during rapid thermal cycles. This cell may be suitable for portable electronic device that requires high power-density and fast thermal cycling.

  6. Enhanced performance of sulfate reducing bacteria based biocathode using stainless steel mesh on activated carbon fabric electrode.

    Science.gov (United States)

    Sharma, Mohita; Jain, Pratiksha; Varanasi, Jhansi L; Lal, Banwari; Rodríguez, Jorge; Lema, Juan M; Sarma, Priyangshu M

    2013-12-01

    An anoxic biocathode was developed using sulfate-reducing bacteria (SRB) consortium on activated carbon fabric (ACF) and the effect of stainless steel (SS) mesh as additional current collector was investigated. Improved performance of biocathode was observed with SS mesh leading to nearly five folds increase in power density (from 4.79 to 23.11 mW/m(2)) and threefolds increase in current density (from 75 to 250 mA/m(2)). Enhanced redox currents and lower Tafel slopes observed from cyclic voltammograms of ACF with SS mesh indicated the positive role of uniform electron collecting points. Differential pulse voltammetry technique was employed as an additional tool to assess the redox carriers involved in bioelectrochemical reactions. SRB biocathode was also tested for reduction of volatile fatty acids (VFA) present in the fermentation effluent stream and the results indicated the possibility of integration of this system with anaerobic fermentation for efficient product recovery.

  7. Preliminary Comparison of Properties between Ni-electroplated Stainless Steel Parts Fabricated with Laser Additive Manufacturing and Conventional Machining

    Science.gov (United States)

    Mäkinen, Mika; Jauhiainen, Eeva; Matilainen, Ville-Pekka; Riihimäki, Jaakko; Ritvanen, Jussi; Piili, Heidi; Salminen, Antti

    Laser additive manufacturing (LAM) is a fabrication technology, which enables production of complex parts from metallic materials with mechanical properties comparable to those of conventionally machined parts. These LAM parts are manufactured via melting metallic powder layer by layer with laser beam. Aim of this study is to define preliminarily the possibilities of using electroplating to supreme surface properties. Electrodeposited nickel and chromium as well as electroless (autocatalytic) deposited nickel was used to enhance laser additive manufactured and machined parts properties, like corrosion resistance, friction and wearing. All test pieces in this study were manufactured with a modified research AM equipment, equal to commercial EOS M series. The laser system used for tests was IPG 200 W CW fiber laser. The material used in this study for additive manufacturing was commercial stainless steel powder grade named SS316L. This SS316L is not equal to AISI 316L grade, but commercial name of this kind of powder is widely known in additive manufacturing as SS316L. Material used for fabrication of comparison test pieces (i.e. conventionally manufactured) was AISI 316L stainless steel bar. Electroplating was done in matrix cell and electroless was done in plastic sink properties of plated parts were tested within acetic acid salt spray corrosion chamber (AASS, SFS-EN-ISO 9227 standard). Adhesion of coating, friction and wearing properties were tested with Pin-On-Rod machine. Results show that in these preliminary tests, LAM parts and machined parts have certain differences due to manufacturing route and surface conditions. These have an effect on electroplated and electroless parts features on adhesion, corrosion, wearing and friction. However, further and more detailed studies are needed to fully understand these phenomena.

  8. Highly flexible TiO2-coated stainless steel fabric electrode prepared by liquid-phase deposition

    Science.gov (United States)

    Hwang, Hong Seo; Lee, Jeong Beom; Jung, Jiwon; Lee, Seyoung; Ryu, Ji Heon; Oh, Seung M.

    2016-10-01

    In order to construct flexible lithium-ion batteries, stainless steel (SUS) fabric is used as a current collector for the negative electrode of lithium-ion batteries. TiO2 is coated onto the SUS fabric by liquid-phase deposition to construct an electrode consisting of an SUS wire core and a TiO2 shell. A folding test is then conducted to assess the robustness of TiO2-coated SUS fabric, during which no detachment of TiO2 particles from the SUS current collector is observed; the negative electrode shows a consistent electrochemical cycle performance even under severe physical duress. The TiO2-SUS fabric integration shows excellent flexibility without loss of electrochemical efficacy under mechanical stress, which occurs owing to three main factors. First, the mechanical stress imposed by folding is effectively dissipated by the 3-dimensional structure of the SUS fabric. Secondly, the TiO2 electrode itself is free from mechanical stress owing to negligible volume change during electrochemical cycling. Thirdly, the high interfacial adhesion strength between TiO2 and SUS fabric due to covalent bond formation during liquid-phase deposition prevents the loss of active material from the negative electrode during the folding tests.

  9. Radiative and convective properties of 316L Stainless Steel fabricated using the Laser Engineered Net Shaping process

    Science.gov (United States)

    Knopp, Jonathan

    Temperature evolution of metallic materials during the additive manufacturing process has direct influence in determining the materials microstructure and resultant characteristics. Through the power of Infrared (IR) thermography it is now possible to monitor thermal trends in a build structure, giving the power to adjust building parameters in real time. The IR camera views radiation in the IR wavelengths and determines temperature of an object by the amount of radiation emitted from the object in those wavelengths. Determining the amount of radiation emitted from the material, known as a materials emissivity, can be difficult in that emissivity is affected by both temperature and surface finish. It has been shown that the use of a micro-blackbody cavity can be used as an accurate reference temperature when the sample is held at thermal equilibrium. A micro-blackbody cavity was created in a sample of 316L Stainless Steel after being fabricated during using the Laser Engineered Net Shaping (LENS) process. Holding the sample at thermal equilibrium and using the micro-blackbody cavity as a reference and thermocouple as a second reference emissivity values were able to be obtained. IR thermography was also used to observe the manufacturing of these samples. When observing the IR thermography, patterns in the thermal history of the build were shown to be present as well as distinct cooling rates of the material. This information can be used to find true temperatures of 316L Stainless Steel during the LENS process for better control of desired material properties as well as future work in determining complete energy balance.

  10. An experience with in-service fabrication and inspection of austenitic stainless steel piping in high temperature sodium system

    Energy Technology Data Exchange (ETDEWEB)

    Ravi, S., E-mail: sravi@igcar.gov.in; Laha, K.; Sakthy, S.; Mathew, M.D.; Bhaduri, A.K.

    2015-04-01

    Highlights: • Procedure for changing 304L SS pipe to 316L SS in sodium loop has been established. • Hot leg made of 304L SS was isolated from existing cold leg made of 316LN SS. • Innovative welding was used in joining the new 316L SS pipe with existing 316LN SS. • The old components of 304L SS piping have been integrated with the new piping. - Abstract: A creep testing facility along with dynamic sodium loop was installed at Indira Gandhi Centre for Atomic Research, Kalpakkam, India to assess the creep behavior of fast reactor structural materials in flowing sodium. Type 304L austenitic stainless steel was used in the low cross section piping of hot-leg whereas 316LN austenitic stainless steel in the high cross section cold-leg of the sodium loop. The intended service life of the sodium loop was 10 years. The loop has performed successfully in the stipulated time period. To enhance its life time, it has been decided to replace the 304L piping with 316L piping in the hot-leg. There were more than 300 welding joints involved in the integration of cold-leg with the new 316L hot-leg. Continuous argon gas flow was maintained in the loop during welding to avoid contamination of sodium residue with air. Several innovative welding procedures have been adopted for joining the new hot-leg with the existing cold-leg in the presence of sodium residue adopting TIG welding technique. The joints were inspected for 100% X-ray radiography and qualified by performing tensile tests. The components used in the discarded hot-leg were retrieved, cleaned and integrated in the renovated loop. A method of cleaning component of sodium residue has been established. This paper highlights the in-service fabrication and inspection of the renovation.

  11. The fabrication of a vanadium-stainless steel test section for MHD testing of insulator coatings in flowing lithium

    Energy Technology Data Exchange (ETDEWEB)

    Reed, C.B.; Mattas, R.F.; Smith, D.L.; Chung, H.; Tsai, H.-C. [Argonne National Lab., IL (United States); Morgan, G.D.; Wille, G.W. [McDonnell Douglas Aerospace, St. Louis, MO (United States). High Energy Systems; Johnson, W.R. [General Atomics, San Diego, CA (United States); Young, C. [Century Tubes, Inc., San Diego, CA (United States)

    1996-12-31

    To test the magnetohydrodynamic (MHD) pressure drop reduction performance of candidate insulator coatings for the ITER Vanadium/Lithium Breeding Blanket, a test section comprised of a V- 4Cr-4Ti liner inside a stainless steel pipe was designed and fabricated. Theoretically, the MHD pressure drop reduction benefit resulting, from an electrically insulating coating on a vanadium- lined pipe is identical to the benefit derived from an insulated pipe fabricated of vanadium alone. A duplex test section design consisting of a V alloy liner encased in a SS pressure boundary provided protection for vanadium from atmospheric contamination during operation at high temperature and obviated any potential problems with vanadium welding while also minimizing the amount of V alloy material required. From the MHD and insulator coating- point of view, the test section outer SS wall and inner V alloy liner can be modeled simply as a wall having a sandwich construction. Two 52.3 mm OD x 2.9 m long V-alloy tubes were fabricated by Century Tubes from 64 mm x 200 mm x 1245 mm extrusions produced by Teledyne Wah Chang. The test section`s duplex structure was subsequently fabricated at Century Tubes by drawing down a SS pipe (2 inch schedule 10) over one of the 53.2 mm diameter V tubes.

  12. Microstructure characteristics of high borated stainless steel fabricated by hot-pressing sintering

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Xuan; Wang, Mingjia, E-mail: mingjiawangysu@126.com; Zhao, Hongchang

    2016-04-25

    The present study investigated the microstructure of powder metallurgy (P/M) high borated stainless steel through hot-pressing sintering in a temperature range of 1000–1150 °C within 30 min under 30 MPa. Microstructure and phase examinations were carried out by applying scanning electron microscope, electron backscatter diffraction and X-ray diffraction analysis. The results of as-atomized powders demonstrated that many powders kept egg-type structure with an austenite outer layer and the eutectic borides were much finer than those in traditional cast products. Microstructure studies revealed that borides suffered Ostwald ripening and were significantly influenced by the sintering temperature. Orientation maps indicated that the inter-particle contact areas consisted of equiaxed grains and the regions consisting of large elongated grains partly inherited the microstructure characteristics of as-atomized powder particles. Furthermore, the mechanisms governing the morphological changes in microstructure were discussed. - Highlights: • Near-complete densification could be obtained through hot-pressing sintering. • There was no phase transformation and present phases were M{sub 2}B and austenite. • Borides suffered Ostwald ripening and were significantly influenced by temperature. • Inter-particle contact areas consisted of equiaxed grains for recrystallization. • Deformation-free zones exhibited elongated grains for dendritic arms coarsening.

  13. Correlation of microstructure with hardness and wear resistance in (TiC, SiC)/stainless steel surface composites fabricated by high-energy electron-beam irradiation

    Science.gov (United States)

    Yun, Eunsub; Kim, Yong Chan; Lee, Sunghak; Kim, Nack J.

    2004-03-01

    Stainless-steel-based surface composites reinforced with TiC and SiC carbides were fabricated by high-energy electron beam irradiation. Four types of powder/flux mixtures, i.e., TiC, (Ti + C), SiC, and (Ti + SiC) powders with 40 wt. pct of CaF2 flux, were deposited evenly on an AISI 304 stainless steel substrate, which was then irradiated with an electron beam. TiC agglomerates and pores were found in the surface composite layer fabricated with TiC powders because of insufficient melting of TiC powders. In the composite layer fabricated with Ti and C powders having lower melting points than TiC powders, a number of primary TiC carbides were precipitated while very few TiC agglomerates or pores were formed. This indicated that more effective TiC precipitation was obtained from the melting of Ti and C powders than of TiC powders. A large amount of precipitates such as TiC and Cr7C3 improved the hardness, high-temperature hardness, and wear resistance of the surface composite layer two to three times greater than that of the stainless steel substrate. In particular, the surface composite fabricated with SiC powders had the highest volume fraction of Cr7C3 distributed along solidification cell boundaries, and thus showed the best hardness, high-temperature hardness, and wear resistance.

  14. Fabrication of sub-micron surface structures on copper, stainless steel and titanium using picosecond laser interference patterning

    Energy Technology Data Exchange (ETDEWEB)

    Bieda, Matthias, E-mail: matthias.bieda@iws.fraunhofer.de [Fraunhofer-Institut für Werkstoff- und Strahltechnik (IWS), Winterbergstr. 28, 01277 Dresden (Germany); Siebold, Mathias, E-mail: m.siebold@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Bautzner Landstr. 400, 01328 Dresden (Germany); Lasagni, Andrés Fabián, E-mail: andres_fabian.lasagni@tu-dresden.de [Fraunhofer-Institut für Werkstoff- und Strahltechnik (IWS), Winterbergstr. 28, 01277 Dresden (Germany); Technische Universität Dresden, Institut für Fertigungstechnik, 01062 Dresden (Germany)

    2016-11-30

    Highlights: • Laser interference patterning is introduced to generate sub-micrometer surface pattern. • The two-temperature model is applied to ps-laser interference patterning of metals. • Line-like structures with a pitch of 0.7 μm were fabricated on SAE 304, Ti and Cu. • The process is governed by a photo-thermal mechanism for a pulse duration of 35 ps. • A “cold”-ablation process for metals requires a pulse duration shorter than 10 ps. - Abstract: Picosecond direct laser interference patterning (ps-DLIP) is investigated theoretically and experimentally for the bulk metals copper, stainless steel and titanium. While surface texturing with nanosecond pulses is limited to feature sizes in the micrometer range, utilizing picosecond pulses can lead to sub-micrometer structures. The modelling and simulation of ps-DLIP are based on the two-temperature model and were carried out for a pulse duration of 35 ps at 515 nm wavelength and a laser fluence of 0.1 J/cm{sup 2}. The subsurface temperature distribution of both electrons and phonons was computed for periodic line-like structures with a pitch of 0.8 μm. The increase in temperature rises for a lower absorption coefficient and a higher thermal conductivity. The distance, at which the maximum subsurface temperature occurs, increases for a small absorption coefficient. High absorption and low thermal conductivity minimize internal heating and give rise to a pronounced surface micro topography with pitches smaller than 1 μm. In order to confirm the computed results, periodic line-like surface structures were produced using two interfering beams of a Yb:YAG-Laser with 515 nm wavelength and a pulse duration of 35 ps. It was possible to obtain a pitch of 0.7 μm on the metallic surfaces.

  15. Selection of micro-fabrication techniques on stainless steel sheet for skin friction

    NARCIS (Netherlands)

    Zhang, Sheng; Zeng, Xiangqiong; Matthews, David Thomas Allan; Igartua, A.; Rodriguez Vidal, E.; Contreras Fortes, J.; Saenz de Viteri, V.; Pagano, F.; Wadman, B.; Wiklund, E.D.; van der Heide, Emile

    2016-01-01

    This review gives a concise introduction to the state-of-art techniques used for surface texturing, e.g., wet etching, plasma etching, laser surface texturing (LST), 3D printing, etc. In order to fabricate deterministic textures with the desired geometric structures and scales, the innovative textur

  16. A comparative study of the mechanical properties and the behavior of carbon and boron in stainless steel cladding tubes fabricated by PM HIP and traditional technologies

    NARCIS (Netherlands)

    Shulga, A. V.

    2013-01-01

    The ring tensile test method was optimized and successfully used to obtain precise data for specimens of the cladding tubes of AISI type 316 austenitic stainless steels and ferritic-martensitic stainless steel. The positive modifications in the tensile properties of the stainless steel cladding tube

  17. Articles comprising ferritic stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    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.

  18. Relationship between binder contents and mechanical properties of 17-4 ph stainless steel fabricated by PIM process and sintering

    Science.gov (United States)

    Khalil, K. A.; Kim, Sug Won

    2006-04-01

    Mechanical properties and microstructures of 17-4 ph stainless steel parts produced using different binder contents (powder loading) of powder injection molding (PIM) feedstock have been studied. The tensile and wear properties have been evaluated. Wear tests were conducted by a pin-on-disk tribometer, without lubricant, at different loads and sliding distance. SEM examination of the fracture sufaces revealed good particle bonding and a high ductile fracture surface for high powder loading. The surface fractures of the bars with higher powder loading show a closed porosity. High performance properties such as fully dense, ultimate tensile strength, hardness and wear resistance are obtained with high powder loading.

  19. Microstructure characteristics and mechanical property of aluminum alloy/stainless steel lap joints fabricated by MIG welding-brazing process

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Hongtao, E-mail: hitzht@yahoo.com.cn [School of Materials Science and Engineering, Harbin Institute of Technology at Weihai, Weihai 264209 (China); Liu Jiakun [School of Materials Science and Engineering, Harbin Institute of Technology at Weihai, Weihai 264209 (China)

    2011-07-25

    Highlights: {yields} Wrought aluminum and stainless steel was joined with welding-brazing process. {yields} Effect of different layers on spreadability of molten filler metal was examined. {yields} Mechanical property of the joints with different heat inputs was investigated. {yields} Microstructure of the joints were also studied by OM, SEM and TEM. {yields} Phase composition was ascertained by diffraction spot and XRD analysis. - Abstract: Lap joints of aluminum alloy 2B50 and stainless steel 1Cr18Ni9Ti were welded by MIG welding-brazing method with 4043 Al-Si filler metal. The effect of aluminizing coating and galvanized zinc coating on fusion metal spreadability were studied. The aluminized coating had limited effect to promote weld surface appearance and obvious micro-cracks were found between the compound layer and the steel side. The fracture in tensile tests occurred at the interfacial layer of the weld with a low tensile strength about 60 MPa. Joints between aluminum alloy and galvanized steel had good surface appearances and the intermetallic compound in fusion zone region close to joint interface was Al{sub 4.5}FeSi. The thickness of the intermetallic compound layer varied from about 5 {mu}m to 15 {mu}m depending on the heat input and the highest tensile strength of lap joint could reached 193.6 MPa when the heat input is 0.846 KJ/cm.

  20. Process-Structure-Property Relationships for 316L Stainless Steel Fabricated by Additive Manufacturing and Its Implication for Component Engineering

    Science.gov (United States)

    Yang, Nancy; Yee, J.; Zheng, B.; Gaiser, K.; Reynolds, T.; Clemon, L.; Lu, W. Y.; Schoenung, J. M.; Lavernia, E. J.

    2017-04-01

    We investigate the process-structure-property relationships for 316L stainless steel prototyping utilizing 3-D laser engineered net shaping (LENS), a commercial direct energy deposition additive manufacturing process. The study concluded that the resultant physical metallurgy of 3-D LENS 316L prototypes is dictated by the interactive metallurgical reactions, during instantaneous powder feeding/melting, molten metal flow and liquid metal solidification. The study also showed 3-D LENS manufacturing is capable of building high strength and ductile 316L prototypes due to its fine cellular spacing from fast solidification cooling, and the well-fused epitaxial interfaces at metal flow trails and interpass boundaries. However, without further LENS process control and optimization, the deposits are vulnerable to localized hardness variation attributed to heterogeneous microstructure, i.e., the interpass heat-affected zone (HAZ) from repetitive thermal heating during successive layer depositions. Most significantly, the current deposits exhibit anisotropic tensile behavior, i.e., lower strain and/or premature interpass delamination parallel to build direction (axial). This anisotropic behavior is attributed to the presence of interpass HAZ, which coexists with flying feedstock inclusions and porosity from incomplete molten metal fusion. The current observations and findings contribute to the scientific basis for future process control and optimization necessary for material property control and defect mitigation.

  1. Process-Structure-Property Relationships for 316L Stainless Steel Fabricated by Additive Manufacturing and Its Implication for Component Engineering

    Science.gov (United States)

    Yang, Nancy; Yee, J.; Zheng, B.; Gaiser, K.; Reynolds, T.; Clemon, L.; Lu, W. Y.; Schoenung, J. M.; Lavernia, E. J.

    2016-12-01

    We investigate the process-structure-property relationships for 316L stainless steel prototyping utilizing 3-D laser engineered net shaping (LENS), a commercial direct energy deposition additive manufacturing process. The study concluded that the resultant physical metallurgy of 3-D LENS 316L prototypes is dictated by the interactive metallurgical reactions, during instantaneous powder feeding/melting, molten metal flow and liquid metal solidification. The study also showed 3-D LENS manufacturing is capable of building high strength and ductile 316L prototypes due to its fine cellular spacing from fast solidification cooling, and the well-fused epitaxial interfaces at metal flow trails and interpass boundaries. However, without further LENS process control and optimization, the deposits are vulnerable to localized hardness variation attributed to heterogeneous microstructure, i.e., the interpass heat-affected zone (HAZ) from repetitive thermal heating during successive layer depositions. Most significantly, the current deposits exhibit anisotropic tensile behavior, i.e., lower strain and/or premature interpass delamination parallel to build direction (axial). This anisotropic behavior is attributed to the presence of interpass HAZ, which coexists with flying feedstock inclusions and porosity from incomplete molten metal fusion. The current observations and findings contribute to the scientific basis for future process control and optimization necessary for material property control and defect mitigation.

  2. Influences of deposition strategies and oblique angle on properties of AISI316L stainless steel oblique thin-walled part by direct laser fabrication

    Science.gov (United States)

    Wang, Xinlin; Deng, Dewei; Qi, Meng; Zhang, Hongchao

    2016-06-01

    Direct laser fabrication (DLF) developed from laser cladding and rapid prototyping technique has been widely used to fabricate thin-walled parts exhibiting more functions without expending weight and size. Oblique thin-walled parts accompanied with inhomogeneous mechanical properties are common in application. In the present study, a series of AISI316L stainless steel oblique thin-walled parts are successfully produced by DLF, in addition, deposition strategies, microstructure, and mechanical property of the oblique thin-walled parts are investigated. The results show that parallel deposition way is more valuable to fabricate oblique thin-walled part than oblique deposition way, because of the more remarkable properties. The hardness of high side initially increases until the distance to the substrate reaches about 25 mm, and then decreases with the increase of the deposition height. Oblique angle has a positive effect on the tensile property but a negative effect on microstructure, hardness and elongation due to the more tempering time. The maximum average ultimate tensile strength (UTS) and elongation are presented 744.3 MPa and 13.5% when the angle between tensile loading direction and horizontal direction is 45° and 90°, respectively.

  3. High transport Jc in magnetic fields up to 28 T of stainless steel/Ag double sheathed Ba122 tapes fabricated by scalable rolling process

    Science.gov (United States)

    Gao, Zhaoshun; Togano, Kazumasa; Matsumoto, Akiyoshi; Kumakura, Hiroaki

    2015-01-01

    The recently discovered iron-based superconductors with very high upper critical field (Hc2) and small anisotropy have been regarded as a potential candidate material for high field applications. However, enhancements of superconducting properties are still needed to boost the successful use of iron-based superconductors in such applications. Here, we propose a new sheath architecture of stainless steel (SS)/Ag double sheath and investigate its influence on the microstructures and Jc-H property. We found that the transport Jc-H curves for rolled and pressed tapes both show extremely small magnetic field dependence and exceed 3 × 104 A cm-2 under 28 T, which are much higher than those of low-temperature superconductors. More interestingly, 12 cm long rolled tape shows very high homogeneity and sustains Jc as high as 7.7 × 104 A cm-2 at 10 T. These are the highest values reported so far for iron-based superconducting wires fabricated by scalable rolling process. The microstructure investigations indicate that such high Jc was achieved by higher density of the core and uniform deformation resulting better texturing. These results indicate that our process is very promising for fabricating long Ba122 wires for high field magnet, i.e. above 20 T.

  4. Laser Rewelding of 304L Stainless Steel.

    Energy Technology Data Exchange (ETDEWEB)

    Maguire, Michael Christopher [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Rodelas, Jeffrey [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2016-11-01

    Laser welding of 304L stainless steel during component fabrication has been found to alter the chemical composition of the steel due to material evaporation. During repair or rework, or during potential reuse/ rewelding of certain components, the potential exists to alter the composition to the extent that the material becomes prone to solidification cracking. This work aims to characterize the extent of this susceptibility in order to make informed decisions regarding rewelding practice and base metal chemistry allowances.

  5. Microstructure and properties of composite of stainless steel and partially stabilized zirconia

    Institute of Scientific and Technical Information of China (English)

    张文泉; 谢建新; 杨志国; 王从曾

    2003-01-01

    To fabricate the metal-ceramics multi-layer hollow functionally gradient materials(FGMs) that mightmeet the requirement of repeated service and long working time of high temperature burners, such as spacecraft en-gine, the microstructure and properties of composite of stainless steel and partially stabilized zirconia were investiga-ted. Samples of different proportions of stainless steel to partially yttria-stabilized zirconia were fabricated by powderextrusion and sintering method. Shrinkage, relative density, microstructure, micro-Vickers hardness, compressionstrength, bending strength, fractography morphology and electrical resistivity of sintered samples with differentproportions of stainless steel were measured. The results show that threshold of metallic matrix composite(MMC)is approximately equal to 60 % (volume fraction) stainless steel. The samples with 0 to 50% (volume fraction) stain-less steel indicate ceramic brittleness and non cutability, and the samples with 70% to 100% (volume fraction) stain-less steel indicate metallic plasticity and cutability.

  6. Fabrication of metal-organic framework MIL-88B films on stainless steel fibers for solid-phase microextraction of polychlorinated biphenyls.

    Science.gov (United States)

    Wu, Ye-Yu; Yang, Cheng-Xiong; Yan, Xiu-Ping

    2014-03-21

    Metal-organic frameworks (MOFs) have received considerable attention as novel sorbents for sample preparation due to their fascinating structures and functionalities such as large surface area, good thermal stability, and uniform structured nanoscale cavities. Here, we report the application of a thermal and solvent stable MOF MIL-88B with nanosized bipyramidal cages and large surface area for solid-phase microextraction (SPME) of polychlorinated biphenyls (PCBs). Novel MIL-88B coated fiber was fabricated via an in situ hydrothermal growth of MIL-88B film on etched stainless steel fiber. The MIL-88B coated fiber gave large enhancement factors (757-2243), low detection limits (0.45-1.32ngL(-1)), and good linearity (5-200ngL(-1)) for PCBs. The relative standard deviation (RSD) for six replicate extractions of PCBs at 100ngL(-1) on MIL-88B coated fiber ranged from 4.2% to 8.7%. The recoveries for spiked PCBs (10ngL(-1)) in water and soil samples were in the range of 79.7-103.2%. Besides, the MIL-88B coated fiber was stable enough for 150 extraction cycles without significant loss of extraction efficiency. The developed method was successfully applied to the determination of PCBs in water samples and soil samples.

  7. Vertically building Zn2SnO4 nanowire arrays on stainless steel mesh toward fabrication of large-area, flexible dye-sensitized solar cells.

    Science.gov (United States)

    Li, Zhengdao; Zhou, Yong; Bao, Chunxiong; Xue, Guogang; Zhang, Jiyuan; Liu, Jianguo; Yu, Tao; Zou, Zhigang

    2012-06-07

    Zn(2)SnO(4) nanowire arrays were for the first time grown onto a stainless steel mesh (SSM) in a binary ethylenediamine (En)/water solvent system using a solvothermal route. The morphology evolution following this reaction was carefully followed to understand the formation mechanism. The SSM-supported Zn(2)SnO(4) nanowire was utilized as a photoanode for fabrication of large-area (10 cm × 5 cm size as a typical sample), flexible dye-sensitized solar cells (DSSCs). The synthesized Zn(2)SnO(4) nanowires exhibit great bendability and flexibility, proving potential advantage over other metal oxide nanowires such as TiO(2), ZnO, and SnO(2) for application in flexible solar cells. Relative to the analogous Zn(2)SnO(4) nanoparticle-based flexible DSSCs, the nanowire geometry proves to enhance solar energy conversion efficiency through enhancement of electron transport. The bendable nature of the DSSCs without obvious degradation of efficiency and facile scale up gives the as-made flexible solar cell device potential for practical application.

  8. Antimicrobial Cu-bearing stainless steel scaffolds.

    Science.gov (United States)

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

    2016-11-01

    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.

  9. 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...

  10. Evaluation of Electrochemical Characteristics on Graphene Coated Austenitic and Martensitic Stainless Steels for Metallic Bipolar Plates in PEMFC Fabricated with Hydrazine Reduction Methods

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Seong-Yun; Lee, Jae-Bong [School of Advanced Materials Engineering, Kookmin University, Seoul (Korea, Republic of)

    2016-04-15

    Graphene was coated on austenitic and martensitic stainless steels to simulate the metallic bipolar plate of proton exchange membrane fuel cell (PEMFC). Graphene oxide (GO) was synthesized and was reduced to reduced graphene oxide (rGO) via a hydrazine process. rGO was confirmed by FE-SEM, Raman spectroscopy and XPS. Interfacial contact resistance (ICR) between the bipolar plate and the gas diffusion layer (GDL) was measured to confirm the electrical conductivity. Both ICR and corrosion current density decreased on graphene coated stainless steels. Corrosion resistance was also improved with immersion time in cathodic environments and satisfied the criteria of the Department of Energy (DOE), USA. The total concentrations of metal ions dissolved from graphene coated stainless steels were reduced. Furthermore hydrophobicity was improved by increasing the contact angle.

  11. Fabrication and application of zinc-zinc oxide nanosheets coating on an etched stainless steel wire as a selective solid-phase microextraction fiber.

    Science.gov (United States)

    Song, Wenlan; Guo, Mei; Zhang, Yida; Zhang, Min; Wang, Xuemei; Du, Xinzhen

    2015-03-06

    A novel zinc-zinc oxide (Zn-ZnO) nanosheets coating was directly fabricated on an etched stainless steel wire substrate as solid-phase microextraction (SPME) fiber via previous electrodeposition of robust Zn coating. The scanning electron micrograph of the Zn-ZnO nanosheets coated fiber exhibits a flower-like nanostructure with high surface area. The SPME performance of as-fabricated fiber was investigated for the concentration and determination of polycyclic aromatic hydrocarbons, phthalates and ultraviolet (UV) filters coupled to high performance liquid chromatography with UV detection (HPLC-UV). It was found that the Zn-ZnO nanosheets coating exhibited high extraction capability, good selectivity and rapid mass transfer for some UV filters. The main parameters affecting extraction performance were investigated and optimized. Under the optimized conditions, the calibration graphs were linear over the range of 0.1-200μgL(-1). The limits of detection of the proposed method were 0.052-0.084μgL(-1) (S/N=3). The single fiber repeatability varied from 5.18% to 7.56% and the fiber-to-fiber reproducibility ranged from 6.74% to 8.83% for the extraction of spiked water with 50μgL(-1) UV filters (n=5). The established SPME-HPLC-UV method was successfully applied to the selective concentration and sensitive determination of target UV filters from real environmental water samples with recoveries from 85.8% to 105% at the spiking level of 10μgL(-1) and 30μgL(-1). The relative standard deviations were below 9.7%.

  12. Cast Stainless Steel Ferrite and Grain Structure

    Energy Technology Data Exchange (ETDEWEB)

    Ruud, Clayton O.; Ramuhalli, Pradeep; Meyer, Ryan M.; Mathews, Royce; Diaz, Aaron A.; Anderson, Michael T.

    2012-09-01

    In-service inspection requirements dictate that piping welds in the primary pressure boundary of light-water reactors be subject to a volumetric examination based on the rules contained within the American Society of Mechanical Engineers Boiler and Pressure Vessel Code, Section XI. The purpose of the inspection is the reliable detection and accurate sizing of service-induced degradation and/or material flaws introduced during fabrication. The volumetric inspection is usually carried out using ultrasonic testing (UT) methods. However, the varied metallurgical macrostructures and microstructures of cast austenitic stainless steel piping and fittings, including statically cast stainless steel and centrifugally cast stainless steel (CCSS), introduce significant variations in the propagation and attenuation of ultrasonic energy. These variations complicate interpretation of the UT responses and may compromise the reliability of UT inspection. A review of the literature indicated that a correlation may exist between the microstructure and the delta ferrite content of the casting alloy. This paper discusses the results of a recent study where the goal was to determine if a correlation existed between measured and/or calculated ferrite content and grain structure in CCSS pipe.

  13. Fabrication of micro-pin array with high aspect ratio on stainless steel using nanosecond laser beam machining

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Se Won [School of Mechanical and Aerospace Engineering, Seoul National University, Gwanak 599 Gwanak-ro, Gwanak-Gu, Seoul, 151-744 (Korea, Republic of); Shin, Hong Shik, E-mail: shinhs05@ut.ac.kr [Department of Energy System Engineering, Korea National University of Transportation, Chungju, Chungbuk, 380-702 (Korea, Republic of); Chu, Chong Nam [School of Mechanical and Aerospace Engineering, Seoul National University, Gwanak 599 Gwanak-ro, Gwanak-Gu, Seoul, 151-744 (Korea, Republic of)

    2013-01-01

    Highlights: Black-Right-Pointing-Pointer A high aspect ratio micro-pin array was fabricated by laser beam machining using the piling of a recast layer. Black-Right-Pointing-Pointer The recast layer could be piled due to the chromium oxide with high surface tension and viscosity of chromium oxide. Black-Right-Pointing-Pointer The machining characteristics for a high aspect ratio micro-pin array were investigated according to laser beam parameters. Black-Right-Pointing-Pointer Experiments for attaching force relative to the surface roughness of the subject plane were carried out. Black-Right-Pointing-Pointer The developed micro-pin array was successfully attached to vertical wall. - Abstract: In this paper, a micro-pin array with a high aspect ratio was fabricated on AISI 304 using laser beam ablation for attachment to a vertical wall. In recent times, there has been research in various fields, including robotics and bio-MEMS, regarding attachment to vertical walls, and micro-pin arrays may offer the best solution. For vertical wall attachment, the micro-pin should have a high aspect ratio, long length, and sharp tip. The recast layer could be piled due to the chromium oxide with high surface tension and viscosity of chromium oxide, and it composed the micro-pins with high aspect ratio. X-ray photoelectron spectroscopy (XPS) was used to identify the characteristics of the piled recast layer. The machining characteristics for a high aspect ratio micro-pin array were investigated according to laser beam machining parameters. In addition, experiments for attaching force relative to the surface roughness of the subject plane were carried out.

  14. 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.

  15. Effect of Welding Processes on Tensile and Impact Properties, Hardness and Microstructure of AISI 409M Ferritic Stainless Joints Fabricated by Duplex Stainless Steel Filler Metal

    Institute of Scientific and Technical Information of China (English)

    A K Lakshminarayanan; K Shanmugam; V Balasubramanian

    2009-01-01

    The effect of welding processes such as shielded metal arc welding, gas metal arc welding and gas tungsten arc welding on tensile and impact properties of the ferritic stainless steel conforming to AISI 409M grade is studied. Rolled plates of 4 mm thickness were used as the base material for preparing single pass butt welded joints. Tensile and impact properties, microhardness, microstructure and fracture surface morphology of the welded joints have been evaluated and the results are compared. From this investigatio.n, it is found that gas tungsten arc welded joints of ferritic stainless steel have superior tensile and impact properties compared with shielded metal are and gas metal arc welded joints and this is mainly due to the presence of finer grains in fusion zone and heat affected zone.

  16. Evaluation of Additive Manufacturing for Stainless Steel Components

    Energy Technology Data Exchange (ETDEWEB)

    Peter, William H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lou, Xiaoyuan [General Electric (GE), Wilmington, NC (United States); List, III, Frederick Alyious [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Webber, David [General Electric (GE), Wilmington, NC (United States)

    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.

  17. Preformed posterior stainless steel crowns: an update.

    Science.gov (United States)

    Croll, T P

    1999-02-01

    For almost 50 years, dentists have used stainless steel crowns for primary and permanent posterior teeth. No other type of restoration offers the convenience, low cost, durability, and reliability of such crowns when interim full-coronal coverage is required. Preformed stainless steel crowns have improved over the years. Better luting cements have been developed and different methods of crown manipulation have evolved. This article reviews stainless steel crown procedures for primary and permanent posterior teeth. Step-by-step placement of a primary molar stainless steel crown is documented and permanent molar stainless steel crown restoration is described. A method for repairing a worn-through crown also is reviewed.

  18. New Application of Stainless Steel

    Institute of Scientific and Technical Information of China (English)

    YANG Jia-long; LI Ying; WANG Fu; ZANG Zheng-gui; LI Si-jun

    2006-01-01

    Several rigid substrates such as stainless steel, titanium alloy, aluminum alloy, nickel foil, silicon, and sodium lime glass have been employed for manufacturing high quality TiO2 films by metal organic chemical vapor deposition (MOCVD). The as-deposited TiO2 films have been characterized with SEM/EDX and XRD. The photocatalytic properties were investigated by decomposition of aqueous orangeⅡ. UV-VIS photospectrometer was employed to check the absorption characteristics and photocatalytic degradation activity. The results show that films synthesized on metal substrates display higher photoactivities than that on absolute substrates such as silicon and glass. It is found that solar light is an alternative to UV-light used for illumination during photodegradation of orange Ⅱ. TiO2 film on stainless steel substrate was regarded as the best one for photocatalysis.

  19. Nickel: makes stainless steel strong

    Science.gov (United States)

    Boland, Maeve A.

    2012-01-01

    Nickel is a silvery-white metal that is used mainly to make stainless steel and other alloys stronger and better able to withstand extreme temperatures and corrosive environments. Nickel was first identified as a unique element in 1751 by Baron Axel Fredrik Cronstedt, a Swedish mineralogist and chemist. He originally called the element kupfernickel because it was found in rock that looked like copper (kupfer) ore and because miners thought that "bad spirits" (nickel) in the rock were making it difficult for them to extract copper from it. Approximately 80 percent of the primary (not recycled) nickel consumed in the United States in 2011 was used in alloys, such as stainless steel and superalloys. Because nickel increases an alloy's resistance to corrosion and its ability to withstand extreme temperatures, equipment and parts made of nickel-bearing alloys are often used in harsh environments, such as those in chemical plants, petroleum refineries, jet engines, power generation facilities, and offshore installations. Medical equipment, cookware, and cutlery are often made of stainless steel because it is easy to clean and sterilize. All U.S. circulating coins except the penny are made of alloys that contain nickel. Nickel alloys are increasingly being used in making rechargeable batteries for portable computers, power tools, and hybrid and electric vehicles. Nickel is also plated onto such items as bathroom fixtures to reduce corrosion and provide an attractive finish.

  20. Thermo-mechanical behavior of stainless steel knitted structures

    Science.gov (United States)

    Hamdani, Syed Talha Ali; Fernando, Anura; Maqsood, Muhammad

    2016-09-01

    Heating fabric is an advanced textile material that is extensively researched by the industrialists and the scientists alike. Ability to create highly flexible and drapeable heating fabrics has many applications in everyday life. This paper presents a study conducted on the comparison of heatability of knitted fabric made of stainless steel yarn. The purpose of the study is to find a suitable material for protective clothing against cold environments. In the current research the ampacity of stainless steel yarn is observed in order to prevent the overheating of the heating fabrics. The behavior of the knitted structure is studied for different levels of supply voltage. Infrared temperature sensing is used to measure the heat generated from the fabrics in order to measure the temperature of the fabrics without physical contact. It is concluded that interlock structure is one of the most suited structures for knitted heating fabrics. As learnt through this research, fabrics made of stainless steel yarn are capable of producing a higher level of heating compared to that of knitted fabric made using silver coated polymeric yarn at the same supply voltage.

  1. Characteristics of vacuum sintered stainless steels

    OpenAIRE

    Z. Brytan; L.A. Dobrzański; M. Actis Grande; Rosso, M.

    2009-01-01

    Purpose: In the present study duplex stainless steels were sintered in vacuum. using rapid cooling form the mixture of prealloyed and alloying element powders The purpose of this paper was to describe the obtained microstructures after sintering as well as the main mechanical properties of sintered stainless steels.Design/methodology/approach: In presented work duplex stainless steels were obtained through powder metallurgy starting from austenitic 316L or ferritic 410L prealloyed stainless s...

  2. Alternative to Nitric Acid for Passivation of Stainless Steel Alloys

    Science.gov (United States)

    Lewis, Pattie L.; Kolody, Mark; Curran, Jerry

    2013-01-01

    Corrosion is an extensive problem that affects the Department of Defense (DoD) and National Aeronautics and Space Administration (NASA). The deleterious effects of corrosion result in steep costs, asset downtime affecting mission readiness, and safety risks to personnel. Consequently, it is vital to reduce corrosion costs and risks in a sustainable manner. The DoD and NASA have numerous structures and equipment that are fabricated from stainless steel. The standard practice for protection of stainless steel is a process called passivation. Typical passivation procedures call for the use of nitric acid; however, there are a number of environmental, worker safety, and operational issues associated with its use. Citric acid offers a variety of benefits including increased safety for personnel, reduced environmental impact, and reduced operational cost. DoD and NASA agreed to collaborate to validate citric acid as an acceptable passivating agent for stainless steel. This paper details our investigation of prior work developing the citric acid passivation process, development of the test plan, optimization of the process for specific stainless steel alloys, ongoing and planned testing to elucidate the process' resistance to corrosion in comparison to nitric acid, and preliminary results.

  3. Interaction between stainless steel and plutonium metal

    Energy Technology Data Exchange (ETDEWEB)

    Dunwoody, John T [Los Alamos National Laboratory; Mason, Richard E [Los Alamos National Laboratory; Freibert, Franz J [Los Alamos National Laboratory; Willson, Stephen P [Los Alamos National Laboratory; Veirs, Douglas K [Los Alamos National Laboratory; Worl, Laura A [Los Alamos National Laboratory; Archuleta, Alonso [Los Alamos National Laboratory; Conger, Donald J [Los Alamos National Laboratory

    2010-01-01

    Long-term storage of excess plutonium is of great concern in the U.S. as well as abroad. The current accepted configuration involves intimate contact between the stored material and an iron-bearing container such as stainless steel. While many safety scenario studies have been conducted and used in the acceptance of stainless steel containers, little information is available on the physical interaction at elevated temperatures between certain forms of stored material and the container itself. The bulk of the safety studies has focused on the ability of a package to keep the primary stainless steel containment below the plutonium-iron eutectic temperature of approximately 410 C. However, the interactions of plutonium metal with stainless steel have been of continuing interest. This paper reports on a scoping study investigating the interaction between stainless steel and plutonium metal in a pseudo diffusion couple at temperatures above the eutectic melt-point.

  4. Fabrication of ciprofloxacin molecular imprinted polymer coating on a stainless steel wire as a selective solid-phase microextraction fiber for sensitive determination of fluoroquinolones in biological fluids and tablet formulation using HPLC-UV detection.

    Science.gov (United States)

    Mirzajani, Roya; Kardani, Fatemeh

    2016-04-15

    A molecularly imprinted polymer (MIP) fiber on stainless steel wire using ciprofloxacin template with a mild template removal condition was synthetized and evaluated for fiber solid phase microextraction (SPME) of fluoroquinolones (FQs) from biological fluids and pharmaceutical samples, followed by high performance liquid chromatography analysis with UV detection (HPLC-UV). The developed MIP fiber exhibited high selectivity for the analytes in complex matrices. The coating of the fibers were inspected using fourier transform infrared spectrophotometry, thermogaravimetric analysis, energy dispersive X-ray (EDX) spectroscopy as well as by scanning electron microscopy (SEM). The fiber shows high thermal stability (up to 300°C), good reproducibility and long lifetime. The composite coating did not swell in organic solvents nor did it strip off from the substrate. It was also highly stable and extremely adherent to the surface of the stainless steel fiber. The fabricated fiber exclusively exhibited excellent extraction efficiency and selectivity for some FQs. The effective parameters influencing the microextraction efficiency such as pH, extraction time, desorption condition, and stirring rate were investigated. Under optimized conditions, the limits of detection of the four FQs ranged from 0.023-0.033 μg L(-1) (S/N=5) and the calibration graphs were linear in the concentration range from 0.1-40 μg L(-1), the inter-day and intraday relative standard deviations (RSD) for various FQs at three different concentration level (n=5) using a single fiber were 1.1-4.4% and the fiber to fiber RSD% (n=5) was 4.3-6.7% at 5 μg L(-1) of each anlyetes. The method was successfully applied for quantification of FQs in real samples including serum, plasma and tablet formulation with the recoveries between 97 to 102%. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. 棉/不锈钢长丝机织物的电磁屏蔽及折皱回复性能%Electromagnetic shielding and wrinkle recovery property of cotton/stainless steel filament woven fabric

    Institute of Scientific and Technical Information of China (English)

    段永洁; 谢春萍; 刘新金

    2016-01-01

    为研究组织结构与磨损对织物屏蔽性能的影响,以及不锈钢长丝对织物折皱回复性的影响,使用自制的棉/不锈钢长丝包芯纱织制了3种不同组织的机织物,测试了织物在0�3~1500 MHz频段上的电磁屏蔽性能,并使用平磨仪对各织物分别摩擦60、120、180、240及300次后,测试了织物磨损后的电磁屏蔽性能;同时,采用视频序列法测试了织物的动态折皱回复角。结果表明:织物组织结构对电磁屏蔽性能有一定影响,平纹组织结构紧密,屏蔽效果好;经过若干次磨损后,织物的电磁屏蔽性能先小幅升高后逐渐降低;相同磨损条件下,试样耐磨性越好,屏蔽效能的降低幅度越小;由于不锈钢长丝的加入使织物的折皱回复性降低,可以采用浮长更长的组织改善织物起皱现象。%In order to study the influence of fabric structure and fabric abrasion on the shielding performance, and the influence of stainless steel filament on the fabric wrinkle recovery, cotton/stainless steel filament core spun yarns were used as materials to weave three kinds of fabrics. The electromagnetic shielding properties in 0�3-1 500 MHz are compared. After the wear tests for 60, 120, 180, 240 and 300 times on the textile abrasion tester, the electromagnetic shielding properties are also tested and compared. The wrinkle recovery properties are tested by video sequence method. Results show that the fabric weaves have some effects on the electromagnetic shielding property. Because of the compact structure, plain fabric has better electromagnetic shielding property. Through several times of friction, the electromagnetic shielding property has a small increase, and then decreased gradually. Under the same wear condition, samples with better wearing resistance property will show a lower reduction degree of the shielding effectiveness. Because of the stainless steel filament, the wrinkle recovery

  6. Preparation of precursor for stainless steel foam

    Institute of Scientific and Technical Information of China (English)

    ZHOU Xiang-yang; LI Shan-ni; LI Jie; LIU Ye-xiang

    2008-01-01

    The effects of polyurethane sponge pretreatment and slurry compositions on the slurry loading in precursor were discussed, and the,performances of stainless steel foams prepared from precursors with different slurry loadings and different particle sizes of the stainless steel powder were also investigated. The experimental results show that the pretreatment of sponge with alkaline solution is effective to reduce the jam of cells in precursor and ensure the slurry to uniformly distribute in sponge, and it is also an effective method for increasing the slurry loading in precursor; the mass fraction of additive A and solid content in slurry greatly affect the slurry loading in precursor, when they are kept in 9%-13% and 52%-75%, respectively, the stainless steel foam may hold excellent 3D open-cell network structure and uniform muscles; the particle size of the stainless steel powder and the slurry loading in precursor have great effects on the bending strength, apparent density and open porosity of stainless steel foam; when the stainless steel powder with particle size of 44 tan and slurry loading of 0.5 g/cm3 in precursor are used, a stainless steel foam can be obtained, which has open porosity of 81.2%, bending strength of about 51.76 MPa and apparent density of about 1.0 g/cm3.

  7. Biocompatibility of MIM 316L stainless steel

    Institute of Scientific and Technical Information of China (English)

    ZHU Shai-hong; WANG Guo-hui; ZHAO Yan-zhong; LI Yi-ming; ZHOU Ke-chao; HUANG Bai-yun

    2005-01-01

    To evaluate the bioeompatibility of MIM 316L stainless steel, the percentage of S-period cells were detected by flow cytometry after L929 incubated with extraction of MIM 316L stainless steel, using titanium implant materials of clinical application as the contrast. Both materials were implanted in animal and the histopathological evaluations were carried out. The statistical analyses show that there are no significant differences between two groups (P>0.05), which demonstrates that MIM 316L stainless steel has a good biocompatibility.

  8. Low-cost flexible supercapacitors with high-energy density based on nanostructured MnO2 and Fe2O3 thin films directly fabricated onto stainless steel

    Science.gov (United States)

    Gund, Girish S.; Dubal, Deepak P.; Chodankar, Nilesh R.; Cho, Jun Y.; Gomez-Romero, Pedro; Park, Chan; Lokhande, Chandrakant D.

    2015-07-01

    The facile and economical electrochemical and successive ionic layer adsorption and reaction (SILAR) methods have been employed in order to prepare manganese oxide (MnO2) and iron oxide (Fe2O3) thin films, respectively with the fine optimized nanostructures on highly flexible stainless steel sheet. The symmetric and asymmetric flexible-solid-state supercapacitors (FSS-SCs) of nanostructured (nanosheets for MnO2 and nanoparticles for Fe2O3) electrodes with Na2SO4/Carboxymethyl cellulose (CMC) gel as a separator and electrolyte were assembled. MnO2 as positive and negative electrodes were used to fabricate symmetric SC, while the asymmetric SC was assembled by employing MnO2 as positive and Fe2O3 as negative electrode. Furthermore, the electrochemical features of symmetric and asymmetric SCs are systematically investigated. The results verify that the fabricated symmetric and asymmetric FSS-SCs present excellent reversibility (within the voltage window of 0-1 V and 0-2 V, respectively) and good cycling stability (83 and 91%, respectively for 3000 of CV cycles). Additionally, the asymmetric SC shows maximum specific capacitance of 92 Fg-1, about 2-fold of higher energy density (41.8 Wh kg-1) than symmetric SC and excellent mechanical flexibility. Furthermore, the “real-life” demonstration of fabricated SCs to the panel of SUK confirms that asymmetric SC has 2-fold higher energy density compare to symmetric SC.

  9. Low-cost flexible supercapacitors with high-energy density based on nanostructured MnO2 and Fe2O3 thin films directly fabricated onto stainless steel

    National Research Council Canada - National Science Library

    Gund, Girish S; Dubal, Deepak P; Chodankar, Nilesh R; Cho, Jun Y; Gomez-Romero, Pedro; Park, Chan; Lokhande, Chandrakant D

    2015-01-01

    ...) methods have been employed in order to prepare manganese oxide (MnO2) and iron oxide (Fe2O3) thin films, respectively with the fine optimized nanostructures on highly flexible stainless steel sheet...

  10. 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.

    Science.gov (United States)

    Khalid, Syed Altaf; Kumar, Vadivel; Jayaram, Prithviraj

    2012-08-01

    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. 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. 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 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.

  11. 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.

  12. Hydrogen compatibility handbook for stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    Caskey, G.R. Jr.

    1983-06-01

    This handbook compiles data on the effects of hydrogen on the mechanical properties of stainless steels and discusses this data within the context of current understanding of hydrogen compatibility of metals. All of the tabulated data derives from continuing studies of hydrogen effects on materials that have been conducted at the Savannah River Laboratory over the past fifteen years. Supplementary data from other sources are included in the discussion. Austenitic, ferritic, martensitic, and precipitation hardenable stainless steels have been studied. Damage caused by helium generated from decay of tritium is a distinctive effect that occurs in addition to the hydrogen isotopes protium and deuterium. The handbook defines the scope of our current knowledge of hydrogen effects in stainless steels and serves as a guide to selection of stainless steels for service in hydrogen.

  13. Characteristics of vacuum sintered stainless steels

    Directory of Open Access Journals (Sweden)

    Z. Brytan

    2009-04-01

    Full Text Available Purpose: In the present study duplex stainless steels were sintered in vacuum. using rapid cooling form the mixture of prealloyed and alloying element powders The purpose of this paper was to describe the obtained microstructures after sintering as well as the main mechanical properties of sintered stainless steels.Design/methodology/approach: In presented work duplex stainless steels were obtained through powder metallurgy starting from austenitic 316L or ferritic 410L prealloyed stainless steels powders by controlled addition of alloying elements powder. Prepared mixes were sintered in a vacuum furnace in 1250°C for 1h. After sintering rapid cooling (6°C/s using nitrogen under pressure was applied. Sintered compositions were subjected to structural examinations by scanning and optical microscopy and EDS analysis as well as X-ray analysis. Mechanical properties were studied through tensile tests and Charpy impact test.Findings: It was demonstrated that austenitic-ferritic microstructures with regular arrangement of both phases and absence of precipitates can be obtained with properly designed powder mix composition as well as sintering cycle with rapid cooling rate. Obtained sintered duplex stainless steels shows good mechanical properties which depends on phases ratio in the microstructure and elements partitioning (Cr/Ni between phases.Research limitations/implications: Basing on alloys characteristics applied cooling rate and powder mix composition seems to be a good compromise to obtain balanced sintered duplex stainless steel microstructures.Practical implications: Mechanical properties of obtained sintered duplex stainless steels structures are rather promising, especially with the aim of extending their field of possible applications.Originality/value: The utilization of vacuum sintering process with rapid cooling after sintering combined with use of elemental powders added to a stainless steel base powder shows its advantages in terms

  14. 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.

  15. 在不锈钢网上快速制备连续致密Silicalite-1分子筛膜%Quick Fabrication of Continuous and Compact Silicalite-1 Membrane on Stainless Steel Net

    Institute of Scientific and Technical Information of China (English)

    张聪; 闫文付; 于吉红; 徐如人

    2012-01-01

    开发了一种在不锈钢网基底上快速制备连续致密Silicalite-1( Si-MFI)分子筛膜的新方法.该制膜过程包括用含有聚氧乙烯(PEO)高分子的氧化硅溶液对不锈钢网基底进行预处理和在预处理后的基底上用二次生长法制备分子筛膜2个步骤.通过该方法可在12 h内制备连续致密的不锈钢网支撑的Si-MFI分子筛膜.SEM分析结果表明,所制备的Si-MF1分子筛膜连续且致密,而XRD分析结果表明,膜中的Si-MFI微晶具有高结晶度.用膜渗透分离装置及气相色谱仪测试了Si-MFI膜的渗透性能及对CO2和N2的分离性能,结果显示,该Si-MFI膜具有很好的渗透性能,并对CO2和N2具有很好的分离性能.%A new method for quick fabrication of continuous and compact silicalite-1 (Si-MFI) membrane on stainless steel net was developed. The method consists of pre-treatment of substrate of stainless steel net with silica solution containing polyethylene oxide (PEO) polymer and a secondary growth process. The continuous and compact Si-MFI membranes were obtained within 12 h. The membrane was further characterized by scanning electron microscopy ( SEM) and X-ray diffraction ( XRD) analyses. SEM analyses show that the membrane is continuous and highly compact. XRD analyses suggest that the micro-crystals embedded in the membrane are well crystallized. The permeance and separation performance of the Si-MFI membrane were examined with a gas-separation setup combining a gas chromatography. The results show that the Si-MFI membrane has an excellent permeance and separation performance for CO2 and N2.

  16. High Mn austenitic stainless steel

    Science.gov (United States)

    Yamamoto, Yukinori [Oak Ridge, TN; Santella, Michael L [Knoxville, TN; Brady, Michael P [Oak Ridge, TN; Maziasz, Philip J [Oak Ridge, TN; Liu, Chain-tsuan [Knoxville, TN

    2010-07-13

    An austenitic stainless steel alloy includes, in weight percent: >4 to 15 Mn; 8 to 15 Ni; 14 to 16 Cr; 2.4 to 3 Al; 0.4 to 1 total of at least one of Nb and Ta; 0.05 to 0.2 C; 0.01 to 0.02 B; no more than 0.3 of combined Ti+V; up to 3 Mo; up to 3 Co; up to 1W; up to 3 Cu; up to 1 Si; up to 0.05 P; up to 1 total of at least one of Y, La, Ce, Hf, and Zr; less than 0.05 N; and base Fe, wherein the weight percent Fe is greater than the weight percent Ni, and wherein the alloy forms an external continuous scale including alumina, nanometer scale sized particles distributed throughout the microstructure, the particles including at least one of NbC and TaC, and a stable essentially single phase FCC austenitic matrix microstructure that is essentially delta-ferrite-free and essentially BCC-phase-free.

  17. Properties, weldability and corrosion behavior of supermartensitic stainless steels for on- and offshore applications

    Energy Technology Data Exchange (ETDEWEB)

    Taban, Emel; Kaluc, Erdinc; Ojo, Olatunji Oladimeji [Kocaeli Univ. (Turkey). Welding Research, Education and Training Center

    2016-08-01

    Stimulated material-environment interactions inside and around flowlines of deep or ultra deep wells during oil and gas exploration, and fabrication economy of pipelines have been the major challenges facing the oil and gas industries. Presumably, an extensive focus on high integrity, performance and material economy of flowlines have realistically made supermartensitic stainless steels (SMSS) efficient and effective material choices for fabricating onshore and offshore pipelines. Supermartensitic stainless steels exhibit high strength, good low temperature toughness, sufficient corrosion resistance in sweet and mildly sour environments, and good quality weldability with both conventional welding processes and modern welding methods such as laser beam welding, electron beam welding and hybrid welding approaches. In terms of economy, supermartensitic stainless steels are cheaper and they are major replacements for more expensive duplex stainless steels required for tubing applications in the oil and gas industry. However, weld areas of SMSS pipes are exposed to sulphide stress cracking (SSC), so intergranular stress corrosion cracking (IGSCC) or stress corrosion cracking can occur. In order to circumvent this risk of cracking, a post-weld heat treatment (PWHT) for 5 minutes at about 650 C is recommended. This paper provides detailed literature perusal on supermartensitic stainless steels, their weldability and corrosion behaviors. It also highlights a major research area that has not been thoroughly expounded in literature; fatigue loading behaviors of welded SMSS under different corrosive environments have not been thoroughly detailed in literature.

  18. A peptide-stainless steel reaction that yields a new bioorganic-metal state of matter.

    Science.gov (United States)

    Davis, Elisabeth M; Li, Dong-Yang; Irvin, Randall T

    2011-08-01

    A synthetic peptide derived from the native protein sequence of a metal binding bacterial pilus was observed to spontaneously react with stainless steel via a previously unreported type of chemical interaction to generate an altered form of stainless steel which we term bioorganic stainless steel. Bioorganic stainless steel has a significantly increased electron work function (4.9 ± 0.05 eV compared to 4.79 ± 0.07 eV), decreased material adhesive force (19.4 ± 8.8 nN compared to 56.7 ± 10.5 nN), and is significantly harder than regular 304 stainless steel (~40% harder). A formal or semi-formal organo-metallic covalent bond is generated between a pilin receptor binding domain and stainless steel based on XPS analysis which indicates that the electronic state of the surface is altered. Further, we establish that the peptide-steel reaction demonstrates a degree of stereospecificity as the reaction of native L-peptide, D-peptide and a retro-inverso-D-peptide yields bioorganic steel products that can be differentiated via the resulting EWF (4.867 ± 0.008 eV, 4.651 ± 0.008 eV, and 4.919 ± 0.007 eV, respectively). We conclude that electron sharing between the peptide and steel surface results in the stabilization of surface electrons to generate bioorganic steel that displays altered properties relative to the initial starting material. The bioorganic steel generated from the retro-inverso-D-peptide yields a protease stable product that is harder (41% harder at a 400 μN load), and has a 50% lower corrosion rate compared with regular stainless steel (0.11 ± 0.03 mpy and 0.22 ± 0.04 mpy, respectively). Bioorganic steel is readily fabricated.

  19. A Stainless-Steel Mandrel for Slumping Glass X-ray Mirrors

    Science.gov (United States)

    Gubarev, Mikhail V.; O'Dell, Stephen L.; Jones, William D.; Kester, Thomas J.; Griffith, Charles W.; Zhang, William W.; Saha, Timo T.; Chan, Kai-Wing

    2009-01-01

    We have fabricated a precision full-cylinder stainless-steel mandrel at Marshall Space Flight Center. The mandrel is figured for a 30-cm diameter primary (paraboloid) mirror of an 840-cm focal-length Wolter-1 telescope. We have developed this mandrel for experiments in slumping.thermal forming at about 600 C.of glass mirror segments at Goddard Space Flight Center, in support of NASA's participation in the International X-ray Observatory (IXO). Precision turning of stainless-steel mandrels may offer a low-cost alternative to conventional figuring of fused-silica or other glassy forming mandrels. We report on the fabrication, metrology, and performance of this first mandrel; then we discuss plans and goals for stainless-steel mandrel technology.

  20. A Stainless-Steel Mandrel for Slumping Glass X-Ray Mirrors

    Science.gov (United States)

    ODell, Stephen L.; Gubarev, Mikhail V.; Jones, William D.; Kester, Thomas J.; Griffith, Charles W.; Zhang, William W.; Saha, Timo T.; Chan, Kai-Wing

    2008-01-01

    We have fabricated a precision full -cylinder stainless-steel mandrel at Marshall Space Flight Center. The mandrel is figured for a 30-cm-diameter primary (paraboloid) mirror of an 840-cm focal-lengthWolter-1 telescope. We have developed this mandrel for experiments in slumping.thermal forming at about 600 C-of glass mirror segments at Goddard Space Flight Center, in support of NASA fs participation in the International X -ray Observatory (IXO). Precision turning of stainless ]steel mandrels may offer a lowcost alternative to conventional figuring of fused -silica or other glassy forming mandrels. We report on the fabrication, metrology, and performance of this first mandrel; then we discuss plans and goals for stainless-steel mandrel technology.

  1. 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....

  2. Thermophysical properties of stainless steel foils

    Energy Technology Data Exchange (ETDEWEB)

    Wilkes, K.E.; Strizak, J.P.; Weaver, F.J. [Oak Ridge National Lab., TN (United States); Besser, J.E.; Smith, D.L. [Aladdin Industries, Inc. (United States)

    1997-10-01

    Evacuated panel superinsulations with very high center-of-panel thermal resistances are being developed for use in refrigerators/freezers. Attainment of high resistances relies upon the maintenance of low vacuum levels by the use of stainless steel vacuum jackets. However, the metal jackets also present a path for heat conduction around the high resistance fillers. This paper presents results of a study of the impact of metal vacuum jackets on the overall thermal performance of vacuum superinsulations when incorporated into the walls and doors of refrigerators/freezers. Results are presented on measurements of the thermophysical properties of several types and thicknesses of stainless steel foils that were being considered for application in superinsulations. A direct electrical heating method was used for simultaneous measurements of the electrical resistivity, total hemispherical emittance, and thermal conductivity of the foils. Results are also presented on simulations of the energy usage of refrigerators/freezers containing stainless-steel-clad vacuum superinsulations.

  3. Ultrasonic Spectroscopy of Stainless Steel Sandwich Panels

    Science.gov (United States)

    Cosgriff, Laura M.; Lerch, Bradley A.; Hebsur, Mohan G.; Baaklini, George Y.; Ghosn, Louis J.

    2003-01-01

    Enhanced, lightweight material systems, such as 17-4PH stainless steel sandwich panels are being developed for use as fan blades and fan containment material systems for next generation engines. In order to improve the production for these systems, nondestructive evaluation (NDE) techniques, such as ultrasonic spectroscopy, are being utilized to evaluate the brazing quality between the 17-4PH stainless steel face plates and the 17-4PH stainless steel foam core. Based on NDE data, shear tests are performed on sections representing various levels of brazing quality from an initial batch of these sandwich structures. Metallographic characterization of brazing is done to corroborate NDE findings and the observed shear failure mechanisms.

  4. General and Localized Corrosion of Borated Stainless Steels

    Energy Technology Data Exchange (ETDEWEB)

    T.E. Lister; Ronald E. Mizia; A.W. Erickson; T.L. Trowbridge; B. S. Matteson

    2008-03-01

    The Transportation, Aging and Disposal (TAD) canister-based system is being proposed to transport and store spent nuclear fuel at the Monitored Geologic Repository (MGR) located at Yucca Mountain, Nevada. The preliminary design of this system identifies borated stainless steel as the neutron absorber material that will be used to fabricate fuel basket inserts for nuclear criticality control. This paper discusses corrosion test results for verifying the performance of this material manufactured to the requirements of ASTM A887, Grade A, under the expected repository conditions.

  5. Low cycle fatigue behavior of aluminum/stainless steel composites

    Science.gov (United States)

    Bhagat, R. B.

    1983-01-01

    Composites consisting of an aluminum matrix reinforced with various volume fractions of stainless steel wire were fabricated by hot die pressing under various conditions of temperature, time, and pressure. The composites were tested in plane bending to complete fracture under cycle loading, and the results were analyzed on a computer to obtain a statistically valid mathematical relationship between the low-cycle fatigue life and the fiber volume fraction of the composite. The fractured surfaces of the composites were examined by scanning electron microscopy to identify the characteristic features of fatigue damage. Fatigue damage mechanisms are proposed and discussed.

  6. 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%.

  7. 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...

  8. 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....

  9. 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....

  10. Activation and Dose Rate Analysis of 316 Stainless Steel

    Institute of Scientific and Technical Information of China (English)

    XU; Zhi-long; SUN; Zheng; LIU; Xing-min; WAN; Hai-xia

    2012-01-01

    <正>In order to conduct research on 316 stainless steel to be used in reactors, neutron activation during irradiation and dose rate after irradiation in China Experiment Fast Reactor (CEFR) are calculated and analyzed. Based on 1 g of 316 stainless steel specimen, analysis on the activity of 316 stainless steel irradiated

  11. 21 CFR 878.4495 - Stainless steel suture.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Stainless steel suture. 878.4495 Section 878.4495...) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4495 Stainless steel suture. (a) Identification. A stainless steel suture is a needled or unneedled nonabsorbable surgical suture composed of...

  12. 21 CFR 872.3350 - Gold or stainless steel cusp.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Gold or stainless steel cusp. 872.3350 Section 872...) 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...

  13. Preparation and Characterization of Stainless Steel/TiC Nanocomposite Particles by Ball-milling Method

    Institute of Scientific and Technical Information of China (English)

    CHEN Wenyi; ZHOU Jian

    2009-01-01

    A stainless steel/10wt%TiC nanocomposite particles were prepared by high-energy ball-milling method using stainless steel, carbon and titanium as raw materials. The evolution of phase composition, microstructure and specific surface area of the stainless steel/TiC nanocomposite particles with increasing ball-milling time in the range of 0-100 h were investigated by XRD, SEM, TEM and BET techniques. The results showed that the stainless steel/TiC nano-composite particles were fabricated when the ball-milling time was longer than 20 h. However, the nanocomposite particles were soldered and agglomerated again when the ball-milling time was longer than 60 h. The microstructure of the composite particles transformed from lamellar structure to nanostructure during the repeated process of the cold welding and cracking. TEM image reveals clearly that the in-situ TiC nanoparticles with grain size of 3-8 nm are in the interior of the stainless steel/TiC nanocomposite particles obtained by ball-milling 100 h.

  14. Plasma assisted nitriding for micro-texturing onto martensitic stainless steels*

    Directory of Open Access Journals (Sweden)

    Katoh Takahisa

    2015-01-01

    Full Text Available Micro-texturing method has grown up to be one of the most promising procedures to form micro-lines, micro-dots and micro-grooves onto the mold-die materials and to duplicate these micro-patterns onto metallic or polymer sheets via stamping or injection molding. This related application requires for large-area, fine micro-texturing onto the martensitic stainless steel mold-die materials. A new method other than laser-machining, micro-milling or micro-EDM is awaited for further advancement of this micro-texturing. In the present paper, a new micro-texturing method is developed on the basis of the plasma assisted nitriding to transform the two-dimensionally designed micro-patterns to the three dimensional micro-textures in the martensitic stainless steels. First, original patterns are printed onto the surface of stainless steel molds by using the dispenser or the ink-jet printer. Then, the masked mold is subjected to high density plasma nitriding; the un-masked surfaces are nitrided to have higher hardness, 1400 Hv than the matrix hardness, 200 Hv of stainless steels. This nitrided mold is further treated by sand-blasting to selectively remove the soft, masked surfaces. Finally, the micro-patterned martensitic stainless steel mold is fabricated as a tool to duplicate these micro-patterns onto the plastic materials by the injection molding.

  15. E347L不锈钢焊带设计生产及其埋弧堆焊层性能%Design and Fabrication of E347L Stainless Steel Surfacing-strip and Properties of SAW Deposited Metal

    Institute of Scientific and Technical Information of China (English)

    张心保

    2011-01-01

    E347L stainless steel strip for SAW strip surfacing was designed and fabricated in order to replace imported EQ347 stainless strip. The design method and key points of the technology were briefly presented. Also, the effects of alloy agents and welding parameters on the formation and properties of the deposited metal layer were analyzed. In the course of fabricating, AOD secondary refining was adopted* hot forging temperature and hot rolling temperature should be below 1 250 t. The specifications of strip after cold rolling is 0. 5 mmX50 mm, and dimensional variation can be controlled within ±0. 01 mm. SAW strip surfacing test and analysis including chemical composition of the deposited metal, mechanical properties and intergranular corrosion test were carried out. The results show that the quality of the E347L strip accords with the specifications of the relevant standards. No flaw was found in bending test and intergranular corrosion test; the measured FN is between 5 and 7, and the hardness of deposited metal of E347 is between 204 and 210 HV. The stainless steel surfacing-strip has been used in hydrogenating reactor in chemical industry as a substitution for imported welding material.%为了替代进口EQ347堆焊用钢带,试制生产了带极堆焊用E347L焊带.介绍了其设计思路及生产技术要点,分析了焊接工艺参数和合金元素对堆焊层成形和性能的影响.生产中采用AOD炉外精炼,热锻及热轧温度低于1 250℃,冷轧后产品规格0.5 mm×50 mm,尺寸偏差可控制在±0.01 mm.进行了埋弧带极堆焊试验及检测,检测内容包括堆焊层的化学成分、力学性能和耐蚀性能等.结果表明,生产的E347L焊带堆焊层化学成分完全满足相关标准的要求,180°弯曲无裂纹,FN值在5~7之间,E347L堆焊层的硬度测试结果在204~210 HV之间,晶间腐蚀后弯曲无裂纹产生.该不锈钢焊带已替代进口焊材并用于化工工业中的加氢反应器中.

  16. Processing and mechanical properties of porous 316L stainless steel for biomedical applications

    Institute of Scientific and Technical Information of China (English)

    Montasser M.DEWIDAR; Khalil A.KHALIL; J. K. LIM

    2007-01-01

    Highly porous 316L stainless steel parts were produced by using a powder metallurgy process, which includes the selective laser sintering(SLS) and traditional sintering. Porous 316L stainless steel suitable for medical applications was successfully fabricated in the porosity range of 40%-50% (volume fraction) by controlling the SLS parameters and sintering behaviour. The porosity of the sintered compacts was investigated as a function of the SLS parameters and the furnace cycle. Compressive stress and elastic modulus of the 316L stainless steel material were determined. The compressive strength was found to be ranging from 21 to 32 MPa and corresponding elastic modulus ranging from 26 to 43 GPa. The present parts are promising for biomedical applications since the optimal porosity of implant materials for ingrowths of new-bone tissues is in the range of 20%-59% (volume fraction) and mechanical properties are matching with human bone.

  17. Brazing open cell reticulated copper foam to stainless steel tubing with vacuum furnace brazed gold/indium alloy plating

    Science.gov (United States)

    Howard, Stanley R.; Korinko, Paul S.

    2008-05-27

    A method of fabricating a heat exchanger includes brush electroplating plated layers for a brazing alloy onto a stainless steel tube in thin layers, over a nickel strike having a 1.3 .mu.m thickness. The resultant Au-18 In composition may be applied as a first layer of indium, 1.47 .mu.m thick, and a second layer of gold, 2.54 .mu.m thick. The order of plating helps control brazing erosion. Excessive amounts of brazing material are avoided by controlling the electroplating process. The reticulated copper foam rings are interference fit to the stainless steel tube, and in contact with the plated layers. The copper foam rings, the plated layers for brazing alloy, and the stainless steel tube are heated and cooled in a vacuum furnace at controlled rates, forming a bond of the copper foam rings to the stainless steel tube that improves heat transfer between the tube and the copper foam.

  18. Decontamination Characteristics of Stainless Steel Surface Contaminated with Cs{sup +} Ion by Light Ablation

    Energy Technology Data Exchange (ETDEWEB)

    Baigalmaa, Byambatseren; Won, Hui-Jun; Moon, Jei-Kwon; Jung, Chong-Hun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Hyun, Jae-Hyuk [Chungnam National University, Daejeon (Korea, Republic of)

    2008-05-15

    The characteristics of decontamination method by light ablation are the remote operation, a short application time, and the high removal efficiency. Furthermore, the generation of the secondary waste is negligible. The radioactivity of hot cells in DFDF (Dupic Fuel Development Facility) is presumed to be very high and the predominant radionuclide is Cs-137. A series of laser decontamination studies by the fabricated Qswitched Nd-YAG laser system were performed on the stainless steel specimens artificially contaminated with Cs{sup +} ion. Decontamination characteristics of the stainless steel were analyzed by SEM and EPMA.

  19. Highly porous, low elastic modulus 316L stainless steel scaffold prepared by selective laser melting.

    Science.gov (United States)

    Čapek, Jaroslav; Machová, Markéta; Fousová, Michaela; Kubásek, Jiří; Vojtěch, Dalibor; Fojt, Jaroslav; Jablonská, Eva; Lipov, Jan; Ruml, Tomáš

    2016-12-01

    Recently, porous metallic materials have been extensively studied as candidates for use in the fabrication of scaffolds and augmentations to repair trabecular bone defects, e.g. in surroundings of joint replacements. Fabricating these complex structures by using common approaches (e.g., casting and machining) is very challenging. Therefore, rapid prototyping techniques, such as selective laser melting (SLM), have been investigated for these applications. In this study, we characterized a highly porous (87 vol.%) 316L stainless steel scaffold prepared by SLM. 316L steel was chosen because it presents a biomaterial still widely used for fabrication of joint replacements and, from the practical point of view, use of the same material for fabrication of an augmentation and a joint replacement is beneficial for corrosion prevention. The results are compared to the reported properties of two representative nonporous 316L stainless steels prepared either by SLM or casting and subsequent hot forging. The microstructural and mechanical properties and the surface chemical composition and interaction with the cells were investigated. The studied material exhibited mechanical properties that were similar to those of trabecular bone (compressive modulus of elasticity ~0.15GPa, compressive yield strength ~3MPa) and cytocompatibility after one day that was similar to that of wrought 316L stainless steel, which is a commonly used biomaterial. Based on the obtained results, SLM is a suitable method for the fabrication of porous 316L stainless steel scaffolds with highly porous structures.

  20. Advances in the research of nitrogen containing stainless steels

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    The current status of nitrogen containing stainless steels at home and aboard has been introduced. The function and existing forms of nitrogen in the stainless steels, influence of nitrogen on mechanical properties and anti-corrosion properties as well as the application of nitrogen containing cast stainless steels were discussed in this paper. It is clear that nitrogen will be a potential and important alloying element in stainless steels. And Argon Oxygen Decarbonization (AOD) refining can provide an advanced manufacture process for nitrogen containing stainless steels with ultra-low- carbon and high cleanliness.

  1. 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...

  2. 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 averag

  3. Forming "dynamic" membranes on stainless steel

    Science.gov (United States)

    Brandon, C. A.; Gaddis, J. L.

    1979-01-01

    "Dynamic" zirconium polyacrylic membrane is formed directly on stainless steel substrate without excessive corrosion of steel. Membrane is potentially useful in removal of contaminated chemicals from solution through reversed osmosis. Application includes use in filtration and desalination equipment, and in textile industry for separation of dyes from aqueous solvents.

  4. Ne Implantation Induced Transformation in Stainless Steel

    NARCIS (Netherlands)

    Noordhuis, J.; Hosson, J.Th.M. De

    1990-01-01

    This paper reports a microstructural investigation of the changes induced by Ne implantation in stainless steel of the austenitic type. At a critical dose of 2.3 · 10^17/cm^2 a martensitic phase transformation was observed. In particular, attention has been paid to the effect of the stress held of n

  5. Stabilizing stainless steel components for cryogenic service

    Science.gov (United States)

    Holden, C. F.

    1967-01-01

    Warpage and creep in stainless steel valve components are decreased by a procedure in which components are machined to a semifinish and then cold soaked in a bath of cryogenic liquid. After the treatment they are returned to ambient temperature and machine finished to the final drawing dimensions.

  6. Effect of surface treatment on mechanical properties of glass fiber/stainless steel wire mesh reinforced epoxy hybrid composites

    Energy Technology Data Exchange (ETDEWEB)

    N, Karunagaran [S.K.P Engineering College, Tiruvannamalai (India); A, Rajadurai [Anna University, Chennai (India)

    2016-06-15

    This paper investigates the effect of surface treatment for glass fiber, stainless steel wire mesh on tensile, flexural, inter-laminar shear and impact properties of glass fiber/stainless steel wire mesh reinforced epoxy hybrid composites. The glass fiber fabric is surface treated either by 1 N solution of sulfuric acid or 1 N solution of sodium hydroxide. The stainless steel wire mesh is also surface treated by either electro dissolution or sand blasting. The hybrid composites are fabricated using epoxy resin reinforced with glass fiber and fine stainless steel wire mesh by hand lay-up technique at room temperature. The hybrid composite consisting of acid treated glass fiber and sand blasted stainless steel wire mesh exhibits a good combination of tensile, flexural, inter-laminar shear and impact behavior in comparison with the composites made without any surface treatment. The fine morphological modifications made on the surface of the glass fiber and stainless steel wire mesh enhances the bonding between the resin and reinforcement which inturn improved the tensile, flexural, inter-laminar shear and impact properties.

  7. Nickel-free austenitic stainless steels for medical applications

    Directory of Open Access Journals (Sweden)

    Ke Yang and Yibin Ren

    2010-01-01

    Full Text Available 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.

  8. Duplex Stainless Steels-An overview

    Directory of Open Access Journals (Sweden)

    Dr. Sunil D.Kahar

    2017-04-01

    Full Text Available Stainless steel is one of the most important materials in the engineering world. The material‟s wide applications in chemical, petrochemical, off-shore, and power generation plants prove that it is one of the most reliable materials. The Newest fast growing family of stainless steels is duplex alloys. The ferritic-austenitic grades have a ferrite matrix intermix with austenite and in other words island of austenite in a continuous matrix of highly alloyed ferrite commonly called „Duplex‟ stainless steel. Duplex stainless steel covers ferritic/austenitic Fe-Cr-Ni alloy with between 30% to 70 % Ferrite .Due to high level of Cr, Mo, and N steels shows high pitting & stress corrosion cracking resistance in chloride-containing environments. Hence it is frequently used in oilrefinery heat exchangers & typical applications where there is a risk for SCC and localized corrosion as a result of chloride-containing process streams, cooling waters or deposits. Modern duplex stainless steels have generally good Weldability. Due to a balanced composition, where nitrogen plays an important role, austenite formation in the heat affected zone (HAZ and weld metal is rapid. Under normal welding conditions a sufficient amount of austenite is formed to maintain good resistance to localized corrosion where as too rapid cooling may result in excessive amounts of ferrite, reducing the toughness. Therefore, welding with low heat input in thick walled materials should be avoided. Welding methods, such as resistance welding, laser welding and electron beam welding, which cause extremely rapid cooling should also be avoided or used with extreme caution. Too slow cooling can in the higher alloyed duplex grades cause formation of inter-metallic phases detrimental to corrosion resistance and toughness.

  9. 2014 Accomplishments-Tritium aging studies on stainless steel: Fracture toughness properties of forged stainless steels-Effect of hydrogen, forging strain rate, and forging temperature

    Energy Technology Data Exchange (ETDEWEB)

    Morgan, Michael J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-02-01

    Forged stainless steels are used as the materials of construction for tritium reservoirs. During service, tritium diffuses into the reservoir walls and radioactively decays to helium-3. Tritium and decay helium cause a higher propensity for cracking which could lead to a tritium leak or delayed failure of a tritium reservoir. The factors that affect the tendency for crack formation and propagation include: Environment; steel type and microstructure; and, vessel configuration (geometry, pressure, residual stress). Fracture toughness properties are needed for evaluating the long-term effects of tritium on their structural properties. Until now, these effects have been characterized by measuring the effects of tritium on the tensile and fracture toughness properties of specimens fabricated from experimental forgings in the form of forward-extruded cylinders. A key result of those studies is that the long-term cracking resistance of stainless steels in tritium service depends greatly on the interaction between decay helium and the steels’ forged microstructure. New experimental research programs are underway and are designed to measure tritium and decay helium effects on the cracking properties of stainless steels using actual tritium reservoir forgings instead of the experimental forgings of past programs. The properties measured should be more representative of actual reservoir properties because the microstructure of the specimens tested will be more like that of the tritium reservoirs. The programs are designed to measure the effects of key forging variables on tritium compatibility and include three stainless steels, multiple yield strengths, and four different forging processes. The effects on fracture toughness of hydrogen and crack orientation were measured for type 316L forgings. In addition, hydrogen effects on toughness were measured for Type 304L block forgings having two different yield strengths. Finally, fracture toughness properties of type 304L

  10. Weldability of Additive Manufactured Stainless Steel

    Science.gov (United States)

    Matilainen, Ville-Pekka; Pekkarinen, Joonas; Salminen, Antti

    Part size in additive manufacturing is limited by the size of building area of AM equipment. Occasionally, larger constructions that AM machines are able to produce, are needed, and this creates demand for welding AM parts together. However there is very little information on welding of additive manufactured stainless steels. The aim of this study was to investigate the weldability aspects of AM material. In this study, comparison of the bead on plate welds between AM parts and sheet metal parts is done. Used material was 316L stainless steel, AM and sheet metal, and parts were welded with laser welding. Weld quality was evaluated visually from macroscopic images. Results show that there are certain differences in the welds in AM parts compared to the welds in sheet metal parts. Differences were found in penetration depths and in type of welding defects. Nevertheless, this study presents that laser welding is suitable process for welding AM parts.

  11. 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.

  12. Warm compacting behavior of stainless steel powders

    Institute of Scientific and Technical Information of China (English)

    肖志瑜; 柯美元; 陈维平; 召明; 李元元

    2004-01-01

    The warm compacting behaviors of four different kinds of stainless steel powders, 304L, 316L, 410L and 430L, were studied. The results show that warm compaction can be applied to stainless steel powders. The green densities and strengths of compacts obtained through warm compaction are generally higher than those obtained through cold compaction. The compacting behaviors in warm compaction and cold compaction are similar.Under the compacting pressure of 700 MPa, the warm compacted densities are 0. 10 - 0.22 g/cm3 higher than the cold compacted ones, and the green strengths are 11.5 %-50 % higher. The optimal warm compacting temperature is 100 - 110 ℃. In the die wall lubricated warm compaction, the optimum internal lubricant content is 0.2%.

  13. Phase Transformation in Cast Superaustenitic Stainless Steels

    Energy Technology Data Exchange (ETDEWEB)

    Lee Phillips, Nathaniel Steven [Iowa State Univ., Ames, IA (United States)

    2006-01-01

    Superaustenitic stainless steels constitute a group of Fe-based alloys that are compositionally balanced to have a purely austenitic matrix and exhibit favorable pitting and crevice corrosion resistant properties and mechanical strength. However, intermetallic precipitates such as sigma and Laves can form during casting or exposure to high-temperature processing, which degrade the corrosion and mechanical properties of the material. The goal of this study was to accurately characterize the solid-solid phase transformations seen in cast superaustenitic stainless steels. Heat treatments were performed to understand the time and temperature ranges for intermetallic phase formations in alloys CN3MN and CK3MCuN. Microstructures were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy and wavelength dispersive spectroscopy (EDS, WDS). The equilibrium microstructures, composed primarily of sigma and Laves within purely austenitic matrices, showed slow transformation kinetics. Factors that determine the extent of transformation, including diffusion, nucleation, and growth, are discussed.

  14. 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.

  15. Impact Simulation Analysis for Stainless Steel with Different Pore Structure Fabricated by Selective Laser Melting%选区激光熔化制备不同孔结构不锈钢冲击性能仿真分析

    Institute of Scientific and Technical Information of China (English)

    王健飞; 卢冠辰

    2015-01-01

    采用316L不锈钢粉末基于选区激光熔化技术(Selective Laser Melting,SLM)制备压缩试样,观测其宏观组织形貌,随后进行压缩实验,获得工程应力-应变曲线及材料参数;利用ABAQUS/STANDARD有限元分析模块模拟试样压缩过程,得出仿真工程应力-应变曲线,将其与实验工程应力-应变曲线比较,验证材料参数设置准确性;最后构建规则栅格孔结构模型与交错栅格孔结构模型,利用ABAQUS/EXPLICIT有限元分析模块模拟落体冲击实验与摆锤冲击实验。结果表明:相同宏观体积条件下,基于SLM制备交错栅格孔结构不锈钢材料在落体冲击实验中对冲击能的消耗高于规则栅格孔结构部件,而在摆锤冲击实验中冲击性能差异不显著。%Compressive specimen are fabricated by selective laser melting (SLM) using 316L stainless steel powder. Its macrostructure is observed ,the engineering stress-strain curves and material parameter of specimen are obtained by the compression testing. The dynamic compression process of specimen is reproduced by ABAQUS simulation and the simulation engineering stress-strain curves is obtained ,then compares with experiment engineering stress-strain curves and the material parameters are verified. Finally ,the regular grid pore structure model and the stagger grid pore structure model and the falling impact experiment and pendulum impact experiment are simulated by ABAQUS. The results show that the energy dissipated by the stagger grid pore structure model is higher than the regular grid pore structure model with the same macroscopic volume in the falling impact experiment ,but the difference of impact property is not significant in the pendulum impact experiment.

  16. 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)....

  17. 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.

  18. Dynamic compressive response of wrought and additive manufactured 304L stainless steels

    Directory of Open Access Journals (Sweden)

    Nishida Erik

    2015-01-01

    Full Text Available Additive manufacturing (AM technology has been developed to fabricate metal components that include complex prototype fabrication, small lot production, precision repair or feature addition, and tooling. However, the mechanical response of the AM materials is a concern to meet requirements for specific applications. Differences between AM materials as compared to wrought materials might be expected, due to possible differences in porosity (voids, grain size, and residual stress levels. When the AM materials are designed for impact applications, the dynamic mechanical properties in both compression and tension need to be fully characterized and understood for reliable designs. In this study, a 304L stainless steel was manufactured with AM technology. For comparison purposes, both the AM and wrought 304L stainless steels were dynamically characterized in compression Kolsky bar techniques. They dynamic compressive stress-strain curves were obtained and the strain rate effects were determined for both the AM and wrought 304L stainless steels. A comprehensive comparison of dynamic compressive response between the AM and wrought 304L stainless steels was performed. SAND2015-0993 C.

  19. The use of stainless steel crowns.

    Science.gov (United States)

    Seale, N Sue

    2002-01-01

    The stainless steel crown (SSC) is an extremely durable restoration with several clear-cut indications for use in primary teeth including: following a pulpotomy/pulpectomy; for teeth with developmental defects or large carious lesions involving multiple surfaces where an amalgam is likely to fail; and for fractured teeth. In other situations, its use is less clear cut, and caries risk factors, restoration longevity and cost effectiveness are considerations in decisions to use the SSC. The literature on caries risk factors in young children indicates that children at high risk exhibiting anterior tooth decay and/or molar caries may benefit by treatment with stainless steel crowns to protect the remaining at-risk tooth surfaces. Studies evaluating restoration longevity, including the durability and lifespan of SSCs and Class II amalgams demonstrate the superiority of SSCs for both parameters. Children with extensive decay, large lesions or multiple surface lesions in primary molars should be treated with stainless steel crowns. Because of the protection from future decay provided by their feature of full coverage and their increased durability and longevity, strong consideration should be given to the use of SSCs in children who require general anesthesia. Finally, a strong argument for the use of the SSC restoration is its cost effectiveness based on its durability and longevity.

  20. SRS stainless steel beneficial reuse program

    Energy Technology Data Exchange (ETDEWEB)

    Boettinger, W.L.

    1997-02-01

    The US Department of Energy`s (DOE) Savannah River Site (SRS) has thousands of tons of stainless steel radioactive scrap metal (RSNI). Much of the metal is volumetrically contaminated. There is no {open_quotes}de minimis{close_quotes} free release level for volumetric material, and therefore no way to recycle the metal into the normal commercial market. If declared waste, the metal would qualify as low level radioactive waste (LLW) and ultimately be dispositioned through shallow land buried at a cost of millions of dollars. The metal however could be recycled in a {open_quotes}controlled release{close_quote} manner, in the form of containers to hold other types of radioactive waste. This form of recycle is generally referred to as {open_quotes}Beneficial Reuse{close_quotes}. Beneficial reuse reduces the amount of disposal space needed and reduces the need for virgin containers which would themselves become contaminated. Stainless steel is particularly suited for long term storage because of its resistance to corrosion. To assess the practicality of stainless steel RSM recycle the SRS Benficial Reuse Program began a demonstration in 1994, funded by the DOE Office of Science and Technology. This paper discusses the experiences gained in this program.

  1. A Stem Analysis of Two Rapidly Solidified Stainless Steels.

    Science.gov (United States)

    1980-03-25

    slightly faster rate than the 303 stainless steel powder and therefore few usable specimens were obtained by electropolishing . The unsuccessful...CONCLUSIONS Rapid solidification processing of a high- sulphur austenitic type 303 stainless steel produces a significant refinement in the...A STEM ANALYSTS OF TWO RAPIDLY SOLIDIFIED STAINLESS STEELS . (U) UN D MAR 80 T F KELLY, J B VANDER SANDE NOBOI-76-C-0171 UNLSSFE7Minrnc UNCLASSIFIED

  2. Structural materialization of stainless steel molds and dies by the low temperature high density plasma nitriding

    Directory of Open Access Journals (Sweden)

    Aizawa Tatsuhiko

    2015-01-01

    Full Text Available Various kinds of stainless steels have been widely utilized as a mold substrate material for injection molding and as a die for mold-stamping and direct stamping processes. Since they suffered from high temperature transients and thermal cycles in practice, they must be surface-treated by dry and wet coatings, or, by plasma nitriding. Martensitic stainless steel mold was first wet plated by the nickel phosphate (NiP, which was unstable at the high temperature stamping condition; and, was easy to crystalize or to fracture by itself. This issue of nuisance significantly lowered the productivity in fabrication of optical elements at present. In the present paper, the stainless steel mold was surface-treated by the low-temperature plasma nitriding. The nitrided layer by this surface modification had higher nitrogen solute content than 4 mass%; the maximum solid-solubility of nitrogen is usually 0.1 mass% in the equilibrium phase diagram. Owing to this solid-solution with high nitrogen concentration, the nitrided layer had high hardness of 1400 Hv within its thickness of 40 μm without any formation of nitrides after 14.4 ks plasma nitriding at 693 K. This nitrogen solid-solution treated stainless steel had thermal resistivity even at the mold-stamping conditions up to 900 K.

  3. In vitro corrosion resistance of Lotus-type porous Ni-free stainless steels.

    Science.gov (United States)

    Alvarez, Kelly; Hyun, Soong-Keun; Fujimoto, Shinji; Nakajima, Hideo

    2008-11-01

    The corrosion behavior of three kinds of austenitic high nitrogen Lotus-type porous Ni-free stainless steels was examined in acellular simulated body fluid solutions and compared with type AISI 316L stainless steel. The corrosion resistance was evaluated by electrochemical techniques, the analysis of released metal ions was performed by inductively coupled plasma mass spectrometry (ICP-MS) and the cytotoxicity was investigated in a culture of murine osteoblasts cells. Total immunity to localized corrosion in simulated body fluid (SBF) solutions was exhibited by Lotus-type porous Ni-free stainless steels, while Lotus-type porous AISI 316L showed very low pitting corrosion resistance evidenced by pitting corrosion at a very low breakdown potential. Additionally, Lotus-type porous Ni-free stainless steels showed a quite low metal ion release in SBF solutions. Furthermore, cell culture studies showed that the fabricated materials were non-cytotoxic to mouse osteoblasts cell line. On the basis of these results, it can be concluded that the investigated alloys are biocompatible and corrosion resistant and a promising material for biomedical applications.

  4. Measurement of bulk residual stresses in molybdenum disilicide/stainless steel joints using neutron scattering

    Energy Technology Data Exchange (ETDEWEB)

    Vaidya, R.U.; Rangaswamy, P.; Bourke, M.A.M.; Butt, D.P. [Los Alamos National Lab., NM (United States). Materials Science and Technology Div.

    1998-03-23

    Neutron diffraction was used to measure the bulk residual strains in molybdenum disilicide (MoSi{sub 2})-316L stainless steel joints. The joints were produced by brazing disks of MoSi{sub 2} and 316L stainless steel along with an interlayer, using Cusil{trademark} as the braze. This study explored the physical parameters of the interlayer on the average phase strains in the MoSi{sub 2} and 316L stainless steel. The effect of the coefficient of thermal expansion was explored by using three different interlayer materials: niobium, nickel, and nickel-iron. The residual strains in MoSi{sub 2} decreased significantly in both radial and axial directions with increasing niobium interlayer thickness. Residual strains were relatively insensitive to changes in 500 {micro}m thick interlayer material. Finite element modeling results were corroborated by the neutron measurements on the joints allowing inferences to be drawn concerning the preference of the interlayer material. The results illustrate the importance of the ductile interlayer in the successful fabrication of MoSi{sub 2}-316L stainless steel joints.

  5. Documentation of Stainless Steel Lithium Circuit Test Section Design. Suppl

    Science.gov (United States)

    Godfroy, Thomas J. (Compiler); Martin, James J.

    2010-01-01

    The Early Flight Fission-Test Facilities (EFF-TF) team was tasked by Naval Reactors Prime Contract Team (NRPCT) to design, fabricate, and test an actively pumped lithium (Li) flow circuit. This Li circuit takes advantage of work in progress at the EFF TF on a stainless steel sodium/potassium (NaK) circuit. The effort involved modifying the original stainless steel NaK circuit such that it could be operated with Li in place of NaK. This new design considered freeze/thaw issues and required the addition of an expansion tank and expansion/extrusion volumes in the circuit plumbing. Instrumentation has been specified for Li and circuit heaters have been placed throughout the design to ensure adequate operational temperatures and no uncontrolled freezing of the Li. All major components have been designed and fabricated prior to circuit redesign for Li and were not modified. Basic circuit components include: reactor segment, Li to gas heat exchanger, electromagnetic liquid metal pump, load/drain reservoir, expansion reservoir, instrumentation, and trace heaters. The reactor segment, based on a Los Alamos National Laboratory 100-kW design study with 120 fuel pins, is the only prototypic component in the circuit. However, due to earlier funding constraints, a 37-pin partial-array of the core, including the central three rings of fuel pins (pin and flow path dimensions are the same as those in the full design), was selected for fabrication and test. This Technical Publication summarizes the design and integration of the pumped liquid metal Li flow circuit as of May 1, 2005. This supplement contains drawings, analysis, and calculations

  6. Documentation of Stainless Steel Lithium Circuit Test Section Design

    Science.gov (United States)

    Godfroy, T. J.; Martin, J. J.; Stewart, E. T.; Rhys, N. O.

    2010-01-01

    The Early Flight Fission-Test Facilities (EFF-TF) team was tasked by Naval Reactors Prime Contract Team (NRPCT) to design, fabricate, and test an actively pumped lithium (Li) flow circuit. This Li circuit takes advantage of work in progress at the EFF TF on a stainless steel sodium/potassium (NaK) circuit. The effort involved modifying the original stainless steel NaK circuit such that it could be operated with Li in place of NaK. This new design considered freeze/thaw issues and required the addition of an expansion tank and expansion/extrusion volumes in the circuit plumbing. Instrumentation has been specified for Li and circuit heaters have been placed throughout the design to ensure adequate operational temperatures and no uncontrolled freezing of the Li. All major components have been designed and fabricated prior to circuit redesign for Li and were not modified. Basic circuit components include: reactor segment, Li to gas heat exchanger, electromagnetic liquid metal pump, load/drain reservoir, expansion reservoir, instrumentation, and trace heaters. The reactor segment, based on a Los Alamos National Laboratory 100-kW design study with 120 fuel pins, is the only prototypic component in the circuit. However, due to earlier funding constraints, a 37-pin partial-array of the core, including the central three rings of fuel pins (pin and flow path dimensions are the same as those in the full design), was selected for fabrication and test. This Technical Publication summarizes the design and integration of the pumped liquid metal Li flow circuit as of May 1, 2005.

  7. The Effect of Constant and Pulsed Current Gas Tungsten Arc Welding on Joint Properties of 2205 Duplex Stainless Steel to 316L Austenitic Stainless Steel

    Science.gov (United States)

    Neissi, R.; Shamanian, M.; Hajihashemi, M.

    2016-05-01

    In this study, dissimilar 316L austenitic stainless steel/2205 duplex stainless steel (DSS) joints were fabricated by constant and pulsed current gas tungsten arc welding process using ER2209 DSS as a filler metal. Microstructures and joint properties were characterized using optical and electron scanning microscopy, tensile, Charpy V-notch impact and micro-hardness tests, and cyclic polarization measurements. Microstructural observations confirmed the presence of chromium nitride and delta ferrite in the heat-affected zone of DSS and 316L, respectively. In addition, there was some deviation in the austenite/ferrite ratio of the surface welding pass in comparison to the root welding pass. Besides having lower pitting potential, welded joints produced by constant current gas tungsten arc welding process, consisted of some brittle sigma phase precipitates, which resulted in some impact energy reduction. The tensile tests showed high tensile strength for the weld joints in which all the specimens were broken in 316L base metal.

  8. Multilayer Clad Plate of Stainless Steel/Aluminum/Aluminum Alloy

    Institute of Scientific and Technical Information of China (English)

    YUAN Jiawei; PANG Yuhua; LI Ting

    2011-01-01

    The 3, 5, 20 layer clad plate from austenitic stainless steel, pure aluminum and aluminum alloy sheets were fabricated in different ways. The stretch and interface properties were measured. The result shows that 20 layer clad plate is better than the others. Well-bonded clad plate was successfully obtained in the following procedure: Basic clad sheet from 18 layer A11060/A13003sheets was firstly obtained with an initial rolling reduction of 44% at 450 ℃, followed by annealing at 300 ℃, and then with reduction of 50% at 550 ℃ from STS304 on each side. The best 20 layer clad plate was of 129 MPa bonding strength and 225 MPa stretch strength.

  9. 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

  10. Temperature Dependence of Radiation Damage in Modified Stainless Steel

    Institute of Scientific and Technical Information of China (English)

    ZHENGYong-nan; PolatAhmat; XUYong-jun; ZHOUDong-mei; DUEn-peng; YUANDa-qing; ZUOYi; WANGZhi-qiang; RUANYu-zhen; ZHUSheng-yun

    2003-01-01

    Stainless steels are often used as target structural materials for spallation neutron sources. The spallation neutron source system is one of the key parts of the ADS system, which provides the source neutrons for driving a sub-critical assembly. Stainless steel (SS) is used for the beam window and target materials of the ADS spallation neutron source system.

  11. A mechanism for the enhanced attachment and proliferation of fibroblasts on anodized 316L stainless steel with nano-pit arrays.

    Science.gov (United States)

    Ni, Siyu; Sun, Linlin; Ercan, Batur; Liu, Luting; Ziemer, Katherine; Webster, Thomas J

    2014-08-01

    In this study, 316L stainless steel with tunable nanometer pit sizes (0, 25, 50, and 60 nm) were fabricated by an anodization procedure in an ethylene glycol electrolyte solution containing 5 vol % perchloric acid. The surface morphology and elemental composition of the 316L stainless steel were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). The nano-pit arrays on all of the 316L stainless steel samples were in a regular arrangement. The surface properties of the 316L stainless steel nano-pit surface showed improved wettability properties as compared with the untreated 316L stainless steel, as demonstrated by the lower contact angles which dropped from 83.0° to 28.6 to 45.4°. The anodized 316L stainless steel surfaces with 50 nm and 60 nm diameter pits were also more rough at the nanoscale. According to MTT assays, compared with unanodized (that is, nano-smooth) surfaces, the 50 and 60 nm diameter nano-pit surfaces dramatically enhanced initial human dermal fibroblast attachment and growth for up to 3 days in culture. Mechanistically, this study also provided the first evidence of greater select protein adsorption (specifically, vitronectin and fibronectin which have been shown to enhance fibroblast adhesion) on the anodized 316L stainless steel compared with unanodized stainless steel. Such nano-pit surfaces can be designed to support fibroblast growth and, thus, improve the use of 316L stainless steel for various implant applications (such as for enhanced skin healing for amputee devices and for percutaneous implants).

  12. Cast alumina forming austenitic stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    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; <0.3Ti+V; <0.03N; and, balance Fe, where the weight percent Fe is greater than the weight percent Ni, and wherein the alloy forms an external continuous scale comprising alumina, and a stable essentially single phase FCC austenitic matrix microstructure, the austenitic matrix being essentially delta-ferrite free and essentially BCC-phase-free. A method of making austenitic stainless steel alloys is also disclosed.

  13. Recycling and valorisation of stainless steel slags

    Energy Technology Data Exchange (ETDEWEB)

    Van Dessel, J. [Belgian Building Research Institute, Brussels (Belgium)

    2001-07-01

    The project described in this paper involves the collaboration of eleven partners. The project aims to create a value-added product by recovering usable non-ferrous metals from the production of stainless steel and use the recycled slag as a secondary material for road construction and concrete applications. The objective of the project is to return the metal contained in the slag to stainless steel production, and to treat the non-metallic slag, perhaps by a metallurgical process based upon direct plasma technology, prior to use in a variety of processes. The project also aims to investigate the environmental characteristics of the slag, which is essential for it to be used as secondary material. The major challenge appears to be the development of an improved process for separating the slag from the metallic particles in order to avoid the frequent breakdowns and significant repairs associated with use of the material. It is expected that using magnetic and density-based separation processes will reduce the cost of maintenance by about 20 per cent. Results achieved to date, and economic factors impacting on feasibility, are also discussed. 2 tabs., 3 figs.

  14. Embrittlement of austenitic stainless steel welds

    Energy Technology Data Exchange (ETDEWEB)

    David, S.A.; Vitek, J.M. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.

    1997-12-31

    The microstructure of type-308 austenitic stainless steel weld metal containing {gamma} and {delta} and ferrite is shown. Typical composition of the weld metal is Cr-20.2, Ni-9.4, Mn-1.7, Si-0.5, C-0.05, N-0.06 and balance Fe (in wt %). Exposure of austenitic stainless steel welds to elevated temperatures can lead to extensive changes in the microstructural features of the weld metal. On exposure to elevated temperatures over a long period of time, a continuous network of M{sub 23}C{sub 6} carbide forms at the austenite/ferrite interface. Upon aging at temperatures between 550--850 C, ferrite in the weld has been found to be unstable and transforms to sigma phase. These changes have been found to influence mechanical behavior of the weld metal, in particular the creep-rupture properties. For aging temperatures below 550 C the ferrite decomposes spinodally into {alpha} and {alpha}{prime} phases. In addition, precipitation of G-phase occurs within the decomposed ferrite. These transformations at temperatures below 550 C lead to embrittlement of the weld metal as revealed by the Charpy impact properties.

  15. 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.

  16. Deformasi Slot Beberapa Produk Braket Stainless Steel Akibat Gaya Torque Pada Kawat Stainless Steel

    Directory of Open Access Journals (Sweden)

    Atika Zairina

    2013-06-01

    Full Text Available Deformasi slot braket dapat mengurangi besar gaya torque  yang akan dihantarkan ke gigi dan jaringan pendukungnya. Beberapa braket stainless steel yang beredar dipasaran belum pernah diteliti kualitasnya dalam perawatan ortodonsi. Tujuan penelitian adalah untuk membandingkan besar gaya torque akibat sudut puntir 30° 45°  kawat stainless steel dan deformasi slot permanen akibat gaya torque tersebut antara kelompok merk braket (3M, Biom, Versadent, Ormco dan Shinye. Penelitian dilakukan pada lima puluh braket stainless steel edgewise dari lima kelompok merk braket (n=10 di lem ke akrilik. Masing-masing braket dilakukan pengukuran tinggi slot dengan mikroskop stereoskopi lalu dipasang ke alat uji torque yang sudah dibuat untuk penelitian ini. Setelah dilakukan uji torque, braket di ukur kembali tinggi slotnya dan dibandingkan dengan pengukuran sebelumnya untuk mengetahui adanya deformasi slot. Hasil analisis statistik menunjukkan perbedaan bermakna besar gaya torque pada sudut puntir 30° dan 45° antara Biom dan Shinye dengan Omrco. Gaya torque paling besar yaitu pada merk braket 3M (30°= 442,12 gmcm dan 45°= 567,99 gmcm, sedangkan yang terkecil adalah Biom (30°= 285,50 gmcm, 45°=361,38 gmcm. Perbedaan deformasi slot braket terjadi hampir pada semua kelompok merk braket. Deformasi slot braket hanya terjadi pada merk braket Biom (2,82 µm dan Shinye (2,52 µm. Kesimpulan, salah satu faktor yang mempengaruhi besar gaya torque dan terjadinya deformasi slot yaitu komposisi dan proses manufaktur dari braket stainless steel. Proses manufaktur yang tidak sesuai standar dapat menyebabkan kualitas braket yang buruk. Deformasi slot permanen dalam penelitian ini terjadi pada merek braket Biom dan Shinye. Slot Deformation of Various Stainless Steel Bracket Due to Torque Expression On The Wire. Bracket slot deformation can reduce the amount of torque that will be transmitted to teeth and supporting tissues. The quality of some stainless steel

  17. Investigation on the Recent Research Trend in the Corrosion Behaviour of Stainless Steel Weldment

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hwan Tae; Kil, Sang Cheol [Korea Institute of Science and Technology Information, Seoul (Korea, Republic of); Hwang, Woon Suk [Inha University, Incheon (Korea, Republic of)

    2011-06-15

    The research trend in the corrosion behaviour of stainless steel weldment has been reviewed. The welding technology plays an important role in the fabrication of structure such as chemical plant, power plant, because welding can influence various factors in the performance of plant and equipment. This has led to an increasing attention towards the corrosion behaviour of weldment which has been one of the major issues for both welding and corrosion research engineers. The aim of this paper is to give a short survey of the recent technical trends of welding and corrosion including the electrochemical corrosion, stress corrosion cracking, and corrosion fatigue in connection with the welding materials, welding process, and welding fabrication. This study covers the corrosion behaviour of stainless steel weldment collected from the COMPENDEX DB analysis of published papers, research subject and research institutes.

  18. Cold drawing of 316L stainless steel thin-walled tubes: experiments and finite element analysis

    OpenAIRE

    Palengat, Muriel; Chagnon, Grégory; Favier, Denis; Louche, Hervé; Linardon, Camille; Plaideau, Christel

    2013-01-01

    International audience; Drawing process of thin walled tubes used to fabricate catheters and stents for medical applications was studied. Medical use needs accurate dimensions and a smooth finish of the inner and outer surfaces. This paper deals with 316L stainless steel tubes which are manufactured by means of cold drawing with or without inner plug (mandrel drawing and hollow sinking, respectively). To improve the quality of the finish of the tubes, numerical modelling can be used. In this ...

  19. Pitting Corrosion of Super Duplex Stainless Steel - Effect of Isothermal Heat Treament

    OpenAIRE

    Lauritsen, Christian Rene

    2016-01-01

    Super duplex stainless steels (SDSS), with a chromium content of 25 wt$\\%$, contain a duplex structure which consists of ferrite and austenite, and have a pitting resistance equivalent number (PREN) equal or higher than 40. SDSS are affected by the alloying elements, microstructure and fabrication processes. The high degree of alloying elements in SDSS can lead to formation of intermetallic precipitates and secondary phases during heat treatments. Detrimental phases, such as sigma ($\\sigma$) ...

  20. Low Background Stainless Steel for the Pressure Vessel in the PandaX-II Dark Matter Experiment

    CERN Document Server

    Zhang, Tao; Ji, Xiangdong; Liu, Jianglai; Liu, Xiang; Wang, Xuming; Yao, Chunfa; Yuan, Xunhua

    2016-01-01

    We report on the custom produced low radiation background stainless steel and the welding rod for the PandaX experiment, one of the deep underground experiments to search for dark matter and neutrinoless double beta decay using xenon. The anthropogenic 60 Co concentration in these samples is at the range of 1 mBq/kg or lower. We also discuss the radioactivity of nuclear-grade stainless steel from TISCO which has a similar background rate. The PandaX-II pressure vessel was thus fabricated using the stainless steel from CISRI and TISCO. Based on the analysis of the radioactivity data, we also made discussions on potential candidate for low background metal materials for future pressure vessel development.

  1. Low background stainless steel for the pressure vessel in the PandaX-II dark matter experiment

    Science.gov (United States)

    Zhang, T.; Fu, C.; Ji, X.; Liu, J.; Liu, X.; Wang, X.; Yao, C.; Yuan, Xunhua

    2016-09-01

    We report on the custom produced low radiation background stainless steel and the welding rod for the PandaX experiment, one of the deep underground experiments to search for dark matter and neutrinoless double beta decay using xenon. The anthropogenic 60Co concentration in these samples is at the range of 1 mBq/kg or lower. We also discuss the radioactivity of nuclear-grade stainless steel from TISCO which has a similar background rate. The PandaX-II pressure vessel was thus fabricated using the stainless steel from CISRI and TISCO. Based on the analysis of the radioactivity data, we also made discussions on potential candidate for low background metal materials for future pressure vessel development.

  2. Separation of water and oil by poly (acrylic acid)-coated stainless steel mesh prepared by radiation crosslinking

    Energy Technology Data Exchange (ETDEWEB)

    Nho, Young Chang; Shin, Jung Woong; Park, Jong Seok; Lim, Young Mook; Jeun, Joon Pyo; Kang, Phil Hyun [Research Division for Industry and Environment, Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2015-05-15

    The stainless steel mesh coated with poly(acrylic acid) hydrogel was fabricated and applied for the separation of water and oil. The stainless steel mesh was immersed in aqueous poly (acrylic acid) solution, and then irradiated by radiation to introduce poly(acrylic acid) hydrogel on the surface of mesh by crosslinking. It was possible to separate oil and water from mixtures of oil/water effectively using the hydrogel-coated mesh. The effect of irradiation dose, coating thickness, size of mesh on the separation efficiency was examined.

  3. Feasibility of surface-coated friction stir welding tools to join AISI 304 grade austenitic stainless steel

    Institute of Scientific and Technical Information of China (English)

    A.K. LAKSHMINARAYANAN; C.S.RAMACHANDRAN; V.BALASUBRAMANIAN

    2014-01-01

    An attempt is made to develop the tools that are capable enough to withstand the shear, impact and thermal forces that occur during friction stir welding of stainless steels. The atmospheric plasma spray and plasma transferred arc hardfacing processes are employed to deposit refractory ceramic based composite coatings on the Inconel 738 alloy. Five different combinations of self-fluxing alloy powder and 60% ceramic rein-forcement particulate mixtures are used for coating. The best friction stir welding tool selected based on tool wear analysis is used to fabricate the austenitic stainless steel joints.

  4. Global stainless steel cycle exemplifies China's rise to metal dominance.

    Science.gov (United States)

    Reck, Barbara K; Chambon, Marine; Hashimoto, Seiji; Graedel, T E

    2010-05-15

    The use of stainless steel, a metal employed in a wide range of technology applications, has been characterized for 51 countries and the world for the years 2000 and 2005. We find that the global stainless steel flow-into-use increased by more than 30% in that 5 year period, as did additions to in-use stocks. This growth was mainly driven by China, which accounted for almost half of the global growth in stainless steel crude production and which tripled its flow into use between 2000 and 2005. The global stainless steel-specific end-of-life recycling rate increased from 66% (2000) to 70% (2005); the landfilling rate was 22% for both years, and 9% (2000) to 12% (2005) was lost into recycled carbon and alloy steels. Within just 5 years, China passed such traditionally strong stainless steel producers and users as Japan, USA, Germany, and South Korea to become the dominant player of the stainless steel industry. However, China did not produce any significant stainless steel end-of-life flows in 2000 or 2005 because its products-in-use are still too new to require replacements. Major Chinese discard flows are expected to begin between 2015 and 2020.

  5. Sigma phase formation kinetics in stainless steel laminate composites

    Energy Technology Data Exchange (ETDEWEB)

    Wenmen, D.W.; Olson, D.L.; Matlock, D.K. [Colorado School of Mines, Golden, CO (United States)] [and others

    1994-12-31

    Stainless steel laminate composites were made to simulate weld microstructures. The use of laminates with variations in chemical composition allows for one dimensional analysis of phase transformation associated with the more complex three-dimensional solidification experience of weld metal. Alternate layers of austenitic (304L and 316L) and ferritic (Ebrite) stainless steels allowed for the study of sigma phase formation at the austenite-ferrite interface in duplex stainless steel. Two austenitic stainless steels, 304L (18.5Cr-9.2Ni-0.3Mo) and 316L (16.2Cr-10.1Ni-2.6Mo), and one ferritic stainless steel, Ebrite (26.3Cr-0Ni-1.0Mo) were received in the form of sheet which was laboratory cold rolled to a final thickness of 0.25 mm (0.030 in.). Laminate composites were prepared by laboratory hot rolling a vacuum encapsulated compact of alternating layers of the ferrite steel with either 304L or 316L stainless steel sheets. Laminate composite specimens, which simulate duplex austenite-ferrite weld metal structure, were used to establish the kinetics of nucleation and growth of sigma phase. The factors affecting sigma phase formation were identified. The effects of time, temperature, and transport of chromium and nickel were evaluated and used to establish a model for sigma phase formation in the austenite-ferrite interfacial region. Information useful for designing stainless steel welding consumables to be used for high temperature service was determined.

  6. 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.

  7. 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.

  8. Fatigue of stainless steel in hydrogen

    Science.gov (United States)

    Schuster, G.; Altstetter, C.

    1983-10-01

    The fatigue crack growth rates of two austenitic stainless steel alloys, AISI 301 and 302, were compared in air, argon, and hydrogen environments at atmospheric pressure and room temperature. Under the stresses at the crack tip the austenite in type 301 steel transformed martensitically to a’ to a greater extent than in type 302 steel. The steels were also tested in the cold worked condition under hydrogen or argon. Hydrogen was found to have a deleterious effect on both steels, but the effect was stronger in the unstable than in the stable alloy. Cold work decreased fatigue crack growth rates in argon and hydrogen, but the decrease was less marked in hydrogen than in argon. Metallographic, fractographic, and microhardness surveys in the vicinity of the fatigue crack were used to try to understand the reasons for the observed fatigue behavior.

  9. MICROSCOPIC CORROSION STUDIES OF DUPLEX STAINLESS STEELS

    Institute of Scientific and Technical Information of China (English)

    C.Leygraf; J.Pan; M.Femenia

    2004-01-01

    Electrochemical scanning tunneling microscopy and scanning electrochemical microscopy have been used for in situ monitoring of localized corrosion processes of different Duplex stainless steels (DSS) in acidic chloride solutions. The techniques allow imaging of local dissolution events with micrometer resolution, as opposed to conventional electrochemical techniques, which only give an overall view of the corrosion behavior. In addition, combined scanning Kelvin probe force microscopy and magnetic force microscopy were used for mapping the Volta potential variation over the surface of DSSs. A significant difference in Volta potential between the austenite and ferrite phases suggests galvanic interaction between the phases. A compositional gradient appears within 2 micrometers across the phase boundary, as seen with scanning Auger microscopy (SAM). In all, the studies suggest that higher alloyed DSS exhibit a more homogeneous dissolution behavior than lower alloyed DSS, due to higher and more similar corrosion resistance of the two phases, and enhanced resistance of the ferrite/austenite phase boundary regions.

  10. Thermodynamic calculation of phase equilibria in stainless steels

    Directory of Open Access Journals (Sweden)

    Klančnik G.

    2012-01-01

    Full Text Available In this paper two examples of thermodynamic investigation of stainless steels using both, experimental and modeling approach are described. The ferritic-austenitic duplex stainless steel and austenitic stainless steel were investigated using thermal analysis. The complex melting behavior was evident for both alloy systems. Experimentally obtained data were compared with the results of the thermodynamic calculations using the CALPHAD method. The equilibrium thermal events were also described by the calculated heat capacity. In spite of the complexity of both selected real alloy systems a relative good agreement was obtained between the thermodynamic calculations and experimental results.

  11. [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.

  12. 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...... in the stainless steel alloys. The presented computational approach for alloy design enables “screening” of hundreds of thousands hypothetical alloy systems by use of Thermo-Calc. Promising compositions for new stainless steel alloys can be selected based on imposed criteria, i.e. facilitating easy selection...

  13. Investigation of the Hot Plasticity of Duplex Stainless Steel

    Institute of Scientific and Technical Information of China (English)

    LIN Gang; ZHANG Zhi-xia; SONG Hong-wei; TONG Jun; ZHOU Can-dong

    2008-01-01

    Hot plasticity of a nitrogen alloyed 25Cr-7Ni-4 Mo duplex stainless steel was investigated.The results indicate that thc main factors affecting the hot plasticity of duplex stainless steel are listed as follows:coalescent force of phase interface,microstructure,and the phase ratio and difference between the mechanicsl propertms of ferrite and austenite.The heat treatment and sulphur contents have a notable effect on the hot plasticity.The reasonable heat treatrnents and the irlcreased interfacial coalescent force will effectively enhance the hot plasticity of duplex stainless steel.

  14. EXAFS investigation of low temperature nitrided stainless steel

    DEFF Research Database (Denmark)

    Oddershede, Jette; Christiansen, Thomas; Ståhl, Kenny

    2008-01-01

    Low temperature nitrided stainless steel AISI 316 flakes were investigated with EXAFS and X-ray diffraction analysis. The stainless steel flakes were transformed into a mixture of nitrogen expanded austenite and nitride phases. Two treatments were carried out yielding different overall nitrogen...... 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...

  15. 不锈钢表面有机-无机复合膜的制备及其抗海水腐蚀性能%Fabrication of organic-inorganic hybrid membrane on 304 stainless steel surface and its anti-corrosion properties

    Institute of Scientific and Technical Information of China (English)

    薛瑞婷; 宋现旺; 尹衍升; 陈守刚

    2011-01-01

    以多巴胺修饰304不锈钢为基体,采用溶胶凝胶法和自组装成膜法制备了SiO2基、TiO2基和SiO2-TiO2混合基有机-无机杂化涂层.探讨了钛酸四丁酯、正硅酸乙酯和11-巯基十一烷酸(MUA)在不锈钢基体上的成膜性和成膜后的抗腐蚀性能.借助金相显微镜观察了不锈钢基体上的杂化膜的显微形貌,塔菲尔曲线和电化学阻抗谱对比分析了杂化膜的抗腐蚀性能.结果表明,MUA和TiO2、SiO2能复合成膜,膜的致密性好,具有可重复性,且引入TiO2和SiO2后,其抗腐蚀性能有较大幅度提高.%In this paper, dopamine is used to modify the surface of 304 stainless steels. TiO2 , SiO2 and TiO2/SiO2 based hybrid membranes are prepared by sol-gel process and self-assambly method. The film forming properties of tetrabutyl titanate,tetraethoxysilane and 11-mercaptoundecanoic acid ( MUA) and anti-corrosion property of the hybrid membranes are investigated. The formation and surface structure of hybrid membranes are characterized by metallurgical microscopy. The results show that hybrid membranes can be successfully fabricated on 304 stainless steel substrates and the compactneas of hybrid membranes is better than the simple organic film. The corrosion behavior of hybrid films are evaluated by potentiodynamic polarization and the electrochemical impedance spectroscopy ( EIS) . The results indicate that hybrid membranes based on the adhesive of poly( dopamine) indeed reduce the corrosion of 304 stainless steels.

  16. Large size austenitic stainless steel forgings for nuclear and cryogenic application - development, manufacturing and properties

    Energy Technology Data Exchange (ETDEWEB)

    Ohnishi, Keizo; Suzuki, Komei; Sato, Ikuo; Murai, Etuso (Japan Steel Works Ltd., Muroran Plant, Hokkaido (Japan))

    1992-01-01

    The high quality one-piece large austenetic stainless steel forgings are required in the several components such as nuclear reactors and run tanks for rocket engine test stand in order to assure the structural integrity and to make it easy to fabricate and inspect the components. When the austenitic stainless steel forgings are increased in size, various problems must be overcome to assure the high quality forgings. The ingot making and hot working play an important role in determining the quality of the products. In such points, the lastest manufacturing techniques such as steel making of large size ingot and hot working to get uniform and fine grains are discussed together with the fundamental data of the material properties. (orig.).

  17. TESTING OF 304L STAINLESS STEEL IN NITRIC ACID ENVIRONMENTS WITH FLUORIDES AND CHLORIDES

    Energy Technology Data Exchange (ETDEWEB)

    Mickalonis, J.

    2010-10-04

    Impure radioactive material processed in nitric acid solutions resulted in the presence of chlorides in a dissolver fabricated from 304L stainless steel. An experimental program was conducted to study the effects of chloride in nitric acid/fluoride solutions on the corrosion of 304L stainless steel. The test variables included temperature (80, 95, and 110 C) and the concentrations of nitric acid (6, 12, and 14 M), fluoride (0.01, 0.1, and 0.2 M) and chloride (100, 350, 1000, and 2000 ppm). The impact of welding was also investigated. Results showed that the chloride concentration alone was not a dominant variable affecting the corrosion, but rather the interaction of chloride with fluoride significantly affected corrosion.

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

    OpenAIRE

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

    2015-01-01

    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 prop...

  19. 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.

  20. Development of a Nitrogen-Modified Stainless-Steel Hardfacing Alloy

    Science.gov (United States)

    Smith, Ryan Thomas

    A 2nd generation hardfacing alloy, Nitromaxx, has been designed though an integrated approach of chemical modification, characterization, and testing. Nitromaxx is a stainless-steel alloy modified with 0.5wt% nitrogen which has improved elevated temperature properties and wear performance. This is achieved by changing both the microstructure phase balance and inherent deformation characteristics of the metal. The alloy is fabricated by a powder metallurgy-hot isostatic pressing (PM-HIP) method, rather than traditional cladding methods. This allows for alloy property modification by equilibrium heat treatment while eliminating significant fabrication defects, so that component life is extended wear and galling performance is improved. The design approach involved extensive characterization of severely worn and galled surfaces of the 1st generation of hardfacing alloys. Observation of samples after galling testing showed highly inhomogeneous deformation in regions of the gall scar, leading to the design hypothesis that strain-localization is a controlling mechanism in severe wear of stainless-steels. Additionally, the presence and subsequent loss was investigated and correlated microstructurally to the transition to poor galling behavior in the existing stainless steel hardfacing NOREM02. This provided new insight and identification of key microstructural and mechanical properties that improve galling performance: 1) increased strain-hardening rate in the metal matrix at elevated temperature, 2) increased yield strength in the matrix leading to higher hardness, and 3) increased volume fraction of hard, non-deforming phases. All of these alloy design goals can be realized by the addition of nitrogen, which 1) at high concentration is shown to lower the stacking fault energy in the stainless steel matrix, 2) increases interstitial matrix strengthening, and 3) increases the volume fraction of nitride phases. These observations have been confirmed qualitatively and

  1. Improved field emission properties of carbon nanotubes grown on stainless steel substrate and its application in ionization gauge

    Energy Technology Data Exchange (ETDEWEB)

    Li, Detian; Cheng, Yongjun [Science and Technology on Vacuum Technology and Physics Laboratory, Lanzhou Institute of Physics, Lanzhou 730000 (China); Wang, Yongjun, E-mail: wyjlxlz@163.com [Science and Technology on Vacuum Technology and Physics Laboratory, Lanzhou Institute of Physics, Lanzhou 730000 (China); Zhang, Huzhong [Science and Technology on Vacuum Technology and Physics Laboratory, Lanzhou Institute of Physics, Lanzhou 730000 (China); Dong, Changkun [Institute of Micro-Nano Structures and Optoelectronics, Wenzhou University, Wenzhou 325035 (China); Li, Da [Division of Advanced Nanomaterials, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215125 (China)

    2016-03-01

    Graphical abstract: - Highlights: • The high quality CNT arrays were successfully grown on conductive stainless steel substrates. • The CNT array grown on stainless steel substrate exhibited superior field emission properties. • A high vacuum level about 10–8 Pa was measured by resultant CNT-based ionization gauge. • The ionization gauge with CNT cathode demonstrated a high stability. - Abstract: Vertically aligned carbon nanotube (CNT) arrays were fabricated by chemical vapor deposition (CVD) technique on different substrates. Microstructures and field emission characteristics of the as-grown CNT arrays were investigated systematically, and its application in ionization gauge was also evaluated preliminarily. The results indicate that the as-grown CNT arrays are vertically well-aligned relating to the substrate surfaces, but the CNTs grown on stainless steel substrate are longer and more crystalline than the ones grown on silicon wafer substrate. The field emission behaviors of the as-grown CNT arrays are strongly dependent upon substrate properties. Namely, the CNT array grown on stainless steel substrate has better field emission properties, including lower turn on and threshold fields, better emission stability and repeatability, compared with the one grown on silicon wafer substrate. The superior field emission properties of the CNT array grown on stainless steel substrate are mainly attributed to low contact resistance, high thermal conductivity, good adhesion strength, etc. In addition, the metrological behaviors of ionization gauge with the CNT array grown on stainless steel substrate as an electron source were investigated, and this novel cathode ionization gauge extends the lower limit of linear pressure measurement to 10{sup −8} Pa, which is one order of magnitude lower than the result reported for the same of gauge with CNT cathode.

  2. Assessment of Crack Detection in Heavy-Walled Cast Stainless Steel Piping Welds Using Advanced Low-Frequency Ultrasonic Methods

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Michael T.; Crawford, Susan L.; Cumblidge, Stephen E.; Denslow, Kayte M.; Diaz, Aaron A.; Doctor, Steven R.

    2007-03-01

    Studies conducted at the Pacific Northwest National Laboratory in Richland, Washington, have focused on assessing the effectiveness and reliability of novel approaches to nondestructive examination (NDE) for inspecting coarse-grained, cast stainless steel reactor components. The primary objective of this work is to provide information to the U.S. Nuclear Regulatory Commission on the effectiveness and reliability of advanced NDE methods as related to the inservice inspection of safety-related components in pressurized water reactors (PWRs). This report provides progress, recent developments, and results from an assessment of low frequency ultrasonic testing (UT) for detection of inside surface-breaking cracks in cast stainless steel reactor piping weldments as applied from the outside surface of the components. Vintage centrifugally cast stainless steel piping segments were examined to assess the capability of low-frequency UT to adequately penetrate challenging microstructures and determine acoustic propagation limitations or conditions that may interfere with reliable flaw detection. In addition, welded specimens containing mechanical and thermal fatigue cracks were examined. The specimens were fabricated using vintage centrifugally cast and statically cast stainless steel materials, which are typical of configurations installed in PWR primary coolant circuits. Ultrasonic studies on the vintage centrifugally cast stainless steel piping segments were conducted with a 400-kHz synthetic aperture focusing technique and phased array technology applied at 500 kHz, 750 kHz, and 1.0 MHz. Flaw detection and characterization on the welded specimens was performed with the phased array method operating at the frequencies stated above. This report documents the methodologies used and provides results from laboratory studies to assess baseline material noise, crack detection, and length-sizing capability for low-frequency UT in cast stainless steel piping.

  3. Damage evolution and failure mechanisms in additively manufactured stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Carlton, Holly D., E-mail: carlton4@llnl.gov [Materials Engineering Division, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550 (United States); Haboub, Abdel [Lincoln University, Life and Physical Sciences Department, 820 Chestnut St, Jefferson City, MO 65101 (United States); Gallegos, Gilbert F. [Materials Engineering Division, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550 (United States); Parkinson, Dilworth Y.; MacDowell, Alastair A. [Advanced Light Source, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States)

    2016-01-10

    In situ tensile tests were performed on additively manufactured austenitic stainless steel to track damage evolution within the material. For these experiments Synchrotron Radiation micro-Tomography was used to measure three-dimensional pore volume, distribution, and morphology in stainless steel at the micrometer length-scale while tensile loading was applied. The results showed that porosity distribution played a larger role in affecting the fracture mechanisms than measured bulk density. Specifically, additively manufactured stainless steel specimens with large inhomogeneous void distributions displayed a flaw-dominated failure where cracks were shown to initiate at pre-existing voids, while annealed additively manufactured stainless steel specimens, which contained low porosity and randomly distributed pores, displayed fracture mechanisms that closely resembled wrought metal.

  4. Eddy sensors for small diameter stainless steel tubes.

    Energy Technology Data Exchange (ETDEWEB)

    Skinner, Jack L.; Morales, Alfredo Martin; Grant, J. Brian; Korellis, Henry James; LaFord, Marianne Elizabeth; Van Blarigan, Benjamin; Andersen, Lisa E.

    2011-08-01

    The goal of this project was to develop non-destructive, minimally disruptive eddy sensors to inspect small diameter stainless steel metal tubes. Modifications to Sandia's Emphasis/EIGER code allowed for the modeling of eddy current bobbin sensors near or around 1/8-inch outer diameter stainless steel tubing. Modeling results indicated that an eddy sensor based on a single axial coil could effectively detect changes in the inner diameter of a stainless steel tubing. Based on the modeling results, sensor coils capable of detecting small changes in the inner diameter of a stainless steel tube were designed, built and tested. The observed sensor response agreed with the results of the modeling and with eddy sensor theory. A separate limited distribution SAND report is being issued demonstrating the application of this sensor.

  5. 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...

  6. Surface modified stainless steels for PEM fuel cell bipolar plates

    Science.gov (United States)

    Brady, Michael P [Oak Ridge, TN; Wang, Heli [Littleton, CO; Turner, John A [Littleton, CO

    2007-07-24

    A nitridation treated stainless steel article (such as a bipolar plate for a proton exchange membrane fuel cell) having lower interfacial contact electrical resistance and better corrosion resistance than an untreated stainless steel article is disclosed. The treated stainless steel article has a surface layer including nitrogen-modified chromium-base oxide and precipitates of chromium nitride formed during nitridation wherein oxygen is present in the surface layer at a greater concentration than nitrogen. The surface layer may further include precipitates of titanium nitride and/or aluminum oxide. The surface layer in the treated article is chemically heterogeneous surface rather than a uniform or semi-uniform surface layer exclusively rich in chromium, titanium or aluminum. The precipitates of titanium nitride and/or aluminum oxide are formed by the nitriding treatment wherein titanium and/or aluminum in the stainless steel are segregated to the surface layer in forms that exhibit a low contact resistance and good corrosion resistance.

  7. Properties of duplex stainless steels made by powder metallurgy

    OpenAIRE

    Rosso, M.; M. Actis Grande; Z. Brytan; L.A. Dobrzański

    2007-01-01

    Purpose: of this paper was to examine the mechanical properties of duplex stainless steels.Design/methodology/approach: In presented study duplex stainless steels were obtained through powder metallurgy starting from austenitic, martensitic base powders by controlled addition of alloying elements, such as Cr, Ni, Mo and Cu. In the studies behind the preparation of mixes, Schaeffler’s diagram was taken into consideration. Prepared mixes have been sintered in a vacuu...

  8. Decomposition of energetic chemicals contaminated with iron or stainless steel.

    Science.gov (United States)

    Chervin, Sima; Bodman, Glenn T; Barnhart, Richard W

    2006-03-17

    Contamination of chemicals or reaction mixtures with iron or stainless steel is likely to take place during chemical processing. If energetic and thermally unstable chemicals are involved in a manufacturing process, contamination with iron or stainless steel can impact the decomposition characteristics of these chemicals and, subsequently, the safety of the processes, and should be investigated. The goal of this project was to undertake a systematic approach to study the impact of iron or stainless steel contamination on the decomposition characteristics of different chemical classes. Differential scanning calorimetry (DSC) was used to study the decomposition reaction by testing each chemical pure, and in mixtures with iron and stainless steel. The following classes of energetic chemicals were investigated: nitrobenzenes, tetrazoles, hydrazines, hydroxylamines and oximes, sulfonic acid derivatives and monomers. The following non-energetic groups were investigated for contributing effects: halogens, hydroxyls, amines, amides, nitriles, sulfonic acid esters, carbonyl halides and salts of hydrochloric acid. Based on the results obtained, conclusions were drawn regarding the sensitivity of the decomposition reaction to contamination with iron and stainless steel for the chemical classes listed above. It was demonstrated that the most sensitive classes are hydrazines and hydroxylamines/oximes. Contamination of these chemicals with iron or stainless steel not only destabilizes them, leading to decomposition at significantly lower temperatures, but also sometimes causes increased severity of the decomposition. The sensitivity of nitrobenzenes to contamination with iron or stainless steel depended upon the presence of other contributing groups: the presence of such groups as acid chlorides or chlorine/fluorine significantly increased the effect of contamination on decomposition characteristics of nitrobenzenes. The decomposition of sulfonic acid derivatives and tetrazoles

  9. Class 4 stainless steel box columns in fire

    OpenAIRE

    Uppfeldt, Björn; Veljkovic, Milan, ed. lit.

    2007-01-01

    A study of stainless steel cold-rolled box columns at elevated temperatures is presented, which is a part of an on-going RFCS project "Stainless Steel in Fire". Experimental results of six, class 4, stub columns at elevated temperature, tested by Ala-Outinen (2005), were used to evaluate the FE model. The FE analysis obtained using the commercially available software, ABAQUS, shows that the critical temperature was closely predicted. Further, a parametric study was performed using the same nu...

  10. Stainless-Steel-Foam Structures Evaluated for Fan and Rotor Blades

    Science.gov (United States)

    Lerch, Bradley A.; Raj, Sai V.; Ghosn, Louis J.; Hebsur, Mohan G.; Cosgriff, Laura M.; Min, James B.; Holland, Frederic A., Jr.

    2005-01-01

    The goal of this project is to use a sandwich structure design, consisting of two stainlesssteel face sheets and a stainless-steel-foam core, to fabricate engine fan and propeller blades. Current fan blades are constructed either of polymer matrix composites (PMCs) or hollow titanium alloys. The PMC blades are expensive and have poor impact resistance on their leading edges, thereby requiring a metallic leading edge to satisfy the Federal Aviation Administration s impact requirements relating to bird strikes. Hollow titanium blades cost more to fabricate because of the intrinsically difficult fabrication issues associated with titanium alloys. However, both these current concepts produce acceptable lightweight fan blades.

  11. 硅酸铝/不锈钢丝耐高温防火卷帘布的研制及性能分析%Preparation and performance analysis of high temperature resistant fireproof shutter fabric of aluminum silicate/stainless steel wire

    Institute of Scientific and Technical Information of China (English)

    李利君; 卢国建; 赵敏; 王新钢

    2013-01-01

      分析防火卷帘应用现状,介绍硅酸铝/不锈钢丝耐高温防火卷帘布的织物结构、规格设计以及织造各工序的技术关键,并对织造的硅酸铝/不锈钢丝耐高温防火卷帘布的强力和耐火性能进行测试与分析。结果表明,硅酸铝/不锈钢丝耐高温防火卷帘布的强力远远超过国家标准GB 14102—2005《防火卷帘》要求,耐火极限可达3 h。%The application status of fire resistant shutter was analyzed .Fabric configuration, specification design and key technics of weaving of fire resistant shutter fabric of aluminum silicate /stainless steel wire were also introduced.Furthermore, intensity and fire resistant performance of the fabric were tested and analyzed.It was found that the intensity of the fabric , prepared in this paper, exceeded the require-ment of GB 14102—2005 Fire Resistant Shutter.Fire resistant limitation of the fabric reached 3 h.

  12. 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.

  13. Natural clinoptilolite composite membranes on tubular stainless steel supports for water softening.

    Science.gov (United States)

    Adamaref, Solmaz; An, Weizhu; Jarligo, Maria Ophelia; Kuznicki, Tetyana; Kuznicki, Steven M

    2014-01-01

    Disk membranes generated from high-purity natural clinoptilolite mineral rock have shown promising water desalination and de-oiling performance. In order to scale up production of these types of membranes for industrial wastewater treatment applications, a coating strategy was devised. A composite mixture of natural clinoptilolite from St. Cloud (Winston, NM, USA) and aluminum phosphate was deposited on the inner surface of porous stainless steel tubes by the slip casting technique. The commercial porous stainless steel tubes were pre-coated with a TiO2 layer of about 10 μm. Phase composition and morphology of the coating materials were investigated using X-ray diffraction and scanning electron microscopy. Water softening performance of the fabricated membranes was evaluated using Edmonton (Alberta, Canada) municipal tap water as feed source. Preliminary experimental results show a high water flux of 7.7 kg/(m(2) h) and 75% reduction of hardness and conductivity in a once-through membrane process at 95 °C and feed pressure of 780 kPa. These results show that natural zeolite coated, stainless steel tubular membranes have high potential for large-scale purification of oil sands steam-assisted gravity drainage water at high temperature and pressure requirements.

  14. Plasma-nitriding assisted micro-texturing into stainless steel molds

    Directory of Open Access Journals (Sweden)

    Aizawa Tatsuhiko

    2015-01-01

    Full Text Available Micro-texturing has grown up to be one of the most promising procedures. This related application required for large-area, fine micro-texturing onto the stainless steel mold materials. A new method other than laser-machining, micro-milling or micro-EDM was awaited for further advancement of this micro-texturing. In the present paper, a plasma nitriding assisted micro-texturing was developed to make various kinds of micro-patterns onto the martensitic stainless steels. First, original patterns were printed onto the surface of substrate by using the ink-jet printer. Then, the masked substrate was subjected to high density plasma nitriding; the un-masked surfaces were nitrided to have higher hardness. This nitrided substrate was further treated by sand-blasting to selectively dig the soft, masked surfaces. Finally, the micro-patterned martensitic stainless steel substrate was fabricated as a mold to duplicate these micro-patterns onto the work materials. The spatial resolution and depth profile controllability of this plasma nitriding assisted micro-texturing was investigated for variety of initial micro-patterns. The original size and dimension of initial micro-patterns were precisely compared with the three dimensional geometry of micro-textures after blasting treatment. The plastic cover case for smart cellular phones was employed to demonstrate how useful this processing is in practice.

  15. Microstructure and Corrosion Resistance of Laser Additively Manufactured 316L Stainless Steel

    Science.gov (United States)

    Trelewicz, Jason R.; Halada, Gary P.; Donaldson, Olivia K.; Manogharan, Guha

    2016-03-01

    Additive manufacturing (AM) of metal alloys to produce complex part designs via powder bed fusion methods such as laser melting promises to be a transformative technology for advanced materials processing. However, effective implementation of AM processes requires a clear understanding of the processing-structure-properties-performance relationships in fabricated components. In this study, we report on the formation of micro and nanoscale structures in 316L stainless steel samples printed by laser AM and their implications for general corrosion resistance. A variety of techniques including x-ray diffraction, optical, scanning and transmission electron microscopy, x-ray fluorescence, and energy dispersive x-ray spectroscopy were employed to characterize the microstructure and chemistry of the laser additively manufactured 316L stainless steel, which are compared with wrought 316L coupons via electrochemical polarization. Apparent segregation of Mo has been found to contribute to a loss of passivity and an increased anodic current density. While porosity will also likely impact the environmental performance (e.g., facilitating crevice corrosion) of AM alloys, this work demonstrates the critical influence of microstructure and heterogeneous solute distributions on the corrosion resistance of laser additively manufactured 316L stainless steel.

  16. 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

  17. 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

  18. Phase Transformations in Cast Duplex Stainless Steels

    Energy Technology Data Exchange (ETDEWEB)

    Yoon-Jun Kim

    2004-12-19

    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} and {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 (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, {sigma} 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

  19. Ferrite Quantification Methodologies for Duplex Stainless Steel

    Directory of Open Access Journals (Sweden)

    Arnaldo Forgas Júnior

    2016-07-01

    Full Text Available In order to quantify ferrite content, three techniques, XRD, ferritoscope and optical metallography, were applied to a duplex stainless steel UNS S31803 solution-treated for 30 min at 1,000, 1,100 and 1,200 °C, and then compared to equilibrium of phases predicted by ThermoCalc® simulation. As expected, the microstructure is composed only by austenite and ferrite phases, and ferrite content increases as the solution treatment temperature increases. The microstructure presents preferred grains orientation along the rolling directions even for a sample solution treated for 30 min at 1,200 °C. For all solution treatment temperatures, the ferrite volume fractions obtained by XRD measurements were higher than those achieved by the other two techniques and ThermoCalc® simulation, probably due to texturing effect of previous rolling process. Values obtained by quantitative metallography look more assertive as it is a direct measurement method but the ferritoscope technique should be considered mainly for in loco measurement.

  20. 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)

  1. Welding Behavior of Free Machining Stainless Steel

    Energy Technology Data Exchange (ETDEWEB)

    BROOKS,JOHN A.; ROBINO,CHARLES V.; HEADLEY,THOMAS J.; MICHAEL,JOSEPH R.

    2000-07-24

    The weld solidification and cracking behavior of sulfur bearing free machining austenitic stainless steel was investigated for both gas-tungsten arc (GTA) and pulsed laser beam weld processes. The GTA weld solidification was consistent with those predicted with existing solidification diagrams and the cracking response was controlled primarily by solidification mode. The solidification behavior of the pulsed laser welds was complex, and often contained regions of primary ferrite and primary austenite solidification, although in all cases the welds were found to be completely austenite at room temperature. Electron backscattered diffraction (EBSD) pattern analysis indicated that the nature of the base metal at the time of solidification plays a primary role in initial solidification. The solid state transformation of austenite to ferrite at the fusion zone boundary, and ferrite to austenite on cooling may both be massive in nature. A range of alloy compositions that exhibited good resistance to solidification cracking and was compatible with both welding processes was identified. The compositional range is bounded by laser weldability at lower Cr{sub eq}/Ni{sub eq} ratios and by the GTA weldability at higher ratios. It was found with both processes that the limiting ratios were somewhat dependent upon sulfur content.

  2. Improved field emission properties of carbon nanotubes grown on stainless steel substrate and its application in ionization gauge

    Science.gov (United States)

    Li, Detian; Cheng, Yongjun; Wang, Yongjun; Zhang, Huzhong; Dong, Changkun; Li, Da

    2016-03-01

    Vertically aligned carbon nanotube (CNT) arrays were fabricated by chemical vapor deposition (CVD) technique on different substrates. Microstructures and field emission characteristics of the as-grown CNT arrays were investigated systematically, and its application in ionization gauge was also evaluated preliminarily. The results indicate that the as-grown CNT arrays are vertically well-aligned relating to the substrate surfaces, but the CNTs grown on stainless steel substrate are longer and more crystalline than the ones grown on silicon wafer substrate. The field emission behaviors of the as-grown CNT arrays are strongly dependent upon substrate properties. Namely, the CNT array grown on stainless steel substrate has better field emission properties, including lower turn on and threshold fields, better emission stability and repeatability, compared with the one grown on silicon wafer substrate. The superior field emission properties of the CNT array grown on stainless steel substrate are mainly attributed to low contact resistance, high thermal conductivity, good adhesion strength, etc. In addition, the metrological behaviors of ionization gauge with the CNT array grown on stainless steel substrate as an electron source were investigated, and this novel cathode ionization gauge extends the lower limit of linear pressure measurement to 10-8 Pa, which is one order of magnitude lower than the result reported for the same of gauge with CNT cathode.

  3. 累积复合轧制不锈钢钢板的组织和性能%Microstructure and mechanical properties of stainless steel plate fabricated by accumulative roll-bonding

    Institute of Scientific and Technical Information of China (English)

    谷坤文; 袁守谦; 张兵; 赵田丽; 卢斌; 余海峰

    2011-01-01

    2, 4, 8, 16-layered laminate stainless steel plates were manufactured by accumulative roll-bonding (ARB) in this experiment. With necessary tests and analysis, the variations of microstructure and mechanical properties with ARB deformation are concluded that grain refinement, tensile strength, bonding strength and micro-hardness of interfaces are improved after ARB, as grain size reaches 1-2 μm and tensile strength is doubled after 4 cycles of ARB; meanwhile, plasticity is obviously decreased, and the elongation is just 5.8% after 4 cycles of ARB.%采用累积复合轧制技术(ARB)成功制备2、4、8、16层不锈钢钢板,通过对不同道次金属材料的测试和分析.结果表明:随累积变形量的增加,材料组织显著得到细化,材料的抗拉强度、硬度提高和界面结合强度的增强,如经过ARB4道次后,试样晶粒直径达到1-2μm,抗拉强度提高了约1倍;材料延伸率随着ARB累积变形量的增加显著下降,ARB4道次后其断后伸长率仅为5.8%.

  4. Fabrication of Minerals Substituted Porous Hydroxyapaptite/Poly(3,4-ethylenedioxy pyrrole-co-3,4-ethylenedioxythiophene) Bilayer Coatings on Surgical Grade Stainless Steel and Its Antibacterial and Biological Activities for Orthopedic Applications.

    Science.gov (United States)

    Subramani, Ramya; Elangomannan, Shinyjoy; Louis, Kavitha; Kannan, Soundarapandian; Gopi, Dhanaraj

    2016-05-18

    Current strategies of bilayer technology have been aimed mainly at the enhancement of bioactivity, mechanical property and corrosion resistance. In the present investigation, the electropolymerization of poly(3,4-ethylenedioxypyrrole-co-3,4-ethylenedioxythiophene) (P(EDOP-co-EDOT)) with various feed ratios of EDOP/EDOT on surgical grade stainless steel (316L SS) and the successive electrodeposition of strontium (Sr(2+)), magnesium (Mg(2+)) and cerium (Ce(3+)) (with 0.05, 0.075 and 0.1 M Ce(3+)) substituted porous hydroxyapatite (M-HA) are successfully combined to produce the bioactive and corrosion resistance P(EDOP-co-EDOT)/M-HA bilayer coatings for orthopedic applications. The existence of as-developed coatings was confirmed by Fourier transform-infrared spectroscopy (FT-IR), X-ray diffraction (XRD), proton nuclear magnetic resonance spectroscopy ((1)H NMR), high resolution scanning electron microscopy (HRSEM), energy dispersive X-ray analysis (EDAX) and atomic force microscopy (AFM). Also, the mechanical and thermal behavior of the bilayer coatings were analyzed. The corrosion resistance of the as-developed coatings and also the influence of copolymer (EDOP:EDOT) feed ratio were studied in Ringer's solution by electrochemical techniques. The as-obtained results are in accord with those obtained from the chemical analysis using inductively coupled plasma atomic emission spectrometry (ICP-AES). In addition, the antibacterial activity, in vitro bioactivity, cell viability and cell adhesion tests were performed to substantiate the biocompatibility of P(EDOP-co-EDOT)/M-HA bilayer coatings. On account of these investigations, it is proved that the as-developed bilayer coatings exhibit superior bioactivity and improved corrosion resistance over 316L SS, which is potential for orthopedic applications.

  5. 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.

  6. Brazing of stainless steel; Stainless ko no rozuke

    Energy Technology Data Exchange (ETDEWEB)

    Matsu, T.

    1996-04-01

    This paper explains brazing of stainless steel as to its processing materials, brazing materials, brazing methods, and brazing works. When performing brazing at higher than 800{degree}C on a martensite-based stainless steel represented by the 13Cr steel, attention is required on cracking caused by quenching. When a ferrite-based stainless steel represented by the 18Cr steel is heated above 900{degree}C, crystalline particles grow coarser, causing their tenacity and corrosion resistance to decline. High-temperature long-time heating in brazing in a furnace demands cautions. Austenite-based stainless steel represented by the 18Cr-8Ni steel has the best brazing performance. However, since the steel has large thermal expansion coefficient and low thermal conductivity, attention is required on strain and deformation due to heating, and on localized overheating. Deposition hardened stainless steel made of the Cr-Ni alloy steel added with aluminum and titanium has poor wettability in a brazing work, hence pretreatment is required for the purpose of activation. 9 figs., 7 tabs.

  7. [Restoration of composite on etched stainless steel crowns. (1)].

    Science.gov (United States)

    Goto, G; Zang, Y; Hosoya, Y

    1990-01-01

    Object of investigation The retention of composite resin to etched stainless steel crowns was tested as a possible method for restoring primary anterior teeth. Method employed 1) SEM observation Stainless steel crowns (Sankin Manufacture Co.) were etched with an aqua resia to create surface roughness and undercut to retain the composite resin to the crowns. Etching times were 1, 2, 3, 5, 8, 10 and 20 minutes, then washed in a 70% alcohol solution using an ultrasonic washer and dried. A total of 96 etched samples and non etched control samples were observed through the scanning electron microscope (Hitachi 520). 2) Shear bond strength test Stainless steel crowns were etched in an aqua resia from 1 to 20 minutes, then washed and dried. Composite resin (Photo Clearfil A, Kuraray Co.) with the bonding agent was placed on the crowns and the shear bond strength was tested in 56 samples using an Autograph (DCS-500, Shimazu). Results 1) SEM observation showed that the etching surface of stainless steel crowns created surface roughness and undercut. The most desirable surface was obtained in the 3 to 5 minute etching time specimens. 2) The highest bond strength was obtained in a 3 minute etching specimen. It was 42.12 MPa, although 29.26 MPa in mean value. Conclusion Etching with an aqua resia increased the adherence of composite resin to the surface of stainless steel crowns.

  8. Evaluation of stainless steels for their resistance to intergranular corrosion

    Science.gov (United States)

    Korostelev, A. B.; Abramov, V. Ya.; Belous, V. N.

    1996-10-01

    Austenitic stainless steels are being considered as structural materials for first wall/blanket systems in the International Thermonuclear Reactor (ITER). The uniform corrosion of stainless steels in water is well known and is not a critical issue limiting its application for the ITER design. The sensitivity of austenitic steels to intergranular corrosion (IGC) can be estimated rather accurately by means of calculation methods, considering structure and chemical composition of steel. There is a maximum permissible carbon content level, at which sensitization of stainless steel is eliminated: K = Cr eff - αC eff, where α-thermodynamic coefficient, Cr eff-effective chromium content (regarding molybdenum influence) and C eff-effective carbon content (taking into account nickel and stabilizing elements). Corrosion tests for 16Cr11Ni3MoTi, 316L and 316LN steel specimens, irradiated up to 2 × 10 22 n/cm 2 fluence have proved the effectiveness of this calculation technique for determination of austenitic steels tendency to IGC. This method is directly applicable in austenitic stainless steel production and enables one to exclude complicated experiments on determination of stainless steel susceptibility to IGC.

  9. Evaluation of stainless steels for their resistance to intergranular corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Korostelev, A.B. [Research and Development Inst. of Power Engineering, Moscow (Russian Federation); Abramov, V.Ya. [Research and Development Inst. of Power Engineering, Moscow (Russian Federation); Belous, V.N. [Research and Development Inst. of Power Engineering, Moscow (Russian Federation)

    1996-10-01

    Austenitic stainless steels are being considered as structural materials for first wall/blanket systems in the international thermonuclear reactor (ITER). The uniform corrosion of stainless steels in water is well known and is not a critical issue limiting its application for the ITER design. The sensitivity of austenitic steels to intergranular corrosion (IGC) can be estimated rather accurately by means of calculation methods, considering structure and chemical composition of steel. There is a maximum permissible carbon content level, at which sensitization of stainless steel is eliminated: K=Cr{sub eff}-{alpha}C{sub eff}, where {alpha}-thermodynamic coefficient, Cr{sub eff}-effective chromium content (regarding molybdenum influence) and C{sub eff}-effective carbon content (taking into account nickel and stabilizing elements). Corrosion tests for 16Cr11Ni3MoTi, 316L and 316LN steel specimens, irradiated up to 2 x 10{sup 22} n/cm{sup 2} fluence have proved the effectiveness of this calculation technique for determination of austenitic steels tendency to IGC. This method is directly applicable in austenitic stainless steel production and enables one to exclude complicated experiments on determination of stainless steel susceptibility to IGC. (orig.).

  10. 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...

  11. New explosive welding technique to weld aluminum alloy and stainless steel plates using a stainless steel intermediate plate

    Energy Technology Data Exchange (ETDEWEB)

    Hokamoto, K.; Fujita, M. (Kumamoto Univ. (Japan). Dept. of Mechanical Engineering); Izuma, T. (Asahi Chemical Industry Co., Ltd., Siga (Japan))

    1993-10-01

    Various aluminum alloys and stainless steel were explosively welded using a thin stainless steel intermediate plate inserted between the aluminum alloy driver and stainless steel base plates. At first. the velocity change of the driver plate with flying distance is calculated using finite-difference analysis. Since the kinetic energy lost by collision affects the amount of the fused layer generated at the interface between the aluminum alloy and stainless steel, the use of a thin stainless steel intermediate plate is effective for decreasing the energy dissipated by the collision. The interfacial zone at the welded interface is composed of a fine eutectic structure of aluminum and Fe[sub 4]Al[sub 13], and the explosive welding, process of this metal combination proceeds mainly by intensive deformation of the aluminum alloy. The weldable region for various aluminum alloys is decided by the change in collision velocity and kinetic energy lost by collision, and the weldable region is decreased with the increase in the strength of the aluminum alloy.

  12. Nickel-free Stainless Steel for Medical Applications

    Institute of Scientific and Technical Information of China (English)

    Yibin REN; Ke YANG; Bingchun ZHANG; Yaqing WANG; Yong LIANG

    2004-01-01

    BIOSS4 steel is essentially a nickel-free austenitic stainless steel developed by the Institute of Metal Research, Chinese Academy of Sciences, in response to nickel allergy problems associated with nickel-containing stainless steels that are widely used in medical applications. The high nitrogen content of this steel effectively maintains the austenitic stability and also contributes to the high levels of corrosion resistance and strength. BIOSS4 steel possesses a good combination of high strength and toughness, better corrosion resistance, and better blood compatibility, in comparison with the medical 316L stainless steel. Potential applications of BIOSS4 steel can include medical implantation material and orthodontic or orthopedic devices, as well as jewelries and other decorations.

  13. Bacterial adhesion on ion-implanted stainless steel surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Q. [Department of Mechanical Engineering, University of Dundee, Dundee DD1 4HN (United Kingdom)]. E-mail: q.zhao@dundee.ac.uk; Liu, Y. [Department of Mechanical Engineering, University of Dundee, Dundee DD1 4HN (United Kingdom); Wang, C. [Department of Mechanical Engineering, University of Dundee, Dundee DD1 4HN (United Kingdom); Wang, S. [Department of Mechanical Engineering, University of Dundee, Dundee DD1 4HN (United Kingdom); Peng, N. [Surrey Ion Beam Centre, University of Surrey, Surrey GU2 7XH (United Kingdom); Jeynes, C. [Surrey Ion Beam Centre, University of Surrey, Surrey GU2 7XH (United Kingdom)

    2007-08-31

    Stainless steel disks were implanted with N{sup +}, O{sup +} and SiF{sub 3} {sup +}, respectively at the Surrey Ion Beam Centre. The surface properties of the implanted surfaces were analyzed, including surface chemical composition, surface topography, surface roughness and surface free energy. Bacterial adhesion of Pseudomonas aeruginosa, Staphylococcus epidermidis and Staphylococcus aureus, which frequently cause medical device-associated infections was evaluated under static condition and laminar flow condition. The effect of contact time, growth media and surface properties of the ion-implanted steels on bacterial adhesion was investigated. The experimental results showed that SiF{sub 3} {sup +}-implanted stainless steel performed much better than N{sup +}-implanted steel, O{sup +}-implanted steel and untreated stainless steel control on reducing bacterial attachment under identical experimental conditions.

  14. 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.

  15. 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.

  16. Fatigue of micromachined stainless steel structural materials for vibrational energy harvesting

    Science.gov (United States)

    Shimizu, Y.; Van Minh, L.; Kitayoshi, H.; Kuwano, H.

    2016-11-01

    This work presents fatigue measurement for micromachined stainless steel (SUS304) structural substrate using resonant bending mode. Micromachined specimens for fatigue test had a cantilever structure with a proof mass. They were fabricated by FeCl3 wet etching and wire-discharged cutting. The SUS specimens had Young's modulus of 198 GPa on average. The endurance limit of micromachined specimens was 213 MPa on average after 108 cycles under our fracture definition. The large SUS specimens had the endurance limit of 229 MPa after 107 cycles.

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

    DEFF Research Database (Denmark)

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

    2011-01-01

    , this type of joint has received little attention in the current literature. The present study was conducted to examine the microstructure and mechanical properties of low carbon vacuum melted 316 stainless steel wire welded to a larger block. Results revealed solid state bonding occurring at low currents......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...

  18. Impact toughness of tungsten films deposited on martensite stainless steel

    Institute of Scientific and Technical Information of China (English)

    HUANG Ning-kang; YANG Bin; WANG De-zhi

    2005-01-01

    Tungsten films were deposited on stainless steel Charpy specimens by magnetron sputtering followed by electron beam heat treatment. Charpy impact tests and scanning electron microscopy were used to investigate the ductile-brittle transition behavior of the specimens. With decreasing test temperature the fracture mode was transformed from ductile to brittle for both kinds of specimens with and without W films. The data of the crack initiation energy, crack propagation energy, impact absorbing energy, fracture time and deflection as well as the fracture morphologies at test temperature of -70 ℃ show that W films can improve the impact toughness of stainless steel.

  19. Studies of Hot Crack Properties of Laser Welded Stainless Steel

    DEFF Research Database (Denmark)

    Juhl, Thomas Winther

    During the present work 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 ·Application of known information to predict solidification phases from the alloy...... investigated and recommendations are given. From studies of literature it is found that the austenitic stainless steels have lowest crack susceptibility by a solidification course leaving approximately 15% rest ferrite in the weld metal. The alloys properties and the solidification rate determines the amount...

  20. Topographical Anisotropy and Wetting of Ground Stainless Steel Surfaces

    Directory of Open Access Journals (Sweden)

    Cornelia Bellmann

    2012-12-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-04-01

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

  2. 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.

  3. Comparison of antibacterial ability of copper and stainless steel

    Institute of Scientific and Technical Information of China (English)

    GENG Ping; ZHANG Wen; TANG Hui; ZHANG Xinai; JIN Litong; FENG Zhen; WU Zirong

    2007-01-01

    In this paper,the electro-analysis and spectrophotometric analysis methods were used to study the antibacterial ability of copper and stainless steel materials.When Escherichia coli (E.coli) and photo-bacteria were used as samples,the antibacterial effect of stainless steel was very weak,while the percentage of bacteria dying from exposure to metallic copper for 30 min was over 90%.The antibacterial ability of copper has a potential application in the field of disinfection,food packaging and piping of drinking water.

  4. Deformation and rupture of stainless steel under cyclic, torsional creep

    OpenAIRE

    Rees, DWA

    2008-01-01

    Copyright 2008 @ Engineering Integrity Society. Recent results from a long-term, strain-limited, cyclic creep test program upon stainless steel tubes are given. The test conditions employed were: constant temperature 500 °C, shear stress Ƭ = ± 300 MPa and shear strain limits ƴ = ± 4%. It is believed that a cyclic creep behaviour for the material has been revealed that has not been reported before in the literature. That is, the creep curves for stainless steel under repeated, shear stress...

  5. From flint to stainless steel: observations on surgical instrument composition.

    Science.gov (United States)

    Kirkup, J.

    1993-01-01

    Man's failure to extract deeply embedded thorns and arrowheads, with bare hands and teeth, stimulated 'instrument substitutes' mimicking these appendages. Evidence from primitive communities suggest animal, plant and mineral items were employed, both before and after metal became the standard material of today's armamentarium. Changing surgical instrument composition has mirrored concurrent technology and manufacturing methods both of which are reviewed. Particular significance is accorded flint, bronze, crucible steel, thermal sterilisation, nickel-plate, stainless steel and disposable plastics. The paper is based on an exhibition From Flint to Stainless Steel on display at the College. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:8215156

  6. 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.

  7. 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... determine whether revocation of the antidumping duty orders on forged stainless steel flanges from India...

  8. 77 FR 39467 - Stainless Steel Bar From India: Final Results of the Antidumping Duty Administrative Review

    Science.gov (United States)

    2012-07-03

    ... International Trade Administration Stainless Steel Bar From India: Final Results of the Antidumping Duty... the administrative review of the antidumping duty order on stainless steel bar from India. The review..., 2012, the Department published Stainless Steel Bar From India: Preliminary Results and...

  9. 77 FR 60478 - Control of Ferrite Content in Stainless Steel Weld Metal

    Science.gov (United States)

    2012-10-03

    ... COMMISSION Control of Ferrite Content in Stainless Steel Weld Metal AGENCY: Nuclear Regulatory Commission... Ferrite Content in Stainless Steel Weld Metal.'' This guide describes a method that the NRC staff considers acceptable for controlling ferrite content in stainless steel weld metal. Revision 4 updates...

  10. 78 FR 63517 - Control of Ferrite Content in Stainless Steel Weld Metal

    Science.gov (United States)

    2013-10-24

    ... COMMISSION Control of Ferrite Content in Stainless Steel Weld Metal AGENCY: Nuclear Regulatory Commission... revision to Regulatory Guide (RG) 1.31, ``Control of Ferrite Content in Stainless Steel Weld Metal.'' This... content in stainless steel weld metal. It updates the guide to remove references to outdated standards...

  11. 76 FR 74831 - Aging Management of Stainless Steel Structures and Components in Treated Borated Water

    Science.gov (United States)

    2011-12-01

    ... COMMISSION Aging Management of Stainless Steel Structures and Components in Treated Borated Water AGENCY...- ISG-2011-01, ``Aging Management of Stainless Steel Structures and Components in Treated Borated Water... management of stainless steel structures and components exposed to treated borated water. In response to...

  12. 75 FR 59744 - Stainless Steel Sheet and Strip From Germany, Italy, Japan, Korea, Mexico, and Taiwan

    Science.gov (United States)

    2010-09-28

    ... COMMISSION Stainless Steel Sheet and Strip From Germany, Italy, Japan, Korea, Mexico, and Taiwan AGENCY... Korea and the antidumping duty orders on stainless steel sheet and strip from Germany, Italy, Japan... antidumping duty orders on stainless steel sheet and strip from Germany, Italy, Japan, Korea, Mexico,...

  13. Laser Rapid Manufacturing of Stainless Steel 316L/Inconel718 Functionally Graded Materials: Microstructure Evolution and Mechanical Properties

    Directory of Open Access Journals (Sweden)

    Dongjiang Wu

    2010-01-01

    Full Text Available Two patterns of functionally graded materials (FGMs were successfully fabricated whose compositions gradually varied from 100% stainless steel 316L to 100% Inconel718 superalloy using laser engineered net shaping process. The microstructure characterization, composition analysis, and microhardness along the graded direction were investigated. The comparison revealed the distinctions in solidification behavior, microstructure evolution of two patterns. In the end, the abrasive wear resistance of the material was investigated.

  14. Microstructure Evolution and Cracking Control of 316L Stainless Steel Manufactured by Multi-layer Laser Cladding

    Institute of Scientific and Technical Information of China (English)

    SONGJian-li; DENGQi-lin; HUDe-jin; SUNKang-kai; ZHOUGuang-cai

    2004-01-01

    Multi-layer laser cladding manufacturing is a newly developed rapid manufacturing technology. It is a powerful tool for direct fabrication of three-dimensional fully dense metal components and part repairing. In this paper, the microstructure evolution and properties of 316L stainless steel deposited with this technology was investigated, compact components with properties similar to the as-cast and wrought annealed material was obtained. Cracking was eliminated by introducing of supersonic vibration and application of parameter adjustment technologies.

  15. Ionic bombardment of stainless steel by nitrogen and nickel ions immersion

    Institute of Scientific and Technical Information of China (English)

    XIONG Ling; HU Yong-jun; XU jian; MENG Ji-long

    2008-01-01

    A new nitriding process was used to carry out the ionic bombardment, in which nickel ion was introduced. The microstructure, composition and properties of the treated stainless steel were studied by means of scanning electron microscopy(SEM), micro-hardness test and electrochemistry method. The results show that the hardness of the stainless steel is greatly increased after ionic bombardment under nitrogen and nickel ions immersion. Vickers' hardness as high as Hv1268 is obtained. The bombarded stainless steel is of a little reduction in corrosion resistance, as compared with the original stainless steel. However, as compared with the traditional ion-nitriding stainless steel, the corrosion resistance is greatly improved.

  16. 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.

  17. 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...

  18. Electrochemically induced annealing of stainless-steel surfaces

    Science.gov (United States)

    Burstein, G. T.; Hutchings, I. M.; Sasaki, K.

    2000-10-01

    Modification of the surface properties of metals without affecting their bulk properties is of technological interest in demanding applications where surface stability and hardness are important. When austenitic stainless steel is heavily plastically deformed by grinding or rolling, a martensitic phase transformation occurs that causes significant changes in the bulk and surface mechanical properties of the alloy. This martensitic phase can also be generated in stainless-steel surfaces by cathodic charging, as a consequence of lattice strain generated by absorbed hydrogen. Heat treatment of the steel to temperatures of several hundred degrees can result in loss of the martensitic structure, but this alters the bulk properties of the alloy. Here we show that martensitic structures in stainless steel can be removed by appropriate electrochemical treatment in aqueous solutions at much lower temperature than conventional annealing treatments. This electrochemically induced annealing process allows the hardness of cold-worked stainless steels to be maintained, while eliminating the brittle martensitic phase from the surface. Using this approach, we are able to anneal the surface and near-surface regions of specimens that contain rolling-induced martensite throughout their bulk, as well as those containing surface martensite induced by grinding. Although the origin of the electrochemical annealing process still needs further clarification, we expect that this treatment will lead to further development in enhancing the surface properties of metals.

  19. Graphene Nanoplatelets Based Protective and Functionalizing Coating for Stainless Steel.

    Science.gov (United States)

    Mondal, Jayanta; Kozlova, Jekaterina; Sammelselg, Väino

    2015-09-01

    Stainless steel is the most widely used alloy for many industrial and everyday applications, and protection of this alloy substrate against corrosion is an important industrial issue. Here we report a promising application of graphene oxide and graphene nanoplatelets as effective corrosion inhibitors for AISI type 304 stainless steel alloy. The graphene oxide and graphene coatings on the stainless steel substrates were prepared using spin coating techniques. Homogeneous and complete surface coverage by the graphene oxide and graphene nanoplatelets were observed with a high-resolution scanning electron microscope. The corrosion inhibition ability of these materials was investigated through measurement of open circuit potential and followed by potentiodymamic polarization analysis in aqueous sodium chloride solution before and after a month of immersion. Analyzed result exhibits effective corrosion inhibition for both substrates coated with graphene oxide or graphene nanoplatelets by increasing corrosion potential, pitting potential and decreasing passive current density. The corrosion inhibition ability of the coated substrates has not changed even after the long-term immersion. The result showed both graphene materials can be used as an effective corrosion inhibitor for the stainless steel substrates, which would certainly increase lifetime the substrate. However, long-term protection ability of the graphene coated susbtsrate showed somewhat better inhibition performance than the ones coated with graphene oxide.

  20. 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.

  1. Stainless steel 301 and Inconel 718 hydrogen embrittlement

    Science.gov (United States)

    Allgeier, R. K.; Forman, R.

    1970-01-01

    Conditions and results of tensile tests of 26 Inconel 718 and four cryoformed stainless steel specimens are presented. Conclusions determine maximum safe hydrogen operating pressure for cryogenic pressure vessels and provide definitive information concerning flaw growth characteristics under the most severe temperature and pressure conditions

  2. Paraequilibrium Carburization of Duplex and Ferritic Stainless Steels

    Science.gov (United States)

    Michal, G. M.; Gu, X.; Jennings, W. D.; Kahn, H.; Ernst, F.; Heuer, A. H.

    2009-08-01

    AISI 301 and E-BRITE stainless steels were subjected to low-temperature (743 K) carburization experiments using a commercial technology developed for carburization of 316 austenitic stainless steels. The AISI 301 steel contained ~40 vol pct ferrite before carburization but had a fully austenitic hardened case, ~20- μm thick, and a surface carbon concentration of ~8 at. pct after treatment; this “colossal” paraequilibrium carbon supersaturation caused an increase in lattice parameter of ~3 pct. The E-BRITE also developed a hardened case, 12- to 18- μm thick, but underwent a more modest (~0.3 pct) increase in lattice parameter; the surface carbon concentration was ~10 at. pct. While the hardened case on the AISI 301 stainless steel appeared to be single-phase austenite, evidence for carbide formation was apparent in X-ray diffractometer (XRD) scans of the E-BRITE. Paraequilibrium phase diagrams were calculated for both AISI 301 and E-BRITE stainless steels using a CALPHAD compound energy-based interstitial solid solution model. In the low-temperature regime of interest, and based upon measured paraequilibrium carbon solubilities, more negative Cr-carbon interaction parameters for austenite than those in the current CALPHAD data base may be appropriate. A sensitivity analysis involving Cr-carbon interaction parameters for ferrite found a strong dependence of carbon solubility on relatively small changes in the magnitude of these parameters.

  3. 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 on aust...

  4. Metal release from stainless steel in biological environments: A review.

    Science.gov (United States)

    Hedberg, Yolanda S; Odnevall Wallinder, Inger

    2015-03-29

    Due to its beneficial corrosion resistance, stainless steel is widely used in, e.g., biomedical applications, as surfaces in food contact, and for products intended to come into skin contact. Low levels of metals can be released from the stainless steel surface into solution, even for these highly corrosion resistant alloys. This needs to be considered in risk assessment and management. This review aims to compile the different metal release mechanisms that are relevant for stainless steel when used in different biological settings. These mechanisms include corrosion-induced metal release, dissolution of the surface oxide, friction-induced metal release, and their combinations. The influence of important physicochemical surface properties, different organic species and proteins in solution, and of biofilm formation on corrosion-induced metal release is discussed. Chemical and electrochemical dissolution mechanisms of the surface oxides of stainless steel are presented with a focus on protonation, complexation/ligand-induced dissolution, and reductive dissolution by applying a perspective on surface adsorption of complexing or reducing ligands and proteins. The influence of alloy composition, microstructure, route of manufacture, and surface finish on the metal release process is furthermore discussed as well as the chemical speciation of released metals. Typical metal release patterns are summarized.

  5. Immobilization of mesoporous silica particles on stainless steel plates

    Science.gov (United States)

    Pasqua, Luigi; Morra, Marco

    2017-03-01

    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.

  6. 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...

  7. 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...

  8. 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...

  9. Developments of New Lubricants for Cold Forging of Stainless Steel

    DEFF Research Database (Denmark)

    Steenberg, Thomas; Christensen, Erik; Olesen, P.

    1997-01-01

    Two new lubricant systems for cold forging of stainless steel have been developed. The main component of these systems are FeCl3 and ZnCa2(PO4)2, respectively. Both lubricant systems have been tested using a backward extrusion test. The results show excellent lubricating properties with respect...

  10. Plastic plus stainless-steel fibers make resilient, impermeable material

    Science.gov (United States)

    Smirra, J. R.

    1965-01-01

    Plastic material combined with stainless-steel fibers and molded under heat and pressure into a desired configuration is both soft enough to deform under a load and resilient enough to return to its original shape when the load is removed.

  11. 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.

  12. Nanoparticle Treated Stainless Steel Filters for Metal Vapor Sequestration

    Science.gov (United States)

    Murph, Simona E. Hunyadi; Larsen, George K.; Korinko, Paul; Coopersmith, Kaitlin J.; Summer, Ansley J.; Lewis, Rebecca

    2017-02-01

    The ability to sequester vapor phase radioactive compounds during industrial processes reduces the exposure of workers and the environment to dangerous radioactive materials. Nanomaterials have a lot of potential in this area because they typically demonstrate size- and shape-dependent properties with higher reactivity than bulk. This is due to the increased surface area-to-volume ratio and quantum size effects. In this report, we developed a gold nanomaterial-treated stainless steel filter, namely wools and coupons, that can be efficiently used for zinc vapor sequestration. Without nanoparticle modification, stainless steel coupons do not react or alloy with Zn. Gold nanomaterials were grown onto various stainless steel filters using solution chemistry that is amenable to scaling up. Materials were characterized by electron microscopy, inductively coupled plasma mass spectroscopy and dynamic light scattering before and after exposure to zinc vapors. X-ray diffraction, high-resolution transmission electron microscopy, energy dispersive x-ray spectroscopy mapping and ultraviolet-visible spectroscopy confirm the formation of gold-zinc alloys after Zn vapor exposure. The effect of surface topography on nanoparticle morphology, size and loading density were also investigated, and stainless steel surface defects were found to have an impact on the Au NP growth and subsequently Zn sequestration.

  13. Transformation in Austenitic Stainless Steel Sheet under Different Loading Directions

    NARCIS (Netherlands)

    Boogaard, van den A.H.; Krauer, J.; Hora, P.

    2011-01-01

    The stress-strain relation for austenitic stainless steels is based on 2 main contributions: work hardening and a phase transformation from austenite to martensite. The transformation is highly temperature dependent. In most models for phase transformation from austenite to martensite, the stress tr

  14. Nanoparticle Treated Stainless Steel Filters for Metal Vapor Sequestration

    Science.gov (United States)

    Murph, Simona E. Hunyadi; Larsen, George K.; Korinko, Paul; Coopersmith, Kaitlin J.; Summer, Ansley J.; Lewis, Rebecca

    2016-12-01

    The ability to sequester vapor phase radioactive compounds during industrial processes reduces the exposure of workers and the environment to dangerous radioactive materials. Nanomaterials have a lot of potential in this area because they typically demonstrate size- and shape-dependent properties with higher reactivity than bulk. This is due to the increased surface area-to-volume ratio and quantum size effects. In this report, we developed a gold nanomaterial-treated stainless steel filter, namely wools and coupons, that can be efficiently used for zinc vapor sequestration. Without nanoparticle modification, stainless steel coupons do not react or alloy with Zn. Gold nanomaterials were grown onto various stainless steel filters using solution chemistry that is amenable to scaling up. Materials were characterized by electron microscopy, inductively coupled plasma mass spectroscopy and dynamic light scattering before and after exposure to zinc vapors. X-ray diffraction, high-resolution transmission electron microscopy, energy dispersive x-ray spectroscopy mapping and ultraviolet-visible spectroscopy confirm the formation of gold-zinc alloys after Zn vapor exposure. The effect of surface topography on nanoparticle morphology, size and loading density were also investigated, and stainless steel surface defects were found to have an impact on the Au NP growth and subsequently Zn sequestration.

  15. Elaboration of selective solar energy absorbers beginning with stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Aries, L.; Bonino, J.P.; Benavente, R.; Laaouini, A.; Traverse, J.P.

    1981-01-01

    An original simple and cheap method of elaboration of selective surfaces is described. The method involves anodic oxydation of stainless steel in acid solution with addition of sulfides; chemical conversion of the metallic surface is achieved. The selective surfaces exhibit an excellent thermal stability.

  16. Failure Assessment Diagram for Brazed 304 Stainless Steel Joints

    Science.gov (United States)

    Flom, Yory

    2011-01-01

    Interaction equations were proposed earlier to predict failure in Albemet 162 brazed joints. Present study demonstrates that the same interaction equations can be used for lower bound estimate of the failure criterion in 304 stainless steel joints brazed with silver-based filler metals as well as for construction of the Failure Assessment Diagrams (FAD).

  17. Cobalt chromium stents versus stainless steel stents in diabetic patients

    Directory of Open Access Journals (Sweden)

    Mahmoud Ahmed Tantawy

    2014-03-01

    Conclusions: We concluded that no significant statistical difference was found between the two stents (cobalt-chromium alloy bare metal stent versus conventional bare metal stainless steel stent in diabetic patients regarding (initial procedural success, in-hospital complications, the incidence of ISR at follow up, event-free survival at follow up.

  18. Solidification cracking in austenitic stainless steel welds

    Indian Academy of Sciences (India)

    V Shankar; T P S Gill; S L Mannan; S Sundaresan

    2003-06-01

    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 used as a general guide to maintain a desirable solidification mode during welding. Nitrogen has complex effects on weld-metal microstructure and cracking. In stabilized stainless steels, Ti and Nb react with S, N and C to form low-melting eutectics. Nitrogen picked up during welding significantly enhances cracking, which is reduced by minimizing the ratio of Ti or Nb to that of C and N present. The metallurgical propensity to solidification cracking is determined by elemental segregation, which manifests itself as a brittleness temperature range or BTR, that can be determined using the varestraint test. Total crack length (TCL), used extensively in hot cracking assessment, exhibits greater variability due to extraneous factors as compared to BTR. In austenitic stainless steels, segregation plays an overwhelming role in determining cracking susceptibility.

  19. Lead-Free Piezoelectric MEMS Energy Harvesters of (K,Na)NbO3 Thin Films on Stainless Steel Cantilevers

    Science.gov (United States)

    Tsujiura, Yuichi; Suwa, Eisaku; Kurokawa, Fumiya; Hida, Hirotaka; Suenaga, Kazufumi; Shibata, Kenji; Kanno, Isaku

    2013-09-01

    We fabricated piezoelectric MEMS energy harvesters (EHs) of lead-free (K,Na)NbO3 (KNN) thin films on microfabricated stainless steel cantilevers. The use of metal substrates makes it possible to fabricate thin cantilevers owing to a large fracture toughness compared with Si substrates. KNN films were directly deposited onto Pt-coated stainless steel cantilevers by rf-magnetron sputtering, thereby simplifying the fabrication process of the EHs. From XRD measurement, we confirmed that the KNN films on Pt-coated stainless steel cantilevers had a perovskite structure with a preferential (001) orientation. The transverse piezoelectric coefficient e31f and relative dielectric constant ɛr were measured to be -3.8 C/m2 and 409, respectively. From the evaluation of the power generation performance of a KNN thin-film EH (length: 7.5 mm, width: 5.0 mm, weight of tip mass: 25 mg), we obtained a large average output power of 1.6 µW under vibration at 393 Hz and 10 m/s2.

  20. 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

  1. Behaviour of cold-formed stainless steel beams at elevated temperatures

    Institute of Scientific and Technical Information of China (English)

    Ju CHEN; Wei-liang JIN

    2008-01-01

    A study of the behaviour of constructional cold-formed stainless steel beams at elevated temperatures was conducted in this paper.An accurate finite element model(FEM)for stainless steel beams was developed using the finite element program ABAQUS.Stainless steel beams having different cross-sections were simulated in this study.The nonlinear FEM was verified against the experimental results.Generally,the developed FEM could accurately simulate the stainless steel beams.Based on the high temperature stainless steel material test results,a parametric study was carried out on stainless steel beams at elevated tem-peratures using the verified FEM.Both high strength stainless steel EN 1.4462 and normal strength stainless steel EN 1.4301 were considered.A total of 42 stainless steel beams were simulated in the parametric study.The effect of temperatures on the behaviour of stainless steel beams was investigated.In addition,a limiting temperature for stainless steel beams was also proposed.

  2. Investigation of phase transformation for ferrite–austenite structure in stainless steel thin films

    Energy Technology Data Exchange (ETDEWEB)

    Merakeb, Noureddine [Laboratory of Physical Metallurgy and Property of Materials (LM2PM), Metallurgy and Materials Engineering Department, Badji Mokhtar University, P.O. Box 12, Annaba 23000 (Algeria); Messai, Amel [Laboratoire d' Ingénierie et Sciences des Matériaux Avancés (ISMA), Institut des Sciences et Technologie, Abbès Laghrour University, Khenchela 40000 (Algeria); Ayesh, Ahmad I., E-mail: ayesh@qu.edu.qa [Department of Mathematics, Statistics and Physics, Qatar University, Doha (Qatar)

    2016-05-01

    In this work we report on phase transformation of 304 stainless steel thin films due to heat treatment. Ex-situ annealing was applied for evaporated 304 stainless steel thin films inside an ultra-high vacuum chamber with a pressure of 3 × 10{sup −7} Pa at temperatures of 500 °C and 600 °C. The structure of thin films was studied by X-ray diffraction (XRD) and conversion electron Mössbauer spectroscopy (CEMS) techniques. The results revealed a transformation from α-phase that exhibits a body-centered cubic structure (BCC) to γ-phase that exhibits a face-centered cubic (FCC) due to annealing. In addition, the percentage of γ-phase structure increased with the increase of annealing temperature. Annealing thin films increased the crystal size of both phases (α and γ), however, the increase was nonlinear. The results also showed that phase transformation was produced by recrystallization of α and γ crystals with a temporal evolution at each annealing temperature. The texture degree of thin films was investigated by XRD rocking curve method, while residual stress was evaluated using curvature method. - Highlights: • Stainless steel thin films were fabricated by thermal evaporation on quartz. • Alpha to gamma phase transformation of thin films was investigated. • Annealing of thin films reduces disruption in crystal lattice. • The stress of as-grown thin films was independent on the thin film thickness. • The stress of the thin films was reduced due to annealing.

  3. Low temperature high density plasma nitriding of stainless steel molds for stamping of oxide glasses

    Directory of Open Access Journals (Sweden)

    Aizawa Tatsuhiko

    2016-01-01

    Full Text Available Various kinds of stainless steels have been widely utilized as a die for mold- and direct-stamping processes of optical oxide glasses. Since they suffered from high temperature transients and thermal cycles in practice, they must be surface-treated by dry and wet coatings, or, by plasma nitriding. Martensitic stainless steel mold was first wet plated by the nickel phosphate (NiP, which was unstable at the high temperature stamping condition; and, was easy to crystalize or to fracture by itself. This issue of nuisance significantly lowered the productivity in fabrication of optical oxide-glass elements. In the present paper, the stainless steel mold was surface-treated by the low-temperature plasma nitriding. The nitrided layer by this surface modification had higher nitrogen solute content than 4 mass%; the maximum solid-solubility of nitrogen is usually 0.1 mass% in the equilibrium phase diagram. Owing to this solid-solution with high nitrogen concentration, the nitrided layer had high hardness over 1400 HV within its thickness of 50 μm without any formation of nitrides after plasma nitriding at 693 K for 14.4 ks. This plasma-nitrided mold was utilized for mold-stamping of two colored oxide glass plates at 833 K; these plates were successfully deformed and joined into a single glass plate by this stamping without adhesion or galling of oxide glasses onto the nitrided mold surface.

  4. Laser etching of austenitic stainless steels for micro-structural evaluation

    Science.gov (United States)

    Baghra, Chetan; Kumar, Aniruddha; Sathe, D. B.; Bhatt, R. B.; Behere, P. G.; Afzal, Mohd

    2015-06-01

    Etching is a key step in metallography to reveal microstructure of polished specimen under an optical microscope. A conventional technique for producing micro-structural contrast is chemical etching. As an alternate, laser etching is investigated since it does not involve use of corrosive reagents and it can be carried out without any physical contact with sample. Laser induced etching technique will be beneficial especially in nuclear industry where materials, being radioactive in nature, are handled inside a glove box. In this paper, experimental results of pulsed Nd-YAG laser based etching of few austenitic stainless steels such as SS 304, SS 316 LN and SS alloy D9 which are chosen as structural material for fabrication of various components of upcoming Prototype Fast Breeder Reactor (PFBR) at Kalpakkam India were reported. Laser etching was done by irradiating samples using nanosecond pulsed Nd-YAG laser beam which was transported into glass paneled glove box using optics. Experiments were carried out to understand effect of laser beam parameters such as wavelength, fluence, pulse repetition rate and number of exposures required for etching of austenitic stainless steel samples. Laser etching of PFBR fuel tube and plug welded joint was also carried to evaluate base metal grain size, depth of fusion at welded joint and heat affected zone in the base metal. Experimental results demonstrated that pulsed Nd-YAG laser etching is a fast and effortless technique which can be effectively employed for non-contact remote etching of austenitic stainless steels for micro-structural evaluation.

  5. Potentiality Studies of Stainless Steel 304 Material for Production of Medical Equipment using Micro Electrical Discharge Machining (micro-EDM) Analysis and Modeling

    DEFF Research Database (Denmark)

    Puthumana, Govindan

    2016-01-01

    Stainless steel 304 (SS304) is a material widely used for production of medical equipment mainly because of its anti-corrosive properties. It has excellent mechanical properties, strength and reliability because of which it is one of the best materials for fabrication of medical devices. This pap...

  6. Wetting Properties of Liquid Lithium on Stainless Steel and Enhanced Stainless Steel Surfaces

    Science.gov (United States)

    Fiflis, P.; Xu, W.; Raman, P.; Andruczyk, D.; Ruzic, D. N.; Curreli, D.

    2012-10-01

    Research into lithium as a first wall material has proven its ability to effectively getter impurities and reduce recycling of hydrogen ions at the wall. Current schemes for introducing lithium into a fusion device consist of lithium evaporators, however, as these devices evolve from pulsed to steady state, new methods will need to be employed such as the LIMIT concept of UIUC, or thin flowing film lithium walls. Critical to their implementation is understanding the interactions of liquid lithium with various surfaces. One such interaction is the wetting of materials by lithium, which may be characterized by the contact angle between the lithium and the surface. Experiments have been performed at UIUC into the contact angle of liquid lithium with a given surface, as well as methods to increase it. To reduce the oxidation rate of the droplets, the experiments were performed in vacuum, using a lithium injector to deposit drops on each surface. Among the materials investigated are stainless steel, both untreated and coated with a diamond like carbon (DLC) layer, molybdenum, and boronized molybdenum. The contact angle and its dependence on temperature is measured.

  7. Optimization of Friction Welding Process Parameters for Joining Carbon Steel and Stainless Steel%Optimization of Friction Welding Process Parameters for Joining Carbon Steel and Stainless Steel

    Institute of Scientific and Technical Information of China (English)

    R Paventhan; P R Lakshminarayanan; V Balasubramanian

    2012-01-01

    Friction weIding is a solid state joining process used extensively currently owing to its advantages such as low heat input, high production efficiency, ease of manufacture, and environment friendliness. Materials difficult to be welded by fusion welding processes can be successfully welded by friction welding. An attempt was made to develop an empirical relationship to predict the tensile strength of friction welded AISI 1040 grade medium carbon steel and AISI 304 austenitic stainless steel, incorporating the process parameters such as friction pressure, forging pressure, friction time and forging time, which have great influence on strength of the joints. Response surface methodology was applied to optimize the friction welding process parameters to attain maximum tensile strength of the joint. The maximum tensile strength of 543 MPa could be obtained for the joints fabricated under the welding conditions of friction pressure of 90 MPa, forging pressure of 90 MPa, friction time of 6 s and forging time of 6 s.

  8. 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

  9. VISCO-PLASTIC CONSTITUTIVE MODEL FOR UNIAXIAL AND MULTIAXIAL RATCHETING AT ELEVATED TEMPERATURES

    Institute of Scientific and Technical Information of China (English)

    G.Z.Kang; Q.Gao; J.Zhang

    2004-01-01

    Based on the experimental results of the ratcheting for SS304 stainless steel, a new visco-plastic cyclic constitutive model was established to describe the uniaxial and multiaxial ratcheting of the material at room and elevated temperatures within the framework of unified visco-plasticity. In the model, the temperature dependence of the ratcheting was emphasized, and the dynamic strain aging occurred in the temperature range of 400-600C for the material was taken into account particularly. Finally, the prediction capability of the developed model was checked by comparing to the corresponding experimental results.

  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. 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

  12. A hollow stainless steel microneedle array to deliver insulin to a diabetic rat

    Science.gov (United States)

    Vinayakumar, K. B.; Kulkarni, Prachit G.; Nayak, M. M.; Dinesh, N. S.; Hegde, Gopalkrishna M.; Ramachandra, S. G.; Rajanna, K.

    2016-06-01

    A novel fabrication process has been described for the development of a hollow stainless steel microneedle array using femto second laser micromachining. Using this method, a complicated microstructure can be fabricated in a single process step without using masks. The mechanical stability of the fabricated microneedle array was measured for axial and transverse loading. Skin histology was carried out to study the microneedle penetration into the rat skin. Fluid flow through the microneedle array was studied for different inlet pressures. The packaging of the microneedle array, to protect the microneedle bore blockage from dust and other atmospheric contaminations, was also considered. Finally, the microneedle array was tested and studied in vivo for insulin delivery to a diabetic rat. The results obtained were compared with the standard subcutaneous delivery with the same dose rate and were found to be in good agreement.

  13. Microstructure and antibacterial property of stainless steel implanted by Cu ions

    Institute of Scientific and Technical Information of China (English)

    XU Bo-fan; NI Hong-wei; XIONG Ping-yuan; XIONG Juan; DAN Zhi-gang

    2004-01-01

    Copper ions were implanted into AISI 304 austenitic stainless steel by metal vapor vacuum are (MEVVA) with 60 - 100 keV energy and a dose range (0.2 - 5.0) × 1017 cm-2. Then Cu-implanted stainless steel was treated by a special antibacterial treatment. Antibacterial rates of Cu-implanted stainless steel, Cu-implanted stainless steel with special antibacterial treatment and un-implanted stainless steel were obtained by agar plate method. Phase composition in the implanted layer was analyzed by glancing X-ray diffraction (GXRD). Microstructure of antibacterial stainless steel was observed with transmission electron microscopy (TEM), and changes of the bacterium appearance after 24 h antibacterial action on the surface of un-implanted and Cu-implanted stainless steel with antibacterial treatment were observed with bio-TEM respectively. The results show that stainless steel obtains antibacterial property against E. coli when the Cu ions dose approaches to the saturated one. A suitable amount of Cu-rich phase uniformly disperses on the surface of Cu-implanted stainless steel that is treated by the special antibacterial treatment. The Cu-rich phase naked on the surface has a function of damage to pericellular membrane and cell wall,the pericellular membrane is thickened and the karyon degraded, and finally, bacteria die. Cu-rich phase naked on the surface endows stainless steel with best antibacterial property.

  14. Micro/nano engineering on stainless steel substrates to produce superhydrophobic surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Beckford, Samuel; Zou Min, E-mail: mzou@uark.edu

    2011-12-30

    Creating micro-/nano-scale topography on material surfaces to change their wetting properties has been a subject of much interest in recent years. Wenzel in 1936 and Cassie and Baxter in 1944 proposed that by microscopically increasing the surface roughness of a substrate, it is possible to increase its hydrophobicity. This paper reports the fabrication of micro-textured surfaces and nano-textured surfaces, and the combination of both on stainless steel substrates by sandblasting, thermal evaporation of aluminum, and aluminum-induced crystallization (AIC) of amorphous silicon (a-Si). Meanwhile, fluorinated carbon films were used to change the chemical composition of the surfaces to render the surfaces more hydrophobic. These surface modifications were investigated to create superhydrophobic surfaces on stainless steel substrates. The topography resulting from these surface modifications was analyzed by scanning electron microscopy and surface profilometry. The wetting properties of these surfaces were characterized by water contact angle measurement. The results of this study show that superhydrophobic surfaces can be produced by either micro-scale surface texturing or nano-scale surface texturing, or the combination of both, after fluorinated carbon film deposition.

  15. Electrophoretic deposition of PEEK-TiO 2 composite coatings on stainless steel

    KAUST Repository

    Seuß, Sigrid

    2012-03-01

    Electrophoretic deposition (EPD) has been successfully used to deposit composite coatings composed of polyetheretherketone (PEEK) and titanium dioxide (TiO 2) nanoparticles on 316L stainless steel substrates. The suspensions of TiO2 nanoparticles and PEEK microparticles for EPD were prepared in ethanol. PEEK-TiO 2 composite coatings were optimized using suspensions containing 6wt% PEEK-TiO 2 in ethanol with a 3:1 ratio of PEEK to TiO 2 in weight and by applying a potential difference of 30 V for 1 minute. A heat-treatment process of the optimized PEEK-TiO 2 composite coatings was erformed at 335°C for 30 minutes with a heating rate of 10°Cmin -1 to densify the deposits. The EPD coatings were microstructurally evaluated by scanning electron microscopy (SEM). It was demonstrated that EPD is a convenient and rapid method to fabricate PEEK/TiO 2 coatings on stainless steel which are interesting for biomedical applications. © (2012) Trans Tech Publications, Switzerland.

  16. Adipose tissue-derived stem cell response to the differently processed 316L stainless steel substrates.

    Science.gov (United States)

    Faghihi, Shahab; Zia, Sonia; Taha, Masoumeh Fakhr

    2012-12-01

    Stainless steel (SS) is one of the most applicable materials in fabrication of cardiac implants. The aim of this study is to investigate the effect of atomic structure of polycrystalline stainless steel on the response of adipose tissue-derived stem cells (ADSCs). Samples are prepared from differently processed extruded rod and rolled sheet of 316L SS having different crystallographic structure. X-ray diffraction analysis indicated (200) and (111) orientations with distinct volume fractions in the specimens. Morphology and ADSCs behavior including adhesion, proliferation and differentiation are assessed. The expression of cardiac specific protein (cardiac troponin I) and genes of differentiating cardiomyocytes is analyzed by immunofluorescence and RT-PCR. The number of attached and grown cells on the rod sample is higher than the sheet sample also the scanning electron microscopy (SEM) analysis of ADSCs grown on the samples demonstrates higher cell density and spreading pattern on the surface of rod sample. In differentiated ADSCs on the rod sample the expression of all genes except ANF are detectable, while on the sheet sample only the MEF2C and β-MHC are expressed. This study shows that the cellular response is influenced by the crystal structure of the substrate therefore; the skill to alter the structure of substrate may lend itself to engineer a biomaterial which could be suitable for differentiation of stem cells into a definite lineage.

  17. Experimental Test of Stainless Steel Wire Mesh and Aluminium Alloy With Glass Fiber Reinforcement Hybrid Composite

    Directory of Open Access Journals (Sweden)

    Ranga Raj R.,

    2015-05-01

    Full Text Available At present, composite materials are mostly used in aircraft structural components, because of their excellent properties like lightweight, high strength to weight ratio, high stiffness, and corrosion resistance and less expensive. In this experimental work, the mechanical properties of laminate, this is reinforced with stainless steel wire mesh, aluminum sheet metal, perforated aluminum sheet metal and glass fibers to be laminate and investigated. The stainless steel wire mesh and perforated aluminum metal were sequentially stacked to fabricate, hybrid composites. The aluminum metal sheet is also employed with that sequence to get maximum strength and less weight. The tensile, compressive and flexure tests carried out on the hybrid composite. To investigate the mechanical properties and elastic properties of the metal matrix composite laminate of a material we are using experimental test and theoretical calculation. The experimental work consists of Tensile, compressive and flexural test. The expectation of this project results in the tensile and compressive properties of this hybrid composite it is slightly lesser than carbon fibers but it could facilitate a weight reduction compared with CFRP panels. So this hybrid laminates composite material offering significant weight savings and maximum strength over some other GFRP conventional panels.

  18. Corrosion of type 316L stainless steel in a mercury thermal convection loop

    Energy Technology Data Exchange (ETDEWEB)

    DiStefano, J.R.; Manneschmidt, E.T.; Pawel, S.J.

    1999-04-01

    Two thermal convection loops fabricated from 316L stainless steel containing mercury (Hg) and Hg with 1000 wppm gallium (Ga), respectively, were operated continuously for about 5000 h. In each case, the maximum loop temperature was constant at about 305 degrees C and the minimum temperature was constant at about 242 degrees C. Coupons in the hot leg of the Hg-loop developed a posous surface layer substantially depleted of nickel and chromium, which resulted in a transformation to ferrite. The coupon exposed at the top of the hot leg in the Hg-loop experienced the maximum degradation, exhibiting a surface layer extending an average of 9-10 mu m after almost 5000 h. Analysis of the corrosion rate data as a function of temperature (position) in the Hg-loop suggests wetting by the mer cury occurred only above about 255 degrees C and that the rate limiting step in the corrosion process above 255 degrees C is solute diffusion through the saturated liquid boundary layer adjacent to the corroding surface. The latter factor suggests that the corrosion of 316L stainless steel in a mercury loop may be velocity dependent. No wetting and no corrosion were observed on the coupons and wall specimens removed from the Hg/Ga loop after 5000 h of operation.

  19. Review of the regulations for the use of stainless steels for orthopedic implants in Argentina

    Science.gov (United States)

    Daga, Bernardo; Rivera, Graciela; Boeri, Roberto

    2007-11-01

    Motivated by the relatively high rate of failure of orthopedic implants in Argentina, the authors review the current normative regulating the use of stainless steels in the fabrication of these metallic parts in the country, and compare it with the regulations currently in use in other countries. The analysis shows that several standards in effect in the country do not comply with broadly recognized international standards. This situation is aggravated by a recent revision of the normative that failed to improve the quality standards to reach levels similar to those applied in developed countries or even in MERCOSUR associates. The national organization in charge of implant certification in Argentina, complying with the law, accepts the applicability of IRAM standards to certify stainless steels implants. In the opinion of the authors, the current practice used to certify implants does not guarantee the structural stability and biocompatibility of the devices, increasing the risk of failure in service, and escalating the cost of the public health care system.

  20. Review of the regulations for the use of stainless steels for orthopedic implants in Argentina

    Energy Technology Data Exchange (ETDEWEB)

    Daga, Bernardo; Rivera, Graciela; Boeri, Roberto [INTEMA, Faculty of Engineering, National University of Mar del Plata - CONICET Juan B.Justo 4302, B7608FDQ, Mar del Plata (Argentina)

    2007-11-15

    Motivated by the relatively high rate of failure of orthopedic implants in Argentina, the authors review the current normative regulating the use of stainless steels in the fabrication of these metallic parts in the country, and compare it with the regulations currently in use in other countries. The analysis shows that several standards in effect in the country do not comply with broadly recognized international standards. This situation is aggravated by a recent revision of the normative that failed to improve the quality standards to reach levels similar to those applied in developed countries or even in MERCOSUR associates. The national organization in charge of implant certification in Argentina, complying with the law, accepts the applicability of IRAM standards to certify stainless steels implants. In the opinion of the authors, the current practice used to certify implants does not guarantee the structural stability and biocompatibility of the devices, increasing the risk of failure in service, and escalating the cost of the public health care system.

  1. Stainless steel binder for the development of novel TiC-reinforced steel cermets

    Institute of Scientific and Technical Information of China (English)

    Akhtar Farid; Shiju Guo; Xia Yang; Yudong Lian

    2006-01-01

    Steel reinforced TiC composites are an attractive choice for wear resistance and corrosion resistance applications. TiCreinforced 17-4PH maraging stainless matrix composites were processed by conventional powder metallurgy (P/M). TiC-reinforced maraging stainless steel composites with >97% of theoretical density were fabricated. The microstructure, mechanical and wear properties of the composites were evaluated. The microstructure of these composites consisted of spherical and semi-spherical TiC particles.A few microcracks appeared in the composites, showing the presence of tensile stress in the composites produced during sintering.Typical properties, namely, hardness and bend strength were reported for the sintered composites. After heat treatment and aging, the increase of hardness was observed. The increase of hardness was attributed to the aging reaction in the 17-4PH stainless steel. The precipitates appeared in the microstructure and were responsible for the increase in hardness. The specific wear behavior of the composites was strongly dependent on the content of TiC particles, the interparticle spacing, and the presence of hard precipitates in the binder phase.

  2. Surface treatment and corrosion behaviour of austenitic stainless steel biomaterial

    Science.gov (United States)

    Oravcová, M.; Palček, P.; Zatkalíková, V.; Tański, T.; Król, M.

    2017-02-01

    In this article results from corrosion behaviour of austenitic stainless steel AISI 316L after different surface treatments are published. “As received” surface and surface after grinding resulted in lower resistance to pitting corrosion in physiological solution than electrochemically polished in H3PO4+H2SO4+H2O. Electropolishing also improved the surface roughness in comparison with the “as received” surface. Deposition of Al2O3 nanometric ALD coating improves the corrosion resistance of stainless steel in chloride-containing environment by shifting the breakdown potential toward more positive values. This oxide coating not only improves the corrosion resistance but it also affects the wettability of the surface, resulting in hydrophobic surface.

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

    Science.gov (United States)

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

    2016-04-01

    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.

  4. Studies of Hot Crack Properties of Laser Welded Stainless Steel

    DEFF Research Database (Denmark)

    Juhl, Thomas Winther

    During the present work 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 ·Application of known information to predict solidification phases from the alloy...... composition. ·Weld metal solidification rate measurements for prediction of phases. ·Various crack tests to assess the crack susceptibility of alloys. ·A combination of the above for selection of suitable, weldable alloys. The possibility of using such specific methods for alloys and applications has been...... investigated and recommendations are given. From studies of literature it is found that the austenitic stainless steels have lowest crack susceptibility by a solidification course leaving approximately 15% rest ferrite in the weld metal. The alloys properties and the solidification rate determines the amount...

  5. Laser Welding Of Thin Sheet Of AISI 301 Stainless Steel

    Science.gov (United States)

    Vilar, R.; Miranda, R. M.

    1989-01-01

    Preliminary results of an investigation on laser welding of AISI 301 stainless steel thin sheet are presented. Welds were made with a CO2 continuous wave laser, varying power density and welding speed. The welds were studied by optical and electron scanning microscopy, X-ray diffraction and hardness tests. Experimental results show that under appropriate conditions, sound welds are obtained, with a negligeable heat affected zoneanda fine microstructure in the fusion zone. The fusion zone shows a cellular - dendritic microstructure, with austenite and ferrite as the major constituents. Ferrite, whose content is 5 to 7%, is predominantly intradendritic with both vermicular and acicular morphologies. However some interdendritic ferrite may also be present. The characteristics of the structure suggest that the solidification mode of AISI 301 stainless steel is essentially ferritic.

  6. Biomaterials. The Behavior of Stainless Steel as a Biomaterial

    Directory of Open Access Journals (Sweden)

    Sanda VISAN

    2011-06-01

    Full Text Available The biomaterials belong to the broad range of biocompatible chemical substances (sometimes even an element, which can be used for a period of time to treat or replace a tissue, organ or function of the human body. These materials bring many advantages in the diagnosis, prevention and medical therapy, reducing downtime for patients, restoring their biological functions, improving hospital management. The market in Romania sells a wide range of biomaterials for dental, cardiovascular medicine, renal, etc. Scientific research contributes to the discovery of new biomaterials or testing known biomaterials, for finding new applications. The paper exemplifies this contribution by presenting the testing of passive stainless steel behaviour in albumin solution using technique of cyclic voltammetry. It was shown that passivation contribute to increased stability of stainless steel implants to corrosive body fluids.

  7. 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.

  8. Stainless steel porous substrates produced by tape casting

    Science.gov (United States)

    Mercadelli, Elisa; Gondolini, Angela; Pinasco, Paola; Sanson, Alessandra

    2017-01-01

    In this work the technological issues related to the production of tape cast large-area porous stainless steel supports for Solid Oxide Fuel Cells (SOFC) applications were carefully investigated. The slurry formulation was optimized in terms of amount and nature of the organic components needed: rice starch and polymethyl metacrylate were found to be, respectively, the most suitable pore former and binder because easily eliminated during the thermal treatment in reducing atmosphere. The compatibility of the binder system chosen with the most widely used solvents for screen printing inks was also evaluated. Finally the influence of the sintering temperature and of the refractory supports to be used during the thermal treatments onto the production of porous stainless steel supports was discussed. The whole process optimization allows to produce flat, crack-free metallic substrate 900-1000 μm thick, dimensions up to 5×5 cm and with a tailored porosity of 40% suitable for SOFCs application.

  9. 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.

  10. Liquid Phase Sintering of Highly Alloyed Stainless Steel

    DEFF Research Database (Denmark)

    Mathiesen, Troels

    1996-01-01

    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...... 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...... steel as base material. The stainless base powders were added different amounts and types of boride and sintered in hydrogen at different temperatures and times in a laboratory furnace. During sintering the outlet gas was analyzed and subsequently related to the obtained microstructure. Thermodynamic...

  11. 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.

  12. Study of Stainless Steel Resistance in Conditions of Tribocorrosion Wear

    Directory of Open Access Journals (Sweden)

    Goran Rozing

    2015-07-01

    Full Text Available Analyzed was the influence of tribocorrosion wear due to effects of fatty acids present in the processed medium. The analysis was conducted on samples made of two austenitic and two martensitic stainless steels. Austenitic steels were tested in their nitrided state and martensitic in their induction hardened state. Conducted were laboratory tests of corrosion resistance of samples, analysis of the microstructure and hardness. To see how the applied processes for modifying the surface of stainless steels behave in realistic conditions, it was conducted the examination of samples/parts of a sunflower cake chain conveyer. Based on the comparison of results obtained in the laboratory and in real conditions, it was estimated that steels AISI 420 and AISI 431 with induction hardened surfaces have a satisfactory resistance to abrasive-adhesive wear in the presence of fatty acids.

  13. COLD ROLLING ORTHODONTIC WIRES OF AUSTENITIC STAINLESS STEEL AISI 304

    Directory of Open Access Journals (Sweden)

    Rodrigo Santos Messner

    2013-03-01

    Full Text Available Austenitic stainless steels wires are widely used in the final stages of orthodontic treatment. The objective of this paper is to study the process of conformation of rectangular wires from round wires commercial austenitic stainless steel AISI 304 by the process of cold rolling. The wire quality is evaluated by means of dimensional analysis, microhardness measurements, tensile strength and fractographic analysis of the wires subjected to tensile tests. Also a study on the application of finite element method to simulate the process, comparing the force and rolling stress obtained in the rolling is done. The simulation results are consistent with those obtained in the actual process and the rolled wires show ductile fracture, tensile strength and dimensional variations appropriate to orthodontic standards. The fracture morphology shows the model cup-cone type besides the high deformation and hardness inherent in the cold rolling process.

  14. Mechanical and physical properties of irradiated type 348 stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Beeston, J.M.

    1980-01-01

    A type 348 stainless steel in-pile tube irradiated to a fluence of 3 x 10/sup 22/ n/cm/sup 2/, E > 1 MeV (57 dpa), was destructively examined. The service had resulted in a maximum total creep of 1.8% at the high fluence. The metal temperature ranged between 623 and 652/sup 0/K, hence the thermal creep portion of the total was negligible. Total creep was greater than had been anticipated from creep data for austenitic stainless steels irradiated in other reactors. The objectives of the destructive examination were to determine the service-induced changes of mechanical and physical properties, and to assess the possibility of adverse effects of both these changes and the greater total creep on the prospective service life of other tubes.

  15. Achievement of a superpolish on bare stainless steel

    Science.gov (United States)

    Howells, Malcolm R.; Casstevens, John M.

    1997-11-01

    We report the achievement of a superpolished surface, suitable for x-ray reflection, on bare stainless steel. The rms roughness obtained on various samples varied from 2.2 to 4.2 angstroms, as measured by an optical profiler with a bandwidth 0.29 - 100 mm-1. The type 17-4 PH precipitation-hardening stainless steel used to make the mirrors is also capable of ultrastability and has good manufacturability. This combination of properties makes it an excellent candidate material for mirror substrates. We describe the successful utilization of this type of steel in making elliptical-cylinder mirrors for a soft-x-ray microprobe system at the Advanced Light Source, and discuss possible reasons for its unusual stability and polishability.

  16. 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

  17. STAINLESS STEEL INTERACTIONS WITH SALT CONTAINING PLUTONIUM OXIDES

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Z.; Chandler, G.; Dunn, K.; Stefek, T.; Summer, M.

    2010-02-01

    Salt containing plutonium oxide materials are treated, packaged and stored within nested, stainless steel containers based on requirements established in the DOE 3013 Standard. The moisture limit for the stored materials is less than 0.5 weight %. Surveillance activities which are conducted to assess the condition of the containers and assure continuing 3013 container integrity include the destructive examination of a select number of containers to determine whether corrosion attack has occurred as a result of stainless steel interactions with salt containing plutonium oxides. To date, some corrosion has been observed on the innermost containers, however, no corrosion has been noted on the outer containers and the integrity of the 3013 container systems is not expected to be compromised over a 50 year storage lifetime.

  18. Nanotribological behavior of deep cryogenically treated martensitic stainless steel

    Science.gov (United States)

    Bakoglidis, Konstantinos D; Tuckart, Walter R; Broitman, Esteban

    2017-01-01

    Cryogenic treatments are increasingly used to improve the wear resistance of various steel alloys by means of transformation of retained austenite, deformation of virgin martensite and carbide refinement. In this work the nanotribological behavior and mechanical properties at the nano-scale of cryogenically and conventionally treated AISI 420 martensitic stainless steel were evaluated. Conventionally treated specimens were subjected to quenching and annealing, while the deep cryogenically treated samples were quenched, soaked in liquid nitrogen for 2 h and annealed. The elastic–plastic parameters of the materials were assessed by nanoindentation tests under displacement control, while the friction behavior and wear rate were evaluated by a nanoscratch testing methodology that it is used for the first time in steels. It was found that cryogenic treatments increased both hardness and elastic limit of a low-carbon martensitic stainless steel, while its tribological performance was enhanced marginally. PMID:28904837

  19. Plasma surface oxidation of 316L stainless steel for improving adhesion strength of silicone rubber coating to metal substrate

    Energy Technology Data Exchange (ETDEWEB)

    Latifi, Afrooz, E-mail: afroozlatifi@yahoo.com [Department of Biomaterials, Biomedical Engineering Faculty, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Imani, Mohammad [Novel Drug Delivery Systems Dept., Iran Polymer and Petrochemical Institute, P.O. Box 14965/115, Tehran (Iran, Islamic Republic of); Khorasani, Mohammad Taghi [Biomaterials Dept., Iran Polymer and Petrochemical Institute, P.O. Box 14965/159, Tehran (Iran, Islamic Republic of); Daliri Joupari, Morteza [Animal and Marine Biotechnology Dept., National Institute of Genetic Engineering and Biotechnology, P.O. Box 14965/161, Tehran (Iran, Islamic Republic of)

    2014-11-30

    Highlights: • Stainless steel 316L was surface modified by plasma surface oxidation (PSO) and silicone rubber (SR) coating. • On the PSO substrates, concentration of oxide species was increased ca. 2.5 times comparing to non-PSO substrates. • The surface wettability was improved to 12.5°, in terms of water contact angle, after PSO. • Adhesion strength of SR coating on the PSO substrates was improved by more than two times comparing to non-PSO ones. • After pull-off test, the fractured area patterns for SR coating were dependent on the type of surface modifications received. - Abstract: Stainless steel 316L is one of the most widely used materials for fabricating of biomedical devices hence, improving its surface properties is still of great interest and challenging in biomaterial sciences. Plasma oxidation, in comparison to the conventional chemical or mechanical methods, is one of the most efficient methods recently used for surface treatment of biomaterials. Here, stainless steel specimens were surface oxidized by radio-frequency plasma irradiation operating at 34 MHz under pure oxygen atmosphere. Surface chemical composition of the samples was significantly changed after plasma oxidation by appearance of the chromium and iron oxides on the plasma-oxidized surface. A wettable surface, possessing high surface energy (83.19 mN m{sup −1}), was observed after plasma oxidation. Upon completion of the surface modification process, silicone rubber was spray coated on the plasma-treated stainless steel surface. Morphology of the silicone rubber coating was investigated by scanning electron microscopy (SEM). A uniform coating was formed on the oxidized surface with no delamination at polymer–metal interface. Pull-off tests showed the lowest adhesion strength of coating to substrate (0.12 MPa) for untreated specimens and the highest (0.89 MPa) for plasma-oxidized ones.

  20. Phases in austenitic stainless steels: Faze v avstenitnih nerjavnih jeklih:

    OpenAIRE

    JANOVEC, Jozef; Jenko, Monika; Medved, Jože; Šuštaršič, Borivoj

    2003-01-01

    The study represents a phase characterisation of austenitic stainless steels. A table presents the basic literature data on the phases to be found in austenitic steels. For the as-cast ASTM A351 steel, a thermodynamic prediction and a metallographic identification of phases is also presented. The thermodynamic calculations performed using ThermoCalc revealed austenite, ferrite, Msub(23)Csub(6), delta, and Laves as the equilibrium phases at temperatures below 866 K (953 compositumC). All the p...

  1. Laser surface modification of 316L stainless steel.

    Science.gov (United States)

    Balla, Vamsi Krishna; Dey, Sangeetha; Muthuchamy, Adiyen A; Janaki Ram, G D; Das, Mitun; Bandyopadhyay, Amit

    2017-02-28

    Medical grade 316L stainless steel was laser surface melted (LSM) using continuous wave Nd-YAG laser in argon atmosphere at 1 and 5 mm/s. The treated surfaces were characterized using electron backscatter diffraction to study the influence of top surface crystallographic orientation and type of grain boundaries on corrosion resistance, wettability, and biocompatibility. The laser scan velocity was found to have a marginal influence on the surface roughness and the type of grain boundaries. However, the crystal orientation density was found to be relatively high in 1 mm/s samples. The LSM samples showed a higher concentration of {101} and {123} planes parallel to the sample surface as well as a higher fraction of low-angle grain boundaries. The LSM samples were found to exhibit better surface wettability and enhanced the viability and proliferation of human fetal osteoblast cells in vitro when compared to the untreated samples. Further, the corrosion protection efficiency of 316L stainless steel was improved up to 70% by LSM in as-processed condition. The increased concentration of {101} and {123} planes on surfaces of LSM samples increases their surface energy, which is believed to be responsible for the improved in vitro cell proliferation. Further, the increased lattice spacing of these planes and high concentration of low-energy grain boundaries in LSM samples would have contributed to the better in vitro corrosion resistance than untreated 316L stainless steel. Our results indicate that LSM can be a potential treatment option for 316L stainless steel-based biomedical devices to improve biocompatibility and corrosion resistance. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2017.

  2. Study of creep cavitation in a stainless steel weldment

    OpenAIRE

    Jazaeri, H.; Bouchard, P. J.; Hutchings, M; Lindner, P.

    2012-01-01

    A study of creep cavities near reheat cracking in AISI Type 316H austenitic stainless steel headers, removed from long-time high temperature operation in nuclear power plants, is reported. It is shown how application of scanning electron microscopy (SEM), cryogenic fractography and small angle neutron scattering (SANS) can be applied, in a complementary way, to observe and quantify creep cavitation damage. Creep cavities in the vicinity of the crack are found to be mainly surrounding inter-gr...

  3. Superhard Nanocrystalline Homometallic Stainless Steel on Steel for Seamless Coatings

    Science.gov (United States)

    Tobin, Eric J.; Hafley, R. (Technical Monitor)

    2002-01-01

    The objective of this work is to deposit nanocrystalline stainless steel onto steel substrates (homometallic) for enhanced wear and corrosion resistance. Homometallic coatings provide superior adhesion, and it has been shown that ultrafine-grained materials exhibit the increased hardness and decreased permeability desired for protective coatings. Nanocrystals will be produced by controlling nucleation and growth and use of an ion beam during deposition by e-beam evaporation or sputtering. Phase I is depositing 31 6L nanocrystalline stainless steel onto 31 6L stainless steel substrates. These coatings exhibit hardnesses comparable to those normally obtained for ceramic coatings such ZrO2, and possess the superior adhesion of seamless, homometallic coatings. Hardening the surface with a similar material also enhances adhesion, by avoiding problems associated with thermal and lattice mismatch. So far we have deposited nanocrystalline homometallic 316L stainless steel coatings by varying the ions and the current density of the ion beams. For all deposition conditions we have produced smooth, uniform, superhard coatings. All coatings exhibit hardness of at least 200% harder than that of bulk materials. Our measurements indicate that there is a direct relationship between nanohardness and the current density of the ion beam. Stress measurements indicate that stress in the films is increasingly proportional to current density of the ion beam. TEM, XPS, and XRD results indicate that the coated layers consist of FCC structure nanocrystallites with a dimension of about 10 to 20 nm. The Ni and Mo concentration of these coating are lower than those of bulk 316L but the concentration of Cr is higher.

  4. Potentiodynamic studies of stainless steel wire for endourology

    OpenAIRE

    J. Przondziono; W. Walke

    2009-01-01

    Purpose: The purpose of the study is to evaluate resistance to electrochemical corrosion of wire made of Cr-Ni stainless steel, designed for use in endourological treatment. The influence of strain formed in the process of drawing and methods of wire surface preparation to corrosive resistance in artificial urine solution were analysed.Design/methodology/approach: Wire corrosion tests were carried out in the solution of artificial urine with the u...

  5. Measurement of local creep properties in stainless steel welds

    OpenAIRE

    Sakanashi, Y.; Gungor, S; Bouchard, J.

    2012-01-01

    A high temperature measurement system for creep deformation based on the digital image correlation (DIC) technique is described. The new system is applied to study the behaviour of a multi-pass welded joint in a high temperature tensile test and a load controlled creep test at 545°C. Spatially resolved tensile properties and time dependent creep deformation properties across a thick section type 316 stainless steel multi-pass welded joint are presented and discussed. Significantly lower creep...

  6. 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)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  8. Thermal Aging Phenomena in Cast Duplex Stainless Steels

    Energy Technology Data Exchange (ETDEWEB)

    Byun, T. S.; Yang, Y.; Overman, N. R.; Busby, J. T.

    2016-02-28

    Cast stainless steels (CASSs) have been extensively used for the large components of light water reactor (LWR) power plants such as primary coolant piping and pump casing. The thermal embrittlement of CASS components is one of the most serious concerns related to the extended-term operation of nuclear power plants. Many past researches have concluded that the formation of Cr–rich α'-phase by Spinodal decomposition of δ-ferrite phase is the primary mechanism for the thermal embrittlement. Cracking mechanism in the thermally-embrittled duplex stainless steels consists of the formation of cleavage at ferrite and its propagation via separation of ferrite-austenite interphase. This article intends to provide an introductory overview on the thermal aging phenomena in LWR relevant conditions. Firstly, the thermal aging effect on toughness is discussed in terms of the cause of embrittlement and influential parameters. An approximate analysis of thermal reaction using Arrhenius equation was carried out to scope the aging temperatures for the accelerated aging experiments to simulate the 60 and 80 years of services. Further, equilibrium precipitation calculation was performed for model CASS alloys using the CALPHAD program and the results are used to describe the precipitation behaviors in duplex stainless steels. These results are also to be used to guide an on-going research aiming to provide knowledge-based conclusive prediction for the integrity of the CASS components of LWR power plants during the service life extended up to and beyond 60 years.

  9. [Clinical evaluation of gingival tissue restored with stainless steel crown].

    Science.gov (United States)

    Chao, D D; Tsai, T P; Chen, T C

    1992-12-01

    The use of stainless steel crown for the restoration of primary molars is widely accepted in pediatric dentistry. There has been a concern regarding their effect on the health of the gingival tissue. It is a possibility that the preformed crown may be a contributing cause of gingivitis. This study evaluated one hundred and thirty-seven crowns in forty-five patients who had received pedodontic treatment at Chang Gung Memorial Hospital. The results indicated that the majority of stainless steel crowns had one or more defects, with crown crimping being the most common error. According to what the paired t-test showed, non-ideal crowns indicated that the gingival index was significantly higher than the entire mouth and control teeth. However the supragingival plaque accumulation of these teeth was significant lower than the entire mouth and control teeth. There was only a moderate positive correlation between supragingival plaque and gingivitis. The operator is necessary to adapt the stainless steel crown margin as closely as possible to the tooth and to avoid the mechanical defect of a crown. It minimizes the irritation of gingival tissue and diminishes the bacterial adherence of subgingival plaque, therefore preserving the health of gingival tissue.

  10. Transuranic contamination of stainless steel in nitric acid

    Science.gov (United States)

    Kerry, Timothy; Banford, Anthony W.; Thompson, Olivia R.; Carey, Thomas; Schild, Dieter; Geist, Andreas; Sharrad, Clint A.

    2017-09-01

    Stainless steels coupons have been exposed to transuranic species in conditions representative of those found in a spent nuclear fuel reprocessing plant. Stainless steel was prepared to different surface finishes and exposed to nitric acid of varying concentrations containing 237Np, 239Pu or 243Am for one month at 50 °C. Contamination by these transuranics has been observed on all surfaces exposed to the solution through the use of autoradiography. This technique showed that samples held in 4 M HNO3 bind 2-3 times as much radionuclide as those held in 10.5 M HNO3. It was also found that the polished steel surfaces generally took up more transuranic contamination than the etched and ;as received; steel finishes. The extent of corrosion on the steel surfaces was found, by scanning electron microscopy, to be greater in solutions containing Np and Pu in comparison to that observed from contact with Am containing solutions, indicating that redox activity of transuranics can influence the mechanism of stainless steel corrosion.

  11. 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.

  12. Deformation behavior of open-cell stainless steel foams

    Energy Technology Data Exchange (ETDEWEB)

    Kaya, A.C., E-mail: a.kaya@campus.tu-berlin.de; Fleck, C.

    2014-10-06

    This study presents the deformation and cell collapse behavior of open-cell stainless steel foams. 316L stainless-steel open-cell foams with two porosities (30 and 45 pores per inch, ppi) were produced with the pressureless powder metallurgical method, and tested in quasi-static compression. As a result of the manufacturing technique, 316L stainless steel open-cell foams have a high amount of microporosity. The deformation behavior was investigated on a macroscopic scale by digital image correlation (DIC) evaluation of light micrographs and on the microscopic scale by in situ loading of cells in the scanning electron microscope. The deformation behavior of the metal foams was highly affected by microstructural features, such as closed pores and their distribution throughout the foam specimen. Moreover, the closed pores made a contribution to the plateau stress of the foams through cell face stretching. Strut buckling and bending are the dominant mechanisms in cell collapse. Although there are edge defects on the struts, the struts have an enormous plastic deformation capability. The cell size of the steel foams had no significant effect on the mechanical properties. Due to the inhomogeneities in the microstructure, the measured plateau stresses of the foams showed about 20% scatter at the same relative density.

  13. Investigations on aged Ti-stabilised stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    Ehrnsten, U.; Karjalainen-Roikonen, P.; Nenonen, P. [VTT Industrial Systems, Espoo (Finland); Korhonen, R. [Fortum Nuclear Services, Vantaa (Finland); Timofeev, B.T.; Bloomin, A.A. [ZNIIKM, St. Petersburg (Russian Federation)

    2003-03-01

    Mechanical and microstructural properties of cast material of type O8X8H10TL and wrought and welded stainless steel pipe material of type O8X8H10T have been determined, aged at NPP operation temperature for about 100 000 h and 200 000 h, respectively. The mechanical properties were determined using tensile testing, impact energy determination and fracture resistance testing. The microstructures were studied using optical, scanning and transmission electron microscopy. The mechanical properties of the cast Ti-stabilised stainless steel material are evaluated to be only slightly affected by long term ({approx} 100 000 hours) operation at NPP operation temperature. Also the effect of even longer ({approx} 200 000 hours) operation on wrought Ti-stabilised pipe material is very small, as the properties of the aged material are within the normal range of as-manufactured material. The mechanical properties of the Mo-alloyed stainless steel weld metal after {approx} 200 000 hours of operation are still good, although indications of changes due to thermal ageing were observed. (orig.)

  14. 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.

  15. In-service thermal ageing of martensitic stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    Tampigny, R.; Molinie, E. [EDF/DIN/CEIDRE (France); Foct, F. [EDF/RD (France); Dignocourt, P. [EDF/DPN/UNIE (France)

    2011-07-01

    Martensitic stainless steels are largely used in Nuclear Power Plants (NPPs) mainly as valve stems, bolts or nuts due to their high mechanical properties and their good resistance to corrosion in primary water. At the end of the eighties, research studies have demonstrated a thermal ageing irreversible embrittlement due to the precipitation of a chromium-rich phase for X6 CrNiCu 17-04, X6 CrNiMo 16.04 and X12 Cr 13 martensitic stainless steels and a semi-empirical modeling has been proposed. Numerous metallurgical examinations have been performed in hot laboratories to consolidate the good correlation between in-service experience and the modeling developed by EDF RD. According to the feedback analysis, thermal ageing embrittlement can appear at different in-service temperatures or do not appear in relation with chemical composition of martensitic stainless steels and end of manufacturing heat treatments associated. A new campaign of metallurgical examinations has been proposed to consolidate previous studies and to contribute to maintenance policy for the next ten years after the third decennial outages for 900 MWe NPP. Influence of real in-service temperatures and end of manufacturing heat treatments have been examined to understand reasons why in some cases thermal ageing embrittlement does not occur or occur with a lowest intensity. These new results have contributed to reinforce EDF RD modeling validity and technical specifications defined in RCC-M for new valve stems, bolts or nuts. (authors)

  16. Recrystallization and Grain Growth of 316L Stainless Steel Wires

    Science.gov (United States)

    Zhao, Xiuyun; Liu, Yong; Wang, Yan; Feng, Ping; Tang, Huiping

    2014-07-01

    Recrystallization and grain growth behaviors of 316L stainless steel wires with a diameter of 12 µm were investigated by optical microscopy, scanning electron microscopy, transmission electron microscopy (TEM), and X-ray diffraction techniques. Heavily cold-drawn wires were isothermally held at temperatures from 1073 K to 1223 K (800 °C to 950 °C) for various holding times. Optical microscopy and TEM observations showed that recrystallization grains have irregular shape and that twins exist. The texture formed during drawing and annealing processes of the wires, as measured by X-ray methods, showed a fiber texture approximated by a and a component. The value of the grain growth exponent n was calculated, and the kinetic rates were plotted using the Arrhenius equation. Results show that the activation energy of the grain growth for 316L stainless steel wire was determined to be 407 kJ/mol, which was much higher than that of the bulk 316L stainless steel. The small wire diameter and the existence of texture played important roles in the increase of the activation energy for grain growth of the wire.

  17. Tensile and wear properties of TiC reinforced 420 stainless steel fabricated by in situ synthesis%原位合成TiC增强420不锈钢的力学性能和抗磨损性能

    Institute of Scientific and Technical Information of China (English)

    汪黎; 孙扬善; 樊泉; 薛烽; 段志超

    2004-01-01

    TiC particle reinforced 420 stainless steel matrix composites were fabricated, and the microstructure, tensile properties and wear resistance of the composites were studied. The experimental results indicate that the distribution of TiC particles with size of 5 to 10 μm in diameter is uniform if the volume fraction of TiC is lower than 6%. However, slight agglomeration can be observed when the TiC content exceeds 6%. With the increase of TiC content the tensile and yield strength of the composites prepared increases and reaches the maximum when the volume fraction of TiC increases to 5%. Further increase of TiC content causes reductions of yield and tensile strength. The ductility of the composites shows a monotone decrease with the increase of TiC addition. The introduction of TiC into 420 stainless steel results in significant improvement on wear resistance, which reaches a steady level when the volume fraction of TiC increases to 11% and does not show obvious variation if the TiC content is further increased.%用原位合成方法制备了TiC增强420不锈钢基复合材料, 并研究了复合材料的显微组织、力学性能和抗磨损性能. 实验结果表明, 当复合材料中TiC颗粒体积分数低于6%时, 材料中TiC颗粒分布均匀, 颗粒的尺寸在5~10 μm左右; 但颗粒体积分数大于6%后, 显微组织中出现TiC颗粒的轻微偏聚. 随着TiC体积分数的增加, 材料的抗拉强度和屈服强度先是增高, 当TiC体积分数达到5%时, 强度达最大值. 此后增加TiC体积分数会导致强度的下降. 复合材料的塑性随TiC体积分数的增加呈单调下降的趋势. TiC颗粒的引入使材料的抗磨损性能得到显著改善, 但当TiC体积分数达到11%时, 抗磨损性能接近一个稳定的水平. 继续增加TiC含量, 材料的抗磨损性能不再发生明显变化.

  18. Adhesion of food-borne bacteria to stainless steel is reduced by food conditioning films

    DEFF Research Database (Denmark)

    Bernbom, Nete; Ng, Yin; Jorgensen, R.L.

    2009-01-01

    also decreases adhesion of other food-relevant bacteria. The manipulation of adhesion was not attributable to growth inhibitory effects. Chemical analysis revealed that the stainless steels were covered by homogenous layers of adsorbed proteins. The presence of tropomyocin was indicated by appearance......Preconditioning of stainless steel with aqueous cod muscle extract significantly impedes subsequent bacterial adhesion most likely due to repelling effects of fish tropomyosin. The purpose of this study was to determine if other food conditioning films decrease or enhance bacterial adhesion...... to stainless steel. Attachment of Pseudomonas fluorescens AH2 to stainless steel coated with water-soluble coatings of animal origin was significantly reduced as compared with noncoated stainless steel or stainless steel coated with laboratory substrate or extracts of plant origin. Coating with animal extracts...

  19. Assembly and Thermal Hydraulic Test of a Stainless Steel Sodium-Potassium Circuit

    Science.gov (United States)

    Garber, A.; Godfroy, T.; Webster, K.

    2007-01-01

    Early Flight Fission Test Facilities (EFF-TF) team has been tasked by the NASA Marshall Space Flight Center Nuclear Systems Office to design, fabricate, and test an actively pumped alkali metal flow circuit. The system was originally built for use with lithium, but due to a shift in focus, it was redesigned for use with a eutectic mixture of sodium potassium (NaK). Basic circuit components include: reactor segment, NaK to gas heat exchanger, electromagnetic (EM) liquid metal pump, load/drain reservoir, expansion reservoir, instrumentation, and a spill reservoir. A 37-pin partial-array core (pin and flow path dimensions are the same as those in a full design) was selected for fabrication and test. This paper summarizes the first fill and checkout testing of the Stainless Steel NaK-Cooled Circuit (SNaKC).

  20. 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.

  1. The influence of sintering time on the properties of PM duplex stainless steel

    OpenAIRE

    Z. Brytan; L.A. Dobrzański; M. Actis Grande; Rosso, M.

    2009-01-01

    Purpose: The purpose of this paper is to analyse the effect of sintering time on the pore morphology, microstructural changes, tensile properties and corrosion resistance of vacuum sintered duplex stainless steel.Design/methodology/approach: In presented study PM duplex stainless steels were obtained through mixing base ferritic stainless steel powder with controlled addition of elemental alloying powders and then sintered in a vacuum furnace with argon backfilling at 1250°C for different tim...

  2. An Investigation of Unipolar Arcing Damage on Stainless Steel and Titanium Carbide Coated Surfaces.

    Science.gov (United States)

    1980-06-01

    STAINLESS STEEL AND TITANIUM CARBIDE COATED SURFACES by Michael Thomas Keville and Robert William Lautrup June 1980 Thesis Advisors: F. Schwirzke K.D...rd"ll SU108016) V " 111. ’Cato .: "? : :V lI . An Investigation of Unipolar Arcing Master’s esis Damage on Stainless Steel and Titanium , Carbide Coated...on Stainless Steel and Titanium Carbide Coated Surfaces by Michael Thomas Keville Lieutenant, United States Navy B.S., United States Naval Academy

  3. Corrosion resistance properties of sintered duplex stainless steel

    Directory of Open Access Journals (Sweden)

    L.A. Dobrzański

    2006-09-01

    Full Text Available Purpose: of this paper was to examine the corrosion resistance of duplex stainless steels using electrochemical methods in 1M NaCl solution. The influence of powder mixes preparation and cooling cycle after sintering on corrosion properties was evaluated.Design/methodology/approach: In presented study duplex stainless steels were obtained through powder metallurgy starting from austenitic, martensitic base powders by controlled addition of alloying elements, such as Cr, Ni, Mo and Cu. In the studies behind the preparation of mixes, Schaeffler’s diagram was taken into consideration. Prepared mixes have been compacted at 800 MPa and sintered in a vacuum furnace with argon backfilling at 1260°C for 1 h. After sintering two different cooling cycles were applied: rapid cooling with an average cooling rate of 245 °C/min and slow cooling of 5 °C/min in argon atmosphere. Produced duplex stainless steels have been studied by scanning and optical microscopy and EDS chemical analysis of microstructure components. Corrosion properties have been studied through electrochemical methods in 1M NaCl water solutionFindings: According to achieved results, it was affirmed that applied sintering method as well as powder mixes preparation allows for manufacturing the sintered duplex steels with good corrosion properties which depends on austenite/ferrite ratio in the microstructure and elements partitioning between phases. Corrosion resistance of sintered stainless steels is strictly connected with the density and the pore morphology present in the microstructure too. The highest resistance to pitting corrosion in 1M NaCl solution was achieved for composition with approximate balance of ferrite and austenite in the microstructure.Research limitations/implications: According to the powders characteristic, the applied fast cooling rate seems to be a good compromise for corrosion properties and microstructures, nevertheless further tests should be carried out in

  4. The Prediction of Long-Term Thermal Aging in Cast Austenitic Stainless Steel

    Energy Technology Data Exchange (ETDEWEB)

    Byun, Thak Sang; Yang, Ying; Lach, Timothy G.

    2017-02-15

    Cast austenitic stainless steel (CASS) materials are extensively used for many massive primary coolant system components of light water reactors (LWRs) including coolant piping, valve bodies, pump casings, and piping elbows. Many of these components are operated in complex and persistently damaging environments of elevated temperature, high pressure, corrosive environment, and sometimes radiation for long periods of time. Since a large number of CASS components are installed in every nuclear power plant and replacing such massive components is prohibitively expensive, any significant degradation in mechanical properties that affects structural integrity, cracking resistance in particular, of CASS components will raise a serious concern on the performance of entire power plant. The CASS materials for nuclear components are highly corrosion-resistant Fe-Cr-Ni alloys with 300 series stainless steel compositions and mostly austenite (γ)–ferrite (δ) duplex structures, which result from the casting processes consisting of alloy melting and pouring or injecting liquid metal into a static or spinning mold. Although the commonly used static and centrifugal casting processes enable the fabrication of massive components with proper resistance to environmental attacks, the alloying and microstructural conditions are not highly controllable in actual fabrication, especially in the casting processes of massive components. In the corrosion-resistant Fe-Cr-Ni alloy system, the minor phase (i.e., the δ-ferrite phase) is inevitably formed during the casting process, and is in a non-equilibrium state subject to detrimental changes during exposure to elevated temperature and/or radiation. In general, relatively few critical degradation modes are expected within the current design lifetime of 40 years, given that the CASS components have been processed properly. It has been well known, however, that both the thermal aging and the neutron irradiation can cause degradation of static

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

    Directory of Open Access Journals (Sweden)

    Hong Luo

    2015-12-01

    Full Text Available 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Taehtinen, S.; Kauppinen, P.; Jeskanen, H.; Lahdenperae, K.; Ehrnsten, U. [VTT Manufacturing Technology, Espoo (Finland). Materials and Structural Integrity

    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.)

  7. 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.

  8. Improved corrosion resistance of 316L stainless steel by nanocrystalline and electrochemical nitridation in artificial saliva solution

    Science.gov (United States)

    Lv, Jinlong; Liang, Tongxiang

    2015-12-01

    The fluoride ion in artificial saliva significantly changed semiconductor characteristic of the passive film formed on the surface of 316L stainless steels. The electrochemical results showed that nanocrystalline α‧-martensite improved corrosion resistance of the stainless steel in a typical artificial saliva compared with coarse grained stainless steel. Moreover, comparing with nitrided coarse grained stainless steel, corrosion resistance of the nitrided nanocrystalline stainless steel was also improved significantly, even in artificial saliva solution containing fluoride ion. The present study showed that the cryogenic cold rolling and electrochemical nitridation improved corrosion resistance of 316L stainless steel for the dental application.

  9. Fe-15Ni-13Cr austenitic stainless steels for fission and fusion reactor applications - Part 1: Effects of minor alloying elements on precipitate phases in melt products and implication in alloy fabrication

    Science.gov (United States)

    Lee, E. H.; Mansur, L. K.

    2000-01-01

    In an effort to develop alloys for fission and fusion reactor applications, 28Fe-15Ni-13Cr base alloys were fabricated by adding various combinations of the minor alloying elements, Mo, Ti, C, Si, P, Nb, and B. The results showed that a significant fraction of undesirable residual oxygen was removed as oxides when Ti, C, and Si were added. Accordingly, the concentrations of the latter three essential alloying elements were reduced also. Among these elements, Ti was the strongest oxide former, but the largest oxygen removal (over 80%) was observed when carbon was added alone without Ti, since gaseous CO boiled off during melting. This paper recommends an alloy melting procedure to mitigate solute losses while reducing the undesirable residual oxygen. In this work, 14 different types of precipitate phases were identified. Compositions of precipitate phases and their crystallographic data are documented. Finally, stability of precipitate phases was examined in view of Gibbs free energy of formation.

  10. A powder metallurgy austenitic stainless steel for application at very low temperatures

    CERN Document Server

    Sgobba, Stefano; Liimatainen, J; Kumpula, M

    2000-01-01

    The Large Hadron Collider to be built at CERN will require 1232 superconducting dipole magnets operating at 1.9 K. By virtue of their mechanical properties, weldability and improved austenite stability, nitrogen enriched austenitic stainless steels have been chosen as the material for several of the structural components of these magnets. Powder Metallurgy (PM) could represent an attractive production technique for components of complex shape for which dimension tolerances, dimensional stability, weldability are key issues during fabrication, and mechanical properties, ductility and leak tightness have to be guaranteed during operation. PM Hot Isostatic Pressed test plates and prototype components of 316LN-type grade have been produced by Santasalo Powdermet Oy. They have been fully characterized and mechanically tested down to 4.2 K at CERN. The fine grained structure, the absence of residual stresses, the full isotropy of mechanical properties associated to the low level of Prior Particle Boundaries oxides ...

  11. Industrial Experience on the Caustic Cracking of Stainless Steels and Nickel Alloys - A Review

    Energy Technology Data Exchange (ETDEWEB)

    Rebak, R B

    2005-10-09

    Caustic environments are present in several industries, from nuclear power generation to the fabrication of alkalis and alumina. The most common material of construction is carbon steel but its application is limited to a maximum temperature of approximately 80 C. The use of Nickel (Ni) alloys is recommended at higher temperatures. Commercially pure Ni is the most resistant material for caustic applications both from the general corrosion and the stress corrosion cracking (SCC) perspectives. Nickel rich alloys also offer a good performance. The most important alloying elements are Ni and chromium (Cr). Molybdenum (Mo) is not a beneficial alloying element and it dissolves preferentially from the alloy in presence of caustic environments. Austenitic stainless steels such as type 304 and 316 seem less resistant to caustic conditions than even plain carbon steel. Experimental evidence shows that the most likely mechanism for SCC is anodic dissolution.

  12. Initial Testing of the Stainless Steel NaK-Cooled Circuit (SNaKC)

    Science.gov (United States)

    Garber, Anne; Godfroy, Thomas

    2007-01-01

    An actively pumped alkali metal flow circuit, designed and fabricated at the NASA Marshall Space Flight Center, is currently undergoing testing in the Early Flight Fission Test Facility (EFF-TF). Sodium potassium (NaK) was selected as the primary coolant. Basic circuit components include: simulated reactor core, NaK to gas heat exchanger, electromagnetic liquid metal pump, liquid metal flowmeter, load/drain reservoir, expansion reservoir, test section, and instrumentation. Operation of the circuit is based around the 37-pin partial-array core (pin and flow path dimensions are the same as those in a full core), designed to operate at 33 kWt. This presentation addresses the construction, fill and initial testing of the Stainless Steel NaK-Cooled Circuit (SNaKC).

  13. Effect of Secondary Phase Precipitation on the Corrosion Behavior of Duplex Stainless Steels

    Directory of Open Access Journals (Sweden)

    Kai Wang Chan

    2014-07-01

    Full Text Available Duplex stainless steels (DSSs with austenitic and ferritic phases have been increasingly used for many industrial applications due to their good mechanical properties and corrosion resistance in acidic, caustic and marine environments. However, DSSs are susceptible to intergranular, pitting and stress corrosion in corrosive environments due to the formation of secondary phases. Such phases are induced in DSSs during the fabrication, improper heat treatment, welding process and prolonged exposure to high temperatures during their service lives. These include the precipitation of sigma and chi phases at 700–900 °C and spinodal decomposition of ferritic grains into Cr-rich and Cr-poor phases at 350–550 °C, respectively. This article gives the state-of the-art review on the microstructural evolution of secondary phase formation and their effects on the corrosion behavior of DSSs.

  14. Ultrathin Polyimide-Stainless Steel Heater for Vacuum System Bake-out

    CERN Document Server

    Rathjen, Christian; Henrist, Bernard; Kölemeijer, Wilhelmus; Libera, Bruno; Lutkiewicz, Przemyslaw

    2005-01-01

    Space constraints in several normal conducting magnets of the LHC required the development of a dedicated permanent heater for vacuum chamber bake-out. The new heater consists of stainless steel bands inside layers of polyimide. The overall heater thickness is about 0.3 mm. The low magnetic permeability is suitable for applications in magnetic fields. The material combination allows for temperatures high enough to activate a NEG coating. Fabrication is performed in consecutive steps of tape wrapping. Automation makes high volume production at low costs possible. About 800 m of warm vacuum system of the long straight sections of the LHC will be equipped with the new heater. This paper covers experience gained at CERN from studies up to industrialization.

  15. Corrosion behavior of niobium coated 304 stainless steel in acid solution

    Science.gov (United States)

    Pan, T. J.; Chen, Y.; Zhang, B.; Hu, J.; Li, C.

    2016-04-01

    The niobium coating is fabricated on the surface of AISI Type 304 stainless steel (304SS) by using a high energy micro arc alloying technique in order to improvecorrosion resistance of the steel against acidic environments. The electrochemical corrosion resistance of the niobium coating in 0.7 M sulfuric acid solutions is evaluated by electrochemical impedance spectroscopy, potentiodynamic polarization and the open circuit potential versus time. Electrochemical measurements indicate that the niobium coating increases the free corrosion potential of the substrate by 110 mV and a reduction in the corrosion rate by two orders of magnitude compared to the substrate alone. The niobium coating maintains large impedance and effectively offers good protection for the substrate during the long-term exposure tests, which is mainly ascribed to the niobium coating acting inhibiting permeation of corrosive species. Finally, the corresponding electrochemical impedance models are proposed to elucidate the corrosion resistance behavior of the niobium coating in acid solutions.

  16. Progress in depositing MgB{sub 2} films on stainless steel substrate

    Energy Technology Data Exchange (ETDEWEB)

    Li Fen [Department of Physics and State Key Laboratory for Artificial Structure and Mesoscopic Physics, Peking University, Beijing 100871 (China); Guo Tao [Department of Physics and State Key Laboratory for Artificial Structure and Mesoscopic Physics, Peking University, Beijing 100871 (China); Zhang Kaicheng [Department of Physics and State Key Laboratory for Artificial Structure and Mesoscopic Physics, Peking University, Beijing 100871 (China); Chen Chinping [Department of Physics and State Key Laboratory for Artificial Structure and Mesoscopic Physics, Peking University, Beijing 100871 (China); Feng Qingrong [Department of Physics and State Key Laboratory for Artificial Structure and Mesoscopic Physics, Peking University, Beijing 100871 (China)]. E-mail: qrfeng@pku.edu.cn

    2007-02-01

    We have made a progress in fabricating MgB{sub 2} films, {approx}25 {mu}m, on the stainless steel substrate by hybrid physical-chemical vapor deposition. The superconducting transition temperature is, T {sub C} (onset) = 39.6 K with a transition width, {delta}T = 0.5 K. The characterization by scanning electron microscope and X-ray diffraction indicates that its structure is polycrystalline. At T = 0 K, the upper critical field H {sub C2} is determined as 15.2 T by extrapolation from a polynomial fitting to the transition temperatures under various applied fields, T {sub C}(H). In the self field, the critical current density J {sub C} is determined as 3.74 MA/cm{sup 2} at T = 15 K by a magnetic measurement according to the Bean model.

  17. Industrial Experience on the Caustic Cracking of Stainless Steels and Nickel Alloys - A Review

    Energy Technology Data Exchange (ETDEWEB)

    Rebak, R B

    2005-10-09

    Caustic environments are present in several industries, from nuclear power generation to the fabrication of alkalis and alumina. The most common material of construction is carbon steel but its application is limited to a maximum temperature of approximately 80 C. The use of Nickel (Ni) alloys is recommended at higher temperatures. Commercially pure Ni is the most resistant material for caustic applications both from the general corrosion and the stress corrosion cracking (SCC) perspectives. Nickel rich alloys also offer a good performance. The most important alloying elements are Ni and chromium (Cr). Molybdenum (Mo) is not a beneficial alloying element and it dissolves preferentially from the alloy in presence of caustic environments. Austenitic stainless steels such as type 304 and 316 seem less resistant to caustic conditions than even plain carbon steel. Experimental evidence shows that the most likely mechanism for SCC is anodic dissolution.

  18. 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.

  19. 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.

  20. 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.

  1. Characterization of laser metal deposited 316L stainless steel

    CSIR Research Space (South Africa)

    Bayode, A

    2016-06-01

    Full Text Available and metallographic samples were prepared according to ASTM E3 – 11 standard for metallurgical preparation of stainless steel [15]. The surface of the polished samples was etched with Kalling’s No. 2 reagent (5g CuCl2, 100 ml HCl, 100 ml ethanol). Microstructural... surface which is typical of most Laser deposited materials. Fig. 2. Deposited tracks at different laser power: (a) 1.8kW, (b) 2.0kW, (c) 2.2 and (d) 2.kW. LMD produces different zones in the processed material [16]. A macro-view of sample 1...

  2. 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...... 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...

  3. Oxidation of molecular tritium in austenitic stainless steel containments

    Energy Technology Data Exchange (ETDEWEB)

    Blet, V.; Brossard, P.; Falanga, A.; Guidon, H.; Le Sergent, C. (CEA, BP 12, 91680 Bruyeres-le-Chatel (FR)); Clavier, B. (USSI Ingenierie, BP 72, 92223 Bagneux (FR))

    1992-03-01

    This paper discusses the rate of oxidation of molecular tritium. determined at room temperature in closed austenitic stainless steel containments versus the tritium concentration of tritium-oxygen gaseous mixtures. With our experimental conditions, the overall rate of oxidation is found to depend not only on tritium concentration but also on initial oxygen concentration. The tritiated water which is produced, does not remain in the gaseous phase but is partially trapped on the surface oxides. In addition, kinetics of reaction are strongly dependent on the geometry of the cylindrical containments. When the vessel diameter is smaller than 4 mm, tritiated water formation is significantly reduced.

  4. 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.

  5. Laser Welding of Large Scale Stainless Steel Aircraft Structures

    Science.gov (United States)

    Reitemeyer, D.; Schultz, V.; Syassen, F.; Seefeld, T.; Vollertsen, F.

    In this paper a welding process for large scale stainless steel structures is presented. The process was developed according to the requirements of an aircraft application. Therefore, stringers are welded on a skin sheet in a t-joint configuration. The 0.6 mm thickness parts are welded with a thin disc laser, seam length up to 1920 mm are demonstrated. The welding process causes angular distortions of the skin sheet which are compensated by a subsequent laser straightening process. Based on a model straightening process parameters matching the induced welding distortion are predicted. The process combination is successfully applied to stringer stiffened specimens.

  6. Dependence of Radiation Damage in Stainless Steel on Irradiation Dose

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The accelerator driven radioactive clean nuclear power system (ADS) is a novel innovative idea forthe sustainable development of nuclear power system. The spallation neutron source system is one of thethree key parts of ADS, which provides source neutrons of about 1018 s-1 for the burning-up of fuels.Stainless steel (SS) is used for the beam window and target materials of the spallation neutron sourcesystem. It is irradiated by high-energy and intense protons and/or neutrons during operation. Theaccumulated displacement damage dose could reach a couple of hundred dpa (displacement per atom) per

  7. Glow Discharge Plasma Nitriding of AISI 304 Stainless Steel

    Institute of Scientific and Technical Information of China (English)

    A.QAYYUM; M.A.NAVEED; S.ZEB; G.MURTAZA; M.ZAKAULLAH

    2007-01-01

    Glow discharge plasma nitriding of AISI 304 austenitic stainless steel has been carried out for different processing time under optimum discharge conditions established by spectroscopic analysis.The treated samples were analysed by X-ray diffraction(XRD)to explore the changes induced in the crystallographic structure.The XRD pattern confirmed the formation of an expanded austenite phase(γN)owing to incorporation of nitrogen as an interstitial solid solution in the iron lattice.A Vickers microhardness tester was used to evaluate the surface hardness as a function of indentation depth(μm).The results showed clear evidence of surface changes with substantial increase in surface hardness.

  8. 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 nitrogen contents as high as corresponding to an occupancy of yN = 0.61 of the interstitial sublattice, i.e. about 38 at.% N. Associated with the dissolution of these unprecedented nitrogen contents in an austenitic matrix a reversible volume expansion of the austenite lattice occurred for yN > 0...

  9. Are Sulfate Reducing Bacteria Important to the Corrosion of Stainless Steels?

    Science.gov (United States)

    2009-01-01

    steel specimens. Concentration of sulfide used was 10ŖM for direct comparison to the McNeil/Odom model1 which predicts sulfide mineral formation . Upon...sulfide mineral formation from stainless steels will be slower than for pure iron and that stainless steels with more than 6% molybdenum will be very

  10. 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.

  11. Development of strategic surface topographies for lubrication in sheet forming of stainless steel

    DEFF Research Database (Denmark)

    Nilsson, Morten; Olsson, David Dam; Petrushina, Irina

    2004-01-01

    . The technique, which has been developed, is based on an electrochemical treatment changing the topography of the stainless steel surface. Comparative testing of the new surface topographies in ironing and deep drawing of stainless steel sheet shows significant improvements and possibilities of replacing...... chlorinated paraffin oils with environmentally friendly, plain mineral oil....

  12. Strategic surface topographies for enhanced lubrication in sheet forming of stainless steel

    DEFF Research Database (Denmark)

    Nilsson, Morten Sixten; Olsson, David Dam; Petrushina, Irina

    2010-01-01

    . The technique, which has been developed, is based on an electrochemical treatment changing the topography of the stainless steel surface. Comparative testing of the new surface topographies in ironing and deep drawing of stainless steel sheet shows significant improvements and possibilities of replacing...... chlorinated paraffin oils with environmentally friendly plain mineral oil...

  13. 76 FR 69292 - Aging Management of Stainless Steel Structures and Components in Treated Borated Water

    Science.gov (United States)

    2011-11-08

    ... COMMISSION Aging Management of Stainless Steel Structures and Components in Treated Borated Water AGENCY... Staff Guidance (LR-ISG), LR- ISG-2011-01, ``Aging Management of Stainless Steel Structures and Components in Treated Borated Water.'' This LR-ISG revises the guidance in the Standard Review Plan...

  14. 77 FR 27815 - Aging Management of Stainless Steel Structures and Components in Treated Borated Water

    Science.gov (United States)

    2012-05-11

    ... COMMISSION Aging Management of Stainless Steel Structures and Components in Treated Borated Water AGENCY..., ``Aging Management of Stainless Steel Structures and Components in Treated Borated Water.'' This LR-ISG... Power Plants (SRP-LR) and Generic Aging Lessons Learned (GALL) Report for the aging management...

  15. 75 FR 76025 - Stainless Steel Butt-Weld Pipe Fittings From Japan, Korea, and Taiwan

    Science.gov (United States)

    2010-12-07

    ... party responded to the sunset review notice of initiation by the applicable deadline * * *'' (75 FR... 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...

  16. 75 FR 53714 - Stainless Steel Butt-Weld Pipe Fittings From Japan, Korea, and Taiwan

    Science.gov (United States)

    2010-09-01

    ... imports of stainless steel butt-weld pipe fittings from Japan (53 FR 9787). On February 23, 1993, Commerce... on imports of stainless steel butt-weld pipe fittings from Japan, Korea, and Taiwan (65 FR 11766... Japan, Korea, and Taiwan (70 FR 61119). The Commission is now conducting third reviews to...

  17. 77 FR 41969 - Stainless Steel Bar From Japan: Rescission of Antidumping Duty Administrative Review

    Science.gov (United States)

    2012-07-17

    ... Revocation in Part, and Deferral of Administrative Review, 77 FR 19179, 19181 (March 30, 2012). Based on a... International Trade Administration Stainless Steel Bar From Japan: Rescission of Antidumping Duty Administrative...) initiated an administrative review of the antidumping duty order on stainless steel bar from Japan...

  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. Male-mediated spontaneous abortion among spouses of stainless steel welders

    DEFF Research Database (Denmark)

    Hjollund, N H; Bonde, Jens Peter; Jensen, Tina Kold

    2000-01-01

    Male-mediated spontaneous abortion has never been documented for humans. The welding of stainless steel is associated with the pulmonary absorption of hexavalent chromium, which has genotoxic effects on germ cells in rodents. Clinical and early subclinical spontaneous abortions were examined among...... spouses of stainless-steel welders....

  20. Low temperature thermochemical treatment of stainless steel; bridging from science to technology

    DEFF Research Database (Denmark)

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

    2010-01-01

    The present contribution gives an overview of some of the fundamental scientific aspects of low temperature thermochemical treatment of stainless steel, in particular the characterisation of socalled expanded austenite is addressed. Selected technological examples of thermochemical treatment...... of stainless steel are presented....

  1. A comparison of radiation shielding of stainless steel with different magnetic properties

    Directory of Open Access Journals (Sweden)

    Calik Adnan

    2014-01-01

    Full Text Available The radiation shielding properties of three different stainless steels have been investigated. For this purpose, linear attenuation coefficients at photon energy levels of 662 keV and 1250 keV have been measured. The obtained results showed that ferritic stainless steel was more capable in stopping the high energy photons than its non-magnetic counterpart.

  2. Influence of surface roughness of stainless steel on microbial adhesion and corrosion resistance

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel; Bagge-Ravn, Dorthe; Kold, John;

    2003-01-01

    Abstract The aim of this study was to evaluate if hygienic characteristics of stainless steel used in the food industry could be improved by smoothing surface roughness from an Ra of 0.9 to 0.01 ƒÝm. The adherence of Pseudomonas sp., Listeria monocytogenes and Candida lipolytica to stainless steel...

  3. 78 FR 45271 - Welded Stainless Steel Pressure Pipe From Malaysia, Thailand, and Vietnam

    Science.gov (United States)

    2013-07-26

    ... COMMISSION Welded Stainless Steel Pressure Pipe From Malaysia, Thailand, and Vietnam Determination On the... injured by reason of imports from Malaysia, Thailand, and Vietnam of welded stainless steel pressure pipe... pipe from Malaysia, Thailand, and Vietnam. Accordingly, effective May 16, 2013, the...

  4. 76 FR 46323 - Stainless Steel Sheet and Strip From Germany, Italy, Japan, Korea, Mexico, and Taiwan

    Science.gov (United States)

    2011-08-02

    ... COMMISSION Stainless Steel Sheet and Strip From Germany, Italy, Japan, Korea, Mexico, and Taiwan... from Germany, Italy, and Mexico \\2\\ would not be likely to lead to continuation or recurrence of... with respect to stainless steel sheet and strip from Germany, Italy, and Mexico, and Commissioner...

  5. Low-temperature gaseous surface hardening of stainless steel: the current status

    DEFF Research Database (Denmark)

    Christiansen, Thomas; Somers, Marcel A. J.

    2009-01-01

    The present review addresses the state of the art of low-temperature gaseous surface engineering of (austenitic) stainless steel and is largely based on the authors' own work in the last 10 years. The main purpose of low temperature gaseous surface engineering of stainless steel is to develop a h...

  6. 76 FR 28809 - Stainless Steel Plate From Belgium; Termination of Five-Year Review

    Science.gov (United States)

    2011-05-18

    ... COMMISSION Stainless Steel Plate From Belgium; Termination of Five-Year Review AGENCY: United States... (``Commerce'') initiated and the U.S. International Trade Commission (``Commission'') instituted a five-year... its full five-year review of the countervailing duty order concerning stainless steel plate from...

  7. Study of Thermocurrents in ILC cavities via measurements of the Seebeck Effect in niobium, titanium, and stainless steel thermocouples

    Energy Technology Data Exchange (ETDEWEB)

    Cooley, Victoria [Univ. of Wisconsin, Madison, WI (United States)

    2014-01-01

    The goals of Fermilab’s Superconductivity and Radio Frequency Development Department are to engineer, fabricate, and improve superconducting radio frequency (SCRF) cavities in the interest of advancing accelerator technology. Improvement includes exploring possible limitations on cavity performance and mitigating such impediments. This report focuses on investigating and measuring the Seebeck Effect observed in cavity constituents titanium, niobium, and stainless steel arranged in thermocouples. These junctions exist between cavities, helium jackets, and bellows, and their connection can produce a loop of electrical current and magnetic flux spontaneously during cooling. The experimental procedure and results are described and analyzed. Implications relating the results to cavity performance are discussed.

  8. Isothermal Calorimetric Observations of the Effect of Welding on Compatibility of Stainless Steels with High-Test Hydrogen Peroxide Propellant

    Science.gov (United States)

    Gostowski, Rudy

    2003-01-01

    High-Test Hydrogen Peroxide (HTP) is receiving renewed interest as a monopropellant and as the oxidizer for bipropellant systems. HTP is hydrogen peroxide having concentrations ranging from 70 to 98%. In these applications the energy and oxygen released during decomposition of HTP is used for propulsion. In propulsion systems components must be fabricated and connected using available joining processes. Welding is a common joining method for metallic components. The goal of this study was to compare the HTP compatibility of welded vs. unwelded stainless steel.

  9. Investigation of Sintering Technology for Composite of Stainless Steel and Partially Stabilized Zirconia

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The sintering technology for mixed powdered extrusion rods of different proportions of stainless steel to magnesiapartially stabilized zirconia (PSZ) was investigated. The effects of some sintering parameters including holdingtime, atmosphere and protective gas pressure on shrinkage, relative density, microstructure, micro-Vickers hardnessand compression strength of sintered samples were mainly researched. The experimental results are as follows: (1)The shrinkage and the relative density of the sintered samples decrease as increasing stainless steel content in thecomposite, except for the case containing 90 percent of stainless steel; (2) The porosity in PSZ matrix rises asincreasing the stainless steel content in the composite; (3) Longer sintering holding time, higher sintering vacuumand gas-pressure sintering process not only enhance the relative density, but also improve microstructure of composite;(4) Micro-Vickers hardness of PSZ matrix decreases as increasing stainless steel content, while that of stainless steelparticles in sintered samples varies unnoticeably.

  10. Biocompatibility of 17-4 PH stainless steel foam for implant applications.

    Science.gov (United States)

    Mutlu, Ilven; Oktay, Enver

    2011-01-01

    In this study, biocompatibility of 17-4 PH stainless steel foam for biomedical implant applications was investigated. 17-4 PH stainless steel foams having porosities in the range of 40-82% with an average pore size of around 600 μm were produced by space holder-sintering technique. Sintered foams were precipitation hardened for times of 1-6 h at temperatures between 450-570 °C. Compressive yield strength and Young's modulus of aged stainless steel foams were observed to vary between 80-130 MPa and 0.73-1.54 GPa, respectively. Pore morphology, pore size and the mechanical properties of the 17-4 PH stainless steel foams were close to cancellous bone. In vitro evaluations of cytotoxicity of the foams were investigated by XTT and MTT assays and showed sufficient biocompatibility. Surface roughness parameters of the stainless steel foams were also determined to characterize the foams.

  11. 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.

  12. 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...

  13. 76 FR 38686 - Stainless Steel Wire Rod From India; Institution of a Five-Year Review Concerning the Antidumping...

    Science.gov (United States)

    2011-07-01

    ... COMMISSION Stainless Steel Wire Rod From India; Institution of a Five-Year Review Concerning the Antidumping Duty Order on Stainless Steel Wire Rod From India AGENCY: United States International Trade Commission... the antidumping duty order on stainless steel wire rod from India would be likely to lead...

  14. Evaluation of metal release and local tissue response to indigenous stainless steel miniplates used in facial fractures

    OpenAIRE

    Dugal, Arun; Dadhe, D. P.

    2009-01-01

    Abstract The issue of metal release from stainless steel bone plates has gained considerable momentum advocating the removal of stainless steel miniplates after healing of fracture. So far no study has been published in the literature regarding metal release with the indigenously manufactured stainless steel miniplates.

  15. 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... published the antidumping duty orders on welded ASTM A-312 stainless steel pipe from Korea and Taiwan.\\1\\...

  16. A porous stainless steel membrane system for extraterrestrial crop production

    Science.gov (United States)

    Koontz, H. V.; Prince, R. P.; Berry, W. L.; Knott, W. M. (Principal Investigator)

    1990-01-01

    A system was developed in which nutrient flow to plant roots is controlled by a thin (0.98 or 1.18 mm) porous (0.2 or 0.5 microns) stainless steel sheet membrane. The flow of nutrient solution through the membrane is controlled by adjusting the relative negative pressure on the nutrient solution side of the membrane. Thus, the nutrient solution is contained by the membrane and cannot escape from the compartment even under microgravity conditions if the appropriate pressure gradient across the membrane is maintained. Plant roots grow directly on the top surface of the membrane and pull the nutrient solution through this membrane interface. The volume of nutrient solution required by this system for plant growth is relatively small, since the plenum, which contains the nutrient solution in contact with the membrane, needs only to be of sufficient size to provide for uniform flow to all parts of the membrane. Solution not passing through the membrane to the root zone is recirculated through a reservoir where pH and nutrient levels are controlled. The size of the solution reservoir depends on the sophistication of the replenishment system. The roots on the surface of the membrane are covered with a polyethylene film (white on top, black on bottom) to maintain a high relative humidity and also limit light to prevent algal growth. Seeds are sown directly on the stainless steel membrane under the holes in the polyethylene film that allow a pathway for the shoots.

  17. 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.

  18. 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.

  19. 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.

  20. Structure change of 430 stainless steel in the heating process

    Institute of Scientific and Technical Information of China (English)

    Xinzhong Liu; Jingtao Han; Wanhua Yu; Shifeng Dai

    2008-01-01

    The microstructure analysis was employed for the ferritic stainless steel (SUS430) with the carbon content from 0.029wt% to 0.100wt% under the simulated heating process condition. The higher carbon sample (430H) contains the duplex phase micro-structure at the temperature of 1150℃; on the other hand, the lower carbon content sample (430L) does not touch two phase area even at the temperature of 1450℃ and has the single phase ferritic microstrucmre. The carbon content need be well controlled for the 430 ferritic stainless steel since it can significandy affect the heating process curve, and the heating process may not be done in the two phase area due to the uncontrolled carbon content. With the low carbon content and the proper soaking time, the grain size is not sensitive to the heating process temperature and the soaking time. In the present heat treatment experiments, the soaking time is about 10 rain, and the processing parameters can be chosen according to the requ'trernent of the gross energy, the efficiency and the continual forming.

  1. Development of Cast Alumina-Forming Austenitic Stainless Steels

    Science.gov (United States)

    Muralidharan, G.; Yamamoto, Y.; Brady, M. P.; Walker, L. R.; Meyer, H. M., III; Leonard, D. N.

    2016-11-01

    Cast Fe-Ni-Cr chromia-forming austenitic stainless steels with Ni levels up to 45 wt.% are used at high temperatures in a wide range of industrial applications that demand microstructural stability, corrosion resistance, and creep strength. Although alumina scales offer better corrosion protection at these temperatures, designing cast austenitic alloys that form a stable alumina scale and achieve creep strength comparable to existing cast chromia-forming alloys is challenging. This work outlines the development of cast Fe-Ni-Cr-Al austenitic stainless steels containing about 25 wt.% Ni with good creep strength and the ability to form a protective alumina scale for use at temperatures up to 800-850°C in H2O-, S-, and C-containing environments. Creep properties of the best alloy were comparable to that of HK-type cast chromia-forming alloys along with improved oxidation resistance typical of alumina-forming alloys. Challenges in the design of cast alloys and a potential path to increasing the temperature capability are discussed.

  2. Malfunction analysis of OPGW of stainless steel-unit structure

    Institute of Scientific and Technical Information of China (English)

    李星梅; 张素芳; 王旭锋; 乞建勋

    2008-01-01

    Composite fiber optic overhead ground wire (OPGW) is increasingly applied in China’s overhead transmission lines. The stainless steel structure is adopted by most OPGWs as it is very small and easy to match the existing ground wire. The malfunction of OPGW in Beijing-Shanghai Optical Communication Project was analyzed through the chemical composition method and spectrum semi-quantitative method. The analysis indicates that the cable fault was due to the failure of seepage and irregular holes in the steel pipe of the optical unit. The rain water and the watery air entered into the optical units, and the water in turn became ice when temperature dropped. The occurrence of ice led to the acceleration of attenuation of the fiber. The results show that the rupture of stainless steel tube is mainly due to the instability of welding technique. The malfunction of OPGW is due to the local defects of welding seam because of local stress concentration in the manufacturing process.

  3. Magnetic anisotropy of ultrafine 316L stainless steel fibers

    Science.gov (United States)

    Shyr, Tien-Wei; Huang, Shih-Ju; Wur, Ching-Shuei

    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.

  4. 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.

  5. Stainless Steel Microstructural Evolution of Hot-Rolled Clad Plate

    Directory of Open Access Journals (Sweden)

    Hai-Bin LI

    2016-11-01

    Full Text Available The stainless steel microstructure evolution of carbon–stainless-clad steel plate was investigated during vacuum hot-rolling bonding under different deformation conditions. The results show that carbide M2C precipitates in the interior of stainless steel (SS and carbon content increases with rising reduction ratio (ε. The dislocation density of the SS surface (ρI is lower than that of the midst (ρM, and ρI decreases with the rising ε. However, ρM increases first and then decreases with rising ε. The dislocation density of bonding interface decreases due to the increasing size of austenite grain. Furthermore, the dislocation density of the midst is high where the high energy of carbide M2C is concentrated for single-pass rolling, and the quantity of M2C increases with reduction ratio. Moreover, carbide almost disappeared while being transformed into austenite, and only minimal granular carbides were formed after two-pass rolling. Bonding strength increases evidently with rising ε and is inversely proportional to ρI.DOI: http://dx.doi.org/10.5755/j01.ms.22.4.12828

  6. 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.

  7. Stable phases in aged type 321 stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Bentley, J.; Leitnaker, J.M.

    1978-01-01

    X-ray diffraction and Analytical Electron Microscopy have been used to characterize the precipitate phases present in type 321 stainless steel after 17 years of service at approximately 600/sup 0/C. The morphology, crystallography, and orientation relationships with the matrix of the precipitates have been determined along with the chemical composition of several of the phases. Long-term aging of type 321 stainless steel indicates TiC, not M/sub 23/C/sub 6/, is the stable carbide phase. A theory is developed to explain appearance of M/sub 23/C/sub 6/ at intermediate times. The theory also indicates the means for preventing M/sub 23/C/sub 6/ formation and hence sensitization of the steel to intergranular corrosion. The amount of sigma found correlates well with results from shorter time studies. Ti/sub 4/C/sub 2/S/sub 2/ and a complex phosphide-arsenide were also present.

  8. Development of Cast Alumina-Forming Austenitic Stainless Steels

    Science.gov (United States)

    Muralidharan, G.; Yamamoto, Y.; Brady, M. P.; Walker, L. R.; Meyer, H. M., III; Leonard, D. N.

    2016-09-01

    Cast Fe-Ni-Cr chromia-forming austenitic stainless steels with Ni levels up to 45 wt.% are used at high temperatures in a wide range of industrial applications that demand microstructural stability, corrosion resistance, and creep strength. Although alumina scales offer better corrosion protection at these temperatures, designing cast austenitic alloys that form a stable alumina scale and achieve creep strength comparable to existing cast chromia-forming alloys is challenging. This work outlines the development of cast Fe-Ni-Cr-Al austenitic stainless steels containing about 25 wt.% Ni with good creep strength and the ability to form a protective alumina scale for use at temperatures up to 800-850°C in H2O-, S-, and C-containing environments. Creep properties of the best alloy were comparable to that of HK-type cast chromia-forming alloys along with improved oxidation resistance typical of alumina-forming alloys. Challenges in the design of cast alloys and a potential path to increasing the temperature capability are discussed.

  9. Large strain cyclic behavior of metastable austenic stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Geijselaers, H.J.M., E-mail: h.j.m.geijselaers@utwente.nl; Hilkhuijsen, P.; Bor, T.C.; Boogaard, A.H. van den

    2015-04-17

    Metastable austenitic stainless steel will transform to martensite when subjected to mechanical working. In this research an austenitic stainless steel has been subjected to large amplitude strain paths containing a strain reversal. During the tests, apart from the stress and the strain also magnetic induction was measured. From the in situ magnetic induction measurements an estimate of the stress partitioning among the phases is determined. When the strain path reversal is applied at low strains, a classical Bauschinger effect is observed. When the strain reversal is applied at higher strains, a higher flow stress is measured after the reversal compared to the flow stress before reversal. Also a stagnation of the transformation is observed, meaning that a higher strain as well as a higher stress than before the strain path change is required to restart the transformation after reversal. The observed behavior can be explained by a model in which for the martensitic transformation a stress induced transformation model is used. The constitutive behavior of both the austenite phase and the martensite is described by a Chaboche model to account for the Bauschinger effect. Mean-field homogenization of the material behavior of the individual phases is employed to obtain a constitutive behavior of the two-phase composite. The overall applied stress, the stress in the martensite phase and the observed transformation behavior during cyclic shear are very well reproduced by the model simulations.

  10. Investigation on the adsorption of alkoxysilanes on stainless steel.

    Science.gov (United States)

    Huser, Julien; Bistac, Sophie; Brogly, Maurice; Delaite, Christelle; Lasuye, Thierry; Stasik, Bernard

    2013-11-01

    Alkoxysilanes, and mainly trialkoxysilanes, have been widely used as coupling agents on metallic surfaces. They are of interest mainly because they form a water-stable covalent bond with a surface composed of hydroxides. The grafting of these molecules should also give rise to the formation of a siloxane network at the substrate's surface. However, only a few studies examine stainless steel substrate, such as AISI 316L, for which the main difficulty is the low surface reactivity. In order to improve the silane anchoring, a prehydrolysis of the alkoxysilane was performed to transform the methoxy groups into silanol groups. This reaction happened in an aqueous medium and at a controlled pH, which impacted the prehydrolysis efficiency. Curing followed this step, which allows the grafting of the alkoxysilane on stainless steel's surface. Polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS) was performed in order to identify the grafting of the silane molecules. Tests were made to compare the grafting of alkoxysilanes as a function of their functional groups and their prehydrolysis conditions. PM-IRRAS coupled with atomic force microscopy allowed the observation of the grafting of the studied alkoxysilanes. The nature of the remaining functional group (its ability to react with polymer, for example) of the alkoxysilane plays a major role in this process, since its chemical nature influences the grafting mechanism.

  11. Water Lubrication of Stainless Steel using Reduced Graphene Oxide Coating

    Science.gov (United States)

    Kim, Hae-Jin; Kim, Dae-Eun

    2015-11-01

    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.

  12. Salt spray corrosion behaviour of austenitic stainless steel matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Velasco, F.; Abenojar, J.; Torralba, J.M. [Dept. de Ciencia de Materiales e Ing. Metalurgica, Univ. Carlos III de Madrid, Leganes (Spain); Lima, W.M. [Univ. Estadual de Maringa, Maringa PR (Brazil); Marce, R.; Bas, J.A. [AMES S.A., Sant Vicenc dels Horts Barcelona (Spain)

    2001-07-01

    This work deals with the possibility of using intermetallics as addition to P/M stainless steel in order to try to sinter these steels in nitrogen-base atmospheres. 316L was chosen as stainless steel matrix, and two intermetallics (from Ti-Al and Cr-Al binary systems), with a sieve size of less than 80 {mu}m, were added in the amount of 3% vol. to obtain MMCs. Powders were mixed, compacted at 700 MPa by uniaxial compacting, and then sintered at two temperatures (1120 and 1230 C) in five different atmospheres (95N{sub 2}/5H{sub 2}, 80N{sub 2}/20H{sub 2}, 25N{sub 2}/75H{sub 2}, hydrogen and vacuum). A complete microstructural study was carried out both by optical and scanning electron microscopy (SEM). Corrosion tests by salt spray fog were done in order to measure the possible improvements of intermetallic addition on the corrosion behaviour of these steels. SEM studies were also carried out on as corroded samples in order to understand the mechanisms of corrosion. Intermetallics absorb nitrogen from the nitrogen based atmospheres, and they develop a duplex (ferrite / austenite) microstructure when composite materials are sintered in hydrogen and vacuum. These microstructural features explain the results obtained in salt spray fog test. (orig.)

  13. 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.

  14. The Effect of Heat Treatments and Coatings on the Outgassing Rate of Stainless Steel Chambers

    Energy Technology Data Exchange (ETDEWEB)

    Mamum, Md Abdullah A. [Old Dominion Univ., Norfolk, VA (United States); Elmustafa, Abdelmageed A, [Old Dominion Univ., Norfolk, VA (United States); Stutzman, Marcy L. [JLAB, Newport News, VA (United States); Adderley, Philip A. [JLAB, Newport News, VA (United States); Poelker, Matthew [JLAB, Newport News, VA (United States)

    2014-03-01

    The outgassing rates of four nominally identical 304L stainless steel vacuum chambers were measured to determine the effect of chamber coatings and heat treatments. One chamber was coated with titanium nitride (TiN) and one with amorphous silicon (a-Si) immediately following fabrication. One chamber remained uncoated throughout, and the last chamber was first tested without any coating, and then coated with a-Si following a series of heat treatments. The outgassing rate of each chamber was measured at room temperatures between 15 and 30 deg C following bakes at temperatures between 90 and 400 deg C. Measurements for bare steel showed a significant reduction in the outgassing rate by more than a factor of 20 after a 400 deg C heat treatment (3.5 x 10{sup 12} TorrL s{sup -1}cm{sup -2} prior to heat treatment, reduced to 1.7 x 10{ sup -13} TorrL s{sup -1}cm{sup -2} following heat treatment). The chambers that were coated with a-Si showed minimal change in outgassing rates with heat treatment, though an outgassing rate reduced by heat treatments prior to a-Si coating was successfully preserved throughout a series of bakes. The TiN coated chamber exhibited remarkably low outgassing rates, up to four orders of magnitude lower than the uncoated stainless steel. An evaluation of coating composition suggests the presence of elemental titanium which could provide pumping and lead to an artificially low outgassing rate. The outgassing results are discussed in terms of diffusion-limited versus recombination-limited processes.

  15. Investigation of AISI 441 Ferritic Stainless Steel and Development of Spinel Coatings for SOFC Interconnect Applications

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Zhenguo; Xia, Guanguang; Wang, Chong M.; Nie, Zimin; Templeton, Joshua D.; Singh, Prabhakar; Stevenson, Jeffry W.

    2008-05-30

    As part of an effort to develop cost-effective ferritic stainless steel-based interconnects for solid oxide fuel cell (SOFC) stacks, both bare and spinel coated AISI 441 were studied in terms of metallurgical characteristics, oxidation behavior, and electrical performance. The conventional melt metallurgy used for the bulk alloy fabrication leads to significant processing cost reduction and the alloy chemistry with the presence of minor alloying additions of Nb and Ti facilitate the strengthening by precipitation and formation of Laves phase both inside grains and along grain boundaries during exposure in the intermediate SOFC operating temperature range. The Laves phase formed along the grain boundaries also ties up Si and prevents the formation of an insulating silica layer at the scale/metal interface during prolonged exposure. The substantial increase in ASR during long term oxidation due to oxide scale growth suggested the need for a conductive protection layer, which could also minimize Cr evaporation. In particular, Mn1.5Co1.5O4 based surface coatings on planar coupons drastically improved the electrical performance of the 441, yielding stable ASR values at 800ºC for over 5,000 hours. Ce-modified spinel coatings retained the advantages of the unmodified spinel coatings, and also appeared to alter the scale growth behavior beneath the coating, leading to a more adherent scale. The spinel protection layers appeared also to improve the surface stability of 441 against the anomalous oxidation that has been observed for ferritic stainless steels exposed to dual atmosphere conditions similar to SOFC interconnect environments. Hence, it is anticipated that, compared to unmodified spinel coatings, the Ce-modified coatings may lead to superior structural stability and electrical performance.

  16. The effect of nitrogen in sintered atmosphere of the ferritic stainless steels AISI 430L P/M; Efecto del nitrogeno en la atmosfera de sinterizacion del acero inoxiable ferritico AISI 430L P/M

    Energy Technology Data Exchange (ETDEWEB)

    Corpas, F. A.; Ruiz-Roman, J. M.; Codina, S.; Iglesias, F. J.

    2005-07-01

    In this paper, we have studied the nitrogen effects different sintering atmospheres (nitrogen-hydrogen, and dissociate ammonia) on ferritic stainless steels (430L), fabricated by powder metallurgy process. We have carried out a study of the physical (density, porosity and dimensional variation) and mechanical properties (hardness, tensile strength, and lengthening) of the ferritic stainless steels sintered in the afore-mentioned atmospheres, as well as of their behaviour in pitting corrosion. We have studied, also the microstructure of the steels, which depends on the atmosphere used for sintering. (Author) 13 refs.

  17. 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...

  18. Characterization of particle exposure in ferrochromium and stainless steel production.

    Science.gov (United States)

    Järvelä, Merja; Huvinen, Markku; Viitanen, Anna-Kaisa; Kanerva, Tomi; Vanhala, Esa; Uitti, Jukka; Koivisto, Antti J; Junttila, Sakari; Luukkonen, Ritva; Tuomi, Timo

    2016-07-01

    This study describes workers' exposure to fine and ultrafine particles in the production chain of ferrochromium and stainless steel during sintering, ferrochromium smelting, stainless steel melting, and hot and cold rolling operations. Workers' personal exposure to inhalable dust was assessed using IOM sampler with a cellulose acetate filter (AAWP, diameter 25 mm; Millipore, Bedford, MA). Filter sampling methods were used to measure particle mass concentrations in fixed locations. Particle number concentrations and size distributions were examined using an SMPS+C sequential mobile particle sizer and counter (series 5.400, Grimm Aerosol Technik, Ainring, Germany), and a hand-held condensation particle counter (CPC, model 3007, TSI Incorporated, MN). The structure and elemental composition of particles were analyzed using TEM-EDXA (TEM: JEM-1220, JEOL, Tokyo, Japan; EDXA: Noran System Six, Thermo Fisher Scientific Inc., Madison,WI). Workers' personal exposure to inhalable dust averaged 1.87, 1.40, 2.34, 0.30, and 0.17 mg m(-3) in sintering plant, ferrochromium smelter, stainless steel melting shop, hot rolling mill, and the cold rolling mill, respectively. Particle number concentrations measured using SMPS+C varied from 58 × 10(3) to 662 × 10(3) cm(-3) in the production areas, whereas concentrations measured using SMPS+C and CPC3007 in control rooms ranged from 24 × 10(3) to 243 × 10(3) cm(-3) and 5.1 × 10(3) to 97 × 10(3) cm(-3), respectively. The elemental composition and the structure of particles in different production phases varied. In the cold-rolling mill non-process particles were abundant. In other sites, chromium and iron originating from ore and recycled steel scrap were the most common elements in the particles studied. Particle mass concentrations were at the same level as that reported earlier. However, particle number measurements showed a high amount of ultrafine particles, especially in sintering, alloy smelting and melting, and tapping

  19. Antibacterial silver nanocluster/silica composite coatings on stainless steel

    Science.gov (United States)

    Ferraris, M.; Perero, S.; Ferraris, S.; Miola, M.; Vernè, E.; Skoglund, S.; Blomberg, E.; Odnevall Wallinder, I.

    2017-02-01

    A coating made of silver nanocluster/silica composites has been deposited, via a radio frequency (RF) co-sputtering technique, for the first time onto stainless steel (AISI 304L) with the aim to improve its antibacterial properties. Different thermal treatments after coating deposition have been applied in order to optimize the coating adhesion, cohesion and its antibacterial properties. Its applicability has been investigated at realistic conditions in a cheese production plant. The physico-chemical characteristics of the coatings have been analyzed by means of different bulk and surface analytical techniques. Field emission scanning electron microscopy (FESEM), X-ray Photoelectron Spectroscopy (XPS), contact angle measurements and atomic force microscopy (AFM) were employed to assess coating morphology, composition, surface roughness, wetting properties, size and local distribution of the nanoparticles within the coating. Tape tests were used to determine the adhesion/cohesion properties of the coating. The amount and time-dependence of released silver in solutions of acetic acid, artificial water, artificial tap water and artificial milk were determined by means of Atomic Absorption Spectroscopy (AAS). The antibacterial effect of the coating was evaluated at different experimental conditions using a standard bacterial strain of Staphylococcus aureus in compliance with National Committee for Clinical Laboratory Standards (NCCLS) and AATCC 147 standards. The Ahearn test was performed to measure the adhesion of bacteria to the coated stainless steel surface compared with a control surface. The antibacterial coating retained its antibacterial activity after thermal treatment up to 450 °C and after soaking in common cleaning products for stainless steel surfaces used for e.g. food applications. The antibacterial capacity of the coating remained at high levels for 1-5 days, and showed a good capacity to reduce the adhesion of bacteria up to 30 days. Only a few

  20. Failure of Stainless Steel Welds Due to Microstructural Damage Prevented by In Situ Metallography

    Directory of Open Access Journals (Sweden)

    Juan Manuel Salgado Lopez

    Full Text Available Abstract In stainless steels, microstructural damage is caused by precipitation of chromium carbides or sigma phase. These microconstituents are detrimental in stainless steel welds because they lead to weld decay. Nevertheless, they are prone to appear in the heat affected zone (HAZ microstructure of stainless steel welds. This is particularly important for repairs of industrial components made of austenitic stainless steel. Non-destructive metallography can be applied in welding repairs of AISI 304 stainless steel components where it is difficult to ensure that no detrimental phase is present in the HAZ microstructure. The need of microstructural inspection in repairs of AISI 304 is caused because it is not possible to manufacture coupons for destructive metallography, with which the microstructure can be analyzed. In this work, it is proposed to apply in situ metallography as non-destructive testing in order to identify microstructural damage in the microstructure of AISI 304 stainless steel welds. The results of this study showed that the external surface micrographs of the weldment are representative of HAZ microstructure of the stainless steel component; because they show the presence of precipitated metallic carbides in the grain boundaries or sigma phase in the microstructure of the HAZ.

  1. 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.

  2. Evaluation of weld defects in stainless steel 316L pipe using guided wave

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Joon Hyun [School of Mechanical Engineering, Pusan National University, Busan (Korea, Republic of); Lee, Jin Kyung [Dept. of Mechanical Engineering, Dongeui University, Busan (Korea, Republic of)

    2015-02-15

    Stainless steel is a popular structural materials for liquid-hydrogen storage containers and piping components for transporting high-temperature fluids because of its superior material properties such as high strength and high corrosion resistance at elevated temperatures. In general, tungsten inert gas (TIG) arc welding is used for bonding stainless steel. However, it is often reported that the thermal fatigue cracks or initial defects in stainless steel after welding decreases the reliability of the material. The objective of this paper is to clarify the characteristics of ultrasonic guided wave propagation in relation to a change in the initial crack length in the welding zone of stainless steel. For this purpose, three specimens with different artificial defects of 5 mm, 10 mm, and 20 mm in stainless steel welds were prepared. By considering the thickness of s stainless steel pipe, special attention was given to both the L(0,1) mode and L(0,2) mode in this study. It was clearly found that the L(0,2) mode was more sensitive to defects than the L(0,1) mode. Based on the results of the L(0,1) and L(0,2) mode analyses, the magnitude ratio of the two modes was more effective than studying each mode when evaluating defects near the welded zone of stainless steel because of its linear relationship with the length of the artificial defect.

  3. THE EFFECT OF W ON THE REPASSIVATION BEHAVIOR OF Ni-ADDED STAINLESS STEELS

    Institute of Scientific and Technical Information of China (English)

    J.X. Pan; K. Y. Kim

    2005-01-01

    The effect of W on the repassivation behavior of Ni-added stainless steels was investigated with respect to the repassivation rate and the SCC susceptibility. It was found that more stable passive film was formed on the W-modified stainless steels than that of steels without W-modification, and the repassivation rate was faster for W-modified stainless steels in acidic chloride solution (0.5M H2SO4+3.5% Cl-). In neutral chloride solution (1M MgCl2), there were no significant differences on both passivation properties and the repassivation rates for duplex stainless steels,while W-modified austenite stainless steel showed faster repassivation rate. The SCC tests verified that W-modified Ni-added stainless steels exhibited better SCC resistance than steels without W in chloride solution. Moreover, W-modification in higher Ni-added stainless steels exhibited more remarkable SCC resistance than steels with lower Ni content in chloride solution.

  4. Effect of Stress Relief Annealing on Microstructure & Mechanical Properties of Welded Joints Between Low Alloy Carbon Steel and Stainless Steel

    Science.gov (United States)

    Nivas, R.; Das, G.; Das, S. K.; Mahato, B.; Kumar, S.; Sivaprasad, K.; Singh, P. K.; Ghosh, M.

    2017-01-01

    Two types of welded joints were prepared using low alloy carbon steel and austenitic stainless steel as base materials. In one variety, buttering material and weld metal were Inconel 82. In another type, buttering material and weld metal were Inconel 182. In case of Inconel 82, method of welding was GTAW. For Inconel 182, welding was done by SMAW technique. For one set of each joints after buttering, stress relief annealing was done at 923 K (650 °C) for 90 minutes before further joining with weld metal. Microstructural investigation and sub-size in situ tensile testing in scanning electron microscope were carried out for buttered-welded and buttered-stress relieved-welded specimens. Adjacent to fusion boundary, heat-affected zone of low alloy steel consisted of ferrite-pearlite phase combination. Immediately after fusion boundary in low alloy steel side, there was increase in matrix grain size. Same trend was observed in the region of austenitic stainless steel that was close to fusion boundary between weld metal-stainless steel. Close to interface between low alloy steel-buttering material, the region contained martensite, Type-I boundary and Type-II boundary. Peak hardness was obtained close to fusion boundary between low alloy steel and buttering material. In this respect, a minimum hardness was observed within buttering material. The peak hardness was shifted toward buttering material after stress relief annealing. During tensile testing no deformation occurred within low alloy steel and failure was completely through buttering material. Crack initiated near fusion boundary between low alloy steel-buttering material for welded specimens and the same shifted away from fusion boundary for stress relieved annealed specimens. This observation was at par with the characteristics of microhardness profile. In as welded condition, joints fabricated with Inconel 82 exhibited superior bond strength than the weld produced with Inconel 182. Stress relief annealing

  5. Assessment of hydrophobicity and roughness of stainless steel adhered by an isolate of Bacillus cereus from a dairy plant

    Directory of Open Access Journals (Sweden)

    Patrícia Campos Bernardes

    2010-12-01

    Full Text Available The interaction between the surface of stainless steel and Bacillus cereus was studied in terms of the characteristics of interfacial interaction determined from the measurement of the contact angle of the surface of B. cereus and stainless steel in the presence or absence of B. cereus adherence. The microtopographies and the roughness of the surface of stainless steel and stainless steel adhered by B. cereus were evaluated with the help of atomic force microscopy and perfilometry. The strain of B. cereus studied was considered hydrophilic, whereas the stainless steel was considered hydrophobic. The adhesion was not thermodynamically favorable (ΔGadhesion > 0 between the stainless steel and the strain of B. cereus studied. Thus, the interaction between them was not favored by the thermodynamic aspect of adhesion. There was no difference (p > 0.05 in the roughness of the surfaces of stainless steel adhered by B. cereus when analyzed by atomic force microscope and perfilometry.

  6. Assessment of hydrophobicity and roughness of stainless steel adhered by an isolate of Bacillus cereus from a dairy plant

    Science.gov (United States)

    Bernardes, Patrícia Campos; de Andrade, Nélio José; Ferreira, Sukarno Olavo; de Sá, João Paulo Natalino; Araújo, Emiliane Andrade; Delatorre, Deyse Maria Zanom; Luiz, Lívia Maria Pinheiro

    2010-01-01

    The interaction between the surface of stainless steel and Bacillus cereus was studied in terms of the characteristics of interfacial interaction determined from the measurement of the contact angle of the surface of B. cereus and stainless steel in the presence or absence of B. cereus adherence. The microtopographies and the roughness of the surface of stainless steel and stainless steel adhered by B. cereus were evaluated with the help of atomic force microscopy and perfilometry. The strain of B. cereus studied was considered hydrophilic, whereas the stainless steel was considered hydrophobic. The adhesion was not thermodynamically favorable (ΔGadhesion > 0) between the stainless steel and the strain of B. cereus studied. Thus, the interaction between them was not favored by the thermodynamic aspect of adhesion. There was no difference (p > 0.05) in the roughness of the surfaces of stainless steel adhered by B. cereus when analyzed by atomic force microscope and perfilometry. PMID:24031578

  7. A facile preparation route for netlike microstructures on a stainless steel using an ethanol-mediated femtosecond laser irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Bian, Hao; Yang, Qing; Liu, Hewei; Chen, Feng, E-mail: chenfeng@mail.xjtu.edu.cn; Du, Guangqing; Si, Jinhai; Hou, Xun

    2013-03-01

    Netlike or porous microstructures are highly desirable in metal implants and biomedical monitoring applications. However, realization of such microstructures remains technically challenging. Here, we report a facile and environmentally friendly method to prepare netlike microstructures on a stainless steel by taking the full advantage of the liquid-mediated femtosecond laser ablation. An unordered netlike structure and a quasi-ordered array of holes can be fabricated on the surface of stainless steel via an ethanol-mediated femtosecond laser line-scan method. SEM analysis of the surface morphology indicates that the porous netlike structure is in the micrometer scale and the diameter of the quasi-ordered holes ranges from 280 nm to 320 nm. Besides, we find that the obtained structures are tunable by altering the laser processing parameters especially scanning speed. - Highlights: Black-Right-Pointing-Pointer A fabrication method of an unordered netlike structure and a quasi-ordered array of holes on metallic surface is developed. Black-Right-Pointing-Pointer The porous netlike structure is in the micrometer scale. Black-Right-Pointing-Pointer The diameter of the quasi-ordered holes ranges from 280 nm to 320 nm. Black-Right-Pointing-Pointer The obtained structures are tunable by altering the laser scanning speed.

  8. Low pressure powder injection moulding of stainless steel powders

    Energy Technology Data Exchange (ETDEWEB)

    Zampieron, J.V.; Soares, J.P.; Mathias, F.; Rossi, J.L. [Powder Processing Center CCP, Inst. de Pesquisas Energeticas e Nucleares, Sao Paulo, SP (Brazil); Filho, F.A. [IPEN, Inst. de Pesquisas Energeticas e Nucleares, Cidade Univ., Sao Paulo, SP (Brazil)

    2001-07-01

    Low-pressure powder injection moulding was used to obtain AISI 316L stainless steel parts. A rheological study was undertaken using gas-atomised powders and binders. The binders used were based on carnauba wax, paraffin, low density polyethylene and microcrystalline wax. The metal powders were characterised in terms of morphology, particle size distribution and specific surface area. These results were correlated to the rheological behaviour. The mixture was injected in the shape of square bar specimens to evaluate the performance of the injection process in the green state, and after sintering. The parameters such as injection pressure, viscosity and temperature were analysed for process optimisation. The binders were thermally removed in low vacuum with the assistance of alumina powders. Debinding and sintering were performed in a single step. This procedure shortened considerably the debinding and sintering time. (orig.)

  9. Fracture properties evaluation of stainless steel piping for LBB applications

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Y.J.; Seok, C.S.; Chang, Y.S. [Sung Kyun Kwan Univ., Suwon (Korea, Republic of)

    1997-04-01

    The objective of this paper is to evaluate the material properties of SA312 TP316 and SA312 TP304 stainless steels and their associated welds manufactured for shutdown cooling line and safety injection line of nuclear generating stations. A total of 82 tensile tests and 58 fracture toughness tests on specimens taken from actual pipes were performed and the effect of various parameters such as the pipe size, the specimen orientation, the test temperature and the welding procedure on the material properties are discussed. Test results show that the effect of the test temperature on the fracture toughness was significant while the effects of the pipe size and the specimen orientation on the fracture toughness were negligible. The material properties of the GTAW weld metal was in general higher than those of the base metal.

  10. Activating Flux Design for Laser Welding of Ferritic Stainless Steel

    Institute of Scientific and Technical Information of China (English)

    马立; 胡绳荪; 胡宝; 申俊琦; 王勇慧

    2014-01-01

    The behaviors of YAG laser welding process of ferritic stainless steel with activating fluxes were investi-gated in this study. Some conventional oxides, halides and carbonates were applied in laser welding. The results showed that the effect of oxides on the penetration depth was more remarkable. Most activating fluxes improved the penetration more effectively at low power than that at high power. The uniform design was adopted to arrange the formula of multicomponent activating fluxes, showing that the optimal formula can make the penetration depth up to 2.23 times as large as that without flux, including 50%ZrO2, 12.09%CaCO3, 10.43%CaO and 27.48%MgO. Through the high-speed photographs of welding process, CaF2 can minimize the plasma volume but slightly improve the pene-tration capability.

  11. Stainless steel crown aspiration during sedation in pediatric dentistry.

    Science.gov (United States)

    Adewumi, A; Kays, David W

    2008-01-01

    Foreign body aspiration (FBA) causes death in more than 300 children every year in the United States. Morbidity and mortality are increased in children due to narrow airways and immature protective mechanisms. Factors to consider in pediatric dentistry are: (1) the patient's age and behavior; (2) presence and extent of disability; (3) local anesthesia; (4) body positioning; and (5) loose teeth. FBA requires prompt recognition and early treatment to minimize potentially serious and sometimes fatal consequences. The purpose of this case report was to describe the aspiration of a stainless steel crown in a 5-year-old boy during conscious sedation. It also discusses how a prompt and accurate diagnosis, early referral, and immediate treatment helped prevent serious complications.

  12. STRUCTURAL STABILITY OF HIGH NITROGEN AUSTENITIC STAINLESS STEELS

    Directory of Open Access Journals (Sweden)

    Jana Bakajová

    2011-05-01

    Full Text Available This paper deals with the structural stability of an austenitic stainless steel with high nitrogen content. The investigated steel was heat treated at 800°C using different annealing times. Investigation was carried out using light microscopy, transmission electron microscopy and thermodynamic calculations. Three phases were identified by electron diffraction: Cr2N, sigma – phase and M23C6. The thermodynamic prediction is in good agreement with the experimental result. The only is the M23C6 carbide phase which is not thermodynamically predicted. Cr2N is the majority secondary phase and occurs in the form of discrete particles or cells (lamellas of Cr2N and austenite.

  13. Laser cladding of Ni-based alloy on stainless steel

    Institute of Scientific and Technical Information of China (English)

    XUE Chun-fang; TIAN Xin-li; TAN Yong-sheng; WU Zhi-yuan

    2004-01-01

    The coatings on a stainless steel substrate were conducted by laser cladding of Ni-based alloy, using a 5 kW continuous wave CO2 flow transverse laser. SEM, EDX and X-ray diffraction were used to analyze the microstructure and constituent phases of the obtained coatings by laser cladding with direct injection of the powder into the melt pool. Solidification planar, cellular and dendrite structures were observed in Ni-based alloy coating. There exists an optimum metallurgical bond between Ni-based laser cladding layer and the base material. The high hardness of the Ni-based alloy coating is attributed to the presence of M7C3-type carbides (essentially chromium-riched carbide) dispersed in the γ(Ni,Fe) phase matrix.

  14. 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...... are given. Results from the solidification rate measurements had high variations. They do not show an expected correlation between the crack resistance and the solidification rate. The employment of pulsed seam welds is assessed not to be usable in the present measurement method. From evaluation of several...... crack tests, the Weeter spot weld test has been chosen to form a basis for the development of a practicable method to select specific alloys for welding applications. A new test, the Groove weld test was developed, which has reduced the time consumption and lightened the analysis effort considerably...

  15. Ultrasound treatment of centrifugally atomized 316 stainless steel powders

    Science.gov (United States)

    Rawers, James C.; McCune, Robert A.; Dunning, John S.

    1991-12-01

    The Bureau of Mines is studying the surface characteristics of rapidly solidified powders and the potential for surface modification of fine powders prior to consolidation. The surface modification and work hardening of fine powders were accomplished by applying high-energy ultrasound to centrifugally atomized austenitic 316 stainless steel powders suspended in liquid media. Cavitation implosion changed the surface morphology, hammering the surface and occasionally fretting off microchips of work-hardened metal. Ultrasound-cavitation work-hardened metal powder surfaces producing a strained, duplex austenite face-centered cubic (fcc)-martensite body-centered tetragonal (bct) phase structure. The amount of work hardening depended upon the quantity of ultrasound energy used, considering both power level and experimental time. Work hardening was relatively independent of the liquid media used.

  16. Thermal Analysis of 3D Printed 420 Stainless Steel

    Science.gov (United States)

    Pawar, Prathamesh Vijay

    Additive manufacturing opens new possibilities in the manufacturing industry. 3D printing is a form of additive manufacturing. 3D printers will have a significant influence over the industrial market, with extremely positive effects in no time. The main aim of this research is to determine the effect of process parameters of Binder Jet manufactured 420 Stainless Steel (420SS) parts on thermal properties such as thermal conductivity. Different parameters, such as layer thickness, sintering time and sintering temperature were varied. A full factorial design of experiment matrix was made by varying these parameters using two levels. Testing showed that different parameters affected the properties in a different manner. Sintering time was very important property as it changed the composition and arrangement of steel and bronze powder during the sintering process. M-flex 3D metal printer by Ex-one was used to print samples of 420SS.

  17. Beneficially reusing LLRW the Savannah River Site Stainless Steel Program

    Energy Technology Data Exchange (ETDEWEB)

    Boettinger, W.L.

    1993-09-09

    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.

  18. Handbook for tensile properties of austenitic stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Kim, D. W.; Ryu, W. S.; Jang, J. S.; Kim, S. H.; Kim, W. G.; Chung, M. K.; Han, C. H. [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2000-03-01

    Database system of nuclear materials has not been developed and the physical and mechanical properties of materials used in nuclear power plant are not summarized systematically in Korea. Although Korea designs nuclear power plant, many materials used in nuclear power plant are imported because we do not have database system of nuclear material yet and it was hard to select a proper material for the structural materials of nuclear power plant. To develop database system of nuclear materials, data of mechanical, corrosion, irradiation properties are needed. Of theses properties, tensile properties are tested and summarized in this report. Tensile properties of stainless steel used in nuclear reactor internal were investigated. Data between Korea Atomic Energy Research Institute and foreign laboratory were compared to determine the precision of the result. To develope database system, materials, chemical composition, heat treatment, manufacturing process, and grain size were classified. Tensile properties were tested and summarized to use input data of database system. 9 figs., 9 tabs. (Author)

  19. Creep-fatigue interactions in an austenitic stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Majumdar, S; Maiya, P S

    1978-01-01

    A phenomenological model of the interaction between creep and fatigue in Type 304 stainless steel at elevated temperatures is presented. The model is based on a crack-growth equation and an equation governing cavity growth, expressed in terms of current plastic strain and plastic strain rate. Failure is assumed to occur when a proposed interaction equation is satisfied. Various parameters of the equations can be obtained by correlation with continuously cycling fatigue and monotonic creep-rupture test data, without the use of any hold-time fatigue tests. Effects of various wave shapes such as tensile, compressive, and symmetrical hold on the low-cycle fatigue life can be computed by integrating the damage-rate equations along the appropriate loading path. Microstructural evidence in support of the proposed model is also discussed.

  20. Thermal deformation behavior and microstructure of nuclear austenitic stainless steel

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Gleeble-1500D thermal simulation tester was employed in the hot-compression investigation of as-cast nuclear 304 austenitic stainless steel under conditions: deformation temperature 950―1200℃; deformations 30% and 50%; deformation rates 0.01 and 0.1 s?1. The results show that the flow stress decreases with temperature rise under the same strain rate and deformation, that the flow stress increases with deformation under the same temperature and strain rate, and that the flow stress increases with strain rate under the same temperature condition, i.e., work hardening becomes distinct. Materials exhibit better strength-toughness when the strain rate is 0.01 s-1, the deformation is 50%, and the temperature is 1050℃.

  1. The stainless steel crown debate: friend or foe?

    Science.gov (United States)

    Uston, Karen A; Estrella, Maria Regina P

    2011-01-01

    In this article, we will explore the use of the stainless steel crown (SSC) in dentistry today. For the pediatric population, many factors can affect the choice of restoration, such as the variations between primary and permanent tooth morphology, oral environment, and patient selection. The current literature and dentistry guidelines encourage dentists to make an informed decision when determining the restoration recommended for a carious primary molar. To further help educate dental providers on the topic of SSCs the following items will be reviewed: the indications; techniques for placement; advantages; and drawbacks when compared to alternative restorative materials. Regardless of personal opinion, the SSC should continue to be recognized for its efficiency, cost-effectiveness, and successful treatment modality.

  2. Laser milling of martensitic stainless steels using spiral trajectories

    Science.gov (United States)

    Romoli, L.; Tantussi, F.; Fuso, F.

    2017-04-01

    A laser beam with sub-picosecond pulse duration was driven in spiral trajectories to perform micro-milling of martensitic stainless steel. The geometry of the machined micro-grooves channels was investigated by a specifically conceived Scanning Probe Microscopy instrument and linked to laser parameters by using an experimental approach combining the beam energy distribution profile and the absorption phenomena in the material. Preliminary analysis shows that, despite the numerous parameters involved in the process, layer removal obtained by spiral trajectories, varying the radial overlap, allows for a controllable depth of cut combined to a flattening effect of surface roughness. Combining the developed machining strategy to a feed motion of the work stage, could represent a method to obtain three-dimensional structures with a resolution of few microns, with an areal roughness Sa below 100 nm.

  3. Elemental distribution inside a heat treated stainless steel weld.

    CERN Multimedia

    2017-01-01

    The video shows the elemental distribution of Molybdenum (red), Manganese (green) and Chromium (blue) within a 20 μm × 20 μm × 20 μm region of a heat treated stainless steel weld. This data has been collected using 3D Focused Ion Beam Milling and Energy Dispersive X-ray Spectroscopy, an elemental characterisation analysis technique. High resolution (75 nm voxel size) mapping is necessary to gain insight into the distribution of regions with distinct elemental composition (phases), which are shown in purple (sigma) and yellow (delta ferrite) in the video. These features have important implications for the toughness and the magnetic properties of the weld, especially at cryogenic temperatures. The video shows the individual slices which were collected in a direction perpendicular to the weld bead direction, followed by a 3D representation of the gauge volume.

  4. Shape retention of injection molded stainless steel compacts

    Institute of Scientific and Technical Information of China (English)

    LI Yi-min; K.A.Khalil; HUANG Bai-yun

    2005-01-01

    The effects of the binder composition, the powder loading, the thermal properties of feedstocks, and the injection molding parameters on the compact shape retention for metal injection molding 17-4PH stainless steel were investigated. The high-density polyethylene is more effective than ethylene vinyl acetate as a second component of the wax-based binder to retain compact shape due to its higher pyrolytic temperature and less heat of fusion. The compact distortion decreases with increasing the powder loading, molding pressure and molding temperature. There exists an optimal process combination including the powder loading of 68%, molding pressure of 120 MPa and molding temperature of 150 ℃. Under this process condition, the percentage of distorted compacts is the lowest.

  5. Investigation of Machinability Characteristics of AISI 316Ti Stainless Steel

    Directory of Open Access Journals (Sweden)

    Yunus Kayır

    2012-01-01

    Full Text Available In this study, many experiments of machinability were carried out on universal turning lathe. The cutting forces that occur during machining of workpieces were measured. A standard dynamometer was used to measure cutting forces. The Dynamometer were assembled on the lathe efficiently. An apart were designed and machined to assembly the dynamometer. Moreover, AISI 316Ti stainless steel parts were turned by carbide cutting tools coated with TiAlN components. Effects of cutting tools with different radius on cutting forces and surface roughness were investigated by using different cutting parameters. Moreover, machined parts' surface roughness was controlled. The experimental results showed that cutting forces increased with the increasing federate, but the surface roughness decreased with increasing the radius of cutting edge.

  6. Small punch creep test in a 316 austenitic stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Saucedo-Munoz, M. L.; Komazaki, S. I.; Hashida, T.; Lopez-Hirata, V. M.

    2015-03-30

    The small punch creep test was applied to evaluate the creep behavior of a 316 type austenitic stainless steel at temperatures of 650, 675 and 700 degree centigrade. The small punch test was carried out using a creep tester with a specimen size of 10x10x0.3 mm at 650, 675 and 700 degree centigrade using loads from 199 to 512 N. The small punch creep curves show the three stages found in the creep curves of the conventional uniaxial test. The conventional creep relationships which involve parameters such as creep rate, stress, time to rupture and temperature were followed with the corresponding parameters of small punch creep test and they permitted to explain the creep behavior in this steel. The mechanism and activation energy of the deformation process were the grain boundary sliding and diffusion, respectively, during creep which caused the intergranular fracture in the tested specimens. (Author)

  7. Interface nanochemistry effects on stainless steel diffusion bonding

    Science.gov (United States)

    Cox, M. J.; Carpenter, R. W.; Kim, M. J.

    2002-02-01

    The diffusion-bonding behavior of single-phase austenitic stainless steel depends strongly on the chemistry of the surfaces to be bounded. We found that very smooth (0.5 nm root-mean-square (RMS) roughness), mechanically polished and lapped substrates would bond completely in ultrahigh vacuum (UHV) in 1 hour at 1000 °C under 3.5 MPa uniaxial pressure, if the native oxide on the substrates was removed by ion-beam cleaning, as shown by in-situ Auger analysis. No voids were observed in these bonded interfaces by transmission electron microscopy (TEM), and the strength was equal to that of the unbounded bare material. No bond formed between the substrates if in-situ ion cleaning was not used. The rougher cleaned substrates partially bonded, indicating that roughness, as well as native oxides, reduced the bonding kinetics.

  8. Cylindrical Shells Made of Stainless Steel - Investigation of Postbuckling

    Science.gov (United States)

    Stehr, Sebastian; Stranghöner, Natalie

    2017-06-01

    The relevant load case of open thin-walled shells is often wind loading during construction. Because of the missing stabilization effect of the roof they show a very high sensitivity to buckling which results into higher wall thicknesses. As part of the European RFCS research project BiogaSS the Institute for Metal and Lightweight Structures of the University of Duisburg-Essen carried out investigations on open thin-walled tanks made of austenitic and duplex stainless steels under wind load to study a possible economic advantage which might be gained from the consideration of the elastic postbuckling behaviour. This contribution presents not only experimental and numerical results but also first recommendations regarding the range of possible buckling reduction factors which might be incorporated in future revisions of EN 1993-1-6 and EN 1993-4-2.

  9. Carbide precipitation in austenitic stainless steel carburized at low temperature

    Energy Technology Data Exchange (ETDEWEB)

    Ernst, F. [Department of Materials Science and Engineering, Case Western Reserve University, Cleveland, OH 44106-7204 (United States)]. E-mail: frank.ernst@case.edu; Cao, Y. [Department of Materials Science and Engineering, Case Western Reserve University, Cleveland, OH 44106-7204 (United States); Michal, G.M. [Department of Materials Science and Engineering, Case Western Reserve University, Cleveland, OH 44106-7204 (United States); Heuer, A.H. [Department of Materials Science and Engineering, Case Western Reserve University, Cleveland, OH 44106-7204 (United States)

    2007-04-15

    Low-temperature gas-phase carburization can significantly improve the surface mechanical properties and corrosion resistance of austenitic stainless steel by generating a single-phase 'case' with concentrations of interstitially dissolved carbon exceeding the equilibrium solubility limit by orders of magnitude. Upon prolonged treatment, however, carbides (mostly {chi}, M{sub 5}C{sub 2}) can precipitate and degrade the properties. High-resolution and spatially resolved analytical transmission electron microscopy revealed the precise carbide-austenite orientation relationship, a highly coherent interface, and that precipitation only occurs when (i) the carbon-induced lattice expansion of the austenite has reached a level that substantially reduces volume-misfit stress and (ii) diffusional transport of nickel, chromium, and iron - enhanced by structural defects - can locally reduce the nickel concentration to the solubility limit of nickel in {chi}-carbide.

  10. Anomalous kinetics of lath martensite formation in stainless steel

    DEFF Research Database (Denmark)

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

    2015-01-01

    isochronal cooling that transformation rate maxima occur, which are interrupted by virtually transformation free temperature regions. Microscopy confirms martensite formation after athermal nucleation of clusters followed by their time dependent growth. The observations are interpreted in terms of time...... dependent autocatalytic lath martensite formation followed by mechanical stabilisation of austenite during the transformation process.......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...

  11. An Overview of Irradiation Creep of Stainless Steels

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Woo Seog [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    This paper reviewed systematically a state-of-art of irradiation creep for stainless steels to provide a background information for performing irradiation creep tests and establishing the creep model for advanced domestic steels effectively. An irradiation creep model of SFR core materials is necessary to apply to the fuel cladding and assembly materials of domestic SFR reactor system. The document of in-reactor irradiation creep has been obtained by investing a long time and large-scale cost using limited experimental research reactors. This paper will provide the knowledge to understand the irradiation creep and to obtain the background information of advanced domestic steels, so that it hopes to practically apply for timely producing the documents of irradiation creep of advanced domestic steels necessary for the national SFR program.

  12. Electrochemical Evaluation of Corrosion Inhibitors to Austenistic Stainless Steel

    Directory of Open Access Journals (Sweden)

    Yosmari Adames Montero

    2014-03-01

    Full Text Available The use of corrosion inhibitors is one of the most universal methods, and diffused for the protection ofmetals, because they reduce substantially the corrosion losses when they are added in smallconcentrations. At the present work it was carried out the electrochemical tests evaluation of twoinhibitors, A and B, to be used in the chemical cleanings for trays of heat interchanger, which aresuffering thickness losses until its perforation. By the chemical composition analysis, it wasdemonstrated that the metal is an austenistic stainless steel and by electrochemical tests of linearpolarization resistance, electrochemical noise and cyclic sweep, were demonstrated the localizedcorrosion. The best efficiency of the inhibitor A was obtained with one and two percent concentration,while the inhibitor B shows values efficiency near 95% with two percent concentration.

  13. The Study of Plasma Nitriding of AISI304 Stainless Steel

    Institute of Scientific and Technical Information of China (English)

    WANG Liang; JI Shi-jun; GAO Yu-zhou; SUN Jun-cai

    2004-01-01

    This paper presents results on the plasma nitriding of AISI 304 stainless steel at different temperatures in NH 3 gas. The working pressure was 100~200 Pa and the discharge voltage was 700~800V. The phase of nitrided layer formed on the surface was confirmed by X-ray diffraction. The hardness of the samples was measured by using a Vickers microhardness tester with the load of 50g. After nitriding at about 400 ℃ for two hours a nitrided layer consisting of single γN phase with thickness of 5μm was obtained. Microhardness measurements showed significant increase in the hardness from 240 HV (for untreated samples) up to 950 HV (for nitrided samples at temperature of 420℃). The phase composition, the thickness, the microstructure and the surface topography of the nitrided layer as well as its properties depend essentially on the process parameters.

  14. Crevice and pitting corrosion behavior of stainless steels in seawater

    Energy Technology Data Exchange (ETDEWEB)

    Zaragoza-Ayala, A.E.; Orozco-Cruz, R. [Univ. Autonoma de Campeche (Mexico). Programa de Corrosion del Golfo de Mexico

    1999-11-01

    Pitting and crevice corrosion tests in natural seawater were performed on a series of stainless steels (i.e., S31603, N08904, S32304, S31803, S32520, N08925 and S31266) in order to determine their resistance to these types of localized corrosion. Open circuit potential (OCP) measurements for these alloys show for short exposure times an ennoblement in the OCP. After a certain time, occasional fall and rise in the OCP values was observed, which can be related to nucleation and repassivation of pits and/or crevices on the metal surface. Analysis of the electrochemical behavior and microscopic observations shows that only S31603 and S32304 alloys were susceptible to crevice and pitting corrosion, whereas the remaining alloys exhibited good resistance. Pitting potentials determined by the potentiodynamic technique also show S3 1603 and S32304 are susceptible to pitting corrosion under the experimental conditions used in this work.

  15. Welding of titanium and stainless steel using the composite insert

    Science.gov (United States)

    Cherepanov, A. N.; Mali, V. I.; Orishich, A. M.; Malikov, A. G.; Drozdov, V. O.; Malyutina, Y. N.

    2016-11-01

    The paper concerns the possibility of obtaining a lasting permanent joint of dissimilar metals: technically pure titanium and stainless steel using laser welding and an intermediate composite insert. The insert was a four-layer composition of plates of steel, copper, niobium, and titanium welded by explosion. The material layers used in the insert prevented the molten steel and titanium from mixing, which excluded the formation of brittle intermetallic compounds, such as FeTi and Fe2Ti. The optimization of explosion welding parameters provided a high quality of the four-layer composition and the absence of defects in the area of the joint of insert plates. The results of strength tests showed that values of the ultimate strength and yield of the permanent joint with the composite insert welded by explosion are comparable to the strength characteristics of titanium.

  16. Electromagnetic non-destructive technique for duplex stainless steel characterization

    Science.gov (United States)

    Rocha, João Vicente; Camerini, Cesar; Pereira, Gabriela

    2016-02-01

    Duplex stainless steel (DSS) is a two-phase (ferrite and austenite) material, which exhibits an attractive combination of mechanical properties and high corrosion resistance, being commonly employed for equipment of petrochemical plants, refining units and oil & gas platforms. The best properties of DSS are achieved when the phases are in equal proportions. However, exposition to high temperatures (e.g. welding process) may entail undesired consequences, such as deleterious phases precipitation (e.g. sigma, chi) and different proportion of the original phases, impairing dramatically the mechanical and corrosion properties of the material. A detailed study of the magnetic behavior of DSS microstructure with different ferrite austenite ratios and deleterious phases content was accomplished. The non destructive method evaluates the electromagnetic properties changes in the material and is capable to identify the presence of deleterious phases into DSS microstructure.

  17. Weld Properties of a Free Machining Stainless Steel

    Energy Technology Data Exchange (ETDEWEB)

    J. A. Brooks; S. H. Goods; C. V. Robino

    2000-08-01

    The all weld metal tensile properties from gas tungsten arc and electron beam welds in free machining austenitic stainless steels have been determined. Ten heats with sulfur contents from 0.04 to 0.4 wt.% and a wide range in Creq/Nieq ratios were studied. Tensile properties of welds with both processes were related to alloy composition and solidification microstructure. The yield and ultimate tensile strengths increased with increasing Creq/Nieq ratios and ferrite content, whereas the ductility measured by RA at fracture decreased with sulfur content. Nevertheless, a range in alloy compositions was identified that provided a good combination of both strength and ductility. The solidification cracking response for the same large range of compositions are discussed, and compositions identified that would be expected to provide good performance in welded applications.

  18. Electrodeposition of dicalcium phosphate dihydrate coatings on stainless steel substrates

    Indian Academy of Sciences (India)

    Belavalli E Prasad; P Vishnu Kamath

    2013-06-01

    Cathodic reduction of an aqueous solution containing dissolved calcium and phosphate ions results in the deposition of micrometer thick CaHPO4.2H2O (dicalcium phosphate dihydrate) coatings on stainless steel substrates. The coating obtained at a low deposition current (8 mA cm-2) comprises lath-like crystallites oriented along 020. The 020 crystal planes are non-polar and have a low surface energy. At a high deposition current (12 mA cm-2), platelets oriented along 12$\\bar{1}$ are deposited. CaHPO4.2H2O is an important precursor to the nucleation of hydroxyapatite, the inorganic component of bones. Differently oriented CaHPO4.2H2Ocoatings transform to hydroxyapatite with different kinetics, the transformation being more facile when the coating is oriented along 12$\\bar{1}$. These observations have implications for the development of electrodeposited biocompatible coatings for metal endoprostheses for medical applications.

  19. Influence of Simulated Outside-Reactor Irradiation on Anticorrosion Property of Austenitic Stainless Steel

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The influence of γ-ray irradiation on the properties of inside-reactor stainless steel structures was studied by simulating the working condition of pressurized water reactor (PWR) first circuit and the outside-reactor γ-ray irradiation. The result shows that the simulated outside-reactor irradiation (irradiation dose 4.4 × 104 Gy) has no influence on anticorrosion properties of solutionized SUS304 austenitic stainless steel, including intergranular corrosion (IC) and stress corrosion cracking (SCC). Anticorrosion properties (IC, SCC) of sensitized SUS304 austenitic stainless steel are reduced by simulated outside-reactor irradiation. The longer the sensitizedtime is, the more obvious the influence is.

  20. Tool degradation during sheet metal forming of three stainless steel alloys

    DEFF Research Database (Denmark)

    Wadman, Boel; Nielsen, Peter Søe; Wiklund, Daniel

    2010-01-01

    To evaluate if changes in tool design and tool surface preparation are needed when low-Ni stainless steels are used instead of austenitic stainless steels, the effect on tool degradation in the form of galling was investigated with three different types of stainless steel. The resistance to tool...... degradation was analysed by the strip reduction test, simulating resistance to galling during ironing. It was shown that the surface condition of both the tools and the sheet metal was of importance to the galling resistance. Numerical simulations of the experimental tests were compared with the experimental...

  1. Comparison of the thermoelastic phenomenon expressions in stainless steels during cyclic loading

    Directory of Open Access Journals (Sweden)

    M. Sapieta

    2017-01-01

    Full Text Available The main purpose of this paper is to compare the thermoelastic stress in specimens of stainless steel. As material specimens we chose stainless steel of AISI 304, AISI 316Ti and AISI 316L types. The specimens were cyclically loaded with three-point bending. The whole process was recorded using an infrared camera. The thermal differences that occurred during the test were evaluated based on the thermoelastic stress equations. Subsequently, stress distributions in the specimens were compared for different types of stainless steel.

  2. An Electrochemical Study on the Corrosion Inhibition of Stainless Steel by Polyaniline Film

    Institute of Scientific and Technical Information of China (English)

    Hao WANG; Lin NIU; Qiu Hong LI; Su Xiang WU; Feng Hua WEI

    2004-01-01

    Polyaniline(PANI) film was electrosynthesized on 304 stainless steel by cyclic voltammetry using aqueous oxalic acid as supporting electrolyte. The potential sweep rates were changed to achieve the PANI film with different thickness and structures. Protective properties of the PANI film for corrosion of stainless steel in 3% NaCl aqueous solution were investigated by monitoring potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS).The results showed that the PANI film which was formed with lower sweep rate led to more positive shift of corrosion potential and greater charge transfer resistance, reflecting higher inhibition for corrosion of the stainless steel.

  3. Measurement of the magnetic moment in a cold worked 304 stainless steel using HTS SQUID

    Energy Technology Data Exchange (ETDEWEB)

    Park, D.G. [Korea Atomic Energy Research Institute, Yusung P.O. Box 105, Taejon 305-600 (Korea, Republic of)], E-mail: dwkim1@kaeri.re.kr; Kim, D.W.; Angani, C.S. [Korea Atomic Energy Research Institute, Yusung P.O. Box 105, Taejon 305-600 (Korea, Republic of); Timofeev, V.P. [B. Verkin Institute for Low Temperature Physics and Engineering, National Academy of Science of Ukraine, 47 Lenin Ave, Kharkov 61103 (Ukraine); Cheong, Y.M. [Korea Atomic Energy Research Institute, Yusung P.O. Box 105, Taejon 305-600 (Korea, Republic of)

    2008-10-15

    The magnetic properties of stainless steel have been investigated using a radio frequency (RF) high-temperature superconductivity (HTS) SQUID (Superconducting QUantum Interference Device)-based susceptometer. The nuclear grade 304 stainless steel is nonmagnetic at a normal condition but it changes to a partially ferromagnetic state associated with martensitic transformation under a plastic deformation. The magnetic moment of the 304 stainless steels was increased with an increasing cold work rate, and decreased with an increasing annealing temperature. The change of mechanical properties such as yield strength and ultimate tensile strength (UTS) are also analyzed in terms of deformation-induced martensitic transformation.

  4. Regular subwavelength surface structures induced by femtosecond laser pulses on stainless steel.

    Science.gov (United States)

    Qi, Litao; Nishii, Kazuhiro; Namba, Yoshiharu

    2009-06-15

    In this research, we studied the formation of laser-induced periodic surface structures on the stainless steel surface using femtosecond laser pulses. A 780 nm wavelength femtosecond laser, through a 0.2 mm pinhole aperture for truncating fluence distribution, was focused onto the stainless steel surface. Under different experimental condition, low-spatial-frequency laser-induced periodic surface structures with a period of 526 nm and high-spatial-frequency laser-induced periodic surface structures with a period of 310 nm were obtained. The mechanism of the formation of laser-induced periodic surface structures on the stainless steel surface is discussed.

  5. General and Localized corrosion of Austenitic and Borated Stainless Steels in Simulated Concentrated Ground Waters

    Energy Technology Data Exchange (ETDEWEB)

    D. Fix; J. Estill; L. Wong; R. Rebak

    2004-05-28

    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.

  6. General and Localized Corrosion of Austenitic And Borated Stainless Steels in Simulated Concentrated Ground Waters

    Energy Technology Data Exchange (ETDEWEB)

    Estill, J C; Rebak, R B; Fix, D V; Wong, L L

    2004-03-11

    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.

  7. An esthetic technique for veneering anterior stainless steel crowns with composite resin.

    Science.gov (United States)

    Wiedenfeld, K R; Draughn, R A; Welford, J B

    1994-01-01

    The restoration of primary anterior teeth presents complicated esthetic and retention problems to the clinician. A technique is described for the chairside veneering of composite resin to stainless steel crowns, which results in well contoured restorations with superior durability and esthetics. A trimmed and fitted stainless steel crown can be veneered in three to five minutes. This provides the adaptability and gingival contour benefits of the stainless steel crown in conjunction with the cosmetics of the composite facings. The technique described produced composite veneers with a mean sheer bond strength of 3520 PSI (24.4 Mpa).

  8. 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.

  9. Numerical modeling and optimization of machining duplex stainless steels

    Directory of Open Access Journals (Sweden)

    Rastee D. Koyee

    2015-01-01

    Full Text Available The shortcomings of the machining analytical and empirical models in combination with the industry demands have to be fulfilled. A three-dimensional finite element modeling (FEM introduces an attractive alternative to bridge the gap between pure empirical and fundamental scientific quantities, and fulfill the industry needs. However, the challenging aspects which hinder the successful adoption of FEM in the machining sector of manufacturing industry have to be solved first. One of the greatest challenges is the identification of the correct set of machining simulation input parameters. This study presents a new methodology to inversely calculate the input parameters when simulating the machining of standard duplex EN 1.4462 and super duplex EN 1.4410 stainless steels. JMatPro software is first used to model elastic–viscoplastic and physical work material behavior. In order to effectively obtain an optimum set of inversely identified friction coefficients, thermal contact conductance, Cockcroft–Latham critical damage value, percentage reduction in flow stress, and Taylor–Quinney coefficient, Taguchi-VIKOR coupled with Firefly Algorithm Neural Network System is applied. The optimization procedure effectively minimizes the overall differences between the experimentally measured performances such as cutting forces, tool nose temperature and chip thickness, and the numerically obtained ones at any specified cutting condition. The optimum set of input parameter is verified and used for the next step of 3D-FEM application. In the next stage of the study, design of experiments, numerical simulations, and fuzzy rule modeling approaches are employed to optimize types of chip breaker, insert shapes, process conditions, cutting parameters, and tool orientation angles based on many important performances. Through this study, not only a new methodology in defining the optimal set of controllable parameters for turning simulations is introduced, but also

  10. 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.

  11. Impact Tensile Testing of Stainless Steels at Various Temperatures

    Energy Technology Data Exchange (ETDEWEB)

    D. K. Morton

    2008-03-01

    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 during accidental drop events. Mechanical characteristics of these base materials and their welds under dynamic loads in the strain rate range of concern (1 to 300 per second) are not well documented. However, research is being performed at the Idaho National Laboratory to quantify these characteristics. The work presented herein discusses tensile impact testing of dual-marked 304/304L and 316/316L stainless steel material specimens. Both base material and welded material specimens were tested at -20 oF, room temperature, 300 oF, and 600 oF conditions. Utilizing a drop weight impact test machine and 1/4-inch and 1/2-inch thick dog bone-shaped test specimens, a strain rate range of approximately 4 to 40 per second (depending on initial temperature conditions) was achieved. Factors were determined that reflect the amount of increased strain energy the material can absorb due to strain rate effects. Using the factors, elevated true stress-strain curves for these materials at various strain rates and temperatures were generated. By incorporating the strain rate elevated true stress-strain material curves into an inelastic finite element computer program as the defined material input, significant improvement in the accuracy of the computer analyses was attained. However, additional impact testing is necessary to achieve higher strain rates (up to 300 per second) before complete definition of strain rate effects can be made for accidental drop events and other similar energy-limited impulsive loads. This research approach, using impact testing and a total energy analysis methodology to quantify strain rate effects, can be applied to many other materials used in government and industry.

  12. Penentuan konsentrasi stainless steel 316L dan kobalt kromium remanium GM-800 pada uji GPMT

    Directory of Open Access Journals (Sweden)

    Ikmal Hafizi

    2016-12-01

    Full Text Available Concentration determination of stainless steel 316L and cobalt chromium remanium GM - 800 on GPMT test. Dentistry had used metals such as cobalt chromium and stainless steel in maxillofacial surgery, cardiovascular, and as a dental material. 316L stainless steel is austenistic stainless steel which has low carbon composition to improve the corrosion resistance as well as the content of molybdenum in the material. Cobalt chromium (CoCr is a cobaltbased alloy with a mixture of chromium. Density of a metal cobalt chromium alloy is about 8-9 g/cm3 that caused metal interference relatively mild. Remanium GM-800 is one type of a cobalt chromium alloy with the advantages of having high resistance to fracture and high modulus of elasticity. This study aims to determine the exact concentration used in 316L stainless steel and cobalt chromium GM-800 as the GPMT test material. Subjects were cobalt chromium Remanium GM-800 and 316L stainless steel concentration of 5%, 10%, 20%, 40% and 80%. Patch containing stainless steel or cobalt chromium paste was af xed for 24 hours each on three experimental animals, then the erythema and edema were observed using the Magnusson and Kligman scale. In the study, concentration of 5% is the concentration recommended for stainless steel 316L and cobalt chromium GM-800 as material in challenge phase GPMT test, while the concentration of 40% is the concentration recommended for stainless steel 316L and cobalt chromium GM-800 in the induction phase. ABSTRAK Dunia kedokteran gigi banyak menggunakan logam pada pembedahan maxillofacial, cardiovascular, dan sebagai material dental. Logam yang banyak digunakan antara lain adalah kobalt kromium dan stainless steel. Stainless steel 316L merupakan austenistic stainless steel yang memiliki komposisi karbon rendah sehingga dapat meningkatkan ketahanan terhadap korosi sama halnya dengan kandungan molybdenum pada material tersebut. Kobalt kromium (CoCr adalah cobalt-based alloy dengan

  13. Optimization of Thermochemical, Kinetic, and Electrochemical Factors Governing Partitioning of Radionuclides During Melt Decontamination of Radioactively Contaminated Stainless Steel

    Energy Technology Data Exchange (ETDEWEB)

    VAN DEN AVYLE,JAMES A.; MALGAARD,DAVID; MOLECKE,MARTIN; PAL,UDAY B.; WILLIAMSON,RODNEY L.; ZHIDKOV,VASILY V.

    1999-06-15

    The Research Objectives of this project are to characterize and optimize the use of molten slags to melt decontaminate radioactive stainless steel scrap metal. The major focus is on optimizing the electroslag remelting (ESR) process, a widely used industrial process for stainless steels and other alloys, which can produce high quality ingots directly suitable for forging, rolling, and parts fabrication. It is our goal to have a melting process ready for a DOE D and D demonstration at the end of the third year of EMSP sponsorship, and this technology could be applied to effective stainless steel scrap recycle for internal DOE applications. It also has potential international applications. The technical approach has several elements: (1) characterize the thermodynamics and kinetics of slag/metal/contaminate reactions by models and experiments, (2) determine the capacity of slags for radioactive containment, (3) characterize the minimum levels of residual slags and contaminates in processed metal, and (4) create an experimental and model-based database on achievable levels of decontamination to support recycle applications. Much of the experimental work on this project is necessarily focused on reactions of slags with surrogate compounds which behave similar to radioactive transuranic and actinide species. This work is being conducted at three locations. At Boston University, Prof. Uday Pal's group conducts fundamental studies on electrochemical and thermochemical reactions among slags, metal, and surrogate contaminate compounds. The purpose of this work is to develop a detailed understanding of reactions in slags through small laboratory scale experiments and modeling. At Sandia, this fundamental information is applied to the design of electroslag melting experiments with surrogates to produce and characterize metal ingots. In addition, ESR furnace conditions are characterized, and both thermodynamic and ESR process models are utilized to optimize the process

  14. Controlling the synergetic effects in (3-aminopropyl) trimethoxysilane and (3-mercaptopropyl) trimethoxysilane coadsorption on stainless steel surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Vuori, Leena, E-mail: leena.vuori@tut.fi [Surface Science Laboratory, Optoelectronics Research Centre, Tampere University of Technology, P.O. Box 692, FI-33101 Tampere (Finland); Hannula, Markku; Lahtonen, Kimmo; Jussila, Petri; Ali-Löytty, Harri; Hirsimäki, Mika [Surface Science Laboratory, Optoelectronics Research Centre, Tampere University of Technology, P.O. Box 692, FI-33101 Tampere (Finland); Pärna, Rainer; Nõmmiste, Ergo [Institute of Physics, University of Tartu, Riia 142, EE-51014 Tartu (Estonia); Valden, Mika [Surface Science Laboratory, Optoelectronics Research Centre, Tampere University of Technology, P.O. Box 692, FI-33101 Tampere (Finland)

    2014-10-30

    Graphical abstract: - Highlights: • We studied the coadsorption of APS and MPS silanes on stainless steel. • Well-ordered monolayers of APS/MPS were fabricated with liquid phase deposition. • SR-PES enabled the determination of the APS and MPS orientation. • Inelastic electron background analysis was used to determine overlayer thicknesses. • The APS/MPS surface concentration is non-equal to the solution concentration. - Abstract: A versatile and economic method of preparing covalently-bound and uniform bifunctional silane monolayers on stainless steel is presented. Stainless steel is first electrochemically hydroxylated to enable the formation of a bifunctional overlayer via simultaneous liquid-phase deposition of two organofunctional silanes: (3-aminopropyl)trimethoxysilane (APS) and (3-mercaptopropyl)trimethoxysilane (MPS). The chemical composition, in-depth distribution, molecular orientation and chemical bonds in APS, MPS and APS/MPS layers over a range of APS/MPS mixing ratios are studied with synchrotron radiation mediated photoelectron spectroscopy (SR-PES), conventional X-ray photoelectron spectroscopy (XPS) and energy filtered X-ray photoemission electron microscopy (EF-XPEEM). Inelastic electron energy-loss background (IEEB) analysis is employed to determine the surface morphology of the silanized samples. Coadsorption is shown to produce a covalently-bound and highly ordered monolayer with a controllable MPS surface concentration within APS matrix. The results show evidence of strong synergistic effects during simultaneous adsorption of MPS and APS from liquid phase. While the uptake of MPS alone is low, the coadsorption of MPS and APS strongly enhances both the uptake of MPS and ordering in the APS/MPS overlayer. Results from PES, EF-XPEEM and IEEB analysis reveal that the surface is predominantly covered by a well-ordered APS/MPS monolayer with only slight degree of clustering. Clustering is attributed to different hydrolysis rates in

  15. Au-coated ZnO nanorods on stainless steel fiber for self-cleaning solid phase microextraction-surface enhanced Raman spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Li, Bo; Shi, Yu-e; Cui, Jingcheng; Liu, Zhen; Zhang, Xiaoli; Zhan, Jinhua, E-mail: jhzhan@sdu.edu.cn

    2016-06-07

    Solid phase microextraction-surface enhanced Raman spectroscopy (SPME–SERS), combining the pretreatment and determination functions, has been successfully used in environmental analysis. In this work, Au-coated ZnO nanorods were fabricated on stainless steel fiber as a self-cleaning SERS-active SPME fiber. The ZnO nanorods grown on stainless steel fiber were prepared via a simple hydrothermal approach. Then the obtained nanostructures were decorated with Au nanoparticles through ion-sputtering at room temperature. The obtained SERS-active SPME fiber is a reproducible sensitivity sensor. Taking p-aminothiophenol as the probe molecule, the RSD value of the SERS-active SPME fiber was 8.9%, indicating the fiber owned good uniformity. The qualitative and quantitative detection of crystal violet and malachite green was also achieved. The log–log plot of SERS intensity to crystal violet and malachite green concentration showed a good linear relationship. Meanwhile, this SERS-active SPME fiber can achieve self-cleaning owning to the excellent photocatalytic performance of ZnO nanorods. Crystal violet was still successfully detected even after five cycles, which indicated the high reproducibility of this SERS-active SPME fiber. - Graphical abstract: Au-coated ZnO NRs on stainless steel fiber were used as SERS-active SPME fiber with good extraction effect, high SERS sensitivity. Self-cleaning function of the fiber was achieved based on the photocatalytic degradation property of ZnO nanorods by UV irradiation. - Highlights: • Au-coated ZnO nanorods on stainless steel fiber as a SERS-active SPME fiber was fabricated. • The SERS-active SPME fiber can directly extract and detect the crystal violet and malachite green. • The SERS-active SPME fiber owns good extraction effect, and high SERS sensitivity. • Self-cleaning property of the fiber were achieved based on the photocatalytic degradation property of ZnO.

  16. Fracture behavior of 304 stainless steel coatings by cold gas dynamic spray

    Institute of Scientific and Technical Information of China (English)

    Wei HAN; Xianming MENG; Jie ZHAO; Junbao ZHANG

    2011-01-01

    304 stainless steel coating was deposited on the Interstitial-Free steel substrate by cold gas dynamic spraying (CGDS). Three-point bending test of the cold sprayed 304 stainless steel coating was tested by SHIMADZU electro-hydraulic servo-controlled fatigue testing machine and the fracture morphology was examined by scanning electron microscopy. The results showed that the fracture behavior of the cold sprayed 304 stainless steel coating was brittleness fracture. The crack in the coating occurred in the interfaces between particles and the crack extended to the internal of the coating with the increase of the load. When the crack has extended to the combination interface between coating and substrate, the crack extended to the two sides. The microstructure and mechanical property of the cold sprayed 304 stainless steel coating have been optimized after heat treatment.

  17. A delayed hypersensitivity reaction to a stainless steel crown: a case report.

    Science.gov (United States)

    Yilmaz, A; Ozdemir, C E; Yilmaz, Y

    2012-01-01

    Stainless steel crowns are commonly used to restore primary or permanent teeth in pediatric restorative dentistry. Here, we describe a case of a delayed hypersensitivity reaction, which manifested itself as perioral skin eruptions, after restoring the decayed first permanent molar tooth of a 13-year-old Caucasian girl with a preformed stainless steel crown. The eruptions completely healed within one week after removal of the stainless steel crown. The decayed tooth was then restored with a bis-acryl crown and bridge. Since no perioral skin eruptions occurred during the six-month follow-up, we presume that the cause of the perioral skin eruptions was a delayed hypersensitivity reaction, which was triggered by the nickel in the stainless steel crown.

  18. Wear resistance and corrosion resistance of VCp particle reinforced stainless steel composites

    Institute of Scientific and Technical Information of China (English)

    YAO Xiu-rong; HAN Jie-cai; ZUO Hong-bo; LIU Zhao-jing; LI Feng-zhen; REN Shan-zhi

    2005-01-01

    The VCp reinforced stainless steel composite was produced by in-situ reaction casting. The composite was tested for its wear resistance under the wet abrasive condition and corrosion resistance, compared with the wear-resistant white iron and stainless steel. The results show that the wear resistance of the composite is slightly inferior to that of the white iron, but much better than that of the stainless steel under the wet grinding abrasive condition. The corrosion resistance of the composite is much better than that of the white iron in the acid medium,and a little worse than that of the stainless steel. Thus the composite exhibits superior properties of wear resistance and corrosion resistance.

  19. Martensitic stainless steel seamless linepipe with superior weldability and CO{sub 2} corrosion resistance

    Energy Technology Data Exchange (ETDEWEB)

    Miyata, Y.; Kimura, M.; Koseki, T.; Toyooka, T.; Murase, F. [Kawasaki Steel Corp., Handa, Aichi (Japan)

    1997-08-01

    Two types of new martensitic stainless steel with good weldability and superior corrosion resistance have been developed for line pipe application. Both steels are suitable for welding without preheating owing to lowering C and N contents, and they show good low temperature toughness in welds without PWHT. One is applied to sweet environments. It gives better resistance to CO{sub 2} corrosion than the 13Cr martensitic stainless steel for OCTG. Lowering C and addition of Ni contribute to reduction of general corrosion rate in the CO{sub 2} environment. The addition of Cu improves the pitting resistance. The other is applied to light sour environments. It gives good SSC resistance in welds owing to the improvement of the pitting resistance due to Mo addition. The seamless pipes of these martensitic stainless steels are applicable as substitutes for a part of duplex stainless steel flow lines.

  20. Effect of Grain Size on Mechanical Properties of Nickel-Free High Nitrogen Austenitic Stainless Steel

    Institute of Scientific and Technical Information of China (English)

    LI Hua-bing; JIANG Zhou-hua; ZHANG Zu-rui; YANG Yan

    2009-01-01

    The fine grained structures of nickel-free high nitrogen austenitic stainless steels had been obtained by means of cold rolling and subsequent annealing.The relationship between microstructure and mechanical properties and gain size of nickel-free high nitrogen austenitic stainless steels was examined.High strength and good ductility of the steel were found.In the grain size range,the Hall-Petch dependency for yield stress,tensile strength,and hardness was valid for grain size ranges for the nickel-free high nitrogen austenitic stainless steel.In the present study,the ductility of cold rolled nickel-free high nitrogen austenitic stainless steel decreased with annealing time when the grain size was refined.The fracture surfaces of the tensile specimens in the grain size range were covered with dimples as usually seen in a ductile fracture mode.

  1. 78 FR 21596 - Drawn Stainless Steel Sinks From the People's Republic of China: Countervailing Duty Order

    Science.gov (United States)

    2013-04-11

    ... welding operation to form one unit are covered by the scope of the order. Drawn stainless steel sinks are... may sometimes be referred to as ``zero radius'' or ``near zero radius'' sinks. The products covered...

  2. Nanosized controlled surface pretreatment of biometallic alloy 316L stainless steel.

    Science.gov (United States)

    Abdel-Fattah, Tarek M; Loftis, Derek; Mahapatro, Anil

    2011-12-01

    Stainless steel (AISI 316L) is a medical grade stainless steel alloy used extensively in medical devices and in the biomedical field. 316L stainless steel was successfully electropolished via an ecologically friendly and biocompatible ionic liquid (IL) medium based on Vitamin B4 (NB4) and resulting in nanosized surface roughness and topography. Voltammetry and chronoamperometry tests determined optimum polishing conditions for the stainless steel alloy while atomic force microscopy (AFM) and scanning electron microscopy (SEM) provided surface morphology comparisons to benchmark success of each electropolishing condition. Energy dispersive X-ray analysis (EDX) combined with SEM revealed significantly smoother surfaces for each alloy surface while indicating that the constituent metals comprising each alloy effectively electropolished at uniform rates.

  3. Research on High-Speed Drilling Performances of Austenitic Stainless Steels

    Institute of Scientific and Technical Information of China (English)

    J.W.Zhong; Y.P.Ma; F.H.Sun; M.Chen

    2004-01-01

    Due to specific properties arising from their structure (high ductility, high toughness,strong tenacious and low heat conductivity), the stainless steels have poor machinability. The drilling of the stainless steels becomes the machining difficulty for their serious work-hardening and abrasion of tools. In this paper, the austenitic stainless steel is used as the work-piece to perform the contrastive experiments with the TiN coated and TiAlN-coated high-speed steel drills. The cutting force, torque, cutting temperature, and the abrasion of drills and tool life are tested and analyzed in the process of high-speed drilling. Experiment results show the effect of drilling speed on cutting force, cutting temperature, and drill wear. TiAlN-coated drills demonstrate better performances in high speed drilling. The research results will be of great benefit in the selection of drills and in the control of tool wear in high speed drilling of stainless steels.

  4. 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...

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    PURPOSE: The purpose was to examine bronchial asthma according to cumulative exposure to fume particulates conferred by stainless steel and mild steel welding through a proxy of redeemed prescribed asthma pharmaceuticals. METHODS: A Danish national company-based historical cohort of 5,303 male ever...... nonsignificant increased rate of redemption of asthma medicine was observed among high-level exposed stainless steel welders in comparison with low-level exposed welders (HR 1.54, 95 % CI 0.76-3.13). This risk increase was driven by an increase risk among non-smoking stainless steel welders (HR 1.46, 95 % CI 1.......06-2.02). Mild steel welding was not associated with increased risk of use asthma pharmaceuticals. CONCLUSION: The present study indicates that long-term exposure to stainless steel welding is related to increased risk of asthma in non-smokers....

  6. Development of Pack Cementation Aluminizing Process on Inner Surface of 316L Stainless Steel Tube

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>In order to form the FeAl coatings on the inner surface of the 316L stainless steel tube,the pack cementation aluminizing process is introduced in this paper. The outside diameter,wall thickness and

  7. Studies of lubricants and punch design in punching of stainless steel

    DEFF Research Database (Denmark)

    Olsson, David Dam; Bay, Niels; Andreasen, Jan Lasson

    2004-01-01

    Environmentally hazardous lubricants such as chlorinated paraffin oils are often applied in punching and blanking operations especially involving stainless steel workpiece materials. This is due to the fact that punching and blanking are among the tribologically most difficult forming operations...

  8. The sub-zero Celsius treatment of precipitation hardenable semi-austenitic stainless steel

    DEFF Research Database (Denmark)

    Villa, Matteo; Hansen, Mikkel Fougt; Somers, Marcel A. J.

    2015-01-01

    A precipitation hardenable semi-austenitic stainless steel AISI 632 grade was austenitized according to industrial specifications and thereafter subjected to isothermal treatment at sub-zero Celsius temperatures. During treatment, austenite transformed to martensite. The isothermal austenite...

  9. Unexpected corrosion of stainless steel in low chloride waters – microbial aspects

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel; Carpén, Leena; Møller, Per

    2009-01-01

    Abstract Stainless steels EN 1.4301 and 1.4401/1.4404 are normally considered corrosion resistant in low chloride natural waters like drinking water. However, a number of corrosion failures have been observed in e.g. fire extinguisher systems and drinking water installations, where stagnant...... stains on the outside of the installation. Corrosion may occur in water qualities with rather low chloride contents and fairly low conductivity, which would usually not be considered especially corrosive towards stainless steel. One key parameter is the ennoblement documented on stainless steel...... of iron facilitates the growth of iron oxidising bacteria. A number of failure cases from Danish and Finnish stainless steel installations are discussed with the objective to identify key parameters, suggest possible mechanisms and discuss whether prediction is possible. The paper includes a short...

  10. On the Plasma (ion) Carburized Layer of High Nitrogen Austenitic Stainless Steel

    Institute of Scientific and Technical Information of China (English)

    Y. Ueda; N. Kanayama; K. Ichii; T. Oishi; H. Miyake

    2004-01-01

    The manganese concentration of austenitic stainless steel decreases from the inner layer towards the surface of the plasma (ion) carburized layer due to the evaporation of manganese from the specimen surface. The carbon concentration in the carburized layer is influenced by alloyed elements such as Ct, Ni, Si, and Mo, as well as Nitrogen. This study examined the effects of nitrogen on the properties of the carburized layer of high nitrogen stainless steel. Plasma (ion)carburizing was carried out for 14.4 ks at 1303 K in an atmosphere of CH4+H2 gas mixtures under a pressure of 350 Pa. The plasma carburized layer of the high nitrogen stainless steel was thinner than that of an austentric stainless steel containing no nitrogen. This suggested that the nitrogen raised the activity of carbon in the plasma carburized layer, GDOES measurement indicated that the nitrogen level in the layer did not vary after plasma (ion) carburizing.

  11. The influence of nickel-nitrogen ratio on the deformation behaviour of austenitic stainless steels

    CSIR Research Space (South Africa)

    Schmid, OE

    1992-01-01

    Full Text Available This study examines the effect that a partial substitution of nickel with nitrogen has on the deformation behaviour of a metastable austenitic stainless steel, AISI 301. The effect on the tensile deformation behaviour is studied in detail...

  12. The precision cutting control research of automotive stainless steel thin wall pipe

    Directory of Open Access Journals (Sweden)

    Jin Lihong

    2015-01-01

    Full Text Available Stainless steel thin-walled tube are widely used in automobile industry at present, but as a result of thin wall pipe is poor strength and poor rigidity,which lead to deformation, shaped differencer and other problems in the process, it is hard to ensure the processing quality of parts. This paper proposes a method of thin stainless steel thin wall pipe cutting process in vehicle, greatly improved the problems and technical difficulties in the traditional process, the main research is about the cutting system and the hydraulic fixture design, obtained under low cost circumstances, it can realize high precision stainless steel pipes, high degree of automation to automatic cutting,simplified operation steps at the same time, increased the applicability of the system, provided a kind of advanced stainless steel thin wall pipe cutting device for the small and medium-sized enterprises.

  13. Galvanic corrosion between dental precious alloys and magnetic stainless steels used for dental magnetic attachments.

    Science.gov (United States)

    Takahashi, Noriko; Takada, Yukyo; Okuno, Osamu

    2008-03-01

    In this study, we examined the corrosion behavior of dental precious alloys and magnetic stainless steels, namely SUS 444, SUS XM27, and SUS 447J1, used for dental magnetic attachments. Their galvanic corrosion behavior was evaluated from the viewpoint of corrosion potentials when they were in contact with each other. Rest potentials of the precious alloys were constantly higher than those of magnetic stainless steels. Since most gold alloys raised the corrosion potential more significantly than silver alloys did, silver alloys seemed to be better suited than gold alloys for combination with magnetic stainless steels. However, all corrosion potential values were sufficiently lower than the breakdown potentials of the stainless steels and existed within their passive regions. Based on the findings of this study, SUS XM27 and SUS 447J1--which exhibited higher breakdown potentials than SUS 444--emerged as the preferred choices for combination with gold alloys.

  14. Effect of Harmonic Microstructure on the Corrosion Behavior of SUS304L Austenitic Stainless Steel

    Science.gov (United States)

    Rai, Prabhat K.; Shekhar, S.; Nakatani, M.; Ota, M.; Vajpai, S. K.; Ameyama, K.; Mondal, K.

    2016-12-01

    Corrosion behavior of a harmonic structured SUS304L austenitic stainless steel was examined and compared with nonharmonic structured SUS304L stainless steel and conventional 304 stainless steel in 3.5 pct NaCl solution. The study was performed using linear polarization, potentiodynamic polarization, cyclic polarization, and a salt fog exposure test for 30 days. Characterization was accomplished using a scanning electron microscope, an electron probe microanalyzer, and Raman spectroscopy. Improved pitting corrosion resistance was found in the case of the harmonic structured steel as compared to that of the nonharmonic and the conventional 304 stainless steel. Harmonically distributed fine-grained structure, less porosity, and higher fraction of passive α-FeOOH are attributed to the improvement in corrosion resistance of the harmonic structured steel.

  15. Friction behavior of 304 stainless steel of varying hardness lubricated with benzene and some benzyl structures

    Science.gov (United States)

    Buckley, D. H.

    1974-01-01

    The lubricating properties of some benzyl and benzene structures were determined by using 304 stainless steel surfaces strained to various hardness. Friction coefficients and wear track widths were measured with a Bowden-Leben type friction apparatus by using a pin-on-disk specimen configuration. Results obtained indicate that benzyl monosulfide, dibenzyl disulfide, and benzyl alcohol resulted in the lowest friction coefficients for 304 stainless steel, while benzyl ether provided the least surface protection and gave the highest friction. Strainhardening of the 304 stainless steel prior to sliding resulted in reduced friction in dry sliding. With benzyl monosulfide, dibenzyl disulfide, and benzyl alcohol changes in 304 stainless steel hardness had no effect upon friction behavior.

  16. 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.

  17. Hot Corrosion Behavior of Stainless Steel with Al-Si/Al-Si-Cr Coating

    Science.gov (United States)

    Fu, Guangyan; Wu, Yongzhao; Liu, Qun; Li, Rongguang; Su, Yong

    2017-03-01

    The 1Cr18Ni9Ti stainless steel with Al-Si/Al-Si-Cr coatings is prepared by slurry process and vacuum diffusion, and the hot corrosion behavior of the stainless steel with/without the coatings is studied under the condition of Na2SO4 film at 950 °C in air. Results show that the corrosion kinetics of stainless steel, the stainless steel with Al-Si coating and the stainless steel with Al-Si-Cr coating follow parabolic laws in several segments. After 24 h corrosion, the sequence of the mass gain for the three alloys is the stainless steel with Al-Si-Cr coating steel with Al-Si coating steel without any coating. The corrosion products of the three alloys are layered. Thereinto, the corrosion products of stainless steel without coating are divided into two layers, where the outside layer contains a composite of Fe2O3 and FeO, and the inner layer is Cr2O3. The corrosion products of the stainless steel with Al-Si coating are also divided into two layers, of which the outside layer mainly consists of Cr2O3, and the inner layer is mainly SiO2. The corrosion film of the stainless steel with Al-Si-Cr coating is thin and dense, which combines well with substrate. Thereinto, the outside layer is mainly Cr2O3, and the inside layer is Al2O3. In the matrix of all of the three alloys, there exist small amount of sulfides. Continuous and protective films of Cr2O3, SiO2 and Al2O3 form on the surface of the stainless steel with Al-Si and Al-Si-Cr coatings, which prevent further oxidation or sulfide corrosion of matrix metals, and this is the main reason for the much smaller mass gain of the two alloys than that of the stainless steel without any coatings in the 24 h hot corrosion process.

  18. Improved impact toughness of 13Cr martensitic stainless steel hardened by laser

    Science.gov (United States)

    Tsay, L. W.; Chang, Y. M.; Torng, S.; Wu, H. C.

    2002-08-01

    The impact toughness of AISI 403 martensitic stainless steel plate and laser-hardened specimens tempered at various temperatures were examined. Phosphorus was the primary residual impurity responsible for tempered embrittlement of this alloy. The experimental result also indicated that AISI 403 stainless steel was very sensitive to reverse-temper embrittlement. The improved impact toughness of the laser-hardened specimen was attributed to the refined microstructure in the laser-hardened zone.

  19. Effect of temperature on sintered austeno-ferritic stainless steel microstructure

    Energy Technology Data Exchange (ETDEWEB)

    Munez, C.J. [Departamento de Ciencia e Ingenieria de Materiales, Escuela Superior de Ciencias Experimentales y Tecnologia, Universidad Rey Juan Carlos, 28933 Mostoles, Madrid (Spain)], E-mail: claudio.munez@urjc.es; Utrilla, M.V.; Urena, A. [Departamento de Ciencia e Ingenieria de Materiales, Escuela Superior de Ciencias Experimentales y Tecnologia, Universidad Rey Juan Carlos, 28933 Mostoles, Madrid (Spain)

    2008-09-08

    The influence of temperature on microstructural changes of sintered austeno-ferritic steels has been investigated. PM stainless steels have been obtained by sintering mixtures of austenitic and ferritic stainless steel powders. Only temperature-induced phase transformation was observed in austenite, as a result of elements interdiffusion between both phases. Microstructural characterization was completed with atomic force microscopy (AFM) and micro- and nano-indentation test, it is revealed an increase in the hardness with respect to the solutionized materials.

  20. Experimental Test of Stainless Steel Wire Mesh and Aluminium Alloy With Glass Fiber Reinforcement Hybrid Composite

    OpenAIRE

    2015-01-01

    At present, composite materials are mostly used in aircraft structural components, because of their excellent properties like lightweight, high strength to weight ratio, high stiffness, and corrosion resistance and less expensive. In this experimental work, the mechanical properties of laminate, this is reinforced with stainless steel wire mesh, aluminum sheet metal, perforated aluminum sheet metal and glass fibers to be laminate and investigated. The stainless steel wire mesh and...

  1. Improvement of Microhardness and Corrosion Resistance of Stainless Steel by Nanocomposite Coating

    OpenAIRE

    Hiba Husam Ismail; Kareem Neamah Sallomi; Hamid S. Mahdi

    2014-01-01

    Stainless steel (AISI 304) has good electrical and thermal conductivities, good corrosion resistance at ambient temperature, apart from these it is cheap and abundantly available; but has good mechanical properties such as hardness. To improve the hardness and corrosion resistance of stainless steel its surface can be modified by developing nanocomposite coatings applied on its surface. The main objective of this paper is to study effect of electroco-deposition method on microhardness and cor...

  2. Aging research of the LAB-based liquid scintillator in stainless steel container

    OpenAIRE

    Chen, Hai-tao; Yu, Bo-Xiang; Shan, Qing; Ding, Ya-yun; Du, Bing; Liu, Shu-tong; Zhang, Xuan; Zhou, Li; Jia, Wen-bao; Fang, Jian; Ye, Xing-Chen; HU, Wei; Niu, Shun-Li; Yan, Jia-qing; Zhao, Hang

    2014-01-01

    Stainless steel is the material used for the storage vessels and piping systems of LAB-based liquid scintillator in JUNO experiment. Aging is recognized as one of the main degradation mechanisms affecting the properties of liquid scintillator. LAB-based liquid scintillator aging experiments were carried out in different material of containers (type 316 and 304 stainless steel and glass) at two different temperature (40 and 25 degrees Celsius). For the continuous liquid scintillator properties...

  3. Ultra-Pure Ferritic Stainless Steels-Grade, Refining Operation, and Application

    Institute of Scientific and Technical Information of China (English)

    YOU Xiang-mi; JIANG Zhou-hua; LI Hua-bing

    2007-01-01

    The grades of ultra-pure ferritic stainless steels, especially the grades used in automobile exhaust system, were reviewed. The dependence of properties on alloying elements, the refining facilities, and the mechanism of the reactions in steel melts were described in detail. Vacuum, strong stirring, and powder injection proved to be effective technologies in the melting of ultra-pure ferritic stainless steels. The application of the ferritic grades was also briefly introduced.

  4. Industrial Experience with Case Hardening of Stainless Steels by Solution Nitriding

    Institute of Scientific and Technical Information of China (English)

    Hans Berns; Bernd Edenhofer; Roland Zaugg

    2004-01-01

    SolNit(R) is a novel heat treatment to case harden stainless steels with nitrogen instead of carbon. The calculated equilibrium pressure of N2 corresponds well with the nitrogen content in the steel surface. The process is carried out in vacuum furnaces with pressurized gas quenching. Numerous parts of different stainless steels have been successfully SolNit(R) treated in industry leading to superior properties in respect to hardness/strength and corrosion resistance

  5. Plasma Nitriding of Austenitic Stainless Steel with Severe Surface Deformation Layer

    Institute of Scientific and Technical Information of China (English)

    JI Shi-jun; GAO Yu-zhou; WANG Liang; SUN Jun-cai; HEI Zu-kun

    2004-01-01

    The dc glow discharge plasma nitriding of austenite stainless steel with severe surface deformation layer is used to produce much thicker surface modified layer. This kind of layers has useful properties such as a high surface hardness of about 1500 Hv 0.1 and high resistance to frictional wear. This paper presents the structures and properties of low temperature plasma nitrided austenitic stainless steel with severe surface deformation layer.

  6. Simultaneous surface engineering and bulk hardening of precipitation hardening stainless steel

    DEFF Research Database (Denmark)

    Frandsen, Rasmus Berg; Christiansen, Thomas; Somers, Marcel A. J.

    2006-01-01

    This article addresses simultaneous bulk precipitation hardening and low temperature surface engineering of two commercial precipitation hardening stainless steels: Sandvik Nanoflex® and Uddeholm Corrax®. Surface engineering comprised gaseous nitriding or gaseous carburising. Microstructural....... The duration and temperature of the nitriding/carburising surface hardening treatment can be chosen in agreement with the thermal treatment for obtaining optimal bulk hardness in the precipitation hardening stainless steel....

  7. Improving Corrosion Resistance of Stainless Steel by Yttrium Addition: An AES Analysis

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The influence of Y addition on the distribution of element concentrations in the passive film of high silicon stainless steel formed in 93% H2SO4 was comparatively studied by using auger electron spectroscopy (AES). The results show that 0.2%Y addition increases the SiO2 proportion in the passive film of stainless steel so that the formation of SiO2 enriched passive film from silicon in the alloy is brought into full play.

  8. Graphene Growth via Carburization of Stainless Steel and Application in Energy Storage

    Science.gov (United States)

    2011-01-01

    1697© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim wileyonlinelibrary.comsmall 2011, 7, No. 12, 1697–1700 1. Introduction Carburization is a...in order to achieve few-layers-thick graphene on stainless steel (SS) substrates. Though the carburization process is similar to the chemi cal...vapor deposition (CVD) tech- nique, which is generally used for growth of graphene on Graphene Growth via Carburization of Stainless Steel and

  9. Cavitation Erosion of Electro Spark Deposited Nitinol vs. Stellite Alloy on Stainless Steel Substrate

    Science.gov (United States)

    2015-07-15

    EROSION OF ELECTRO SPARK DEPOSITED NITINOL VS. STELLITE® ALLOY ON STAINLESS STEEL SUBSTRATE Theresa A. Hoffard Lean-Miguel San Pedro Mikhail...SUBTITLE 5a. CONTRACT NUMBER CAVITATION EROSION TESTING OF ELECTRO SPARK DEPOSITED NITINOL VS STELLITE® ALLOY ON STAINLESS STEEL SUBTRATE 5b. GRANT...of combining Nitinol (NiTi) superelastic metal alloy with ElectroSpark Deposition (ESD) technology to increase the cavitation erosion resistance of

  10. Anti-adhesion effects of liquid-infused textured surfaces on high-temperature stainless steel for soft tissue

    Science.gov (United States)

    Zhang, Pengfei; Chen, Huawei; Zhang, Liwen; Zhang, Deyuan

    2016-11-01

    Soft tissue adhesion on the electrosurgical instruments can induce many serious complications, such as failure of hemostasis and damage to the surrounding soft tissue. The soft tissue adhesion is mainly caused by the high temperature on the instrument surface generally made of stainless steel. Nepenthes inspired liquid-infused surfaces (LIS), highly promising for anti-adhesion, have attracted considerable interests. In this paper, we investigated the anti-adhesion effects of LIS on high-temperature stainless steel for soft tissue for the first time, aiming to develop a new approach to solve the soft tissue adhesion problem. The textured surface, acting as the holding structures, was fabricated by photolithography-assisted chemical etching. Silicone oil, with good biocompatibility and high-temperature resistance, was chosen as the infused liquid. The adhesion force measurements for soft tissue on the LIS at high temperatures indicated that the soft tissue adhesion force was decreased by approximately 80% at 250 °C. Besides, the cycle tests of soft tissue adhesion force demonstrated the excellent stability of prepared LIS. We anticipate that LIS will be of great promise for practical applications on the electrosurgical instruments.

  11. In-situ preparation of Fe2O3 hierarchical arrays on stainless steel substrate for high efficient catalysis

    Science.gov (United States)

    Yang, Zeheng; Wang, Kun; Shao, Zongming; Tian, Yuan; Chen, Gongde; Wang, Kai; Chen, Zhangxian; Dou, Yan; Zhang, Weixin

    2017-02-01

    Hierarchical array catalysts with micro/nano structures on substrates not only possess high reactivity from large surface area and suitable interface, but intensify mass transfer through shortening the diffusion paths of both reactants and products for high catalytic efficiency. Herein, we first demonstrate fabrication of Fe2O3 hierarchical arrays grown on stainless-steel substrates via in-situ hydrothermal chemical oxidation followed by heat treatment in N2 atmosphere. As a Fenton-like catalyst, Fe2O3 hierarchical arrays exhibit excellent catalytic activity and life cycle performance for methylene blue (MB) dye degradation in aqueous solution in the presence of H2O2. The Fe2O3 catalyst with unique hierarchical structures and efficient transport channels, effectively activates H2O2 to generate large quantity of •OH radicals and highly promotes reaction kinetics between MB and •OH radicals. Immobilization of hierarchical array catalysts on stainless-steel can prevent particles agglomeration, facilitate the recovery and reuse of the catalysts, which is expected promising applications in wastewater remediation.

  12. HANARO instrumented capsule development for supporting a study on the irradiation damage of stainless steels for nuclear applications

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Y. H.; Cho, M. S.; Sohn, J. M.; Kim, H. R.; Lee, B. C.; Kim, K. H

    2000-10-01

    As a part of the program for the maximum utilization of HANARO by MOST, Korea, an instrumented capsule (00M-01U) was designed and fabricated for supporting a study on the irradiation damage of stainless steels for nuclear applications. The basic structure of the capsule for the irradiation of Stainless steels was based on that of the 99M-01K capsule irradiated successfully in HANARO. To satisfy the user requirements such as irradiation temperature and neutron fluence, the optimal arrangement of test specimens was done in the axial and circumferential direction. The temperature distribution and thermal stress of a capsule with multi-holes were obtained by a finite element analysis code, ANSYS. From these analyzed data, this capsule was found to be compatible with HANARO design requirement. Various types of specimens such as small tensile, Charpy, TEM and EPMA specimens were inserted in the capsule. The specimens will be irradiated in the IR2 test hole of HANARO at 288, 300 and 350 deg C up to a fast neutron fluence of 1.0x10{sup 20}(n/cm{sup 2})(E>1.0MeV)

  13. Dynamical recrystallization of high purity austenitic stainless steels; Recristallisation dynamique d'aciers inoxydables austenitiques de haute purete

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  14. Study of biocompatibility of medical grade high nitrogen nickel-free austenitic stainless steel in vitro.

    Science.gov (United States)

    Li, Menghua; Yin, Tieying; Wang, Yazhou; Du, Feifei; Zou, Xingzheng; Gregersen, Hans; Wang, Guixue

    2014-10-01

    Adverse effects of nickel ions being released into the living organism have resulted in development of high nitrogen nickel-free austenitic stainless steels for medical applications. Nitrogen not only replaces nickel for austenitic structure stability but also improves steel properties. The cell cytocompatibility, blood compatibility and cell response of high nitrogen nickel-free austenitic stainless steel were studied in vitro. The mechanical properties and microstructure of this stainless steel were compared to the currently used 316L stainless steel. It was shown that the new steel material had comparable basic mechanical properties to 316L stainless steel and preserved the single austenite organization. The cell toxicity test showed no significant toxic side effects for MC3T3-E1 cells compared to nitinol alloy. Cell adhesion testing showed that the number of MC3T3-E1 cells was more than that on nitinol alloy and the cells grew in good condition. The hemolysis rate was lower than the national standard of 5% without influence on platelets. The total intracellular protein content and ALP activity and quantification of mineralization showed good cell response. We conclude that the high nitrogen nickel-free austenitic stainless steel is a promising new biomedical material for coronary stent development.

  15. Characterization of corrosion scale formed on stainless steel delivery pipe for reclaimed water treatment.

    Science.gov (United States)

    Cui, Yong; Liu, Shuming; Smith, Kate; Yu, Kanghua; Hu, Hongying; Jiang, Wei; Li, Yuhong

    2016-01-01

    To reveal corrosion behavior of stainless steel delivery pipe used in reclaimed water treatment, this research focused on the morphological, mineralogical and chemical characteristics of stainless steel corrosion scale and corroded passive film. Corrosion scale and coupon samples were taken from a type 304 pipe delivering reclaimed water to a clear well in service for more than 12 years. Stainless steel corrosion scales and four representative pipe coupons were investigated using mineralogy and material science research methods. The results showed corrosion scale was predominantly composed of goethite, lepidocrocite, hematite, magnetite, ferrous oxide, siderite, chrome green and chromite, the same as that of corroded pipe coupons. Hence, corrosion scale can be identified as podiform chromite deposit. The loss of chromium in passive film is a critical phenomenon when stainless steel passive film is damaged by localized corrosion. This may provide key insights toward improving a better comprehension of the formation of stainless steel corrosion scale and the process of localized corrosion. The localized corrosion behavior of stainless steel is directly connected with reclaimed water quality parameters such as residual chlorine, DO, Cl(-) and SO4(2-). In particular, when a certain amount of residual chlorine in reclaimed water is present as an oxidant, ferric iron is the main chemical state of iron minerals.

  16. Utilization of stainless steel crowns by general dentists and pediatric dental specialists in Indiana.

    Science.gov (United States)

    Kowolik, Joan; Kozlowski, Diana; Jones, James E

    2007-01-01

    The purpose of this study was to evaluate utilization of the stainless steel crown by both the general and pediatric dentists in Indiana. Although reports indicate that there has been a dramatic reduction in dental caries in the US, almost 20 percent of children have dental decay by age four, with almost 80 percent having a cavity by 17 years of age. After reviewing the literature, Seale has recommended that the stainless steel crown is the most successful restoration for children with a rate of high caries. All dental schools in North America teach the value of using stainless steel crowns and the method of tooth preparation. We hypothesized that greater use of the stainless steel crowns would be made by specialists than by general dentists. In this study, of the 200 questionnaires distributed, 62.5 percent were returned and analyzed. The results imply that stainless steel crowns are being significantly underutilized in general dental practice. It is interesting, and perhaps of concern, that the general dentists are not interested in continuing education courses about this subject. Over the next few years, with the aging of the pediatric dental community in Indiana, general (not specialty) dentists will treat most of the children. Because of this, pre-doctoral education needs to place more emphasis on preparation and utilization of the stainless steel crown.

  17. TiC-Maraging stainless steel composite: microstructure, mechanical and wear properties

    Institute of Scientific and Technical Information of China (English)

    Akhtar Farid; GUO Shiju; FENG Peizhong; Khadijah Ali Shah; Syed Javid Askari

    2006-01-01

    Particulate TiC reinforced 17-4PH and 465 maraging stainless steel matrix composites were processed by conventional powder metallurgy (P/M). TiC-maraging stainless steel composites with theoretical density >97% were produced using conventional P/M. The microstructure, and mechanical and wear properties of the composites were evaluated. The microstructure of the composites consisted of (core-rim structure) spherical and semi-spherical TiC particles depending on the wettability of the matrix with TiC particles. In TiC-maraging stainless steel composites, 465 stainless steel binder phase showed good wettability with TiC particles. Some microcracks appeared in the composites, indicating the presence of tensile stresses in the composites produced during sintering. The typical properties, hardness, and bend strength were reported for the composites. After heat treatment and aging, an increase in hardness was observed. The increase in hardness was attributed to the aging reaction in maraging stainless steel. The specific wear behavior of the composites strongly depends on the content of TiC particles and their interparticle spacing, and on the heat treatment of the maraging stainless steel.

  18. 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.

  19. Biofilm formation by Listeria monocytogenes on stainless steel surface and biotransfer potential

    Directory of Open Access Journals (Sweden)

    Maíra Maciel Mattos de Oliveira

    2010-03-01

    Full Text Available An experimental model was proposed to study biofilm formation by Listeria monocytogenes ATCC 19117 on AISI 304 (#4 stainless steel surface and biotransfer potential during this process. In this model, biofilm formation was conducted on the surface of stainless steel coupons, set on a stainless steel base with 4 divisions, each one supporting 21 coupons. Trypic Soy Broth was used as bacterial growth substrate, with incubation at 37 ºC and stirring of 50 rpm. The number of adhered cells was determined after 3, 48, 96, 144, 192 and 240 hours of biofilm formation and biotransfer potential from 96 hours. Stainless steel coupons were submitted to Scanning Electron Microscopy (SEM after 3, 144 and 240 hours. Based on the number of adhered cells and SEM, it was observed that L. monocytogenes adhered rapidly to the stainless steel surface, with mature biofilm being formed after 240 hours. The biotransfer potential of bacterium to substrate occurred at all the stages analyzed. The rapid capacity of adhesion to surface, combined with biotransfer potential throughout the biofilm formation stages, make L. monocytogenes a potential risk to the food industry. Both the experimental model developed and the methodology used were efficient in the study of biofilm formation by L. monocytogenes on stainless steel surface and biotransfer potential.

  20. The study of high speed fine turning of austenitic stainless steel

    Directory of Open Access Journals (Sweden)

    W.S. Lin

    2008-04-01

    Full Text Available Purpose: The purpose of this research paper is focused on the surface roughness variation in high speed fine turning of the austenitic stainless steel.Design/methodology/approach: A series of experimental tests have been done to evaluate the possibility of high speed fine turning of the austenitic stainless steel from the surface roughness variation and machining stability.Findings: It was found that, the smaller the feed rate, the smaller the surface roughness value. But when the feed rate smaller than the critical feed rate, the chatter will occurs and the surface roughness of the work piece would be deteriorated.The higher the cutting speed is, the higher the cutting temperature of cutting tool is. The cutting tool will be soften and the surface roughness of the workpiece will be deteriorated.Research limitations/implications: The tool chattering would caused poor surface roughness in high speed fine turning for feed rate smaller than 0.02 mm/rev. The chatter suppression method must be considered when high speed fine turning of austenitic stainless steel.Originality/value: Most of the stainless steel machining proceeds at low cutting speed because the austenitic stainless steel is a hard machining material. The research result of this paper indicated that high speed fine turning of austenitic stainless steel is possible.

  1. Marine microbial fuel cell: Use of stainless steel electrodes as anode and cathode materials

    Energy Technology Data Exchange (ETDEWEB)

    Dumas, C.; Basseguy, R.; Etcheverry, L.; Bergel, A. [Laboratoire de Genie Chimique, CNRS-INPT, Toulouse Cedex (France); Mollica, A. [CNR-ISMAR, Genoa (Italy); Feron, D. [SCCME, CEA Saclay, Gif-sur-Yvette (France)

    2007-12-01

    Numerous biocorrosion studies have stated that biofilms formed in aerobic seawater induce an efficient catalysis of the oxygen reduction on stainless steels. This property was implemented here for the first time in a marine microbial fuel cell (MFC). A prototype was designed with a stainless steel anode embedded in marine sediments coupled to a stainless steel cathode in the overlying seawater. Recording current/potential curves during the progress of the experiment confirmed that the cathode progressively acquired effective catalytic properties. The maximal power density produced of 4 mW m{sup -2} was lower than those reported previously with marine MFC using graphite electrodes. Decoupling anode and cathode showed that the cathode suffered practical problems related to implementation in the sea, which may found easy technical solutions. A laboratory fuel cell based on the same principle demonstrated that the biofilm-covered stainless steel cathode was able to supply current density up to 140 mA m{sup -2} at +0.05 V versus Ag/AgCl. The power density of 23 mW m{sup -2} was in this case limited by the anode. These first tests presented the biofilm-covered stainless steel cathodes as very promising candidates to be implemented in marine MFC. The suitability of stainless steel as anode has to be further investigated. (author)

  2. Experimental Analysis of Residual Stresses in Samples of Austenitic Stainless Steel Welded on Martensitic Stainless Steel Used for Kaplan Blades Repairs

    Directory of Open Access Journals (Sweden)

    Vasile Cojocaru

    2011-01-01

    Full Text Available Residual stresses occur in materials as a result of mechanical processes: welding, machining, grinding etc. If residual stresses reach high values they can accelerate the occurrence of cracks and erosion of material. An experimental research was made in order to study the occurrence of residual stresses in the repaired areas of hydraulic turbine components damaged by cavitation erosion. An austenitic stainless steel was welded in various layer thicknesses on a martensitic stainless steel base. The residual stresses were determined using the hole drilling strain gage method.

  3. Deformation induced martensite in AISI 316 stainless steel

    Directory of Open Access Journals (Sweden)

    Solomon, N.

    2010-04-01

    Full Text Available The forming process leads to a considerable differentiation of the strain field within the billet, and finally causes the non-uniform distribution of the total strain, microstrusture and properties of the material over the product cross-section. This paper focus on the influence of stress states on the deformation-induced a’ martensitic transformation in AISI Type 316 austenitic stainless steel. The formation of deformation-induced martensite is related to the austenite (g instability at temperatures close or below room temperature. The structural transformation susceptibility is correlated to the stacking fault energy (SFE, which is a function not only of the chemical composition, but also of the testing temperature. Austenitic stainless steels possess high plasticity and can be easily cold formed. However, during cold processing the hardening phenomena always occurs. Nevertheless, the deformation-induced martensite transformation may enhance the rate of work-hardening and it may or may not be in favour of further material processing. Due to their high corrosion resistance and versatile mechanical properties the austenitic stainless steels are used in pressing of heat exchanger plates. However, this corrosion resistance is influenced by the amount of martensite formed during processing. In order to establish the links between total plastic strain, and martensitic transformation, the experimental tests were followed by numerical simulation.

    El proceso de conformación da a lugar a una considerable diferenciación del campo de tensiones dentro de una barra de extrusión y, finalmente, causa una distribución no uniforme de la tensión total, la microestructura y propiedades del material sobre el corte transversal. En este trabajo se estudia la influencia de los estados de tensión sobre la transformación martensítica inducida por deformación en un acero inoxidable austenítico tipo AISI 316. La formación de martensita inducida por

  4. Effect of Reinforcement Using Stainless Steel Mesh, Glass Fibers, and Polyethylene on the Impact Strength of Heat Cure Denture Base Resin - An In Vitro Study

    Science.gov (United States)

    Murthy, H B Mallikarjuna; Shaik, Sharaz; Sachdeva, Harleen; Khare, Sumit; Haralur, Satheesh B; Roopa, K T

    2015-01-01

    Background: The impact strength of denture base resin is of great concern and many approaches have been made to strengthen acrylic resin dentures. The objective of this study was to compare the impact strength of the denture base resin with and without reinforcement and to evaluate the impact strength of denture base resin when reinforced with stainless steel mesh, glass fiber, and polyethylene fibers in the woven form. Materials and Methods: The specimens (maxillary denture bases) were fabricated using a standard polyvinylsiloxane mold with conventional heat cured polymethyl methacrylate resin. The specimens were divided into four groups (n = 10). Group I specimens or control group were not reinforced. Group II specimens were reinforced with stainless steel mesh and Group III and Group IV specimens were reinforced with three percent by weight of glass fibers and polyethylene fibers in weave form respectively. All the specimens were immersed in water for 1-week before testing. The impact strength was measured with falling weight impact testing machine. One-way analysis of variance and Tukey’s post-hoc test were used for statistical analysis. Results: Highest impact strength values were exhibited by the specimens reinforced with polyethylene fibers followed by glass fibers, stainless steel mesh, and control group. Conclusions: Reinforcement of maxillary complete dentures showed a significant increase in impact strength when compared to unreinforced dentures. Polyethylene fibers exhibit better impact strength followed by glass fibers and stainless steel mesh. By using pre-impregnated glass and polyethylene fibers in woven form (prepregs) the impact strength of the denture bases can be increased effectively. PMID:26124604

  5. Study on tempering behaviour of AISI 410 stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Chakraborty, Gopa, E-mail: gopa_mjs@igcar.gov.in [Metallurgy & Materials Group, Indira Gandhi Center for Atomic Research, Kalpakkam 603102 (India); Das, C.R.; Albert, S.K.; Bhaduri, A.K.; Thomas Paul, V. [Metallurgy & Materials Group, Indira Gandhi Center for Atomic Research, Kalpakkam 603102 (India); Panneerselvam, G. [Chemistry Group, Indira Gandhi Center for Atomic Research, Kalpakkam 603102 (India); Dasgupta, Arup [Metallurgy & Materials Group, Indira Gandhi Center for Atomic Research, Kalpakkam 603102 (India)

    2015-02-15

    Martensitic stainless steels find extensive applications due to their optimum combination of strength, hardness and wear-resistance in tempered condition. However, this class of steels is susceptible to embrittlement during tempering if it is carried out in a specific temperature range resulting in significant reduction in toughness. Embrittlement of as-normalised AISI 410 martensitic stainless steel, subjected to tempering treatment in the temperature range of 673–923 K was studied using Charpy impact tests followed by metallurgical investigations using field emission scanning electron and transmission electron microscopes. Carbides precipitated during tempering were extracted by electrochemical dissolution of the matrix and identified by X-ray diffraction. Studies indicated that temper embrittlement is highest when the steel is tempered at 823 K. Mostly iron rich carbides are present in the steel subjected to tempering at low temperatures of around 723 K, whereas chromium rich carbides (M{sub 23}C{sub 6}) dominate precipitation at high temperature tempering. The range 773–823 K is the transition temperature range for the precipitates, with both Fe{sub 2}C and M{sub 23}C{sub 6} types of carbides coexisting in the material. The nucleation of Fe{sub 2}C within the martensite lath, during low temperature tempering, has a definite role in the embrittlement of this steel. Embrittlement is not observed at high temperature tempering because of precipitation of M{sub 23}C{sub 6} carbides, instead of Fe{sub 2}C, preferentially along the lath and prior austenite boundaries. Segregation of S and P, which is widely reported as one of the causes for temper embrittlement, could not be detected in the material even through Auger electron spectroscopy studies. - Highlights: • Tempering behaviour of AISI 410 steel is studied within 673–923 K temperature range. • Temperature regime of maximum embrittlement is identified as 773–848 K. • Results show that type of

  6. Effects of Thermocapillary Forces during Welding of 316L-Type Wrought, Cast and Powder Metallurgy Austenitic Stainless Steels

    CERN Document Server

    Sgobba, Stefano

    2003-01-01

    The Large Hadron Collider (LHC) is now under construction at the European Organization for Nuclear Research (CERN). This 27 km long accelerator requires 1248 superconducting dipole magnets operating at 1.9 K. The cold mass of the dipole magnets is closed by a shrinking cylinder with two longitudinal welds and two end covers at both extremities of the cylinder. The end covers, for which fabrication by welding, casting or Powder Metallurgy (PM) was considered, are dished-heads equipped with a number of protruding nozzles for the passage of the different cryogenic lines. Structural materials and welds must retain high strength and toughness at cryogenic temperature. AISI 316L-type austenitic stainless steel grades have been selected because of their mechanical properties, ductility, weldability and stability of the austenitic phase against low-temperature spontaneous martensitic transformation. 316LN is chosen for the fabrication of the end covers, while the interconnection components to be welded on the protrud...

  7. Heat sink welding of austenitic stainless steel pipes to control distortion and residual stress

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, H.; Albert, S.K.; Bhaduri, A.K. [Materials Technology Div., Indira Gandhi Centre for Atomic Research, Kalpakkam (India)

    2007-07-01

    Construction of India's Prototype Fast Breeder Reactor (PFBR) involves extensive welding of austenitic stainless steels pipes of different dimensions. Due to high thermal expansion coefficient and poor thermal conductivity of this class of steels, welding can result in significant distortion of these pipes. Attempts to arrest this distortion can lead to high levels of residual stresses in the welded parts. Heat sink welding is one of the techniques often employed to minimize distortion and residual stress in austenitic stainless steel pipe welding. This technique has also been employed to repair welding of the piping of the Boiling Water Reactors (BWRs) subjected to radiation induced intergranular stress corrosion cracking (IGSCC). In the present study, a comparison of the distortion in two pipe welds, one made with heat sink welding and another a normal welds. Pipes of dimensions 350{phi} x 250(L) x 8(t) mm was fabricated from 316LN plates of dimensions 1100 x 250 x 8 mm by bending and long seam (L-seam) welding by SMAW process. Two fit ups with a root gap of 2 mm, land height of 1mm and a groove angle of 70 were prepared using these pipes for circumferential seam (C-seam) welding. Dimensions at predetermined points in the fit up were made before and after welding to check the variation in radius, circumference and and ovality of the pipes. Root pass for both the pipe fit up were carried out using conventional GTAW process with 1.6 mm AWS ER 16-8-2 as consumables. Welding of one of the pipe fit ups were completed using conventions GTAW process while the other was completed using heat sink welding. For second and subsequent layers of welding using this process, water was sprayed at the root side of the joint while welding was in progress. Flow rate of the water was {proportional_to}6 1/minute. Welding parameters employed were same as those used for the other pipe weld. Results of the dimensional measurements showed that there is no circumferential shrinkage in

  8. Evaluation of Direct Diode Laser Deposited Stainless Steel 316L on 4340 Steel Substrate for Aircraft Landing Gear Application

    Science.gov (United States)

    2010-03-01

    AFRL-RX-WP-TP-2010-4149 EVALUATION OF DIRECT DIODE LASER DEPOSITED STAINLESS STEEL 316L ON 4340 STEEL SUBSTRATE FOR AIRCRAFT LANDING GEAR...March 2010 – 01 March 2010 4. TITLE AND SUBTITLE EVALUATION OF DIRECT DIODE LASER DEPOSITED STAINLESS STEEL 316L ON 4340 STEEL SUBSTRATE FOR...Code) N/A Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std. Z39-18 Evaluation of Direct Diode Laser Deposited Stainless Steel 316L on

  9. Antibacterial and corrosive properties of copper implanted austenitic stainless steel

    Institute of Scientific and Technical Information of China (English)

    Juan Xiong; Bo-fan Xu; Hong-wei Ni

    2009-01-01

    Copper ions were implanted into austenitic stainless steel (SS) by metal vapor vacuum arc with a energy of 100 keV and an ions dose range of (0.5-8.0)x 1017 cm-2. The Cu-implanted SS was annealed in an Ar atmosphere furnace. Glancing X-ray diffraction (GXRD), transmission electron microscopy (TEM) and Auger electron spectroscopy (AES) were used to reveal the phase com-positions, microstructures, and concentration profiles of copper ions in the implanted layer. The results show that the antibacterialproperty of Cu-implanted SS is attributed to Cu9.9Fe0.1 which precipitated as needles. The depth of copper in Cu-implanted SS with annealing treatment is greater than that in Cu-implanted SS without annealing treatment, which improves the antibacterial property against S. Aureus. The salt wetting-drying combined cyclic test was used to evaluate the corrosion-resistance of antibacterial SS, and the results reveal that the antibacterial SS has a level of corrosion-resistance equivalent to that of un-implanted SS.

  10. Solidification microstructures in single-crystal stainless steel melt pools

    Energy Technology Data Exchange (ETDEWEB)

    Sipf, J.B.; Boatner, L.A.; David, S.A.

    1994-03-01

    Development of microstructure of stationary melt pools of oriented stainless steel single crystals (70%Fe-15%Ni-15%Cr was analyzed. Stationary melt pools were formed by electron-beam and gas-tungsten-arc heating on (001), (011), and (111) oriented planes of the austenitic, fcc-alloy crystals. Characterization and analysis of resulting microstructure was carried out for each crystallographic plane and welding method. Results showed that crystallography which favors ``easy growth`` along the <100> family of directions is a controlling factor in the microstructural formation along with the melt-pool shape. The microstructure was found to depend on the melting method, since each method forms a unique melt-pool shape. These results are used in making a three-dimensional reconstruction of the microstructure for each plane and melting method employed. This investigation also suggests avenues for future research into the microstructural properties of electron-beam welds as well as providing an experimental basis for mathematical models for the prediction of solidification microstructures.

  11. Study of Ce-modified antibacterial 316L stainless steel

    Directory of Open Access Journals (Sweden)

    Yuan Junping

    2012-11-01

    Full Text Available 316L stainless steel is widely used for fashion jewelry, but it can carry a large number of bacteria and bring the risk of infection since the steel has no antimicrobial performance. In this paper, the effects of Ce on the antibacterial property, corrosion resistance and processability of 316L were studied by microscopic observation, thin-film adhering quantitative bacteriostasis, and electrochemical and mechanical tests. The results show that a trace of Ce can distribute uniformly in the matrix of 316L and slightly improve its corrosion resistance in artificial sweat. With an increase in Ce content, the Ce is prone to form clustering, which degrades the corrosion resistance and the processability. The Ce-containing 316L exhibits Hormesis effect against S. aureus. A small Ce addition stimulates the growth of S. aureus. As the Ce content increases, the modified 316L exhibits an improved antibacterial efficacy. The more Ce is added, the better antibacterial capability is achieved. Overall, if the 316L is modified with Ce alone, it is difficult to obtain the optimal combination of corrosion resistance, antibacterial performance and processability. In spite of that, 0.15 wt.%-0.20 wt.% Ce around is inferred to be the best trade-off.

  12. Accurate modelling of anisotropic effects in austenitic stainless steel welds

    Science.gov (United States)

    Nowers, O. D.; Duxbury, D. J.; Drinkwater, B. W.

    2014-02-01

    The ultrasonic inspection of austenitic steel welds is challenging due to the formation of highly anisotropic and heterogeneous structures post-welding. This is due to the intrinsic crystallographic structure of austenitic steel, driving the formation of dendritic grain structures on cooling. The anisotropy is manifested as both a `steering' of the ultrasonic beam and the back-scatter of energy due to the macroscopic granular structure of the weld. However, the quantitative effects and relative impacts of these phenomena are not well-understood. A semi-analytical simulation framework has been developed to allow the study of anisotropic effects in austenitic stainless steel welds. Frequency-dependent scatterers are allocated to a weld-region to approximate the coarse grain-structures observed within austenitic welds and imaged using a simulated array. The simulated A-scans are compared against an equivalent experimental setup demonstrating excellent agreement of the Signal to Noise (S/N) ratio. Comparison of images of the simulated and experimental data generated using the Total Focusing Method (TFM) indicate a prominent layered effect in the simulated data. A superior grain allocation routine is required to improve upon this.

  13. The Unified Creep-Fatigue Equation for Stainless Steel 316

    Directory of Open Access Journals (Sweden)

    Dan Liu

    2016-09-01

    Full Text Available Background—The creep-fatigue properties of stainless steel 316 are of interest because of the wide use of this material in demanding service environments, such as the nuclear industry. Need—A number of models exist to describe creep-fatigue behaviours, but they are limited by the need to obtain specialized coefficients from a large number of experiments, which are time-consuming and expensive. Also, they do not generalise to other situations of temperature and frequency. There is a need for improved formulations for creep-fatigue, with coefficients that determinable directly from the existing and simple creep-fatigue tests and creep rupture tests. Outcomes—A unified creep-fatigue equation is proposed, based on an extension of the Coffin-Manson equation, to introduce dependencies on temperature and frequency. The equation may be formulated for strain as ε p = C 0 c ( T , t , ε p N − β 0 , or as a power-law ε p = C 0 c ( T , t N − β 0 b ( T , t . These were then validated against existing experimental data. The equations provide an excellent fit to data (r2 = 0.97 or better. Originality—This work develops a novel formulation for creep-fatigue that accommodates temperature and frequency. The coefficients can be obtained with minimum experimental effort, being based on standard rather than specialized tests.

  14. 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.

  15. Fracture toughness evaluations of TP304 stainless steel pipes

    Energy Technology Data Exchange (ETDEWEB)

    Rudland, D.L.; Brust, F.W.; Wilkowski, G.M. [Battelle, Columbus, OH (United States)

    1997-02-01

    In the IPIRG-1 program, the J-R curve calculated for a 16-inch nominal diameter, Schedule 100 TP304 stainless steel (DP2-A8) surface-cracked pipe experiment (Experiment 1.3-3) was considerably lower than the quasi-static, monotonic J-R curve calculated from a C(T) specimen (A8-12a). The results from several related investigations conducted to determine the cause of the observed toughness difference are: (1) chemical analyses on sections of Pipe DP2-A8 from several surface-cracked pipe and material property specimen fracture surfaces indicate that there are two distinct heats of material within Pipe DP2-A8 that differ in chemical composition; (2) SEN(T) specimen experimental results indicate that the toughness of a surface-cracked specimen is highly dependent on the depth of the initial crack, in addition, the J-R curves from the SEN(T) specimens closely match the J-R curve from the surface-cracked pipe experiment; (3) C(T) experimental results suggest that there is a large difference in the quasi-static, monotonic toughness between the two heats of DP2-A8, as well as a toughness degradation in the lower toughness heat of material (DP2-A8II) when loaded with a dynamic, cyclic (R = {minus}0.3) loading history.

  16. Hardfacing of duplex stainless steel using melting and diffusion processes

    Science.gov (United States)

    Lailatul, H.; Maleque, M. A.

    2017-03-01

    Duplex stainless steel (DSS) is a material with high potential successes in many new applications such as rail car manufacturing, automotive and chemical industries. Although DSS is widely used in various industries, this material has faced wear and hardness problems which obstruct a wider capability of this material and causes problems in current application. Therefore, development of surface modification has been introduced to produce hard protective layer or coating on DSS. The main aim of this work is to brief review on hard surface layer formation on DSS using melting and diffusion processes. Melting technique using tungsten inert gas (TIG) torch and diffusion technique using gas nitriding are the effective process to meet this requirement. The processing route plays a significant role in developing the hard surface layer for any application with effective cost and environmental factors. The good understanding and careful selection of processing route to form products are very important factors to decide the suitable techniques for surface engineering treatment. In this paper, an attempt is also made to consolidate the important research works done on melting and diffusion techniques of DSS in the past. The advantages and disadvantages between melting and diffusion technique are presented for better understanding on the feasibility of hard surface formation on DSS. Finally, it can be concluded that this work will open an avenue for further research on the application of suitable process for hard surface formation on DSS.

  17. Creep properties of aged duplex stainless steels containing [sigma] phase

    Energy Technology Data Exchange (ETDEWEB)

    Shek, C.H.; Wong, K.W.; Lai, J.K.L. (City Univ. of Hong Kong, Kowloon (Hong Kong). Dept. of Physics and Materials Science); Li, D.J. (Department of Materials Engineering, Dalian University of Technology, Dalian 116 024 (China))

    1999-06-30

    The creep properties of a cast of duplex stainless steel were characterized at temperatures 550-800 C under different loading conditions. For fully aged specimens containing [sigma], the stress exponent for creep was close to 3 and the activation energy was 281[+-]9 kJ mol[sup -1]. The results suggested that the creep mechanism in the samples in this investigation was controlled by dislocation movement. Extensive [sigma]/[gamma][sub 2] interfaces introduced during ageing improved the creep resistance of the material and related to a reduction of the creep rate in Stage II creep and an increase in the creep rupture strength of the material. Microstructural studies revealed the dependence of the creep properties on the morphology of the microstructure. Among the aged specimens containing [sigma], the creep strength and ductility were higher for specimens having larger [gamma] grain thickness measured on the longitudinal plane. This characteristic was related to the crack propagation and interconnection of voids within [gamma] matrix during tertiary creep. With appropriate solution treatment, the creep strength of [sigma]-containing steels can be improved to a value exceeding that of type 316 steels. (orig.) 14 refs.

  18. Electrochemical reduction of hydrogen peroxide on stainless steel

    Indian Academy of Sciences (India)

    S Patra; N Munichandraiah

    2009-09-01

    Electrochemical reduction of hydrogen peroxide is studied on a sand-blasted stainless steel (SSS) electrode in an aqueous solution of NaClO4. The cyclic voltammetric reduction of H2O2 at low concentrations is characterized by a cathodic peak at -0.40 V versus standard calomel electrode (SCE). Cyclic voltammetry is studied by varying the concentration of H2O2 in the range from 0.2 mM to 20 mM and the sweep rate in the range from 2 to 100 mV s-1. Voltammograms at concentrations of H2O2 higher than 2 mM or at high sweep rates consist of an additional current peak, which may be due to the reduction of adsorbed species formed during the reduction of H2O2. Amperometric determination of H2O2 at -0.50 V vs SCE provides the detection limit of 5 M H2O2. A plot of current density versus concentration has two segments suggesting a change in the mechanism of H2O2 reduction at concentrations of H2O2 ≥ 2 mM. From the rotating disc electrode study, diffusion co-efficient of H2O2 and rate constant for reduction of H2O2 are evaluated.

  19. Quantification of fibrinogen adsorption onto 316L stainless steel.

    Science.gov (United States)

    Gettens, Robert T T; Gilbert, Jeremy L

    2007-05-01

    Adsorption of the plasma protein fibrinogen (Fb) onto 316L stainless steel (316L SS) was observed and quantified using both in situ and ex situ atomic force microscopy techniques. Industry standard mechanical and electrochemical polishing techniques were used to prepare bulk alloy 316L SS samples, rendering the surfaces flat enough to directly observe and measure Fb adsorption. The data were analyzed kinetically using a Langmuir model. Largely irreversible adsorption was found on the 316L SS surface with an adsorption rate constant (k(o)) of 1.9 x 10(-4) mL microg(-1) s(-1) using the ex situ method and 1.7 x 10(-4) mL microg(-1) s(-1) using the in situ method. Additionally, protein conformation and assembly orientation on these surfaces were documented, where the adsorption pattern appeared random. Complete area coverage was never obtained. That is, after adsorption for over 5 time constants (5tau), voids in the structure were always observed.

  20. Fibrinogen adsorption onto 316L stainless steel under polarized conditions.

    Science.gov (United States)

    Gettens, Robert T T; Gilbert, Jeremy L

    2008-04-01

    Adsorption of the plasma protein fibrinogen onto electrically polarized 316L stainless steel was observed and quantified using both in situ and ex situ atomic force microscopy (AFM) techniques. Significant differences in fibrinogen adsorption were observed across voltages. Ex situ studies showed significantly lower area coverage (theta) and height of adsorbed Fb on cathodically polarized surfaces when compared to anodically polarized surfaces. Conformational differences in the protein may explain the distinctions in Fb surface area coverage (theta) and height between the anodic and cathodic cases. In situ studies showed significantly slower kinetics of Fb adsorption onto surfaces below -100 mV (vs. Ag/AgCl) compared to surfaces polarized above -100 mV. Electrochemical current density data showed large charge transfer processes (approximately 1 x 10(-5) to 1 x 10(-4) A/cm(2)) taking place on the 316L SS surfaces at voltages below -100 mV (vs. Ag/AgCl). These relatively large current densities point to flux of ionic species away from the surface as a major source of the reduction in adsorption kinetics rather than just hydrophilic or electrostatic effects.