Study of carbonitriding thermochemical treatment by plasma screen in active with pressures main austenitic stainless steels AISI 409 and AISI 316L; Estudo do tratamento termoquimico de carbonitretacao por plasma em tela ativa com pressoes variaveis nos acos inoxidaveis austenitico AISI 316L e ferririco AISI 409

Energy Technology Data Exchange (ETDEWEB)

Melo, M.S.; Oliveira, A.M.; Leal, V.S.; Sousa, R.R.M. de; Alves Junior, C. [Centro Federal de Educacao Tecnologica do Maranhao (CEFET/MA), Sao Luis, MA (Brazil); Centro Federal de Educacao Tecnologica do Piaui (CEFET/PI), Teresina, PI (Brazil); Universidade Federal do Rio Grande do Norte (DF/UFRN), Natal, RN (Brazil). Dept. de Fisica. Labplasma

2010-07-01

The technique called Active Screen Plasma Nitriding (ASPN) is being used as an alternative once it offers several advantages with respect to conventional DC plasma. In this method, the plasma does not form directly in the sample's surface but on a screen, in such a way that undesired effects such as the edge effect is minimized. Stainless steels present not very satisfactory wearing characteristics. However, plasma carbonitriding has been used as to improve its resistance to wearing due to the formation of a fine surface layer with good properties. In this work, samples of stainless steel AISI 316L and AISI 409 were treated at pressures of 2.5 and 5 mbar. After the treatments they were characterized by microhardness, microscopy and Xray diffraction. Microscopy and hardness analysis showed satisfactory layers and toughness in those steels. (author)

Microstructural changes of AISI 316L due to structural sensitization and its influence on the fatigue properties

Directory of Open Access Journals (Sweden)

Sylvia Dundeková

2014-11-01

Full Text Available Mechanical and fatigue properties of material are dependent on its microstructure. The microstructure of AISI 316L stainless steel commonly used for the production of medical tools, equipment and implants can be easily influenced by its heat treatment. Microstructural changes and fatigue properties of AISI 316L stainless steel due to the heat treatment consisted of annealing at the temperature of 815°C with the dwell time of 500 hours were analyzed in the present paper. Precipitation of intermetallic phases and carbides was observed as a response of the material to the applied heat treatment. Small negative influence was observed in the case of fatigue region bellow 105 cycles; however the fatigue limit remains unchanged due to the structural sensitization.

Cold deformation effect on the microstructures and mechanical properties of AISI 301LN and 316L stainless steels

International Nuclear Information System (INIS)

Silva, Paulo Maria de O.; Abreu, Hamilton Ferreira G. de; Albuquerque, Victor Hugo C. de; Neto, Pedro de Lima; Tavares, Joao Manuel R.S.

2011-01-01

As austenitic stainless steels have an adequate combination of mechanical resistance, conformability and resistance to corrosion they are used in a wide variety of industries, such as the food, transport, nuclear and petrochemical industries. Among these austenitic steels, the AISI 301LN and 316L steels have attracted prominent attention due to their excellent mechanical resistance. In this paper a microstructural characterization of AISI 301LN and 316L steels was made using various techniques such as metallography, optical microscopy, scanning electronic microscopy and atomic force microscopy, in order to analyze the cold deformation effect. Also, the microstructural changes were correlated with the alterations of mechanical properties of the materials under study. One of the numerous uses of AISI 301LN and 316L steels is in the structure of wagons for metropolitan surface trains. For this type of application it is imperative to know their microstructural behavior when subjected to cold deformation and correlate it with their mechanical properties and resistance to corrosion. Microstructural analysis showed that cold deformation causes significant microstructural modifications in these steels, mainly hardening. This modification increases the mechanical resistance of the materials appropriately for their foreseen application. Nonetheless, the materials become susceptible to pitting corrosion.

Microstructural changes of AISI 316L due to structural sensitization and its influence on the fatigue properties

Czech Academy of Sciences Publication Activity Database

Dundeková, S.; Nový, F.; Fintová, Stanislava

2014-01-01

Roč. 21, č. 4 (2014), s. 172-177 ISSN 1335-0803 Institutional support: RVO:68081723 Keywords : AISI 316L * Structural sensitization * Rotating bending fatigue test Subject RIV: JL - Materials Fatigue, Friction Mechanics

Study of carbonitriding thermochemical treatment by plasma screen in active with pressures main austenitic stainless steels AISI 409 and AISI 316L

International Nuclear Information System (INIS)

Melo, M.S.; Oliveira, A.M.; Leal, V.S.; Sousa, R.R.M. de; Alves Junior, C.; Centro Federal de Educacao Tecnologica do Piaui; Universidade Federal do Rio Grande do Norte

2010-01-01

The technique called Active Screen Plasma Nitriding (ASPN) is being used as an alternative once it offers several advantages with respect to conventional DC plasma. In this method, the plasma does not form directly in the sample's surface but on a screen, in such a way that undesired effects such as the edge effect is minimized. Stainless steels present not very satisfactory wearing characteristics. However, plasma carbonitriding has been used as to improve its resistance to wearing due to the formation of a fine surface layer with good properties. In this work, samples of stainless steel AISI 316L and AISI 409 were treated at pressures of 2.5 and 5 mbar. After the treatments they were characterized by microhardness, microscopy and Xray diffraction. Microscopy and hardness analysis showed satisfactory layers and toughness in those steels. (author)

Z phase stability in AISI 316LN + Nb austenitic steels during creep at 650 C

Energy Technology Data Exchange (ETDEWEB)

Vodarek, Vlastimil [Technical Univ. Ostrava (Czech Republic)

2010-07-01

The creep resistance of austenitic CrNi(Mo) steels strongly depends on microstructural stability during creep exposure. Nitrogen additions to CrNi(Mo) austenitic steels can significantly improve the creep strength. One of the most successful methods of improving the long-term creep resistance of austenitic steels is based on increasing the extent of precipitation strengthening during creep exposure. The role of precipitates in the achievements of good creep properties has been extensively studied for a long time. Although many minor phases are now well documented there are still contractions and missing thermodynamic data about some minor phases. This contribution deals with results of microstructural studies on the minor phase evolution in wrought AISI 316LN niobium stabilised steels during long-term creep exposure at 650 C. Microstructural investigations were carried out on specimens taken from both heads and gauge lengths of ruptured test-pieces by means of optical metallography, transmission and scanning electron microscopy. The attention has been paid to evaluation of thermodynamic and dimensional stability of Z phase and other nitrogen bearing minor phases. Only two nitrogen-bearing minor phases formed in the casts investigated: Z phase and M{sub 6}X. The dimensional stability of Z phase particles was very high. (orig.)

Corrosion and microstructural analysis data for AISI 316L and AISI 347H stainless steels after exposure to a supercritical water environment

Directory of Open Access Journals (Sweden)

A. Ruiz

2016-06-01

Full Text Available This article presents corrosion data and microstructural analysis data of austenitic stainless steels AISI 316L and AISI 347H exposed to supercritical water (25 MPa, 550 °C with 2000 ppb of dissolved oxygen. The corrosion tests lasted a total of 1200 h but were interrupted at 600 h to allow measurements to be made. The microstructural data have been collected in the grain interior and at grain boundaries of the bulk of the materials and at the superficial oxide layer developed during the corrosion exposure.

Effect of the hydrogen charging of AISI 316 stainless steel from solutions containing As2 O3

International Nuclear Information System (INIS)

Brito, S.D. de.

1973-01-01

The hydrogen charging of AISI 316 stainless steel has turned unstable the austenitic structure which partially decomposes into two phases: ε (hexagonal close packed) and α ' (body centered cubic). A 1 N H 2 SO 4 solution was used as electrolyte, with varying concentrations of As 2 O 3 (0, 1, 5 and 100 mg/l) for a single constant applied current density (i o = 0,22 A/cm 2 ). It was observed that a smaller austenitic grain as well as a larger hydrogen charging time, improve the phase transformation. It was established that the order in which the transformation products of the austenite appear through hydrogen charging follows the sequence: Y → Y-bar + ε → Y + ε + α ', although there is still some doubt about the equivalent transformation order by plastic deformation. (author)

The effect of CO{sub 2} laser beam welded AISI 316L austenitic stainless steel on the viability of fibroblast cells, in vitro

Energy Technology Data Exchange (ETDEWEB)

Köse, Ceyhun, E-mail: ceyhun.kose@gop.edu.tr [Faculty of Natural Sciences and Engineering, Department of Mechanical Engineering, Gaziosmanpaşa University, Tokat (Turkey); Kaçar, Ramazan, E-mail: rkacar@karabuk.edu.tr [Faculty of Technology Department of Manufacturing Engineering, Karabuk University, Karabuk 78050 (Turkey); Zorba, Aslı Pınar, E-mail: aslipinarzorba@gmail.com [Graduate School of Natural and Applied Sciences, Department of Bioengineering Cell Culture and Tissue Engineering, Yıldız Technical University, Istanbul (Turkey); Bağırova, Melahat, E-mail: mbagir@yildiz.edu.tr [Department of Bioengineering Cell Culture and Tissue Engineering, Yıldız Technical University, Istanbul (Turkey); Allahverdiyev, Adil M., E-mail: adil@yildiz.edu.tr [Department of Bioengineering Cell Culture and Tissue Engineering, Yıldız Technical University, Istanbul (Turkey)

2016-03-01

It has been determined by the literature research that there is no clinical study on the in vivo and in vitro interaction of the cells with the laser beam welded joints of AISI 316L biomaterial. It is used as a prosthesis and implant material and that has adequate mechanical properties and corrosion resistance characteristics. Therefore, the interaction of the CO{sub 2} laser beam welded samples and samples of the base metal of AISI 316L austenitic stainless steel with L929 fibroblast cells as an element of connective tissue under in vitro conditions has been studied. To study the effect of the base metal and the laser welded test specimens on the viability of the fibroblast cells that act as an element of connective tissues in the body, they were kept in DMEMF-12 medium for 7, 14, 28 days and 18 months. The viability study was experimentally studied using the MTT method for 7, 14, 28 days. In addition, the direct interaction of the fibroblast cells seeded on 6 different plates with the samples was examined with an inverted microscope. The MTT cell viability experiment was repeated on the cells that were in contact with the samples. The statistical relationship was analyzed using a Tukey test for the variance with the GraphPad statistics software. The data regarding metallic ion release were identified with the ICP-MS method after the laser welded and main material samples were kept in cell culture medium for 18 months. The cell viability of the laser welded sample has been detected to be higher than that of the base metal and the control based on 7th day data. However, the laser welded sample's viability of the fibroblast cells has diminished by time during the test period of 14 and 28 days and base metal shows better viability when compared to the laser welded samples. On the other hand, the base metal and the laser welded sample show better cell viability effect when compared to the control group. According to the ICP-MS results of the main material and

Corrosion Resistance Evaluation of Welded AISI 316 Stainless Steel by Electrochemical Method

International Nuclear Information System (INIS)

Baik, Shin Young; Kim, Kwan Hyu

1990-01-01

Electrochemical potentiokinetic polarization technique is known as quantitative, non-destructive and a rapid method for detecting sensitization and is essentially suitable for use in industrial fields and as laboratory research tools. In this study, electrochemical method was tested as a convenient means of the corrosion resistance evaluation for AISI 316L and 316 stainless steel(SS) and their welded sections. The sections were welded by TIG, MIG, CO 2 and ARC in 0.5N HCl as well as 1N H 2 SO 4 electrolyte with or without 0.01N KSCN. The results confirmed that electrochemical method could be used conveniently for corrosion resistance evaluation except reactivation aspect

Long-range effect in nitrogen ion-implanted AISI 316L stainless steel

Science.gov (United States)

Budzynski, P.

2015-01-01

The effect of nitrogen ion implantation on AISI 316L stainless steel was investigated. The microstructure and composition of an N implanted layer were studied by RBS, GIXRD, SEM, and EDX measurements. Friction and wear tests were also performed. The discrepancy between the measured and calculated stopped ion maximum range does not exceed 0.03 μm. After nitrogen implantation with a fluence of 5 × 1017 ion/cm2, additional phases of expanded austenite were detected. At a 5-fold larger depth than the maximum ion range, improvement in the coefficient of friction and wear was detected. We have shown, for the first time, the long-range effect in tribological investigations. The long-range effect is caused by movement of not only defects along the depth of the sample, as assumed so far, but also nitrogen atoms.

Corrosion studies on type AISI 316L stainless steel and other materials in lithium-salt solutions

International Nuclear Information System (INIS)

Zheng, J.H.; Bogaerts, W.F.; Agema, K.; Phlippo, K.; Bruggeman, A.; Lorenzetto, P.; Embrechts, M.J.

1991-01-01

A possible concept for the blanket for next generation fusion devices is the lithium salt blanket, where lithium salt is dissolved in an aqueous coolant in order to provide for tritium. Type AISI 316L stainless steel has been considered as a structural material for such a blanket for NET (Next European Torus), and a systematic study of the corrosion behaviour of 316L stainless steel has been carried out in a number of lithium salt solutions. The experiments include cyclic potentiodynamic polarization measurement, crevice corrosion fatigue and stress corrosion cracking (SCC) tests. This paper presents a part of novel corrosion results concerning the compatibility of 316L steel and a series of other materials relevant to a fusion blanket environment. No major uniform corrosion problem has been observed, but localized corrosion, particularly corrosion fatigue and SCC, of 316L stainless steel have been found so far in a lithium hydroxide solution under some specific potential conditions. The critical electrochemical potential zones for SCC have been identified in the present study. (orig.)

Swelling behavior of titanium-modified AISI 316 alloys

International Nuclear Information System (INIS)

Garner, F.A.; Brager, H.R.; Puigh, R.J.

1984-01-01

It appears that titanium additions to stainless steels covering a wide compositional range around the specifications of AISI 316 result only in an increased delay period before neutron-induced void swelling proceeds. Once swelling is initiated the post transient behavior of both annealed and cold-worked titanium-modified steels is quite consistent with that of AISI 316, approaching a relatively temperature-independent swelling rate of approx. 1% per dpa

Characterization of metallurgical and mechanical properties on the multi-pass welding of Inconel 625 and AISI 316L

Energy Technology Data Exchange (ETDEWEB)

Kumar, K. Gokul; Ramkumar, K. Devendranath; Arivazhagan, N. [VIT University, Vellore (India)

2015-03-15

This article investigated the weldability, metallurgical and mechanical properties of Inconel 625 and AISI 316L stainless steel weldments obtained by continuous current (CC) and pulsed current (PC) gas tungsten arc welding (GTAW) processes employing ERNiCr-3 and ER2209 fillers. Microstructure studies showed the migrated grain boundaries at the weld zone of ERNiCr-3 weldments and multidirectional grain growth for ER2209 weldments. It was inferred from the tension tests that the fracture occurred at the parent metal of AISI 316L in all the cases. Charpy V-notch impact tests accentuated that the CCGTA weldments employing ERNiCr-3 filler offered better impact toughness of 77 J at room temperature. Further a detailed study has been carried out to analyze the structure - property relationships of these weldments using the combined techniques of scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analysis.

Development of AISI 316L stainless steel coronary stent

Science.gov (United States)

García-López, Erika; Siller, Héctor R.; Rodríguez, Ciro A.

2018-02-01

Coronary stents are manufactured through a sequence of processes and each step demands the process control to assure surface quality. This study is focused on the influence of laser cutting parameters and electropolishing on average surface roughness and back wall dross percentage for fiber laser cutting of AISI 316L coronary struts. A preliminary test and a design of experiments (DOE) were implemented to determine the limiting cutting conditions and the effect of these parameters on quality indicators. Preliminary results identify four cutting zones from a non-cut zone to a burned zone, in a frequency range between 1000 and 1500 Hz and a peak power between 160 to 180 W for clean cuts. From the DOE results, several interactions between factors were observed; however, a laser frequency of 1000 to 1500 Hz and a cutting speed of 250 mm/min minimize the backwall dross percentage and the surface roughness to values less than 2% and 0.9 μm, respectively. After the laser conditions selection, coronary stents were manufactured and electropolished to reduce the surface roughness on the strut edge. Electropolishing results indicate a surface roughness reduction from 0.9 μm to 0.3 μm after 300 s of electropolishing time.

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

Indian Academy of Sciences (India)

Unknown

rical relation connecting the aging temperature, aging time and nitrogen ... strength, high tensile strength, are easy to fabricate and ... However, the ferrite is a metastable phase which ... 2. Experimental. 2.1 Materials. Nuclear grade AISI 316 stainless steel plates ( .... fore, it is desirable to develop empirical relations con-.

Thermogalvanic corrosion and galvanic effects of copper and AISI 316L stainless steel pairs in heavy LiBr brines under hydrodynamic conditions

International Nuclear Information System (INIS)

Sánchez-Tovar, R.; Montañés, M.T.; García-Antón, J.

2012-01-01

Highlights: ► Thermogalvanic corrosion results in an increase of the current densities. ► Thermogalvanic effect increases as temperature difference between tubes is higher. ► Potentials fit linearly with increase in temperature. ► ZRA shows hot cathodes for AISI 316L while cold ones for copper and galvanic pairs. ► Weight loss tests show a combined effect between thermogalvanic and galvanic effects. - Abstract: Thermogalvanic corrosion of the copper/copper and AISI 316L/AISI 316L stainless steel pairs was studied in heavy lithium bromide brines under hydrodynamic conditions. The galvanic coupling effect between copper and stainless steel was also analysed. The cold electrode (25 °C) was the stainless steel for the galvanic pair, whereas copper temperature varied (25, 50 and 75 °C). A hydrodynamic circuit was designed to study thermogalvanic corrosion by means of the zero resistance ammeter technique. Hot cathodes take place in stainless steel pairs while cold cathodes are present in copper/copper and stainless steel/copper pairs; this agrees with the thermal temperature coefficient of the potential sign. Thermogalvanic corrosion increases corrosion rates, especially working with copper. Weight loss measurements show that there is a combined effect due to the thermogalvanic and the galvanic effects.

Quantitative Evaluation of Aged AISI 316L Stainless Steel Sensitization to Intergranular Corrosion: Comparison Between Microstructural Electrochemical and Analytical Methods

Science.gov (United States)

Sidhom, H.; Amadou, T.; Sahlaoui, H.; Braham, C.

2007-06-01

The evaluation of the degree of sensitization (DOS) to intergranular corrosion (IGC) of a commercial AISI 316L austenitic stainless steel aged at temperatures ranging from 550 °C to 800 °C during 100 to 80,000 hours was carried out using three different assessment methods. (1) The microstructural method coupled with the Strauss standard test (ASTM A262). This method establishes the kinetics of the precipitation phenomenon under different aging conditions, by transmission electronic microscope (TEM) examination of thin foils and electron diffraction. The subsequent chromium-depleted zones are characterized by X-ray microanalysis using scanning transmission electronic microscope (STEM). The superimposition of microstructural time-temperature-precipitation (TTP) and ASTM A262 time-temperature-sensitization (TTS) diagrams provides the relationship between aged microstructure and IGC. Moreover, by considering the chromium-depleted zone characteristics, sensitization and desensitization criteria could be established. (2) The electrochemical method involving the double loop-electrochemical potentiokinetic reactivation (DL-EPR) test. The operating conditions of this test were initially optimized using the experimental design method on the bases of the reliability, the selectivity, and the reproducibility of test responses for both annealed and sensitized steels. The TTS diagram of the AISI 316L stainless steel was established using this method. This diagram offers a quantitative assessment of the DOS and a possibility to appreciate the time-temperature equivalence of the IGC sensitization and desensitization. (3) The analytical method based on the chromium diffusion models. Using the IGC sensitization and desensitization criteria established by the microstructural method, numerical solving of the chromium diffusion equations leads to a calculated AISI 316L TTS diagram. Comparison of these three methods gives a clear advantage to the nondestructive DL-EPR test when it is

Pre- and postirradiation properties of brazed joints of AISI 316L stainless steel

International Nuclear Information System (INIS)

Brossa, M.; Franconi, E.; Guerreschi, U.; Pierazzi, L.; Poggi, P.; Rustia, V.

1994-01-01

An extensive test campaign has been performed to verify the reliability and the endurance of brazed joints between AISI 316L parts for structural applications in the nuclear field. The tests, conducted for comparison with three different high melting temperature alloys, included tensile tests (normal and shear), fatigue tests (fatigue crack propagation, low cycle fatigue, 4-point bending fatigue) and impact tests; besides, tensile tests have been performed with both unirradiated and irradiated specimens. Generally, the tests demonstrated satisfactory mechanical properties of the joints and revealed occasionally strong differences in the behaviour of the different brazing alloys, thus providing important design indications. ((orig.))

Investigations on the creep-rupture behaviour of the austenitic stainless steel AISI 316 NET

International Nuclear Information System (INIS)

Schirra, M.; Ritter, B.

1988-12-01

The report describes the creep-rupture tests carried out with a 17/13/2 CrNiMo-steel in the frame of the German-Spanish collaboration (KfK-CIEMAT). The material studied is the austenitic steel AISI 316(L) selected as potential first-wall material for NET (Next European Torus). The test programme on base material with a NET specified batch encompasses until now in the temperature range 500-750 0 C the rupture-time-range till 20 000 h. The results permit statements to the creep- and creep-rupture behaviour and ductility. Metallography examinations give information about fracture behaviour and demonstrate the complex precipitation happening. The results are compared with the literature and own test results from two batches of the Fast-Breeder-Program. (orig.) [de

Laser cladding of Colmonoy 6 powder on AISI316L austenitic stainless steel

International Nuclear Information System (INIS)

Zhang, H.; Shi, Y.; Kutsuna, M.; Xu, G.J.

2010-01-01

Stainless steels are widely used in nuclear power plant due to their good corrosion resistance, but their wear resistance is relatively low. Therefore, it is very important to improve this property by surface treatment. This paper investigates cladding Colmonoy 6 powder on AISI316L austenitic stainless steel by CO 2 laser. It is found that preheating is necessary for preventing cracking in the laser cladding procedure and 450 o C is the proper preheating temperature. The effects of laser power, traveling speed, defocusing distance, powder feed rate on the bead height, bead width, penetration depth and dilution are investigated. The friction and wear test results show that the friction coefficient of specimens with laser cladding is lower than that of specimens without laser cladding, and the wear resistance of specimens has been increased 53 times after laser cladding, which reveals that laser cladding layer plays roles on wear resistance. The microstructures of laser cladding layer are composed of Ni-rich austenitic, boride and carbide.

Adhesion of composite carbon/hydroxyapatite coatings on AISI 316L medical steel

Directory of Open Access Journals (Sweden)

J. Gawroński

2009-07-01

Full Text Available In this paper are contains the results of studies concerning the problems associated with increased of hydroxyapatite (HAp adhesion, manufactured by using Pulse Laser Deposition (PLD method, to the austenitic steel (AISI 316L through the coating of carbon interlayer on it. Carbon coating was deposited by Radio Frequency Plasma Assisted Chemical Vapour Deposition (RF PACVD method.Test results unequivocally showed that the intermediate carbon layer in a determined manner increase the adhesion of hydroxyapatite to the metallic substrate. Obtained results give rise to deal with issues of manufacturing composite bilayer – carbon film/HAp – on ready implants, casted from austenitic cast steel by lost-wax process method as well as in gypsum forms.

The effect of CO2 laser beam welded AISI 316L austenitic stainless steel on the viability of fibroblast cells, in vitro.

Science.gov (United States)

Köse, Ceyhun; Kaçar, Ramazan; Zorba, Aslı Pınar; Bağırova, Melahat; Allahverdiyev, Adil M

2016-03-01

It has been determined by the literature research that there is no clinical study on the in vivo and in vitro interaction of the cells with the laser beam welded joints of AISI 316L biomaterial. It is used as a prosthesis and implant material and that has adequate mechanical properties and corrosion resistance characteristics. Therefore, the interaction of the CO2 laser beam welded samples and samples of the base metal of AISI 316L austenitic stainless steel with L929 fibroblast cells as an element of connective tissue under in vitro conditions has been studied. To study the effect of the base metal and the laser welded test specimens on the viability of the fibroblast cells that act as an element of connective tissues in the body, they were kept in DMEMF-12 medium for 7, 14, 28 days and 18 months. The viability study was experimentally studied using the MTT method for 7, 14, 28 days. In addition, the direct interaction of the fibroblast cells seeded on 6 different plates with the samples was examined with an inverted microscope. The MTT cell viability experiment was repeated on the cells that were in contact with the samples. The statistical relationship was analyzed using a Tukey test for the variance with the GraphPad statistics software. The data regarding metallic ion release were identified with the ICP-MS method after the laser welded and main material samples were kept in cell culture medium for 18 months. The cell viability of the laser welded sample has been detected to be higher than that of the base metal and the control based on 7th day data. However, the laser welded sample's viability of the fibroblast cells has diminished by time during the test period of 14 and 28 days and base metal shows better viability when compared to the laser welded samples. On the other hand, the base metal and the laser welded sample show better cell viability effect when compared to the control group. According to the ICP-MS results of the main material and laser welded

Radiation-induced evolution of austenite matrix in silicon-modified AISI 316 alloys

International Nuclear Information System (INIS)

Garner, F.A.; Brager, H.R.

1980-01-01

The microstructures of a series of silicon-modified AISI 316 alloys irradiated to fast neutron fluences of about 2-3 and 10 x 10 22 n/cm 2 (E > 0.1 MeV at temperatures ranging from 400 0 C to 600 0 C have been examined. The irradiation of AISI 316 leads to an extensive repartition of several elements, particularly nickel and silicon, between the matrix and various precipitate phases. The segregation of nickel at void and grain boundary surfaces at the expense of other faster-diffusing elements is a clear indication that one of the mechanisms driving the microchemical evolution is the Inverse Kirkendall effect. There is evidence that at one sink this mechanism is in competition with the solute drag process associated with interstitial gradients

Impact of the surface roughness of AISI 316L stainless steel on biofilm adhesion in a seawater-cooled tubular heat exchanger-condenser.

Science.gov (United States)

García, Sergio; Trueba, Alfredo; Vega, Luis M; Madariaga, Ernesto

2016-11-01

The present study evaluated biofilm growth in AISI 316L stainless steel tubes for seawater-cooled exchanger-condensers that had four different arithmetic mean surface roughness values ranging from 0.14 μm to 1.2 μm. The results of fluid frictional resistance and heat transfer resistance regarding biofilm formation in the roughest surface showed increases of 28.2% and 19.1% respectively, compared with the smoothest surface. The biofilm thickness taken at the end of the experiment showed variations of up to 74% between the smoothest and roughest surfaces. The thermal efficiency of the heat transfer process in the tube with the roughest surface was 17.4% greater than that in the tube with the smoothest surface. The results suggest that the finish of the inner surfaces of the tubes in heat exchanger-condensers is critical for improving energy efficiency and avoiding biofilm adhesion. This may be utilised to reduce biofilm adhesion and growth in the design of heat exchanger-condensers.

TIG AISI-316 welds using an inert gas welding chamber and different filler metals: Changes in mechanical properties and microstructure

Directory of Open Access Journals (Sweden)

Sánchez, A.

2010-12-01

Full Text Available This report analyses the influence of the use of an inert gas welding chamber with a totally inert atmosphere on the microstructure and mechanical properties of austenitic AISI 316L stainless steel TIG welds, using AISI ER316L, AISI 308L and Inconel 625 as filler metals. When compared with the typical TIG process, the use of the inert gas chamber induced changes in the microstructure, mainly an increase in the presence of vermicular ferrite and ferrite stringers, what resulted in higher yield strengths and lower values of hardness. Its effect on other characteristics of the joins, such as tensile strength, depended on the filler metal. The best combination of mechanical characteristics was obtained when welding in the inert gas chamber using Inconel 625 as filler metal.

En este estudio se analiza la influencia que el uso de una cámara de soldadura de gas inerte tiene sobre la microestructura y las propiedades mecánicas de las soldaduras TIG en el acero inoxidable austenítico AISI-316L cuando se emplean AISI ER316L, AISI 308L e Inconel 625 como materiales de aporte. Cuando se compara con el típico proceso de TIG, el uso de una cámara de gas inerte induce cambios en la microestructura, incrementando la presencia de ferrita vermicular y de laminillas de ferrita, resultando en un aumento del límite elástico y una pérdida de dureza. Su influencia sobre otras características de las soldaduras como la carga de rotura depende de la composición del material de aporte. La mejor combinación de propiedades mecánicas se obtuvo usando el Inconel 625 como material de aporte y soldando en la cámara de gas inerte.

Effects of nitrogen and pulsed mean welding current in AISI 316 austenitic stainless steel solidification cracks; Efecto del nitrogeno y la corriente media pulsada de soldadura en la formacion de grietas de solidificacion en aceros inoxidables AISI 316L

Energy Technology Data Exchange (ETDEWEB)

Trevisan, R. E.; Braga, E.; Fals, H. C.

2002-07-01

An analysis of the influence of nitrogen concentration in the weld zone and the pulsed mean welding current in the solidification crack formation is presented in this paper. The AISI 316L austenitic stainless steel was employed as the metal base. The welding was done using CC+ pulsed flux cored are welding process and AWS E316L wire type. The tests were conducted using CO{sub 2} shielding gas with four different nitrogen levels (0,5; 10 and 15%) in order to induce different nitrogen weld metal concentrations. The pulsed mean welding current was varied in three levels and the. Transvarestraint tangential strain test was fixed of 5%. The results showed that the solidification cracking decreased as the pulsed mean welding current increase. It was also verified that an increase of the weld zone nitrogen level was associated with a decrease in both the total length of solidification crack and the amount of {delta} ferrite. (AUthor) 20 refs.

Ion Beam Analysis, structure and corrosion studies of nc-TiN/a-Si{sub 3}N{sub 4} nanocomposite coatings deposited by sputtering on AISI 316L

Energy Technology Data Exchange (ETDEWEB)

García, J. [Departamento de Ingeniería de Proyectos, CUCEI, Universidad de Guadalajara, J. Guadalupe Zuno 48, Los Belenes, Zapopan, Jal. 45101 (Mexico); Canto, C.E. [Instituto de Física, UNAM, Avenida de la Investigación S/N, Coyoacán, México, D.F. 04510 (Mexico); Flores, M. [Departamento de Ingeniería de Proyectos, CUCEI, Universidad de Guadalajara, J. Guadalupe Zuno 48, Los Belenes, Zapopan, Jal. 45101 (Mexico); Andrade, E., E-mail: andrade@fisica.unam.mx [Instituto de Física, UNAM, Avenida de la Investigación S/N, Coyoacán, México, D.F. 04510 (Mexico); Rodríguez, E.; Jiménez, O. [Departamento de Ingeniería de Proyectos, CUCEI, Universidad de Guadalajara, J. Guadalupe Zuno 48, Los Belenes, Zapopan, Jal. 45101 (Mexico); Solis, C.; Lucio, O.G. de [Instituto de Física, UNAM, Avenida de la Investigación S/N, Coyoacán, México, D.F. 04510 (Mexico); Rocha, M.F. [ESIME-Z, Instituto Politécnico Nacional, ALM Zacatenco, México, D.F. 07738 (Mexico)

2014-07-15

In this work, nanocomposite coatings of nc-TiN/a-Si{sub 3}N{sub 4}, were deposited on AISI 316L stainless steel substrate by a DC and RF reactive magnetron co-sputtering technique using an Ar–N{sub 2} plasma. The structure of the coatings was characterized by means of XRD (X-ray Diffraction). The substrate and coating corrosion resistance were evaluated by potentiodynamic polarization using a Ringer solution as electrolyte. Corrosion tests were conducted with the purpose to evaluate the potential of this coating to be used on biomedical alloys. IBA (Ion Beam Analysis) techniques were applied to measure the elemental composition profiles of the films and, XPS (X-ray Photoelectron Spectroscopy) were used as a complementary technique to obtain information about the compounds present in the films. The nanocomposite coatings of nc-TiN/a-Si{sub 3}N{sub 4} show crystalline (TiN) and amorphous (Si{sub 3}N{sub 4}) phases which confer a better protection against the corrosion effects compared with that of the AISI 316L.

Helium and its effects on the creep-fatigue behaviour of electron beam welds in the steel AISI-316-L

International Nuclear Information System (INIS)

Paulus, M.

1992-12-01

Within the scope of R and D work for materials development for the NET fusion experiment (Next European Torus) and the International Thermonuclear Experimental Reactor (ITER), the task reported was to examine electron beam welds in the austenitic stainless steel AISI 316 L (NET reference material) for their fatigue behaviour under creep load, and the effects of helium implantation on there mechanical properties. (orig.) [de

Spinodal decomposition in AISI 316L stainless steel via high-speed laser remelting

Energy Technology Data Exchange (ETDEWEB)

Chikarakara, Evans, E-mail: evans.chikarakara2@mail.dcu.ie [Advanced Processing Technology Research Centre, Dublin City University, Dublin (Ireland); Naher, Sumsun, E-mail: sumsun.naher@city.ac.uk [School of Engineering and Mathematical Sciences, City University London (United Kingdom); Brabazon, Dermot, E-mail: dermot.brabazon@dcu.ie [Advanced Processing Technology Research Centre, Dublin City University, Dublin (Ireland)

2014-05-01

A 1.5 kW CO{sub 2} pulsed laser was used to melt the surface of AISI 316L stainless steel with a view to enhancing the surface properties for engineering applications. A 90 μm laser beam spot size focused onto the surface was used to provide high irradiances (up to 23.56 MW/cm{sup 2}) with low residence times (as low as 50 μs) in order to induce rapid surface melting and solidification. Variations in microstructure at different points within the laser treated region were investigated. From this processing refined lamellar and nodular microstructures were produced. These sets of unique microstructures were produced within the remelted region when the highest energy densities were selected in conjunction with the lowest residence times. The transformation from the typical austenitic structure to much finer unique lamellar and nodular structures was attributed to the high thermal gradients achieved using these selected laser processing parameters. These structures resulted in unique characteristics including elimination of cracks and a reduction of inclusions within the treated region. Grain structure reorientation between the bulk alloy and laser-treated region occurred due to the induced thermal gradients. This present article reports on microstructure forms resulting from the high-speed laser surface remelting and corresponding underlying kinetics.

TIG AISI-316 welds using an inert gas welding chamber and different filler metals: Changes in mechanical properties and microstructure

Energy Technology Data Exchange (ETDEWEB)

Pascual, M.; Salas, F.; Carcel, F.J.; Perales, M.; Sanchez, A.

2010-07-01

This report analyses the influence of the use of an inert gas welding chamber with a totally inert atmosphere on the microstructure and mechanical properties of austenitic AISI 316L stainless steel TIG welds, using AISI ER316L, AISI 308L and Inconel 625 as filler metals. When compared with the typical TIG process, the use of the inert gas chamber induced changes in the microstructure, mainly an increase in the presence of vermicular ferrite and ferrite stringers, what resulted in higher yield strengths and lower values of hardness. Its effect on other characteristics of the joins, such as tensile strength, depended on the filler metal. The best combination of mechanical characteristics was obtained when welding in the inert gas chamber using Inconel 625 as filler metal. (Author). 12 refs.

Effect of temperature and pressure on wear properties of ion nitrided AISI 316 and 409 stainless steels

International Nuclear Information System (INIS)

Fernandes, Frederico Augusto Pires; Heck, Stenio Cristaldo; Pereira, Ricardo Gomes; Casteletti, Luiz Carlos; Nascente, Pedro Augusto de Paula

2010-01-01

Stainless steels are widely used in chemical and other industries due to their corrosion resistance property. However, because of their low hardness and wear properties, their applications are limited. Many attempts have been made to increase the surface hardness of these materials by using plasma techniques. Plasma nitriding is distinguished by its effectiveness, and for presenting a relatively low cost and being a clean process, producing hard surface layers on stainless steels. Aiming to verify the influence of the temperature and pressure on the modified resultant layers, samples of AISI 316 and 409 stainless steels were plasma nitrided in two different temperatures (450 and 500°C) and pressures of 400, 500, and 600Pa for 5h. After the nitriding treatment, the layers were analyzed by means of optical microscopy and wear tests. Wear tests were conducted in a fixed-ball micro-wear machine without lubrication. After the plasma nitriding treatment on AISI 316 and 409 samples, homogeneous and continuous layers were produced and their thicknesses increased as the temperature increased, and as the pressure decreased. The nitriding treatment on the AISI 316 steel sample resulted on the formation of expanded austenite layers at 450°C, and chromium nitrides (CrN and Cr_2N) phases at 500°C. The nitriding treatment on AISI 409 sample yielded the formation of similar layers for both treatment temperatures; these layers constituted mainly by chromium (Cr_2N) and iron (Fe_2N, Fe3_N, and Fe_4N) nitrides. After the nitriding treatment, the AISI 316 steel sample presented higher wear resistance for lower temperature and pressure values. The increase on layer fragility, for higher temperature and pressure values can be responsible for this inverse tendency. The wear resistance of the nitrided AISI 409 sample followed a logic tendency: the harder the layer the better the performance, i.e. the performance was improved with the increase in both the temperature and pressure

Influence of enzymatic reactions on the electrochemical behavior of EN X2CrNiMo17-11-2 (AISI 316L) stainless steel in bio-corrosion: role of interfacial processes on the modification of the passive layer; Influence des reactions enzymatiques sur le comportement electrochimique de l'acier inoxydable ENX2CrNiMo17-11-2 (AISI 316L) en biocorrosion: role des processus interfaciaux sur la modification du film passif

Energy Technology Data Exchange (ETDEWEB)

Landoulsi, J

2008-01-15

The outstanding corrosion behavior of stainless steels (SS) results from the presence of thin oxide layer (some nanometers). In non sterile aqueous media, stainless steels may exhibit a non stable behavior resulting from interactions between microbial species and passive film. In fact, microorganisms can be deeply involved in the corrosion processes usually reported as Microbial Influenced Corrosion (MIC). They can induce the initiation or the acceleration of this phenomenon and they do so when organized in bio-films. From the electrochemical point of view, stainless steels showed an increase of the free corrosion potential (Ecorr) attributed to the bio-film settlement. The Eco' ennoblement was broadly reported in seawater and seems to be confirmed in fresh water according to recent findings. A considerable progress in the comprehension of MIC processes was related to the role of extracellular species, essentially enzymes. Many enzymatic reactions occurring in bio-films consist on using oxygen as electron acceptor to generate hydrogen peroxide and related species. The aim of this work is to understand the mechanisms involved in the electrochemical behavior of stainless steel according to an enzymatic approach in medium simulating fresh water. To this end, glucose oxidase was chosen to globalize aerobic activities of bio-films. Electrochemical measurements in situ and surface analysis allow the comprehension of the role and the nature of interfacial processes. Surface characterization was performed with the help of a new quantitative utilization of XPS analysis and AFM. Results show a significant evolution in term of morphology (surface organization), (ii) chemical composition (passive layer, adsorbed organic species) and (iii) chemical reaction (oxidation, dissolution, effect of enzyme). Finally, a new enzymatic system is proposed to mimic specific physicochemical conditions at the SS / bio-film interface, in particular enzymatic generation of oxidant species in diffusion limiting conditions. (author)

Improving the corrosion wear resistance of AISI 316L stainless steel by particulate reinforced Ni matrix composite alloying layer

Science.gov (United States)

Xu, Jiang; Zhuo, Chengzhi; Tao, Jie; Jiang, Shuyun; Liu, Linlin

2009-01-01

In order to overcome the problem of corrosion wear of AISI 316L stainless steel (SS), two kinds of composite alloying layers were prepared by a duplex treatment, consisting of Ni/nano-SiC and Ni/nano-SiO2 predeposited by brush plating, respectively, and subsequent surface alloying with Ni-Cr-Mo-Cu by a double glow process. The microstructure of the two kinds of nanoparticle reinforced Ni-based composite alloying layers was investigated by means of SEM and TEM. The electrochemical corrosion behaviour of composite alloying layers compared with the Ni-based alloying layer and 316L SS under different conditions was characterized by potentiodynamic polarization test and electrochemical impedance spectroscopy. Results showed that under alloying temperature (1000 °C) conditions, amorphous nano-SiO2 particles still retained the amorphous structure, whereas nano-SiC particles were decomposed and Ni, Cr reacted with SiC to form Cr6.5Ni2.5Si and Cr23C6. In static acidic solution, the corrosion resistance of the composite alloying layer with the brush plating Ni/nano-SiO2 particles interlayer is lower than that of the Ni-based alloying layer. However, the corrosion resistance of the composite alloying layer with the brush plating Ni/nano-SiO2 particles interlayer is prominently superior to that of the Ni-based alloying layer under acidic flow medium condition and acidic slurry flow condition. The corrosion resistance of the composite alloying layer with the brush plating Ni/nano-SiC particles interlayer is evidently lower than that of the Ni-based alloying layer, but higher than that of 316L SS under all test conditions. The results show that the highly dispersive nano-SiO2 particles are helpful in improving the corrosion wear resistance of the Ni-based alloying layer, whereas carbides and silicide phase are deleterious to that of the Ni-based alloying layer due to the fact that the preferential removal of the matrix around the precipitated phase takes place by the chemical

Effects of microplasma arc AISI 316L welds on the corrosion behaviour of pipelines in LiBr cooling systems

International Nuclear Information System (INIS)

Sánchez-Tovar, R.; Montañés, M.T.; García-Antón, J.

2013-01-01

Highlights: •SECM tests reveal differences in electrochemical activity of base and welded alloys. •The highest electrochemical activity is obtained for the welded alloy. •Microplasma arc welding process hinders passivation in lithium bromide. •Microplasma arc welding increases corrosion rate and susceptibility to pitting. •The galvanic pair between base and welded alloys in LiBr is weak. -- Abstract: The effect of microplasma arc welding (MPAW) on the electrochemical and corrosion behaviour of AISI 316L stainless steel tubes has been studied. Scanning electrochemical measurements were performed in sodium chloride to evaluate the difference in the electrochemical activity of base (non-welded) and welded samples. Oxygen reduction rates increase in AISI 316L due to the heat treatment effect induced by welding, indicating a higher electrochemical activity in the welded samples. Additionally, the use of MPA weldments in lithium bromide (LiBr) absorption machines was also analysed at typical operating temperatures and Reynolds numbers. The welding process increases corrosion rates, hinders passivation and increases the susceptibility to pitting attack in LiBr. However, zero-resistance ammeter and localization index measurements show that the galvanic pair generated between the base and welded alloys is weak, both electrodes being in their passive state. Temperature greatly affects the corrosion process

Aluminum coating by fluidized bed chemical vapor deposition on austenitic stainless steels AISI 304 and AISI 316

Directory of Open Access Journals (Sweden)

Jose Luddey Marulanda-Arevalo

2015-01-01

Full Text Available Los revestimientos de aluminio f ueron depositados sobre aceros inoxidables AISI 304 y AISI 316 en el rango de temperatura de 5 60 a 600 °C por deposición química de vapor en lecho fluidizado(CVD – FBR. Se utilizó un lecho que consistía en 10 % de aluminio en polvo y 90 % de lecho inerte (alúmina, el cual fue fluidizado con Ar y como ga ses activadores se utilizó una mezcla de ácido clorhídrico con hidrógeno (HCl/H 2 . En el recubrimiento si n tratamiento térmico están las siguiente s especies: Al 13 Fe 4 , Fe 2 Al 5 , FeAl 2 y Al 5 FeNi, las cuales están presentes para ambos aceros. Además, el tratamiento térmico provoca la difusa de alu minio hacia el sustrato y la difusa de hierro del sustrato haci a la superficie del recubrimiento, haciendo la trans formación de los compuestos ant eriores a FeAl, Fe 2 Al 5 , FeAl 2 , Al 0.99 Fe 0.99 Ni 0.02 , AlNi y el Fe 2 AlCr. Se realizó la simulación termodinámica con el s oftware Thermo Calc para obt ener información de la posible composición y la cantidad de mat erial depositado, para condiciones seleccionadas. Las muestras recubi ertas y sin recubrir, se expus ieron a 750 ºC en una atmósfera d onde el vapor agua se transporta a las muestras usando un flujo de N 2 de 40 ml/min, más 100 % vapor de agua (H 2 O. Los dos sustratos sin revestir se comportaron de manera diferente, ya que el acero AISI 304 soportó bien el a taque y ganó poco peso (0.49 mg/cm 2 , en comparación con el acero AISI 316 que perdió mucho peso (25.4 mg/cm 2 . Los aceros recubiertos ganaron poco de peso durante las mil horas de exposición (0.26 mg/cm 2 y soportaron muy bien el ataque corrosivo en c omparación con sustratos sin r ecubrimiento.

Effective Duration of Gas Nitriding Process on AISI 316L for the Formation of a Desired Thickness of Surface Nitrided Layer

Directory of Open Access Journals (Sweden)

Mahmoud Hassan R. S.

2014-07-01

Full Text Available High temperature gas nitriding performed on AISI 316L at the temperature of 1200°C. The microstructure of treated AISI 316L samples were observed to identify the formation of the microstructure of nitrided surface layer. The grain size of austenite tends to be enlarged when the nitriding time increases, but the austenite single phase structure is maintained even after the long-time solution nitriding. Using microhardness testing, the hardness values drop to the center of the samples. The increase in surface hardness is due to the high nitrogen concentration at or near the surface. At 245HV, the graph of the effective duration of nitriding process was plotted to achieve the maximum depth of nitrogen diffuse under the surface. Using Sigma Plot software best fit lines of the experimental result found and plotted to find out effective duration of nitriding equation as Y=1.9491(1-0.7947x, where Y is the thickness of nitrided layer below the surface and X is duration of nitriding process. Based on this equation, the duration of gas nitriding process can be estimated to produce desired thickness of nitrided layer.

PERFORMANCE STUDY ON AISI316 AND AISI410 USING DIFFERENT LAYERED COATED CUTTING TOOLS IN CNC TURNING

Directory of Open Access Journals (Sweden)

K. RAJA

2015-01-01

Full Text Available Stainless steel (SS is used for many commercial and industrial applications owing to its high resistance to corrosion. It is too hard to machine due to its high strength and high work hardening property. A surface property such as surface roughness (SR is critical to the function-ability of machined components. SS is generally regarded as more difficult to machine material and poor SR is obtained during machining. In this paper an attempt has been made to investigate the SR produced by CNC turning on austenitic stainless steel (AISI316 and martensitic stainless steel (AISI410 by different cases of coated cutting tool used at dry conditions. Multilayered coated with TiCN/Al2O3, multilayered coated with Ti(C, N, B and single layered coated with TiAlN coated cutting tools are used. Experiments were carried out by using Taguchi’s L27 orthogonal array. The effect of cutting parameters on SR is evaluated and optimum cutting conditions for minimizing the SR are determined. Analysis of variance (ANOVA is used for identifying the significant parameters affecting the responses. Confirmation experiments are conducted to validate the results obtained from optimization.

Microstructural interpretation of the fluence and temperature dependence of the mechanical properties of irradiated AISI 316

International Nuclear Information System (INIS)

Johnson, G.D.; Garner, F.A.; Brager, H.R.; Fish, R.L.

1980-01-01

The effects of neutron irradiation on the mechanical properties of annealed and 20% cold-worked AISI 316 irradiated in EBR-II were determined for the temperature regime of 370 to 760 0 C for fluences up to 8.4 x 10 22 n/cm 2 (E > 0.1 MeV). At irradiation temperatures below about 500 0 C, both annealed and cold-worked material exhibit a substantial increase in the flow stress with increasing fluence. Furthermore, both materials eventually exhibit the same flow stress, which is independent of fluence. At temperatures in the range of 538 to 650 0 C, the cold-worked material exhibits a softening with increasing fluence. Annealed AISI 316 in this temperature regime exhibits hardening and at a fluence of 2 to 3 x 10 22 n/cm 2 (E > 0.1 MeV) reaches the same value of flow stress as the cold-worked material

Evaluation of performance of AISI 444 steel for application in distillation towers; Avaliacao do desempenho do aco AISI 444 para aplicacao como 'lining' em torres de destilacao

Energy Technology Data Exchange (ETDEWEB)

Guimaraes, R.F.; Miranda, H.C. de; Farias, J.P. [Universidade Federal do Ceara (DEMM/UFC), Fortaleza, CE (Brazil). Dept. de Engenharia Metalurgica e de Materiais. Lab. de Caracterizacao de Materiais], e-mail: rf.guimaraes@yahoo.com.br

2008-07-01

In this work, the behavior of the AISI 444 ferritic stainless steel submitted to thermal fatigue test and their corrosion resistance in heavy crude oil was evaluated. The AWS E309MoL-16 and E316L-17 weld metal was employed as filler metal. Plates of the AISI 444 were welded on ASTM A-516 Gr. 60 plates and submitted to fatigue thermal cycle. Samples were extracted from plates welded and heat treated immersed in heavy crude oil at 300 deg C. Optical microscopy (OM), scanning electron microscopy (SEM) and energy dispersive of X-ray analysis (EDX) were used to characterize the microstructure and the corroded surface. The results show that the AISI 444 stainless steels did not present cracks after the thermal fatigue cycle and the heat treated immerse in heavy crude oil. The electrode AWS E309MoL-16 show better corrosion resistance than the AWS E316L-17. (author)

The influence of plasma nitriding on the fatigue behavior of austenitic stainless steel types AISI 316 and AISI 304

International Nuclear Information System (INIS)

Varavallo, Rogerio; Manfrinato, Marcos Dorigao; Rossino, Luciana Sgarbi; Spinelli, Dirceu; Riofano, Rosamel Melita Munoz

2010-01-01

The plasma nitriding process has been used as an efficient method to optimize the surface properties of steel and alloy in order to increase their wear, fatigue and corrosion resistance. This paper reports on a study of the composition and influence of the nitrided layer on the high-cycle fatigue properties of the AISI 316 and 304 type austenitic stainless steels. Test specimens of AISI 316 and 304 steel were nitrided at 400 deg C for 6 hours under a pressure of 4.5 mbar, using a gas mixture of 80% volume of H 2 and 20% volume of N 2 . The rotary fatigue limit of both nitrided and non-nitrided steels was determined, and the effect of the treatment on the fatigue limit of the two steels was evaluated. The mechanical properties of the materials were evaluated based on tensile tests, and the nitrided layer was characterized by microhardness tests, scanning electron microscopy and X-ray diffraction. The resulting nitride layer showed high hardness and mechanical strength, increasing the fatigue limit of the nitrided material in comparison with the non-nitrided one. The fatigue limit of the 316 steel increased from 400 MPa to 510 MPa in response to nitriding, while that of the 304 steel increased from 380 MPa to 560 MPa. One of the contributing factors of this increase was the introduction of residual compressive stresses during the surface hardening process, which reduce the onset of crack formation underneath the nitride layer. (author)

Physical and Tribological Properties of Nitrided AISI 316 Stainless Steel Balls

Directory of Open Access Journals (Sweden)

Yang Shicai

2016-01-01

Full Text Available AISI 316 austenitic stainless steel balls (diameters 5.0 and 12.0 mm, typical hardness 250 HV0.3 and flat samples (20×20×2.0 mm were nitrided by a pulsed glow discharge Ar/N2 plasma. Hardness of the ball surfaces was analysed using Vickers indentation. Thermal stability of the nitrided balls (diameter 12.0 mm was studied using a furnace to heat them in air for 8 hours at temperatures up to 700.0°C and then, after cooling to room temperature, the surface hardness of the heated balls was re-measured. Scanning electron microscopy and X-ray diffraction were used to study the microstructures, composition and phase formation of the nitrided sublayers. Unlubricated pin-on-disc wear testing was used to evaluate the wear resistance of nitrided stainless steel balls (5.0 mm diameter and the results were compared with similar testing on hardened Cr-Steel balls (5 mm diameter with hardness of about 650 HV0.3. All the test results indicated that the nitrided AISI 316 austenitic stainless steel balls have advantages over the hardened Cr-Steel balls in terms of retaining high hardness after heat treatment and high resistance to sliding wear at room temperature under higher counterpart stress. These properties are expected to be beneficial for wide range of bearing applications.

Cultures and co-cultures of human blood mononuclear cells and endothelial cells for the biocompatibility assessment of surface modified AISI 316L austenitic stainless steel

Energy Technology Data Exchange (ETDEWEB)

Stio, Maria; Martinesi, Maria; Treves, Cristina [Dipartimento di Scienze Biomediche, Sperimentali e Cliniche ‘Mario Serio’, Sezione di Scienze Biochimiche, Università di Firenze, viale Morgagni 50, 50134 Firenze (Italy); Borgioli, Francesca, E-mail: francesca.borgioli@unifi.it [Dipartimento di Ingegneria Industriale (DIEF), Università di Firenze, via S. Marta 3, 50139 Firenze (Italy)

2016-12-01

Samples of AISI 316L austenitic stainless steel were subjected either to grinding and polishing procedure, or to grinding and then low temperature glow-discharge nitriding treatment, or to grinding, nitriding and subsequently coating with collagen-I. Nitrided samples, even if only ground, show a higher corrosion resistance in PBS solution, in comparison with ground and polished AISI 316L. Biocompatibility was evaluated in vitro by incubating the samples with either peripheral blood mononuclear cells (PBMC) or human umbilical vein endothelial cells (HUVEC), tested separately or in co-culture. HUVEC-PBMC co-culture and co-incubation of HUVEC with PBMC culture medium, after the previous incubation of PBMC with metallic samples, allowed to determine whether the incubation of PBMC with the different samples might affect HUVEC behaviour. Many biological parameters were considered: cell proliferation, release of cytokines, matrix metalloproteinases (MMPs) and sICAM-1, gelatinolytic activity of MMPs, and ICAM-1 protein expression. Nitriding treatment, with or without collagen coating of the samples, is able to ameliorate some of the biological parameters taken into account. The obtained results point out that biocompatibility may be successfully tested in vitro, using cultures of normal human cells, as blood and endothelial cells, but more than one cell line should be used, separately or in co-culture, and different parameters should be determined, in particular those correlated with inflammatory phenomena. - Highlights: • Nitriding improves corrosion resistance and biocompatibility of ground AISI 316L. • The metallic samples differently affect different human cell cultures. • PBMC and HUVEC are a suitable model to test in vitro biocompatibility. • Co-cultures show that HUVEC are affected by pre-incubation of PBMC with the samples. • Inflammation parameters must be taken into account for assessing biocompatibility.

Cultures and co-cultures of human blood mononuclear cells and endothelial cells for the biocompatibility assessment of surface modified AISI 316L austenitic stainless steel

International Nuclear Information System (INIS)

Stio, Maria; Martinesi, Maria; Treves, Cristina; Borgioli, Francesca

2016-01-01

Samples of AISI 316L austenitic stainless steel were subjected either to grinding and polishing procedure, or to grinding and then low temperature glow-discharge nitriding treatment, or to grinding, nitriding and subsequently coating with collagen-I. Nitrided samples, even if only ground, show a higher corrosion resistance in PBS solution, in comparison with ground and polished AISI 316L. Biocompatibility was evaluated in vitro by incubating the samples with either peripheral blood mononuclear cells (PBMC) or human umbilical vein endothelial cells (HUVEC), tested separately or in co-culture. HUVEC-PBMC co-culture and co-incubation of HUVEC with PBMC culture medium, after the previous incubation of PBMC with metallic samples, allowed to determine whether the incubation of PBMC with the different samples might affect HUVEC behaviour. Many biological parameters were considered: cell proliferation, release of cytokines, matrix metalloproteinases (MMPs) and sICAM-1, gelatinolytic activity of MMPs, and ICAM-1 protein expression. Nitriding treatment, with or without collagen coating of the samples, is able to ameliorate some of the biological parameters taken into account. The obtained results point out that biocompatibility may be successfully tested in vitro, using cultures of normal human cells, as blood and endothelial cells, but more than one cell line should be used, separately or in co-culture, and different parameters should be determined, in particular those correlated with inflammatory phenomena. - Highlights: • Nitriding improves corrosion resistance and biocompatibility of ground AISI 316L. • The metallic samples differently affect different human cell cultures. • PBMC and HUVEC are a suitable model to test in vitro biocompatibility. • Co-cultures show that HUVEC are affected by pre-incubation of PBMC with the samples. • Inflammation parameters must be taken into account for assessing biocompatibility.

Micro-electrochemical characterization of galvanic corrosion of TA2/316L composite plate

Energy Technology Data Exchange (ETDEWEB)

Cheng, X.; Li, X.; Dong, C.; Xiao, K. [Corrosion and Protection Center, University of Science and Technology Beijing (China)

2011-12-15

Galvanic corrosion behavior of TA2/316L composite plate was investigated in the solution of 3.5 wt% NaCl by galvanic potential monitoring, scanning localized electrochemical impedance spectroscopy (LEIS) and scanning vibrating micro-electrode (SVME) techniques. The results demonstrated that the pitting corrosion resistance of 316L for the galvanic combination sample is lower, and the coupled current density is higher than for the single 316L sample. It indicates that the galvanic action works on the corrosion behavior of the TA2 titanium alloy/316L stainless steel galvanic combination in sodium chloride solution. The galvanic effect width was determined as 1500 {mu}m. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Dynamic strain ageing of deformed nitrogen-alloyed AISI 316 stainless steels

International Nuclear Information System (INIS)

Ehrnsten, U.; Toivonen, A.; Ivanchenko, M.; Nevdacha, V.; Yagozinskyy, Y.; Haenninen, H.

2004-01-01

Intergranular stress corrosion cracking has occurred in BWR environment in non-sensitized, deformed austenitic stainless steel materials. The affecting parameters are so far not fully known, but deformation mechanisms may be decisive. The effect of deformation and nitrogen content on the behaviour of austenitic stainless steels was investigated. The materials were austenitic stainless steels of AISI 316L type with different amounts of nitrogen (0.03 - 0.18%) and they were mechanically deformed 0, 5 and 20%. The investigations are focused on the dynamic strain ageing (DSA) behaviour. A few crack growth rate measurements are performed on nuclear grade AISI 316NG material with different degrees of deformation (0, 5 and 20%). The effects of DSA on mechanical properties of these materials are evaluated based on peaks in ultimate tensile strength and strain hardening coefficient and minimum in ductility in the DSA temperature range. Additionally, internal friction measurements have been performed in the temperature range of -100 to 600 deg. C for determining nitrogen interactions with other alloying elements and dislocations (cold-worked samples). The results show an effect of nitrogen on the stainless steel behaviour, e.g. clear indications of dynamic strain ageing and changes in the internal friction peaks as a function of nitrogen content and amount of deformation. (authors)

Microstructural Evolutions During Reversion Annealing of Cold-Rolled AISI 316 Austenitic Stainless Steel

Science.gov (United States)

Naghizadeh, Meysam; Mirzadeh, Hamed

2018-06-01

Microstructural evolutions during reversion annealing of a plastically deformed AISI 316 stainless steel were investigated and three distinct stages were identified: the reversion of strain-induced martensite to austenite, the primary recrystallization of the retained austenite, and the grain growth process. It was found that the slow kinetics of recrystallization at lower annealing temperatures inhibit the formation of an equiaxed microstructure and might effectively impair the usefulness of this thermomechanical treatment for the objective of grain refinement. By comparing the behavior of AISI 316 and 304 alloys, it was found that the mentioned slow kinetics is related to the retardation effect of solute Mo in the former alloy. At high reversion annealing temperature, however, an equiaxed austenitic microstructure was achieved quickly in AISI 316 stainless steel due to the temperature dependency of retardation effect of molybdenum, which allowed the process of recrystallization to happen easily. Conclusively, this work can shed some light on the issues of this efficient grain refining approach for microstructural control of austenitic stainless steels.

Studies on corrosion protection of laser hybrid welded AISI 316 by laser remelting

DEFF Research Database (Denmark)

Olsen, Flemming Ove; Ambat, Rajan; Rasmussen, A.J.

2005-01-01

laser surface melting on microstructure and corrosion behaviour of AISI 316L welds. Welding and laser treatment parameters were varied. General corrosion behaviour of the weld and laser treated surface was characterised using a gel visualization test. The local electrochemistry of the weld and laser......Unlike in autogenous laser welding, hybrid laser welding of stainless steel could introduce grain boundary carbides due to low cooling rates. Formation of grain boundary carbides leads to reduced corrosion properties. Studies have initially been carried out on hybrid laser welding and subsequent...... treated surface was investigated using a novel micro electrochemical technique with a tip resolution of ~1 mm. Results show that hybrid laser welding of 316L has increased corrosion susceptibility probably as a result of grain boundary carbide formation. However a suitable post laser treatment could...

Comparing creep in two stainless steels AISI 316

International Nuclear Information System (INIS)

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

1976-07-01

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

Crack propagation behaviour in stainless steel AISI 316L at elevated temperatures under static and cyclic loading

International Nuclear Information System (INIS)

Lange, H.

1991-01-01

Experimental investigations of crack growth under creep and creep-fatigue conditions are presented. The experiments were performed with the austenitic steel AISI 316L, that will be used in fast breeder reactors. A comparison of crack propagation behaviour at temperatures of T = 550deg C and T = 700deg C in common through-thickness cracked specimens and in plates containing surface cracks is carried out by application of several fracture mechanics parameters. The quantitative description of crack initiation times and crack velocities is persued particularly. The propagation rate of one-dimensional cracks under cyclic loading conditions at T = 550deg C is also treated with fracture mechanical methods. The influence of the hold periods on crack speed is discussed. (orig.) [de

Relating high-temperature flow stress of AISI 316 stainless steel to strain and strain rate

International Nuclear Information System (INIS)

Matteazzi, S.; Paitti, G.; Boerman, D.

1982-01-01

The authors have performed an experimental determination of tensile stress-strain curves for different strain rates (4.67 x 10 - 5 , 4.67 x 10 - 2 s - 1 ) and for a variety of temperature conditions (773-1073 K) of AISI 316H stainless steel (annealed conditions) and also a computer analysis of the experimental curves using a fitting program which takes into consideration different constitutive relations describing the plastic flow behaviour of the metals. The results show that the materials tested are clearly affected by strain rate only at the highest temperature investigated (1073 K) and that the plastic strain is the more significant variable. Of the constitutive equations considered, Voce's relation gives the best fit for the true stress-time-strain curves. However, the Ludwik and Ludwigson equations also provide a description of the experimental data, whereas Hollomon's equation does not suitably characterize AISI 316H stainless steel and can be applied with some accuracy only at 1073 K. (author)

Effect of temperature changes on swelling and creep of AISI 316

International Nuclear Information System (INIS)

Garner, F.A.; Gilbert, E.R.; Gelles, D.S.; Foster, J.P.

1980-04-01

A number of previous publications have shown that the swelling of cold-worked AISI 316 is quite sensitive to changes in temperature which occur during irradiation. In this report those data are expanded and reanalyzed to show that the concurrent irradiation creep is also quite sensitive to changes in irradiation temperature. An explanation is advanced to explain this behavior in terms of the sensitivity to temperture history of the radiation-induced microchemical evolution of this steel. In particular, the sensitivity to temperature history of the radiation-stabilized gamma prime phase is invoked to explain the enhanced creep and swelling behavior of AISI 316 components which experienced either gradual or abrupt decreases in temperature. The phase development observed in this steel in response to temperature changes during irradiation is also compared to the similar behavior found in aged specimens subjected to isothermal irradiation

The effect of internal hydrogen on surface slip localisation on polycrystalline AISI 316L stainless steel

International Nuclear Information System (INIS)

Aubert, Isabelle; Olive, Jean-Marc; Saintier, Nicolas

2010-01-01

A statistical analysis of the effect of internal hydrogen on the surface slip morphology of relatively high nickel content AISI 316L type austenitic stainless steel was carried out on high resolution data obtained by atomic force microscopy. Surface plastic strain localisation was studied for different hydrogen contents, two grain sizes, and two plastic strain levels. The height and spacing of approximately 8000 slip bands, observed on 12 specimens, are shown to follow log-normal distributions. Hydrogen increased the mean slip-band height and the mean slip-band spacing for the two macroscopic plastic strain levels considered, and for the two hydrogen concentrations in coarse-grained specimens. The hydrogen effect was also observed for fine-grained specimens, but only for the highest hydrogen concentration. In addition, the emerging dislocation velocity increased by a factor 3 for high hydrogen content.

Development of nanostructured SUS316L-2%TiC with superior tensile properties

Science.gov (United States)

Sakamoto, T.; Kurishita, H.; Matsuo, S.; Arakawa, H.; Takahashi, S.; Tsuchida, M.; Kobayashi, S.; Nakai, K.; Terasawa, M.; Yamasaki, T.; Kawai, M.

2015-11-01

Structural materials used in radiation environments require radiation tolerance and sufficient mechanical properties in the controlled state. In order to offer SUS316L austenitic stainless steel with the assumed requirements, nanostructured SUS316L with TiC addition of 2% (SUS316L-2TiC) that is capable of exhibiting enhanced tensile ductility and flow strength sufficient for structural applications was fabricated by advanced powder metallurgical methods. The methods include MA (Mechanical Alloying), HIP (Hot Isostatic Pressing), GSMM (Grain boundary Sliding Microstructural Modification) for ductility enhancement, cold rolling at temperatures below Md (the temperature where the martensite phase occurs by plastic deformation) for phase transformation from austenite to martensite and heat treatment for reverse transformation from martensite to austenite. It is shown that the developed SUS316L-2TiC exhibits ultrafine grains with sizes of 90-270 nm, accompanied by TiC precipitates with 20-50 nm in grain interior and 70-110 nm at grain boundaries, yield strengths of 1850 to 900 MPa, tensile strengths of 1920 to 1100 MPa and uniform elongations of 0.6-21%, respectively, depending on the heat treatment temperature after rolling at -196 °C.

Comparison of the corrosion resistance of DIN W. Nr. 1.4970 (15%Cr-15%Ni-1.2%Mo-Ti and ASTM F-138 (17%Cr-13%Ni-2.5%Mo austenitic stainless steels for biomedical applications

Directory of Open Access Journals (Sweden)

Maysa Terada

2006-09-01

Full Text Available The resistance to localised corrosion of the full austenitic 15%Cr-15%Ni-1.2%Mo titanium stabilized stainless steel (DIN W. Nr. 1.4970 was investigated by electrochemical methods including electrochemical impedance spectroscopy (EIS, potentiodynamic polarization and potentiostatic polarization measurements in a phosphate-buffered solution (PBS. The low carbon and non-stabilized austenitic stainless steel, AISI 316L (ASTM F-138, widely used for surgical implants, was also tested for comparison. The tests were conducted at room temperature after a stable potential had been reached. After the electrochemical measurements, the surfaces of the specimens were observed using SEM to evaluate the presence of pits. Potentiodynamic polarization results showed that both steels are prone to localized corrosion. Larger pits were found on the surface of AISI 316L specimens after the electrochemical tests. EIS response has indicated the duplex structure of the passive oxides. The results showed that the electrochemical behaviour of the DIN W. Nr. 1.4970 is better than of AISI 316L steel. Therefore, their application as an implant material may be considered.

Regression models to predict the behavior of the coefficient of friction of AISI 316L on UHMWPE under ISO 14243-3 conditions.

Science.gov (United States)

Garcia-Garcia, A L; Alvarez-Vera, M; Montoya-Santiyanes, L A; Dominguez-Lopez, I; Montes-Seguedo, J L; Sosa-Savedra, J C; Barceinas-Sanchez, J D O

2018-06-01

Friction is the natural response of all tribosystems. In a total knee replacement (TKR) prosthetic device, its measurement is hindered by the complex geometry of its integrating parts and that of the testing simulation rig operating under the ISO 14243-3:2014 standard. To develop prediction models of the coefficient of friction (COF) between AISI 316L steel and ultra-high molecular weight polyethylene (UHMWPE) lubricated with fetal bovine serum dilutions, the arthrokinematics and loading conditions prescribed by the ISO 142433: 2014 standard were translated to a simpler geometrical setup, via Hertz contact theory. Tribological testing proceeded by loading a stainless steel AISI 316L ball against the surface of a UHMWPE disk, with the test fluid at 37 °C. The method has been applied to study the behavior of the COF during a whole walking cycle. On the other hand, the role of protein aggregation phenomena as a lubrication mechanism has been extensively studied in hip joint replacements but little explored for the operating conditions of a TKR. Lubricant testing fluids were prepared with fetal bovine serum (FBS) dilutions having protein mass concentrations of 5, 10, 20 and 36 g/L. The results were contrasted against deionized, sterilized water. The results indicate that even at protein concentration as low as 5 g/L, protein aggregation phenomena play an important role in the lubrication of the metal-on-polymer tribopair. The regression models of the COF developed herein are available for numerical simulations of the tribological behavior of the aforementioned tribosystem. In this case, surface stress rather than film thickness should be considered. Copyright © 2018 Elsevier Ltd. All rights reserved.

Antibacterial and Tribological Performance of Carbonitride Coatings Doped with W, Ti, Zr, or Cr Deposited on AISI 316L Stainless Steel

Science.gov (United States)

Yao, Sun-Hui; Su, Yen-Liang; Lai, Yu-Cheng

2017-01-01

Carbonitride (CNx) coatings have existed for several decades but are not well understood. Related studies have indicated that CNx coatings exhibit behaviors comparable to diamond-like carbon (DLC) coatings. Metal-doped CNx coatings are expected to show superior performance to single CNx coatings. In this study, a CNx coating and a group of CNx coatings with 6 at. % metal doping (W, Ti, Zr, or Cr) were prepared on biograde AISI 316L stainless steel (SS316L) substrates, and they were then characterized and studied for antibacterial and wear performance. The microstructure, constituent phase, nanohardness, adhesion, surface roughness, and contact angle were evaluated. The antimicrobial test used Staphylococcus aureus and followed the Japanese Industrial Standard JIS Z 2801:2010. Finally, the wear behavior was assessed. The results showed that the CNx coating was a composite of amorphous CNx and amorphous C structures. The metal doping caused crystalline metal carbides/nitrides to form in the CNx coatings, which weakened their overall integrity. All the coatings showed antimicrobial ability for the SS316L samples. The CNx-Zr coating, the surface of which had the highest hydrophilicity, produced the best antibacterial performance. However, the CNx-Zr coating showed lower wear resistance than the CNx-W and CNx-Ti coatings. The CNx-Ti coating with a highly hydrophilic surface exhibited the lowest antibacterial ability. PMID:29039782

Antibacterial and Tribological Performance of Carbonitride Coatings Doped with W, Ti, Zr, or Cr Deposited on AISI 316L Stainless Steel

Directory of Open Access Journals (Sweden)

Sun-Hui Yao

2017-10-01

Full Text Available Carbonitride (CNx coatings have existed for several decades but are not well understood. Related studies have indicated that CNx coatings exhibit behaviors comparable to diamond-like carbon (DLC coatings. Metal-doped CNx coatings are expected to show superior performance to single CNx coatings. In this study, a CNx coating and a group of CNx coatings with 6 at. % metal doping (W, Ti, Zr, or Cr were prepared on biograde AISI 316L stainless steel (SS316L substrates, and they were then characterized and studied for antibacterial and wear performance. The microstructure, constituent phase, nanohardness, adhesion, surface roughness, and contact angle were evaluated. The antimicrobial test used Staphylococcus aureus and followed the Japanese Industrial Standard JIS Z 2801:2010. Finally, the wear behavior was assessed. The results showed that the CNx coating was a composite of amorphous CNx and amorphous C structures. The metal doping caused crystalline metal carbides/nitrides to form in the CNx coatings, which weakened their overall integrity. All the coatings showed antimicrobial ability for the SS316L samples. The CNx-Zr coating, the surface of which had the highest hydrophilicity, produced the best antibacterial performance. However, the CNx-Zr coating showed lower wear resistance than the CNx-W and CNx-Ti coatings. The CNx-Ti coating with a highly hydrophilic surface exhibited the lowest antibacterial ability.

Microscopic analysis of the influence of ratcheting on the evolution of dislocation structures observed in AISI 316L stainless steel during low cycle fatigue

Energy Technology Data Exchange (ETDEWEB)

Facheris, G., E-mail: giacomo.facheris@psi.ch [Laboratory for Nuclear Materials, Nuclear Energy and Safety Research Department, Paul Scherrer Institute, Villigen PSI (Switzerland); Pham, M.-S. [Department of Materials Science and Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213 (United States); High Temperature Integrity Group, Mechanics for Modelling and Simulation, Swiss Federal Laboratories for Materials Science and Technology, EMPA, Dübendorf (Switzerland); Janssens, K.G.F., E-mail: koen.janssens@psi.ch [Laboratory for Nuclear Materials, Nuclear Energy and Safety Research Department, Paul Scherrer Institute, Villigen PSI (Switzerland); Holdsworth, S.R. [High Temperature Integrity Group, Mechanics for Modelling and Simulation, Swiss Federal Laboratories for Materials Science and Technology, EMPA, Dübendorf (Switzerland)

2013-12-10

When subjected to controlled cyclic deformation, the response of austenitic stainless steel typically involves primary hardening followed by softening, and eventually cyclic stabilization with or without secondary hardening. If a continuously drifting mean strain is superposed to an alternating strain path (i.e. strain controlled ratcheting), the response in terms of mean stress and strain amplitude is significantly different. A series of low cycle fatigue and ratcheting experiments are performed at room temperature on round specimens extracted from a batch of AISI 316L hot rolled plate. The experiments are interrupted at cycle numbers selected to correspond with the different strain controlled cycle response stages. The as-received material and the fatigued specimens are analyzed by means of transmission electron microscopy to characterize the microstructure and its evolution with cyclic loading. The low cycle fatigue experiments, performed to establish a reference point for the zero mean strain loading condition, are in line with observations reported for AISI 316L stainless steel by other authors. The continuously increasing mean strain is found to induce higher dislocation densities in the channels of the evolving microstructure, being responsible for the macroscopically observed additional hardening. The observed polarized dislocation walls at least partially accommodate the continuously drifting mean strain and play a role in the non-zero mean stress response.

Development of nanostructured SUS316L-2%TiC with superior tensile properties

Energy Technology Data Exchange (ETDEWEB)

Sakamoto, T., E-mail: sakamoto.tatsuaki.mm@ehime-u.ac.jp [Department of Materials Science and Biotechnology, Ehime University, Matsuyama 790-8577 (Japan); Kurishita, H.; Matsuo, S.; Arakawa, H. [International Research Center for Nuclear Materials Science, IMR, Tohoku University, Oarai, Ibaraki 311-1313 (Japan); Takahashi, S.; Tsuchida, M. [Ehime University, Matsuyama 790-8577 (Japan); Kobayashi, S.; Nakai, K. [Department of Materials Science and Biotechnology, Ehime University, Matsuyama 790-8577 (Japan); Terasawa, M. [Laboratory of Advanced Science & Technology for Industry, University of Hyogo, 3-1-2 Koto, Kamigori-cho, Hyogo 678-1205 (Japan); Yamasaki, T. [Department of Materials Science & Chemistry, Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2201 (Japan); Kawai, M. [High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki-ken 305-0801 (Japan)

2015-11-15

Structural materials used in radiation environments require radiation tolerance and sufficient mechanical properties in the controlled state. In order to offer SUS316L austenitic stainless steel with the assumed requirements, nanostructured SUS316L with TiC addition of 2% (SUS316L-2TiC) that is capable of exhibiting enhanced tensile ductility and flow strength sufficient for structural applications was fabricated by advanced powder metallurgical methods. The methods include MA (Mechanical Alloying), HIP (Hot Isostatic Pressing), GSMM (Grain boundary Sliding Microstructural Modification) for ductility enhancement, cold rolling at temperatures below M{sub d} (the temperature where the martensite phase occurs by plastic deformation) for phase transformation from austenite to martensite and heat treatment for reverse transformation from martensite to austenite. It is shown that the developed SUS316L-2TiC exhibits ultrafine grains with sizes of 90–270 nm, accompanied by TiC precipitates with 20–50 nm in grain interior and 70–110 nm at grain boundaries, yield strengths of 1850 to 900 MPa, tensile strengths of 1920 to 1100 MPa and uniform elongations of 0.6–21%, respectively, depending on the heat treatment temperature after rolling at −196 °C. - Highlights: • Nanostructured SUS316L-2%TiC exhibiting sufficient tensile ductility and strength is developed. • The development requires an advanced powder metallurgical route. • The route includes MA, HIP, GSMM and thermo-mechanical treatments for phase transformation. • The austenite grain sizes are 90–270 nm and TiC precipitates 20–50 nm in grain interior. • The tensile strength are 1100–1920 MPa and uniform elongation 0.6–21%.

Development of nanostructured SUS316L-2%TiC with superior tensile properties

International Nuclear Information System (INIS)

Sakamoto, T.; Kurishita, H.; Matsuo, S.; Arakawa, H.; Takahashi, S.; Tsuchida, M.; Kobayashi, S.; Nakai, K.; Terasawa, M.; Yamasaki, T.; Kawai, M.

2015-01-01

Structural materials used in radiation environments require radiation tolerance and sufficient mechanical properties in the controlled state. In order to offer SUS316L austenitic stainless steel with the assumed requirements, nanostructured SUS316L with TiC addition of 2% (SUS316L-2TiC) that is capable of exhibiting enhanced tensile ductility and flow strength sufficient for structural applications was fabricated by advanced powder metallurgical methods. The methods include MA (Mechanical Alloying), HIP (Hot Isostatic Pressing), GSMM (Grain boundary Sliding Microstructural Modification) for ductility enhancement, cold rolling at temperatures below M_d (the temperature where the martensite phase occurs by plastic deformation) for phase transformation from austenite to martensite and heat treatment for reverse transformation from martensite to austenite. It is shown that the developed SUS316L-2TiC exhibits ultrafine grains with sizes of 90–270 nm, accompanied by TiC precipitates with 20–50 nm in grain interior and 70–110 nm at grain boundaries, yield strengths of 1850 to 900 MPa, tensile strengths of 1920 to 1100 MPa and uniform elongations of 0.6–21%, respectively, depending on the heat treatment temperature after rolling at −196 °C. - Highlights: • Nanostructured SUS316L-2%TiC exhibiting sufficient tensile ductility and strength is developed. • The development requires an advanced powder metallurgical route. • The route includes MA, HIP, GSMM and thermo-mechanical treatments for phase transformation. • The austenite grain sizes are 90–270 nm and TiC precipitates 20–50 nm in grain interior. • The tensile strength are 1100–1920 MPa and uniform elongation 0.6–21%.

High-temperature strength of AISI 316 steel

International Nuclear Information System (INIS)

Antunes, A.E.B.; Monteiro, S.N.

1975-01-01

The mechanical properties, especially elastic limit and strain hardening of AISI-316 austenitic stainless steel were investigated within the temperature range 150-800 0 C for two strain rates. The results showed anomalous behaviour between 200 and 650 0 C, over which range there was an increase in maximum strenght and hardening, with a tendency to show peaks. These apparentley three in number, may be connected with the effects of interaction between point defects and dislocations leading to dinamic aging phenomena. The mechanisms responsible for this anomalous behaviour produce a negative dependence on strain rate [pt

Compatibility of 316L stainless steel with the liquid alloy Pb17Li

International Nuclear Information System (INIS)

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

1988-01-01

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

Surface interactions of a W-DLC-coated biomedical AISI 316L stainless steel in physiological solution.

Science.gov (United States)

Antunes, Renato A; de Lima, Nelson Batista; Rizzutto, Márcia de Almeida; Higa, Olga Zazuco; Saiki, Mitiko; Costa, Isolda

2013-04-01

The corrosion stability of a W-DLC coated surgical AISI 316L stainless steel in Hanks' solution has been evaluated. Particle induced X-ray emission (PIXE) measurements were performed to evaluate the incorporation of potentially bioactive elements from the physiological solution. The film structure was analyzed by X-ray diffractometry and micro-Raman spectroscopy. The wear behavior was assessed using the sphere-on-disc geometry. The in vitro biocompatibility of the W-DLC film was evaluated by cytotoxicity tests. The corrosion resistance of the stainless steel substrate decreased in the presence of the PVD layer. EIS measurements suggest that this behavior was closely related to the corrosion attack through the coating pores. PIXE measurements revealed the presence of Ca and P in the W-DLC film after immersion in Hanks' solution. This result shows that the PIXE technique can be applied to identify and evaluate the incorporation of bioactive elements by W-DLC films. The film showed good wear resistance and biocompatibility.

Low pressure tritium interaction with Inconel 625 and AISI 316 L stainless steel surfaces: an evaluation of the recombination and adsorption constants

International Nuclear Information System (INIS)

Perujo, A.; Douglas, K.; Serra, E.

1996-01-01

The surface constants for the recombination (σk 2 ) and adsorption (σk 1 ) of tritium in Inconel 625 and austenitic stainless steel AISI 316 L were determined from the measurement of tritium permeation through engineering components (bellows) typical of those used on large fusion devices which will operate with tritium. Experimental permeation measurements were performed over the temperature range 450-620 K and an interpretation of the data was attempted based on a surface-limited tritium release model. At the tritium partial pressure of 0.1 Pa present in a machine such as JET, the flow of tritium is strongly influenced by surface reactions. Furthermore, it is often assumed that oxide layers, acting as permeation barriers, are present on such components. However, for effectiveness, such barriers must be intact and this may not necessarily be the case for engineering components in which mechanical stresses can lead to oxide cracking. The recombination (σk 2 ) and adsorption (σk 1 ) constants of tritium were estimated for both stationary and continually flexing bellows. (orig.)

Identification of the mechanism that confers superhydrophobicity on 316L stainless steel

Energy Technology Data Exchange (ETDEWEB)

Escobar, Ana M.; Llorca-Isern, Nuria; Rius-Ayra, Oriol

2016-01-15

This study develops a rapid method to confer superhydrophobicity on 316L stainless steel surfaces with an amphiphilic reagent such as dodecanoic acid. The highest contact angle (approaching 173°) was obtained after forming hierarchical structures with a non-aqueous electrolyte by an electrolytic process. Our goal was to induce superhydrophobicity directly on 316L stainless steel substrates and to establish which molecules cause the effect. The superhydrophobic behaviour is analysed by contact angle measurements, scanning electron microscopy (SEM), IR spectroscopy and atomic force microscopy (AFM). The growth mechanism is analysed using FE-SEM, TOF-SIMS and XPS in order to determine the molecules involved in the reaction and the growth. The TOF-SIMS analysis revealed that the Ni{sup 2+} ions react with lauric acid to create an ester on the stainless steel surface. - Highlights: • This study develops a rapid and facile approach to impart superhydrophobicity properties to 316L stainless steel surfaces with an amphiphilic reagent such as dodecanoic acid. Surface character changes from superhydrophilicity to superhydrophobicity. • This process changes the surface character from superhydrophilicity to superhydrophobicity. • The process based on electrolysis of a nickel salt in lauric acid provides superhydrophobic behaviour in 316L stainless steel. • The growth mechanism is proposed as a mode island (Volmert- Weber mode). • TOF-SIMS and XPS provided the identification of the molecules involved in the surface modification reaction on AISI 316L inducing superhydrophobicity.

Relationship between phase development and swelling of AISI 316 during temperature changes

International Nuclear Information System (INIS)

Yang, W.J.S.; Garner, F.A.

1982-04-01

The effect of temperature changes on radiation-induced swelling and phase development of AISI 316 has been examined for specimens irradiated in two different experiments. The formation of radiation-stable phases at low temperature appears to precede swelling but these phases tend to dissolve when subsequently subjected to higher temperature. Phases which develop at high temperature persist when the temperature is subsequently lowered. Once nucleated at low temperatures, voids tend to persist without reduction in density at higher temperatures. However, a new round of void nucleation occurs when the temperature is decreased during irradiation. If the swelling has entered the steady-state swelling regime prior to the temperature change, there is no effect on the subsequent swelling rate. For temperature changes that occur before the end of the transient swelling regime, substantial changes can occur in the swelling behavior, particularly if the changes occur in the range around 500 0 . The isothermal swelling behavior of AISI 316 is much less sensitive to irradiation temperature than previously envisioned

A Study on the Effects of the Use of Gas or Water Atomized AISI 316L Steel Powder on the Corrosion Resistance of Laser Deposited Material

Science.gov (United States)

Tobar, M. J.; Amado, J. M.; Montero, J.; Yáñez, A.

Water atomized and gas atomized powders are commonly used in 3D laser manufacturing. Both types of AISI 316L stainless steel powders are available which differ in their manganese content. This is due to specific procedures related to the two different atomization process. The amount of manganese in the laser processed part might have important implications in its corrosion resistance. It could lead to the formation of manganese sulfides (MnS) which are known to be initiation sites for pitting corrosion. In this work, corrosion performance of laser deposited 316L steel using gas and atomized powders is compared by means of potentiodynamic polarization tests in 0.35%wt. NaCL solution. Worse performance of the gas atomized samples is observed as with respect to the water atomized ones in terms of polarization resistance, corrosion rate and pitting susceptibility.

Vida a la fatiga de juntas soldadas del acero inoxidable AISI 316L obtenidas mediante el proceso GMAW

Directory of Open Access Journals (Sweden)

Puchi-Cabrera, E. S.

2007-06-01

Full Text Available An investigation has been conducted in order to determine the effect of both the metallic transfer mode (pulsed arc or short circuit and the O2 content in the Ar/O2 gas mixture, of the gas-metal arc welding process (GMAW, on the fatigue life under uniaxial conditions of welded joints of 316L stainless steel. It has been concluded that the mixture of the protective gases employed in the process could have an important influence on the fatigue life of the welded joints of such steel in two different ways. Firstly, through the modification of the radius of curvature at the joint between the welding toe and the base metal and, secondly, through a more pronounced degree of oxidation of the alloying elements induced by a higher O2 content in the mixture. As far as the metallic transfer mode is concerned, it has been determined that the welded joints obtained under a pulsed arc mode show a greater fatigue life in comparison with the joints obtained under short circuit for both gas mixtures.

Se ha llevado a cabo una investigación con la finalidad de determinar el efecto, tanto del modo de transferencia metálica (arco pulsado o cortocircuito como del contenido de O2 en la mezcla de gases protectores Ar/O2, del proceso de soldadura a tope mediante arco metálico con protección gaseosa (GMAW, sobre la vida a la fatiga en condiciones uniaxiales de juntas soldadas del acero inoxidable AISI 316L. Dicho trabajo ha permitido concluir que la composición de la mezcla de gases protectores del proceso GMAW pudiera tener una influencia importante en la vida a la fatiga de las juntas soldadas de dicho material, a través de dos formas distintas: primero, mediante la modificación del radio de curvatura entre la raíz del cordón de soldadura y el metal base y, en segundo lugar, a través del mayor grado de oxidación de los elementos de aleación. En cuanto al modo de transferencia metálica, se determinó que las juntas soldadas mediante arco pulsado

L2 Milestone 5433: Characterization of Dynamic Behavior of AM and Conventionally Processed Stainless Steel (316L and 304L)

Energy Technology Data Exchange (ETDEWEB)

Gray, George Thompson [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Livescu, Veronica [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rigg, P. A. [Washington State Univ., Pullman, WA (United States). Inst. for Shock Physics; Trujillo, Carl Patrick [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Cady, Carl McElhinney [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Chen, Shuh-Rong [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Carpenter, John S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lienert, Thomas J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Fensin, Saryu Jindal [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Knapp, Cameron M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Beal, Roberta Ann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Morrow, Benjamin [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dippo, Olivia F. [Univ. of California, San Diego, CA (United States); Jones, David Robert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Martinez, Daniel Tito [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Valdez, James Anthony [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-09-26

For additive manufacturing (AM) of metallic materials, the certification and qualification paradigm needs to evolve as there currently exists no broadly accepted “ASTM- or DIN-type” additive manufacturing certified process or AM-material produced specifications. Accordingly, design, manufacture, and thereafter implementation and insertion of AM materials to meet engineering applications requires detailed quantification of the constitutive (strength and damage) properties of these evolving materials, across the spectrum of metallic AM methods, in comparison/contrast to conventionally-manufactured metals and alloys. This report summarizes the 316L SS research results and presents initial results of the follow-on study of 304L SS. For the AM-316L SS investigation, cylindrical samples of 316L SS were produced using a LENS MR-7 laser additive manufacturing system from Optomec (Albuquerque, NM) equipped with a 1kW Yb-fiber laser. The microstructure of the AM-316L SS was characterized in both the “as-built” Additively Manufactured state and following a heat-treatment designed to obtain full recrystallization to facilitate comparison with annealed wrought 316L SS. The dynamic shock-loading-induced damage evolution and failure response of all three 316L SS materials was quantified using flyer-plate impact driven spallation experiments at peak stresses of 4.5 and 6.35 GPa. The results of these studies are reported in detail in the first section of the report. Publication of the 316L SS results in an archival journal is planned. Following on from the 316L SS completed work, initial results on a study of AM 304L SS are in progress and presented herein. Preliminary results on the structure/dynamic spallation property behavior of AM-304L SS fabricated using both the directed-energy LENS and an EOS powder-bed AM techniques in comparison to wrought 304L SS is detailed in this Level 2 Milestone report.

Comparative evaluation of laser-assisted micro-milling for AISI 316, AISI 422, TI-6AL-4V and Inconel 718 in a side-cutting configuration

International Nuclear Information System (INIS)

Shelton, Jonathan A; Shin, Yung C

2010-01-01

This paper is focused on numerical modeling and experimental evaluation of laser-assisted micro-milling (LAMM). An experimental setup consisting of a 25 W CO 2 laser, three-axis CNC linear stages and a high-speed spindle was used to implement the LAMM process. Micro-endmills between 100 and 300 µm in diameter were used to perform side-cutting operations with and without laser preheat on four materials: AISI 316, AISI 422, Ti-6Al-4V and Inconel 718. A three-dimensional transient finite-volume-based thermal model was used to analytically predict appropriate process parameters on the basis of material-removal temperatures. The effects of LAMM on the machined surface finish, edge burrs, tool wear and workpiece microstructure were evaluated experimentally.

The Effects of The Industrial Cryogenic Process on The Wear Behaviours of AISI D2 Cold Work Tool Steels

OpenAIRE

Ersöz, Enes; Ovalı, İsmail

2018-01-01

In this study, industrial cryogenic process afterconventional heat treatment process for various holding time was applied toAISI D2 (DIN 1.2379) cold work tool steel. The effects of the industrialcryogenic process on the wear behavior was investigated. In the wear test 5,10and 15 N forces were carried out to all group specimens at a constant shearrate (3,16 m/s) and three different wear distances. Experimental results showthat cryogenic processing of AISI D2 cold work tool steels have a signi...

Evaluation of corrosion products formed by sulfidation as inhibitors of the naphthenic corrosion of AISI-316 steel

Science.gov (United States)

Sanabria-Cala, J. A.; Montañez, N. D.; Laverde Cataño, D.; Y Peña Ballesteros, D.; Mejía, C. A.

2017-12-01

Naphthenic acids present in oil from most regions worldwide currently stand as the main responsible for the naphthenic corrosion problems, affecting the oil-refining industry. The phenomenon of sulfidation, accompanying corrosion processes brought about by naphthenic acids in high-temperature refining plant applications, takes place when the combination of sulfidic acid (H2S) with Fe forms layers of iron sulphide (FeS) on the material surface, layers with the potential to protect the material from attack by other corrosive species like naphthenic acids. This work assessed corrosion products formed by sulfidation as inhibitors of naphthenic corrosion rate in AISI-316 steel exposed to processing conditions of simulated crude oil in a dynamic autoclave. Calculation of the sulfidation and naphthenic corrosion rates were determined by gravimetry. The surfaces of the AISI-316 gravimetric coupons exposed to acid systems; were characterized morphologically by X-Ray Diffraction (XRD) and X-ray Fluorescence by Energy Dispersive Spectroscopy (EDS) combined with Scanning Electron Microscopy (SEM). One of the results obtained was the determination of an inhibiting effect of corrosion products at 250 and 300°C, where lower corrosion rate levels were detected. For the temperature of 350°C, naphthenic corrosion rates increased due to deposition of naphthenic acids on the areas where corrosion products formed by sulfidation have lower homogeneity and stability on the surface, thus accelerating the destruction of AISI-316 steel. The above provides an initial contribution to oil industry in search of new alternatives to corrosion control by the attack of naphthenic acids, from the formation of FeS layers on exposed materials in the processing of heavy crude oils with high sulphur content.

Corrosion behavior of TiO{sub 2}-NiO nanocomposite thin films on AISI 316L stainless steel prepared by sol-gel method

Energy Technology Data Exchange (ETDEWEB)

Cheraghi, H., E-mail: hoch2020@yahoo.com [Materials Science and Engineering Department, Iran University of Science and Technology (IUST), P.O. Box: 16765163, Narrmak Street, Tehran (Iran, Islamic Republic of); Shahmiri, M., E-mail: mshahmiri@iust.ac.ir [Materials Science and Engineering Department, Iran University of Science and Technology (IUST), P.O. Box: 16765163, Narrmak Street, Tehran (Iran, Islamic Republic of); Sadeghian, Z. [Research Institute of Petroleum Industry (RIPI), P.O. Box: 14857-3311, West Blvd. Azadi Sport Complex, Tehran (Iran, Islamic Republic of)

2012-11-01

TiO{sub 2}-NiO nanocomposite thin films were deposited on the 316L stainless steel using sol-gel method by a dip coating technique. Different techniques such as differential thermal analysis, thermogravimetric analysis, X-ray diffraction, Fourier transform infrared spectrometry, scanning electron microscopy and scanning probe microscopy were carried out in order to characterize the structure of the coatings. The corrosion resistance of the coatings was evaluated by using Tafel polarization and electrochemical impedance spectroscopy tests of uncoated and coated specimens in a 3.5% NaCl solution at room temperature. It was found that to obtain desirable structure in coatings, the coatings should be calcined at 600 Degree-Sign C for one and half hour. NiTiO{sub 3}, anatase and rutile were the phases obtained in different calcination conditions in air atmosphere. The results of corrosion tests indicated that with increasing the dipping times from 2 to 4, the corrosion current density first decreases but when increasing the dipping times to 6, it increases. Also the corrosion current density decreased from 186.7 nA.cm{sup -2} (uncoated steel) to 34.21 nA.cm{sup -2} (80%TiO{sub 2}-20%NiO) and corrosion potential increased from - 150.2 mV (uncoated steel) to - 107.3 mV (67%TiO{sub 2}-33%NiO). - Highlights: Black-Right-Pointing-Pointer TiO{sub 2}-NiO thin films were deposited on the 316L stainless steel using sol-gel method. Black-Right-Pointing-Pointer Different compositions, annealing times and temperatures resulted in various phases. Black-Right-Pointing-Pointer Films having different compositions showed various surface morphologies. Black-Right-Pointing-Pointer Films having a composition of 80%TiO{sub 2}-20%NiO showed a good corrosion protection.

Rainbow fringes around crevice corrosion formed on stainless steel AISI 316 after ennoblement in seawater

Energy Technology Data Exchange (ETDEWEB)

Wang, W.; Zhang, X. [College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao (China); Wang, J. [College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao (China); State Key Laboratory for Corrosion and Protection, Shenyang (China)

2009-10-15

The crevice corrosion occurrence probability of stainless steel (SS) AISI 316 was increased under ennoblement condition due to chemically added H{sub 2}O{sub 2} into seawater. The H{sub 2}O{sub 2} was used to simulate the important factor causing ennoblement in natural marine biofilm. Morphology of the crevice corrosion was observed using an incident-light source microscopy. Some interesting ''rainbow'' fringes were observed around micro-crevices. The mechanism was discussed from the ions diffusion and potential distribution during the crevice formation. This result shows that under ennoblement condition the colored fringe is a distinct characteristic of the morphology of localized corrosion for stainless steel. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

Fabrication of nanoporous Sr incorporated TiO{sub 2} coating on 316L SS: Evaluation of bioactivity and corrosion protection

Energy Technology Data Exchange (ETDEWEB)

Anne Pauline, S. [Department of Chemistry, Anna University, Chennai 600025 (India); Kamachi Mudali, U. [Corrosion Science and Technology Section, IGCAR, Kalpakkam 603102 (India); Rajendran, N., E-mail: nrajendran@annauniv.edu [Department of Chemistry, Anna University, Chennai 600025 (India)

2013-10-01

In this paper, nanoporous TiO{sub 2} and Sr-incorporated TiO{sub 2} coated 316L SS were prepared by sol–gel methodology. The effect of Sr incorporation into TiO{sub 2} coating on bioactivity and corrosion resistance was investigated. Attenuated total reflectance–Fourier transform infrared (ATR–FTIR) spectroscopy, X-ray diffraction analysis (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX) results obtained after in vitro bioactivity test confirm the excellent growth of crystalline hydroxyapatite (HAp) over nanoporous Sr-incorporated TiO{sub 2} coated 316L SS which may be attributed to the slow and steady release of Sr ions from the coatings. The electrochemical evaluation of the coatings confirms that Sr-incorporated TiO{sub 2} coating offer excellent protection to 316L SS by acting as a barrier layer. The results showed that the incorporation of Sr enhanced both bioactivity and corrosion resistance of 316L SS. Hence Sr-incorporated TiO{sub 2} coated 316L SS is a promising material for orthopaedic implant applications. - Highlights: • Nanoporous Sr-incorporated TiO{sub 2} coatings were successfully fabricated on 316L SS. • The coatings have excellent adhesion to the substrate and appreciable Vickers micro hardness value. • Sr-incorporated TiO{sub 2} coated specimens exhibited excellent hydroxyapatite growth due to slow release of Sr from the coating. • Sr incorporation enhances the corrosion resistance of TiO{sub 2} coating.

Effect of helium on creep and fatigue (MAT 11)

International Nuclear Information System (INIS)

Schroeder, H.

1991-03-01

This final report contains experimental results on mechanical properties (creep, fatigue, tensile) and microstructural investigations (SEM, TEM) of pre-implanted samples of steels or alloys. (AISI 316, AISI 316L, DIN 1.4970, JPCA 8206, DIN 1.4914; Incoloy 800H, Hastelloy X, DIN 1.4981, (Fe 0.49 Ni 0.51 ) 3 V, Fe17Ni17Cr, Fe15Ni15Cr, Nimonic PE 16, Ni8Si). Furthermore theoretical aspects and developed models and mechanisms for helium embrittlement are described. This report is presented in the form of an extended summary without figures. (MM)

Tratamiento térmico del acero inoxidable ferrítico AISI 430L sinterizado en atmósfera de N2-H2

Directory of Open Access Journals (Sweden)

Ruiz-Prieto, J. M.

2005-12-01

Full Text Available In this Work the influence of sintering AISI 430L stainless steel in N2-H2 atmosphere on its properties and microstructure have been studied. The presence of nitrogen in the sintering atmosphere leads to complex nitrides formation the AISI 430L sintered steel microstructure. A subsequent heat treatment was applied to modify this microstructure in order to improve the mechanical properties and corrosion resistance of these ferritic stainless steels.Los aceros inoxidables ferríticos, son aceros que contienen esencialmente cromo (12-30 % junto con níquel y molibdeno en cantidades que, en general, no sobrepasan el 1 % y, en ocasiones, se les adicionan otros elementos como son el aluminio, silicio, titanio o niobio. En el presente trabajo de investigación se ha evaluado la influencia del nitrógeno presente en la atmósfera de sinterización sobre la microestructura y propiedades del acero inoxidable ferrítico AISI 430L. Además, se ha realizado un tratamiento térmico posterior de hipertemple y maduración con el objeto de incrementar las propiedades mecánicas y a corrosión de este acero inoxidable, mediante la modificación microestructural de los nitruros complejos de hierro y cromo precipitados durante la etapa de sinterización.

Influence of the cutting parameters on flank wear of coated inserts during turning of AISI 316L

Directory of Open Access Journals (Sweden)

Yusimit Zamora Hernández

2015-03-01

Full Text Available (Received: 2015/01/20 - Accepted: 2015/03/25The continuous improvement of manufacturing processes is critical to achieve optimum levels of productivity, quality and cut production of components and products. This research aims to determine the cutting tool flank wearing progression, during a high speed dry turning, for AISI 316L steel parts. Experimental data were acquired using two cutting feed levels, two material levels, three cutting speeds, and four principal cutting times. A scanning electron microscope (SEM was used to measure and analyze the wear of the cutting tools. Results were compared using analysis of variance and multiple regression for describing the relation between the variables used in the study. The analysis showed that the three layers coating insert did not exceed the end of life wearing criterion, while the one layer insert suffered a catastrophic wearing at the highest cutting speed. It was found that a relation exists between the experimental data and the predicted values for flank wear with a general average error of 4.1182%.

Structure and properties of the Stainless steel AISI 316 nitrided with microwave plasma; Estructura y propiedades del acero inoxidable AISI 316 nitrurado con plasmas de microondas

Energy Technology Data Exchange (ETDEWEB)

Becerril R, F

1999-07-01

In this work were presented the results obtained by nitridation on stainless steel AISI 316 using a plasma generated through a microwave discharge with an external magnetic field using several moistures hydrogen / nitrogen to form a plasma. The purpose of nitridation was to increase the surface hardness of stainless steel through a phase formation knew as {gamma}N which has been reported that produces such effect without affect the corrosion resistance proper of this material. (Author)

Evaluation of the TIG welding mechanical behavior in AISI 316 tubes for fuel rods

International Nuclear Information System (INIS)

Bittencourt, M.S.Q.; Carvalho Perdigao, S. de

1985-10-01

The effect of service temperature, the mechanical resistance and the creep behaviour of a steel which is intendend to be used as fuel rods in Nuclear Reactors was investigated. The tests were performed in seamless tubes of austenitic stainless steel, AISI 316, 20% cold worked, TIG welded. (Author) [pt

Swelling of AISI 304L in response to simultaneous variations in stress and displacement rate

International Nuclear Information System (INIS)

Porter, D.L.; Garner, F.A.

1984-01-01

The duration of the transient regime of neutron-induced swelling in annealed AISI 304L at 400 0 C is sensitive to both stress and displacement rate variations. The simultaneous application of both variables exerts a synergistic effect on the transient regime. The duration of this regime cannot be reduced below a required intrinsic exposure of approx. 10 dpa, however, which has been found to be characteristic of all Fe-Ni-Cr austenitic alloys. This is four times larger than that currently assumed in the stress-affected swelling equation for 20% cold-worked AISI 316

Evaluation of the corrosion resistance of AISI 316 stainless steel filters

Directory of Open Access Journals (Sweden)

Luzinete Pereira Barbosa

2005-06-01

Full Text Available In this investigation, the corrosion resistance of AISI 316 SS filters prepared with powders in the size ranges 74-44 µm and 210-105 µm and compacted with pressures of 300 MPa and 400 MPa has been evaluated in naturally aerated 0.5 M H2SO4 solution at 25 °C. Weight loss of filters manufactured with compacting pressure of 400 MPa were significantly higher than that of filters compacted at 300 MPa. The filter compacted at 400 MPa had higher carbon and nitrogen contents compared to those compacted at 300 MPa. The former also had chromium rich precipitates and oxides in the grain boundaries. The pores in filters compacted at 400 MPa were smaller than in filters compacted at 300 MPa. Smaller pores favor the formation of concentration cells and consequently, increased crevice corrosion.

Investigating Tribological Characteristics of HVOF Sprayed AISI 316 Stainless Steel Coating by Pulsed Plasma Nitriding

Science.gov (United States)

Mindivan, H.

2018-01-01

In this study, surface modification of aluminum alloy using High-Velocity Oxygen Fuel (HVOF) thermal spray and pulsed plasma nitriding processes was investigated. AISI 316 stainless steel coating on 1050 aluminum alloy substrate by HVOF process was pulsed plasma nitrided at 793 K under 0.00025 MPa pressure for 43200 s in a gas mixture of 75 % N2 and 25 % H2. The results showed that the pulse plasma nitriding process produced a surface layer with CrN, iron nitrides (Fe3N, Fe4N) and expanded austenite (γN). The pulsed plasma nitrided HVOF-sprayed coating showed higher surface hardness, lower wear rate and coefficient of friction than the untreated HVOF-sprayed one.

A preliminary study of laser cladding of AISI 316 stainless steel using preplaced NiTi wire

International Nuclear Information System (INIS)

Cheng, F.T.; Lo, K.H.; Man, H.C.

2004-01-01

NiTi wire of diameter 1 mm was preplaced on AISI 316 stainless steel samples by using a binder. Melting of the NiTi wire to form a clad track on the steel substrate was achieved by means of a high-power CW Nd:YAG laser using different processing parameters. The geometry and microstructure of the clad deposit were studied by optical microscopy and scanning electron microscopy (SEM), respectively. The hardness and compositional profiles along the depth of the deposit were acquired by microhardness testing and energy-dispersive spectroscopy (EDS), respectively. The elastic behavior of the deposit was analyzed using nanoindentation, and compared with that of the NiTi wire. The dilution of the NiTi clad by the substrate material beneath was substantial in single clad tracks, but could be successively reduced in multiple clad layers. A strong fusion bonding with tough interface could be obtained as evidenced by the integrity of Vickers indentations in the interfacial region. In comparison with the NiTi cladding on AISI 316 using the tungsten inert gas (TIG) process, the laser process was capable of producing a much less defective cladding with a more homogeneous microstructure, which is an essential cladding quality with respect to cavitation erosion and corrosion resistance. Thus, the present preliminary study shows that laser cladding using preplaced wire is a feasible method to obtain a thick and homogeneous NiTi-based alloy layer on AISI 316 stainless steel substrate

Improving by postoxidation of corrosion resistance of plasma nitrocarburized AISI 316 stainless steels

Science.gov (United States)

Yenilmez, A.; Karakan, M.; Çelik, İ.

2017-01-01

Austenitic stainless steels are widely used in several industries such as chemistry, food, health and space due to their perfect corrosion resistance. However, in addition to corrosion resistance, the mechanic and tribological features such as wear resistance and friction are required to be good in the production and engineering of this type of machines, equipment and mechanic parts. In this study, ferritic (FNC) and austenitic (ANC) nitrocarburizing were applied on AISI 316 stainless steel specimens with perfect corrosion resistance in the plasma environment at the definite time (4 h) and constant gas mixture atmosphere. In order to recover corrosion resistance which was deteriorated after nitrocarburizing again, plasma postoxidation process (45 min) was applied. After the duplex treatment, the specimens' structural analyses with XRD and SEM methods, corrosion analysis with polarization method and surface hardness with microhardness method were examined. At the end of the studies, AISI 316 surface hardness of stainless steel increased with nitrocarburizing process, but the corrosion resistance was deteriorated with FNC (570 °C) and ANC (670 °C) nitrocarburizing. With the following of the postoxidation treatment, it was detected that the corrosion resistance became better and it approached its value before the process.

Characterization, Corrosion Resistance, and Cell Response of High-Velocity Flame-Sprayed HA and HA/TiO2 Coatings on 316L SS

Science.gov (United States)

Singh, Tejinder Pal; Singh, Harpreet; Singh, Hazoor

2012-09-01

The main aim of this study is to evaluate corrosion and biocompatibility behavior of thermal spray hydroxyapatite (HA) and hydroxyapatite/titania bond (HA/TiO2)-coated 316L stainless steel (316L SS). In HA/TiO2 coatings, TiO2 was used as a bond coat between HA top coat and 316L SS substrate. The coatings were characterized by x-ray diffraction and scanning electron microscopy/energy dispersive spectroscopy, and corrosion resistance determined for the uncoated substrate and the two coatings. The biological behavior was investigated by the cell culture studies using osteosarcoma cell line KHOS-NP (R-970-5). The corrosion resistance of the steel was found to increase after the deposition of the HA and HA/TiO2 bond coatings. Both HA, as well as, HA/TiO2 coatings exhibit excellent bond strength of 49 and 47 MPa, respectively. The cell culture studies showed that HA-coated 316L SS specimens appeared more biocompatible than the uncoated and HA/TiO2-coated 316L SS specimens.

Effect of cold working on nitriding process of AISI 304 and 316 austenitic stainless steel

International Nuclear Information System (INIS)

Pereira, Silvio Andre de Lima

2012-01-01

The nitriding behavior of AISI 304 and 316 austenitic stainless steel was studied by different cold work degree before nitriding processes. The microstructure, thickness, microhardness and chemical micro-composition were evaluated through optical microscopy, microhardness, scanner electronic microscopy and x ray diffraction techniques. Through them, it was observed that previous plastic deformations do not have influence on layer thickness. However, a nitrided layer thicker can be noticed in the AISI 304 steel. In addition, two different layers can be identified as resulted of the nitriding, composed for austenitic matrix expanded by nitrogen atoms and another thinner immediately below expanded by Carbon atoms. (author)

Experimental Investigation and Analytical Prediction of σ-Phase Precipitation in AISI 316L Austenitic Stainless Steel

Science.gov (United States)

Sahlaoui, Habib; Sidhom, Habib

2013-07-01

The phase precipitation in industrial AISI 316L stainless steel during aging for up to 80,000 hours between 823 K and 1073 K (550 °C and 800 °C) has been studied using transmission electron microscopy, scanning transmission electron microscopy, and carbon replica energy-dispersive X-ray microanalysis. Three phases were identified: Chromium carbides (M23C6), Laves phase ( η), and σ-phase (Fe-Cr). M23C6 carbide precipitation occurred firstly and was followed by the η and σ-phases at grain boundaries when the aging temperature is higher than 873 K (600 °C). Precipitation and growth of M23C6 create chromium depletion zones at the grain boundaries and also retard the σ-phase formation. Thus, the σ-phase is controlled by the kinetic of chromium bulk diffusion and can appear only when the chromium reaches, at grain boundaries and at the M23C6/ γ and M23C6/ η/ γ interfaces, content higher than a critical value obtained by self-healing. An analytical model, based on equivalent chromium content, has been established in this study and successfully validated to predict the time-temperature-precipitation diagram of the σ-phase. The obtained diagram is in good agreement with the experimental results.

Production and characterization of multilayer coatings of Ti/TiN on AISI 316L stainless steel by the PVD technique of cathodic arc ion plating

International Nuclear Information System (INIS)

Forlerer, Elena; Rodriguez, Fernando; Mingolo, Norma

2006-01-01

Multilayer coatings were produced from bi-layers (compound layers) of Ti/TiN in a PVD reactor of cathodic arc ion plating. The process was carried out at an Argon gas pressure of 5x10 -3 Torr for the interlayer of Ti and a nitrogen + argon pressure of 2x10 -2 Torr for the deposit of TiN and a Bias voltage of -500V for the Ti layer and -100V for the TiN layer. The arc current held constant at 80 amp. The samples were kept at high temperatures ≥ 300 o C, mounted on a rotating system that held the test piece 15-25 cm from the Ti electrode. Certified composition AISI 316L and AISI 410 stainless steel were used for the substrate. Coatings with one or two compound layers with similar thicknesses were made. The coatings were characterized mechanically by adherence, thickness and microhardness by Vickers indentation with 25g loads. The texture was studied by X-ray diffraction and present phases and residual tensions were determined. The results of the X-ray diffraction show the presence of the mostly TiN phase, with fcc structure in the mono-layer and the bi-layer. Residual tensions are compressive and elevated due to the expansion of the TiN network during the deposition process. Measurements of the bi-layers at different angles showed a relaxing of the tensions close to the surface, which could be due to the effect of the second interlayer of Ti. Preferential orientations associated with the growth process of the layers and the developed microstructure were detected in the TiN (CW)

Effect of Spreading Time on Contact Angle of Nanofluid on the Surface of Stainless Steel AISI 316 and Zircalloy 4

Science.gov (United States)

Prajitno, D. H.; Trisnawan, V.; Syarif, D. G.

2017-05-01

The solid surface tension plays an important role in the heat and mass transfer system for heat exchanger equipment. In the nuclear power plant industry, the stainless steel AISI 316 and Zircalloy 4 have been used for long time as structure materials. The purpose of the experimental is to study solid state surface tension behavior by measure contact angle Nano fluid contain nano particle alumina on metal surface of stainless steel AISI 316 and Zircalloy 4 by sessile drop method. The experiment is to measure the static contact angle and drop nano fluid contains nano particle alumina on stainless steel 316 and zircalloy 4 with different spreading time from 1 to 30 minute. It was observed that stainless steel 316 and zircalloy 4 lose their hydrophobic properties with increasing elapsed time during drop of nano fluid on the surface of alloy. As a result the contact angle of nano fluid on surface of metal is decrease with increasing elapsed time. While the magnitude diameter of drop nano fluid and wetting surface is increase with increasing elapsed time on the surface of the stainless steel SS 316 and Zircalloy 4.

An Investigation of the Microstructure and Fatigue Behavior of Additively Manufactured AISI 316L Stainless Steel with Regard to the Influence of Heat Treatment

Directory of Open Access Journals (Sweden)

Bastian Blinn

2018-03-01

Full Text Available To exploit the whole potential of Additive Manufacturing, it is essential to investigate the complex relationships between Additive Manufacturing processes, the resulting microstructure, and mechanical properties of the materials and components. In the present work, Selective Laser Melted (SLM (process category: powder bed fusion, Laser Deposition Welded (LDW (process category: direct energy deposition and, for comparison, Continuous Casted and then hot and cold drawn (CC austenitic stainless steel AISI 316L blanks were investigated with regard to their microstructure and mechanical properties. To exclude the influence of surface topography and focus the investigation on the volume microstructure, the blanks were turned into final geometry of specimens. The additively manufactured (AM- blanks were manufactured in both the horizontal and vertical building directions. In the horizontally built specimens, the layer planes are perpendicular and in vertical building direction, they are parallel to the load axis of the specimens. The materials from different manufacturing processes exhibit different chemical composition and hence, austenite stability. Additionally, all types of blanks were heat treated (2 h, 1070 °C, H2O and the influence of the heat treatment on the properties of differently manufactured materials were investigated. From the cyclic deformation curves obtained in the load increase tests, the anisotropic fatigue behavior of the AM-specimens could be detected with only one specimen in each building direction for the different Additive Manufacturing processes, which could be confirmed by constant amplitude tests. The results showed higher fatigue strength for horizontally built specimens compared to the vertical building direction. Furthermore, the constant amplitude tests show that the austenite stability influences the fatigue behavior of differently manufactured 316L. Using load increase tests as an efficient rating method of the

Aluminum-silicon co-deposition by FB-CVD on austenitic stainless steel AISI 316

International Nuclear Information System (INIS)

Marulanda, J L; Perez, F J; Remolina-Millán, A

2013-01-01

Aluminum-silicon coatings were deposited on stainless steel AISI 316 in the temperature range of 540 to 560°C by CVD-FBR. It was used a fluidized bed with 2.5% silicon and 7.5% aluminum powder and 90% inert (alumina). This bed was fluidized with Ar and as an activator a mixture of HCl/H2 in ratios of 1/10 to 1/16. Furthermore, the deposition time of the coatings was varied between 45 minutes to 1.5 hours, with a 50% active gas, neutral gases 50%. Thermodynamic simulation was conducted with the Thermocalc software to get the possible compositions and amount of material deposited for the chosen conditions. The coatings presented the follow compounds FeAl 2 Si, FeAl 2 and Fe 2 Al 5 . Aluminum-silicon coatings were heat treated to improve its mechanical properties and its behavior against oxidation for the inter diffusion of the alloying elements. The heat treatment causes the aluminum diffuse into the substrate and the iron diffuse into coating surface. This leads to the transformation of the above compounds in FeAl, Al 2 FeSi, Cr 3 Si, AlFeNi and AlCrFe

Structure and properties of the Stainless steel AISI 316 nitrided with microwave plasma

International Nuclear Information System (INIS)

Becerril R, F.

1999-01-01

In this work were presented the results obtained by nitridation on stainless steel AISI 316 using a plasma generated through a microwave discharge with an external magnetic field using several moistures hydrogen / nitrogen to form a plasma. The purpose of nitridation was to increase the surface hardness of stainless steel through a phase formation knew as γN which has been reported that produces such effect without affect the corrosion resistance proper of this material. (Author)

Avaliação da suscetibilidade à corrosão sob tensão da ZAC do aço inoxidável AISI 316L em ambiente de reator nuclear PWR Stress corrosion cracking of stainless steel AISI 316L HAZ in PWR Nuclear reactor environment

Directory of Open Access Journals (Sweden)

Mônica Maria de Abreu Mendonça Schvartzman

2009-09-01

Full Text Available Aços carbono de baixa liga e aços inoxidáveis são amplamente utilizados nos circuitos primários de reatores nucleares do tipo PWR (Pressurized Water Reactor. Ligas de níquel são empregadas na soldagem destes materiais devido a características como elevadas resistências mecânica e à corrosão, coeficiente de expansão térmica adequado, etc. Nos últimos 30 anos, a corrosão sob tensão (CST tem sido observada principalmente nas regiões das soldas entre materiais dissimilares existentes nestes reatores. Este trabalho teve como objetivo avaliar, por comparação, a suscetibilidade à corrosão sob tensão da zona afetada pelo calor (ZAC do aço inoxidável austenítico AISI 316L quando submetida a um ambiente similar ao do circuito primário de um reator nuclear PWR nas temperaturas de 303ºC e 325ºC. Para esta avaliação empregou-se o ensaio de taxa de deformação lenta - SSRT (Slow Strain Rate Test. Os resultados indicaram que a CST é ativada termicamente e que a 325ºC pode-se observar a presença mais significativa de fratura frágil decorrente do processo de corrosão sob tensão.In pressurized water reactors (PWRs, low alloy carbon steels and stainless steel are widely used in the primary water circuits. In most cases, Ni alloys are used to joint these materials and form dissimilar welds. These alloys are known to accommodate the differences in composition and thermal expansion of the two materials. Stress corrosion cracking of metals and alloys is caused by synergistic effects of environment, material condition and stress. Over the last thirty years, CST has been observed in dissimilar metal welds. This study presents a comparative work between the CST in the HAZ (Heat Affected Zone of the AISI 316L in two different temperatures (303ºC and 325ºC. The susceptibility to stress corrosion cracking was assessed using the slow strain rate tensile (SSRT test. The results of the SSRT tests indicated that CST is a thermally

Casting AISI 316 steel by gel cast

International Nuclear Information System (INIS)

Ozols, A; Thern, G; Rozenberg, S; Barreiro, M; Marajofsky, A

2004-01-01

The feasibility of producing AISI 316 steel components from their powders and avoiding their compaction is analyzed. A casting technique is tested that is similar to gel casting, used for ceramic materials. In the initial stage, the process consists of the formulation of a concentrated barbotine of powdered metal in a solution of water soluble organic monomers, which is cast in a mold and polymerized in situ to form a raw piece in the shape of the cavity. The process can be performed under controlled conditions using barbotines with a high monomer content from the acrylimide family. Then, the molded piece is slowly heated until the polymer is eliminated, and it is sintered at temperatures of 1160 o C to 1300 o C under a dry hydrogen atmosphere, until the desired densities are attained. The density and micro structure of the materials obtained are compared with those for the materials compacted and synthesized by the conventional processes. The preliminary results show the feasibility of the process for the production of certain kinds of structural components (CW)

An Electrochemical Processing Strategy for Improving Tribological Performance of Aisi 316 Stainless Steel Under Grease Lubrication

Science.gov (United States)

Zou, Jiaojuan; Li, Maolin; Lin, Naiming; Zhang, Xiangyu; Qin, Lin; Tang, Bin

2014-12-01

In order to improve the tribological performance of AISI 316 stainless steel (316 SS) under grease lubrication, electrochemical processing was conducted on it to obtain a rough (surface texturing-like) surface by making use of the high sensitivity of austenitic stainless steel to pitting corrosion in Cl--rich environment. Numerous corrosion pits or micro-ditches acted as micro-reservoirs on the obtained surface. While the grease could offer consistent lubrication, and then improve the tribological performance of 316 SS. Tribological behaviors of raw 316 SS and the treated sample were measured using a reciprocating type tribometer sliding against GCr15 steel counterpart under dry and grease lubrication conditions. The results showed that the mass losses of the two samples were in the same order of magnitude, and the raw sample exhibited lower friction coefficient in dry sliding. When the tests were conducted under grease lubrication condition, the friction coefficients and mass losses of the treated sample were far lower than those of the raw 316 SS. The tribological performance of 316 SS under grease lubrication was drastically improved after electrochemical processing.

Temperature Effects on Stainless Steel 316L Corrosion in the Environment of Sulphuric Acid (H2SO4)

Science.gov (United States)

Ayu Arwati, I. G.; Herianto Majlan, Edy; Daud, Wan Ramli Wan; Shyuan, Loh Kee; Arifin, Khuzaimah Binti; Husaini, Teuku; Alfa, Sagir; Ashidiq, Fakhruddien

2018-03-01

In its application, metal is always in contact with its environment whether air, vapor, water, and other chemicals. During contact, chemical interactions emerge between metals and their respective environments such that the metal surface corrodes. This study aims to determine the corrosion rate of 316L stainless steel sulphuric acid environment (H2SO4) with weight loss and electrochemical methods. The corrosion rate (CR) is value of 316L stainless steel by weight loss method with sulfuric acid (H2SO4) with concentration of 0.5 M. The result obtained in conjunction with the increase of temperature the rate of erosion obtained appears to be larger, with a consecutive 3 hour the temperature of 50°C is 0.27 mg/cm2h, temperature 70°C 0.38 mg/cm2h, and temperature 90 °C 0.52 mg/cm2h. With the electrochemical method, the current value increases by using a C350 potentiostal tool. The higher the current, the longer the time the corrosion rate increases, where the current is at 90 °C with a 10-minute treatment time of 0.0014736 A. The 316L stainless steel in surface metal morphology is shown by using a Scanning Electron Microscope (SEM).

Structure and Composition of Scales Formed on AISI 316 L Steel Alloyed with Ce/La Using High Intensity Plasma Pulses after Oxidation in 1000o

International Nuclear Information System (INIS)

Sartowska, B.; Walis, L.; Starosta, W.; Piekoszewski, J.; Barlak, M.; Pochrybniak, C.; Bochenska, K.

2011-01-01

It is well documented that the high oxygen affinity elements such as Y, Ce, La, Er and other rare earth elements added to steel in small amounts can improve their high temperature oxidation resistance. Rare earth elements can be either alloyed during the steel making process or introduced through surface treatment techniques. Improvement of high temperature oxidation resistance of AISI 316 L steel by incorporation Ce and La elements into its near surface region using high intensity pulsed plasma beams in so-called deposition by the pulse erosion mode was investigated in the present work. The samples were irradiated with 3 short (μs scale) intense (energy density 3 J/cm 2 ) plasma pulses. Heating and cooling processes occur under non-equilibrium conditions. In all samples the near surface layer of the thickness in μm range was melted and simultaneously doped with cerium and lanthanum. The modified samples were oxidized at 1000 o C for 100 h in air. The obtained effects were: oxide scales formed on the treated samples were more fine-grained, compact and adhering better that those formed on the un-treated samples. (author)

The pitting resistance of AISI 316 stainless steel passivated in diluted nitric acid

International Nuclear Information System (INIS)

Barbosa, M.A.

1983-01-01

The pitting resistance of AISI 316 stainless steel after passivation in diluted nitric acid was studied in comparison with that of non-passivated specimens. The passivation treatment increased the pitting potential but decreased the resistance to crevice corrosion under open circuit conditions in aerated sea water. Immersion in the nitric acid solution was found to remove the sulphide inclusions from the metal surface, thus eliminating the most susceptible sites for attack. In the absence of sulphide particles pitting nucleated at aluminium-rich oxides. (author)

16-8-2 weld metal design data for 316L(N) steel

Energy Technology Data Exchange (ETDEWEB)

Tavassoli, A.-A.F. [Commissariat a l' Energie Atomique, CEA/Saclay, 91191 Gif sur Yvette (France)], E-mail: tavassoli@cea.fr

2008-12-15

ITER materials properties documentation is extended to weld metals used for welding Type 316L(N) steel, i.e. the structural material retained for manufacturing ITER major components, such as the vacuum vessel. The data presented here are mainly for the Type 16-8-2 and complete those already reported for the low temperature (Type 316L) and the high temperature (Type 19-12-2) filler metals. The weld metal properties data for Type 16-8-2 filler metal and its joints are collected, sorted and analysed according to the French design and construction rules for nuclear components (RCC-MR). Particular attention is paid to the type of weld metal (e.g. wire for TIG, covered electrode for manual arc, flux wire for automatic welding), as well as, to the weld geometry and welding position. Design allowables are derived from validated data for each category of weld and compared with those of the base metal. In most cases, the analyses performed are extended beyond the conventional analyses required for codes to cover specific needs of ITER. These include effects of exposures to high temperature cycles during component fabrication, e.g. HIPing and low dose neutron irradiation at low and medium temperatures. The ITER Materials Properties Handbook (MPH) is, here, enriched with files for physical and mechanical properties of Type 16-8-2 weld metal. These files, combined with the codification and inspection files, are part of the documentation required for ITER licensing needs. They show that all three weld-metals satisfy the code requirements, provided compositions and types of welds used correspond to those specified in RCC-MR.

Surface Texturing-Plasma Nitriding Duplex Treatment for Improving Tribological Performance of AISI 316 Stainless Steel

Directory of Open Access Journals (Sweden)

Naiming Lin

2016-10-01

Full Text Available Surface texturing-plasma nitriding duplex treatment was conducted on AISI 316 stainless steel to improve its tribological performance. Tribological behaviors of ground 316 substrates, plasma-nitrided 316 (PN-316, surface-textured 316 (ST-316, and duplex-treated 316 (DT-316 in air and under grease lubrication were investigated using a pin-on-disc rotary tribometer against counterparts of high carbon chromium bearing steel GCr15 and silicon nitride Si3N4 balls. The variations in friction coefficient, mass loss, and worn trace morphology of the tested samples were systemically investigated and analyzed. The results showed that a textured surface was formed on 316 after electrochemical processing in a 15 wt % NaCl solution. Grooves and dimples were found on the textured surface. As plasma nitriding was conducted on a 316 substrate and ST-316, continuous and uniform nitriding layers were successfully fabricated on the surfaces of the 316 substrate and ST-316. Both of the obtained nitriding layers presented thickness values of more than 30 μm. The nitriding layers were composed of iron nitrides and chromium nitride. The 316 substrate and ST-316 received improved surface hardness after plasma nitriding. When the tribological tests were carried out under dry sliding and grease lubrication conditions, the tested samples showed different tribological behaviors. As expected, the DT-316 samples revealed the most promising tribological properties, reflected by the lowest mass loss and worn morphologies. The DT-316 received the slightest damage, and its excellent tribological performance was attributed to the following aspects: firstly, the nitriding layer had high surface hardness; secondly, the surface texture was able to capture wear debris, store up grease, and then provide continuous lubrication.

In-reactor creep rupture of 20% cold-worked AISI 316 stainless steel

International Nuclear Information System (INIS)

Lovell, A.J.; Chin, B.A.; Gilbert, E.R.

1981-01-01

Results of an experiment designed to measure in-reactor stress-to-rupture properties of 20% cold-worked AISI 316 stainless steel are reported. The in-reactor rupture data are compared with postirradiation and unirradiated test results. In-reactor rupture lives were found to exceed rupture predictions of postirradiation tests. This longer in-reactor rupture life is attributed to dynamic point defect generation which is absent during postirradiation testing. The in-reactor stress-to-rupture properties are shown to be equal to or greater than the unirradiated material stress-to-rupture properties for times up to 7000 h. (author)

Near-threshold fatigue crack growth behavior of AISI 316 stainless steel

International Nuclear Information System (INIS)

Tobler, R.L.

1986-01-01

The near-threshold fatigue behavior of an AISI 316 alloy was characterized using a newly developed, fully automatic fatigue test apparatus. Significant differences in the near-threshold behavior at temperatures of 295 and 4 K are observed. At 295 K, where the operationally defined threshold at 10 -10 m/cycle is insensitive contains stress ratio and strongly affected by crack closure, the effective threshold stress intensity factor (ΔK/sub Th/)/sub eff/) is about 4.65 MPa m/sub 1/2/ at R = 0.3. At 4 K, the threshold is higher, crack closure is less pronounced, and there is a stress ratio dependency: (ΔK/sub Th/)/sub eff/ is 5.1 MPa m/sup 1/2/ at R = 0.3 and 6.1 MPa m/sup 1/2/ at R - 0.1. There is also a significant difference in the form of the da/dN-versus-ΔK curves on log-log coordinates: at 4 K the curve has the expected sigmoidal shape, but at 295 K the trend is linear over the region of da/dN from 10 -7 to 10 -10 m/cycle. Other results suggest that the near-threshold measurements of a 6.4-mm-thick specimen of this alloy are insensitive to cyclic test frequency below 40 Hz

High temperature chlorosilane corrosion of iron and AISI 316L stainless steel

Science.gov (United States)

Aller, Joshua Loren

Chlorosilane gas streams are used at high temperatures (>500°C) throughout the semiconductor, polycrystalline silicon, and fumed silica industries, primarily as a way to refine, deposit, and produce silicon and silicon containing materials. The presence of both chlorine and silicon in chlorosilane species creates unique corrosion environments due to the ability of many metals to form both metal-chlorides and metal-silicides, and it is further complicated by the fact that many metal-chlorides are volatile at high-temperatures while metal-silicides are generally stable. To withstand the uniquely corrosive environments, expensive alloys are often utilized, which increases the cost of final products. This work focuses on the corrosion behavior of iron, the primary component of low-cost alloys, and AISI 316L, a common low-cost stainless steel, in environments representative of industrial processes. The experiments were conducted using a customized high temperature chlorosilane corrosion system that exposed samples to an atmospheric pressure, high temperature, chlorosilane environment with variable input amounts of hydrogen, silicon tetrachloride, and hydrogen chloride plus the option of embedding samples in silicon during the exposure. Pre and post exposure sample analysis including scanning electron microscopy, x-ray diffraction, energy dispersive x-ray spectroscopy, and gravimetric analysis showed the surface corrosion products varied depending on the time, temperature, and environment that the samples were exposed to. Most commonly, a volatile chloride product formed first, followed by a stratified metal silicide layer. The chlorine and silicon activities in the corrosion environment were changed independently and were found to significantly alter the corrosion behavior; a phenomenon supported by computational thermodynamic equilibrium simulations. It was found that in comparable environments, the stainless steel corroded significantly less than the pure iron. This

Reassessment of the swelling behavior of AISI 304 stainless steel

International Nuclear Information System (INIS)

Garner, F.A.; Porter, D.L.

1982-03-01

Published swelling data derived from EBR-II irradiations of AISI 304 and 304L have been reanalyzed in light of insights gained from irradiation of AISI 316 and Fe-15Cr-25Ni. The primary influence of temperature, displacement rate and compositional variations in the 300 series stainless steels lies in the duration of the transient regime of swelling and not in the steady-state or constant swelling rate regime

STUDY OF POLISHING AISI 316L WITH STRUCTURED ABRASIVE

Directory of Open Access Journals (Sweden)

François GOOSSENS

2015-05-01

Full Text Available Finishing process like polishing is usually used to obtain high quality mechanical surface characteristics such as texture and roughness. These operations are mainly handmade and need highly trained operators thus limiting their repeatability and profitability. To optimize the industrialization of the polishing process, it is therefore necessary to modelize the process to built efficient parameter database. The aim of this study is to characterise the polishing of 316L stainless steel with structured abrasive belts. The geometric data of the belts are given, and we then propose a model to determine material removal. An experimental test bench is set up to test this model and characterise the polishing process in terms of forces. It produces samples for different polishing conditions. The different polished surfaces are then analyzed thanks to the roughness and the wettability. Using experimental designs, we are able to validate the proposed model and identify the parameters that influence a polishing operation.

16 CFR 316.2 - Definitions.

Science.gov (United States)

2010-01-01

... or general partnership, corporation, or other business entity. (i) The definition of the term... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Definitions. 316.2 Section 316.2 Commercial... Definitions. (a) The definition of the term “affirmative consent” is the same as the definition of that term...

Biocompatibility behavior of β–tricalcium phosphate-chitosan coatings obtained on 316L stainless steel

International Nuclear Information System (INIS)

Mina, A.; Caicedo, H.H.; Uquillas, J.A.; Aperador, W.; Gutiérrez, O.; Caicedo, J.C.

2016-01-01

Biological interfaces involve the interaction of complex macromolecular systems and other biomolecules or biomaterials. Researchers have used a combination of cell, material sciences and engineering approaches to create functional biointerfaces to help improve biological functions. Materials such as hydroxyapatite (HA), β-tricalcium phosphate (β-TCP) and chitosan are important biomaterials to be used in biomedical applications such as bone-prosthesis interfaces. In this work, it was evaluated the effect of different concentrations of chitosan on the structural, electrochemical and biocompatible properties of β-tricalcium phosphate-chitosan ((β-Ca 3 (PO 4 ) 2 )-(C 6 H 11 NO 4 )n) hybrid coatings. β–tricalcium phosphate-chitosan coatings were deposited on 316L stainless steel substrates applying 260 mA AC, an agitation velocity of 250 rpm, and temperature deposition of 60 °C. It was possible to obtain coatings of 600 μm of thickness. Structure and surface properties were analyzed by X-ray diffraction (XRD) and dispersive X-ray analysis (EDX). It was found that the arrangement of the β-TCP crystal lattice changed with increasing chitosan weight concentration, showing that the orthorhombic structure of β-TCP is under tensile stress. The electrochemical properties of β–tricalcium phosphate/chitosan (β-TCP–Ch) coatings were analyzed by electrochemical impedance spectroscopy (EIS). Cellular biocompatibility was determined by lactate dehydrogenase (LDH) cytotoxicity assay using primary chinese hamster ovary (CHO) cells. β-TCP–Ch coatings with chitosan concentrations up to 25% caused cytotoxic effects to only 5–10% of CHO cells. Obtained results showed the influence of chitosan in the structural, electrochemical, and biocompatible properties of AISI 316L Stainless Steel. Consequently, the electrochemical and cytotoxic behavior of β-TCP–Ch on 316L Stainless Steel indicated that the coatings might be a promising material in biomedical applications

Electrochemical characterization of AISI 316L stainless steel in contact with simulated body fluid under infection conditions.

Science.gov (United States)

López, Danián Alejandro; Durán, Alicia; Ceré, Silvia Marcela

2008-05-01

Titanium and cobalt alloys, as well as some stainless steels, are among the most frequently used materials in orthopaedic surgery. In industrialized countries, stainless steel devices are used only for temporary implants due to their lower corrosion resistance in physiologic media when compared to other alloys. However, due to economical reasons, the use of stainless steel alloys for permanent implants is very common in developing countries. The implantation of foreign bodies is sometimes necessary in the modern medical practice. However, the complex interactions between the host and the can implant weaken the local immune system, increasing the risk of infections. Therefore, it is necessary to further study these materials as well as the characteristics of the superficial film formed in physiologic media in infection conditions in order to control their potential toxicity due to the release of metallic ions in the human body. This work presents a study of the superficial composition and the corrosion resistance of AISI 316L stainless steel and the influence of its main alloying elements when they are exposed to an acidic solution that simulates the change of pH that occurs when an infection develops. Aerated simulated body fluid (SBF) was employed as working solution at 37 degrees C. The pH was adjusted to 7.25 and 4 in order to reproduce normal body and disease state respectively. Corrosion resistance was measured by means of electrochemical impedance spectroscopy (EIS) and anodic polarization curves.

History dependence and consequences of the microchemical evolution of AISI 316

International Nuclear Information System (INIS)

Garner, F.A.; Porter, D.L.

1982-04-01

The onset of void swelling in AISI 316 can be correlated with the removal of the elements nickel and silicon into precipitate phases. This conclusion was reached earlier based on measurement of microscopic volumes and has now been confirmed by the use of bulk extraction and elemental analysis of precipitates formed during irradiation. It appears that the average level of nickel remaining in the alloy matrix can be used as an index to assess the degree of completion of the microchemical evolution. The dependence of nickel removal on neutron flux and fluence, irradiation temperature, applied stress and preirradiation thermal-mechanical treatment is consistent with the behavior of swelling in response to these variables. It appears that at 400 0 C the microchemical evolution is very sluggish and still in progress at 14 x 10 22 n/cm 2 (E > 0.1 MeV). This suggests that the swelling rate at low temperatures will continue to increase with fluence and will approach that measured at higher temperatures. This higher swelling rate can be realized for some temperature histories which accelerate the kinetics of phase evolution

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

Science.gov (United States)

Trigwell, Steve; Selvaduray, Guna

2005-01-01

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

Effects of ageing conditions on the precipitates evolution, chromium depletion and intergranular corrosion susceptibility of AISI 316L: experimental and modeling results

Energy Technology Data Exchange (ETDEWEB)

Sahlaoui, H.; Makhlouf, K.; Sidhom, H.; Philibert, J

2004-05-15

Chromium carbides and intermetallic phases which form in industrial AISI 316L stainless steel during ageing for up to 80 000 h between 550 and 650 deg. C were identified by combining transmission electron microscopy (TEM) thin foil imaging and electron diffraction and used to establish the time-temperature-precipitation (TTP) diagram. Following the precipitation phenomena, the chemical changes in the grain boundary region were determined by energy-dispersive X-ray microprobe analysis using a scanning transmission electron microscope (STEM). From the experimentally determined chromium profiles the chromium depleted zones were quantified. The interactions between carbide precipitation involving chromium depletion and intergranular corrosion (IGC) were clearly visible from superposition of TTP diagrams and time-temperature-sensitization (TTS) diagrams obtained from ASTM standardized tests. In addition, an experimental criterion to sensitization-desensitization phenomenon was established. Moreover, an analytical model has been developed in this study and successfully validated to predict the profiles of chromium depleted zones. This model coupled with the previously described criterion provides TTS diagrams in good agreement with experimental results.

Can gamma irradiation during radiotherapy influence the metal release process for biomedical CoCrMo and 316L alloys?

Science.gov (United States)

Wei, Zheng; Edin, Jonathan; Karlsson, Anna Emelie; Petrovic, Katarina; Soroka, Inna L; Odnevall Wallinder, Inger; Hedberg, Yolanda

2018-02-09

The extent of metal release from implant materials that are irradiated during radiotherapy may be influenced by irradiation-formed radicals. The influence of gamma irradiation, with a total dose of relevance for radiotherapy (e.g., for cancer treatments) on the extent of metal release from biomedical stainless steel AISI 316L and a cobalt-chromium alloy (CoCrMo) was investigated in physiological relevant solutions (phosphate buffered saline with and without 10 g/L bovine serum albumin) at pH 7.3. Directly after irradiation, the released amounts of metals were significantly higher for irradiated CoCrMo as compared to nonirradiated CoCrMo, resulting in an increased surface passivation (enhanced passive conditions) that hindered further release. A similar effect was observed for 316L showing lower nickel release after 1 h of initially irradiated samples as compared to nonirradiated samples. However, the effect of irradiation (total dose of 16.5 Gy) on metal release and surface oxide composition and thickness was generally small. Most metals were released initially (within seconds) upon immersion from CoCrMo but not from 316L. Albumin induced an increased amount of released metals from AISI 316L but not from CoCrMo. Albumin was not found to aggregate to any greater extent either upon gamma irradiation or in the presence of trace metal ions, as determined using different light scattering techniques. Further studies should elucidate the effect of repeated friction and fractionated low irradiation doses on the short- and long term metal release process of biomedical materials. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2018. © 2018 The Authors Journal of Biomedical Materials Research Part B: Applied Biomaterials Published by Wiley Periodicals, Inc.

Irradiation creep and swelling of AISI 316 to exposures of 130 dpa at 385?400$deg;C

Science.gov (United States)

Garner, F. A.; Porter, D. L.

1988-07-01

The creep and swelling of AISI 316 stainless steel have been studied at 385 to 400°C in EBR-II to doses of 130 dpa. Most creep capsules were operated at constant stress and temperature but mid-life changes in these variables were also made. This paper concentrates on the behavior of the 20% cold-worked condition but five other conditions were also studied. Swelling at ⩽ 400° C was found to lose the sensitivity to stress exhibited at higher temperatures while the creep rate was found to retain linear dependencies on both stress and swelling rate. The creep coefficients extracted at 400°C agree with those found in other experiments conducted at higher temperatures. In the temperature range of ⩽ 400° C, swelling is in the recombinationdominated regime and the swelling rate falls strongly away from the ~1%/dpa rate observed at higher temperatures. These lower rates of creep and swelling, coupled with the attainment of high damage levels without failure, encourage the use of AISI 316 in the construction of water-cooled fusion first walls operating at temperatures below 400°C.

Thermodynamic modeling and kinetics simulation of precipitate phases in AISI 316 stainless steels

International Nuclear Information System (INIS)

Yang, Y.; Busby, J.T.

2014-01-01

This work aims at utilizing modern computational microstructural modeling tools to accelerate the understanding of phase stability in austenitic steels under extended thermal aging. Using the CALPHAD approach, a thermodynamic database OCTANT (ORNL Computational Thermodynamics for Applied Nuclear Technology), including elements of Fe, C, Cr, Ni, Mn, Mo, Si, and Ti, has been developed with a focus on reliable thermodynamic modeling of precipitate phases in AISI 316 austenitic stainless steels. The thermodynamic database was validated by comparing the calculated results with experimental data from commercial 316 austenitic steels. The developed computational thermodynamics was then coupled with precipitation kinetics simulation to understand the temporal evolution of precipitates in austenitic steels under long-term thermal aging (up to 600,000 h) at a temperature regime from 300 to 900 °C. This study discusses the effect of dislocation density and difusion coefficients on the precipitation kinetics at low temperatures, which shed a light on investigating the phase stability and transformation in austenitic steels used in light water reactors

Caracterização microestrutural de soldas dissimilares dos aços ASTM A-508 e AISI 316L Characterization of dissimilar metal weld between low alloy steel ASTM A-508 and 316L stainless steel

Directory of Open Access Journals (Sweden)

Luciana Iglésias Lourenço Lima

2010-06-01

Full Text Available As soldas dissimilares (dissimilar metal welds - DMWs são utilizadas em diversos segmentos da indústria. No caso específico de usinas nucleares, tais soldas são necessárias para conectar tubulações de aço inoxidável com componentes fabricados em aços baixa liga. Os materiais de adição mais utilizados neste tipo de solda são as ligas de níquel 82 e 182. Este trabalho consistiu na soldagem de uma junta dissimilar de aço baixa liga ASTM A-508 G3 e aço inoxidável austenítico AISI 316L utilizando as ligas de níquel 82 e 182 como metais de adição. A soldagem foi realizada manualmente empregando os processos de soldagem ao arco SMAW (Shielded Metal Arc Welding e GTAW (Gas Tungsten Arc Welding. Os corpos de prova foram caracterizados microestruturalmente utilizando-se microscópio óptico e microscópio eletrônico de varredura com microanálise por dispersão de energia de raios X (EDS e ensaios de microdureza Vickers. Observou-se uma microestrutura constituída de dendritas de austenita com a presença de precipitados com formas e dimensões definidas pelo aporte térmico e pela direção de soldagem. Não houve variação significativa da dureza ao longo da junta soldada, demonstrando a adequação dos parâmetros de soldagem utilizados.The dissimilar metal welds (DMWs are used in several areas of the industries. In the nuclear power plant, this weld using nickel alloy welding wires is used to connect stainless steel pipes to low alloy steel components on the reactor pressured vessels. The filler materials commonly used in this type of weld are nickel alloys 82 and 182.. In this study, dissimilar metal welds composed of low alloy steel ASTM A-508 G3, nickel alloys 82 e 182 as weld metals, and austenitic stainless steel AISI 316L were prepared by manual shielded metal arc welding (SMAW and gas tungsten arc welding techniques (GTAW. Samples were microstructural characterized by optical microscopy and scanning electron microscopy

pH effect on pit potential and protection potential of stainless steels AISI-304, 310 and 316 in NaCl solution

International Nuclear Information System (INIS)

Cabral, U.Q.; Sathler, L.; Mariano Neto, F.

1973-06-01

For three austenitic stainless steels, AISI 304, 310 and 316, the pH influence on the rupture, protection and corrosion potentials was studied in a 0,5N NACl solution. The pit potentials determined by the chronogalvonometric method, are pH independent within the acid range. They showed a rough linear variation within the basic range having a maximum corresponding to the pH value of 8.8. The electrochemical hysteresis method, employed for determining the protection potential, presented a total pH independence for the AISI 316. The other steels showed a small dependence within the basic range but with a tendency for the protection potential to become slightly more active with increasing pH, within the acid range. It was also noted for the three steels studied that the corrosion potental became more active with increasing pH, within the basic range [pt

Compatibility behavior of beryllium with LiAlO2 and Li2ZrO3 ceramics, with 316L and 1.4914 steels in Sibelius

International Nuclear Information System (INIS)

Flament, T.; Roux, N.; Abassin, J.J.; Briec, M.; Cruz, D.; Schuster, I.

1991-01-01

The compatibility under irradiation of beryllium with Li 2 O, LiAlO 2 , Li 4 SiO 4 and Li 2 ZrO 3 ceramics and with 316L and 1.4914 steels was investigated in SIBELIUS. The irradiation was performed in the SILOE reactor at 550 deg C for 1690 hours in He + 0.1%H 2 purge pas. Examinations of the LiAlO 2 /Be and Li 2 ZrO 3 /Be couples show a weak oxidation of beryllium and the presence of cavities near the interface with ceramics. Examinations of the 316L/Be and 1.4914/Be couples show the formation of an oxide layer on all beryllium and steel surfaces suggesting that corrosion arises from a species (most likely T 2 O and/or H 2 O) present in the environmental atmosphere. Post-irradiation annealing tests of beryllium indicate that the major part of helium is released during irradiation whereas the major part of tritium is released above 700 deg C

Enhancing the CuCrZr/316L HIP-joint by Ni electroplating

Energy Technology Data Exchange (ETDEWEB)

Wei, R. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, 230031 (China); Science Island Branch of Graduate School, University of Science & Technology of China, Hefei, 230031 (China); Zhao, S.X., E-mail: sxzhao@impcas.ac.cn [Institute of Modern Physics, Chinese Academy of Science, Lanzhou, 730000 (China); Dong, H.; Che, H.Y. [Advanced Technology and Materials Co. Ltd., Beijing, 100081 (China); Li, Q.; Wang, W.J.; Wang, J.C.; Wang, X.L.; Sun, Z.X. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, 230031 (China); Luo, G.-N. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, 230031 (China); Science Island Branch of Graduate School, University of Science & Technology of China, Hefei, 230031 (China); Hefei Center for Physical Science and Technology, Hefei, 230022 (China); Hefei Science Center of Chinese Academy of Sciences, Hefei, 230027 (China)

2017-04-15

Highlights: • The quality of CuCrZr/316L HIP-joint can be enhanced by nickel electroplating on CuCrZr and 316L. • Nickel layer can prevent the occurrence of nickel-poor region in 316L and protect CuCrZr from oxidation. • A Charpy Impact Value as high as 111.5 ± 3.3 J/cm{sup 2} can be obtained by HIP at 980 °C, 140 MPa for 2 h. • At high temperature, CuCrZr is easily oxidized even in the situation of a high vacuum degree of 2 × 10{sup −5} Pa. - Abstract: The quality of CuCrZr/316L joint is crucial for the safety of ITER hypervapotron cooling structure and hot isostatic pressing (HIP) is an important bonding technique for this structure. In this paper, the authors present a finding that the CuCrZr/316L HIP-joint can be enhanced by nickel electroplating on 316L and CuCrZr. A Charpy Impact Value as high as 111.5 ± 3.3 J/cm{sup 2}, which is more than two times the value in a published article, is obtained. The influence of nickel electroplating is twofold: (1) it can prevent the occurrence of nickel-poor region in 316L and the formation of ferrite; (2) it can protect CuCrZr from oxidation during the heating stage of HIP. However, tensile test is not as effective as Charpy Impact Test in characterizing the bonding quality of the CuCrZr/316L HIP-joint. The surface treatment employed in this study is amenable to batch-scale industrial manufacturing at low cost.

Microstructural characterization of pulsed plasma nitrided 316L stainless steel

International Nuclear Information System (INIS)

Asgari, M.; Barnoush, A.; Johnsen, R.; Hoel, R.

2011-01-01

Highlights: → The low temperature pulsed plasma nitrided layer of 316 SS was studied. → The plastic deformation induced in the austenite due to nitriding is characterized by EBSD at different depths (i.e., nitrogen concentration). → Nanomechanical properties of the nitride layer was investigated by nanoindentation at different depths (i.e., nitrogen concentration). → High hardness, high nitrogen concentration and high dislocation density is detected in the nitride layer. → The hardness and nitrogen concentration decreased sharply beyond the nitride layer. - Abstract: Pulsed plasma nitriding (PPN) treatment is one of the new processes to improve the surface hardness and tribology behavior of austenitic stainless steels. Through low temperature treatment (<440 deg. C), it is possible to obtain unique combinations of wear and corrosion properties. Such a combination is achieved through the formation of a so-called 'extended austenite phase'. These surface layers are often also referred to as S-phase, m-phase or γ-phase. In this work, nitrided layers on austenitic stainless steels AISI 316L (SS316L) were examined by means of a nanoindentation method at different loads. Additionally, the mechanical properties of the S-phase at different depths were studied. Electron back-scatter diffraction (EBSD) examination of the layer showed a high amount of plasticity induced in the layer during its formation. XRD results confirmed the formation of the S-phase, and no deleterious CrN phase was detected.

Sensitization behaviour of modified 316N and 316L stainless steel weld metals after complex annealing and stress relieving cycles

International Nuclear Information System (INIS)

Parvathavarthini, N.; Dayal, R.K.; Khatak, H.S.; Shankar, V.; Shanmugam, V.

2006-01-01

Sensitization behaviour of austenitic stainless steel weld metals prepared using indigenously developed modified 316N (C = 0.05%; N = 0.12%) and 316L (C = 0.02%; N = 0.07%) electrodes was studied. Detailed optical and scanning electron microscopic examination was carried out to understand the microstructural changes occurring in the weld metal during isothermal exposure at various temperatures ranging from 500 deg. C to 850 deg. C (773-1123 K). Based on these studies the mechanism of sensitization in the austenite-ferrite weld metal has been explained. Time-temperature-sensitization (TTS) diagrams were established using ASTM A262 Practice E test. From the TTS diagrams, critical cooling rate (CCR) above which there is no risk of sensitization was calculated for both materials. The heating/cooling rates to be followed for avoiding sensitization during heat treatment cycles consisting of solution-annealing and stress-relieving in fabrication of welded components of AISI 316LN stainless steel (SS) were estimated taking into account the soaking time and the number of times the component undergoes thermal excursions in the sensitization regime. The results were validated by performing controlled heating and cooling heat treatment trials on welded specimens

Microstructural origins of yield-strength changes in AISI 316 during fission or fusion irradiation

International Nuclear Information System (INIS)

Garner, F.A.; Hamilton, M.L.; Panayotou, N.F.; Johnson, G.D.

1981-08-01

The changes in yield strength of AISI 316 irradiated in breeder reactors have been successfully modeled in terms of concurrent changes in microstructural components. Two new insights involving the strength contributions of voids and Frank loops have been incorporated into the hardening models. Both the radiation-induced microstructure and the yield strength exhibit transients which are then followed by saturation at a level dependent on the irradiation temperature. Extrapolation to anticipated fusion behavior based on microstructural comparisons leads to the conclusion that the primary influence of transmutational differences is only to alter the transient behavior and not the saturation level of yield strength

A Study on the Effect of the Boron Potential on the Mechanical Properties of the Borided Layers Obtained by Boron Diffusion at the Surface of AISI 316L Steel

Directory of Open Access Journals (Sweden)

E. Hernández-Sánchez

2014-01-01

Full Text Available The effect of the boron potential on the thickness and the mechanical properties of borided layers was evaluated. The boron potential was established by means of the available atoms of boron contained in a control volume inside a cylinder. The cylinders were manufactured from AISI 316L steel, and the boriding treatment was performed using the powder pack technique at a temperature of 1273 K over an exposure time of 6 h. Four different internal diameters of the cylinders were evaluated (3.17, 4.76, 6.35, and 7.93 mm. The mechanical properties were evaluated using the Berkovich instrumented indentation technique. The results showed a clear influence of the boron potential on the mechanical properties of the layers. The hardness of the layers was stablished in the range of 16.22 to 21.16 GPa. Young’s modulus values were stablished in the range of 255.96 to 341.37 GPa. Also the fracture toughness and brittleness of the layers reflected the influence of the boron potential supplied during the boriding process. Finally, the influence of the boron potential on the constant of parabolic growth (K was also established as a function of the inner diameter of the cylinders.

Analysis of the cold compaction behaviour of TiH2-316L nanocomposite powder blend using compaction models

CSIR Research Space (South Africa)

Machio, Christopher N

2015-07-01

Full Text Available The paper captures the effect of structure and the applicability of compaction models using the cold compaction of a TiH2-SS316L composite powder prepared by high energy mechanical milling. The composite blend was cold pressed uniaxially...

Physical characterization of austenitic stainless steels AISI 304 and AISI 348 L*

International Nuclear Information System (INIS)

Teodoro, Celso Antonio; Silva, Jose Eduardo Rosa da

2009-01-01

The study of radiation damages in metals and metallic alloys used as structural materials in nuclear reactors has a strategic meaning to the nuclear technology because it treats of performance of these materials in conditions that simulate the conditions of work in power reactors. Then it becomes necessary to know the essential physical properties of these materials, properties that are sensitive to the microstructural changes that occurred during the irradiation. The purpose of this work is to characterize, initially, some pre-irradiation properties of the stainless steels AISI 304 and AISI 348 L * , such as mechanical (stress-strain and microhardness) and electrical (resistivity). The AISI 348 L * has been studied for use as fuel cladding material. Both materials will be tested after irradiation in the IEA-R1 core and their properties will be compared with those in the pre-irradiated condition. The morphology of the fractured zones after tensile tests was observed using SEM (scanning electron microscopy). (author)

17 CFR 31.6 - Registration of leverage commodities.

Science.gov (United States)

2010-04-01

... taking delivery to buy or sell the leverage commodity; (2) Explain the effect of such changes upon the... 17 Commodity and Securities Exchanges 1 2010-04-01 2010-04-01 false Registration of leverage... LEVERAGE TRANSACTIONS § 31.6 Registration of leverage commodities. (a) Registration of leverage commodities...

Influence of prior deformation on the sensitization of AISI Type 316LN stainless steel

Energy Technology Data Exchange (ETDEWEB)

Parvathavarthini, N. (Metallurgy Div., Indira Gandhi Centre for Atomic Research, Tamilnadu (India)); Dayal, R.K. (Metallurgy Div., Indira Gandhi Centre for Atomic Research, Tamilnadu (India)); Gnanamoorthy, J.B. (Metallurgy Div., Indira Gandhi Centre for Atomic Research, Tamilnadu (India))

1994-02-01

The sensitization behaviour of a nuclear grade AISI 316LN stainless steel (SS) was studied for various cold-work levels ranging from 0% (mill-annealed) to 25% reduction in thickness. ASTM standard A262 Practices A and E were adopted to detect the susceptibility to intergranular corrosion. The results obtained in these tests were used to construct time-temperature-sensitization (TTS) diagrams. Using these data, the critical linear cooling rate was calculated, above which there is no risk of sensitization. In order to predict the sensitization behaviour during practical cooling conditions, Continuous-cooling-sensitization (CCS) diagrams were established utilising the TTS diagrams by a mathematical method. The influences of prior deformation and nitrogen in the alloy on the sensitization kinetics are discussed. It was found that nitrogen addition retards the sensitization kinetics and that t[sub min] (minimum time required for sensitization at nose temperature) increases by two orders of magnitude in Type 316LN SS compared to that of Type 316 SS at the different prior deformation levels. Cold-working up to 15% accelerates the onset of carbide precipitation and on further cold working there is not much difference in the kinetics. Desensitization is faster in highly cold-worked material, especially at high temperatures. (orig.)

Biocompatibility behavior of β–tricalcium phosphate-chitosan coatings obtained on 316L stainless steel

Energy Technology Data Exchange (ETDEWEB)

Mina, A. [Tribology, Powder Metallurgy and Processing of Solid Recycled Research Group, Universidad del Valle, Cali (Colombia); Caicedo, H.H. [Department of Anatomy and Cell Biology, University of Illinois at Chicago, IL, 60612 (United States); National Biotechnology & Pharmaceutical Association, Chicago, IL, 60606 (United States); Uquillas, J.A. [Universidad San Francisco de Quito USFQ, Colegio de Ciencias de la Salud COCSA, Escuela de Medicina, Hospital de los Valles, Edificio de Especialidades Médicas, Av. Interoceánica km 12 1/2 Cumbayá, Quito (Ecuador); Biomaterials Innovation Research Center, Department of Medicine, Brigham and Women' s Hospital, Harvard Medical School, Boston, MA, 02139 (United States); Aperador, W. [Departament of Engineering, Universidad Militar Nueva Granada, Bogotá (Colombia); Gutiérrez, O. [Departament of Pharmacology Universidad del Valle, Cali (Colombia); Caicedo, J.C., E-mail: julio.cesar.caicedo@correounivalle.edu.co [Tribology, Powder Metallurgy and Processing of Solid Recycled Research Group, Universidad del Valle, Cali (Colombia)

2016-06-01

Biological interfaces involve the interaction of complex macromolecular systems and other biomolecules or biomaterials. Researchers have used a combination of cell, material sciences and engineering approaches to create functional biointerfaces to help improve biological functions. Materials such as hydroxyapatite (HA), β-tricalcium phosphate (β-TCP) and chitosan are important biomaterials to be used in biomedical applications such as bone-prosthesis interfaces. In this work, it was evaluated the effect of different concentrations of chitosan on the structural, electrochemical and biocompatible properties of β-tricalcium phosphate-chitosan ((β-Ca{sub 3}(PO{sub 4}){sub 2})-(C{sub 6}H{sub 11}NO{sub 4})n) hybrid coatings. β–tricalcium phosphate-chitosan coatings were deposited on 316L stainless steel substrates applying 260 mA AC, an agitation velocity of 250 rpm, and temperature deposition of 60 °C. It was possible to obtain coatings of 600 μm of thickness. Structure and surface properties were analyzed by X-ray diffraction (XRD) and dispersive X-ray analysis (EDX). It was found that the arrangement of the β-TCP crystal lattice changed with increasing chitosan weight concentration, showing that the orthorhombic structure of β-TCP is under tensile stress. The electrochemical properties of β–tricalcium phosphate/chitosan (β-TCP–Ch) coatings were analyzed by electrochemical impedance spectroscopy (EIS). Cellular biocompatibility was determined by lactate dehydrogenase (LDH) cytotoxicity assay using primary chinese hamster ovary (CHO) cells. β-TCP–Ch coatings with chitosan concentrations up to 25% caused cytotoxic effects to only 5–10% of CHO cells. Obtained results showed the influence of chitosan in the structural, electrochemical, and biocompatible properties of AISI 316L Stainless Steel. Consequently, the electrochemical and cytotoxic behavior of β-TCP–Ch on 316L Stainless Steel indicated that the coatings might be a promising material in

Investigation of Boron addition and compaction pressure on the compactibility, densification and microhardness of 316L Stainless Steel

Science.gov (United States)

Ali, S.; Rani, A. M. A.; Altaf, K.; Baig, Z.

2018-04-01

Powder Metallurgy (P/M) is one of the continually evolving technologies used for producing metal materials of various sizes and shapes. However, some P/M materials have limited use in engineering for their performance deficiency including fully dense components. AISI 316L Stainless Steel (SS) is one of the promising materials used in P/M that combines outstanding corrosion resistance, strength and ductility for numerous applications. It is important to analyze the material composition along with the processing conditions that lead to a superior behaviour of the parts manufactured with P/M technique. This research investigates the effect of Boron addition on the compactibility, densification, sintering characteristics and microhardness of 316L SS parts produced with P/M. In this study, 0.25% Boron was added to the 316L Stainless Steel matrix to study the increase in densification of the 316L SS samples. The samples were made at different compaction pressures ranging from 100 MPa to 600 MPa and sintered in Nitrogen atmosphere at a temperature of 1200°C. The effect of compaction pressure and sintering temperature and atmosphere on the density and microhardness was evaluated. The microstructure of the samples was examined by optical microscope and microhardness was found using Vickers hardness machine. Results of the study showed that sintered samples with Boron addition exhibited high densification with increase in microhardness as compared to pure 316L SS sintered samples.

The permeation of tritium through 316L stainless steel with multiple coatings

International Nuclear Information System (INIS)

Yao Zhenyu; Hao Jiakun; Zhou Changshan; Shan Changqi; Yu Jinnan

2000-01-01

TiN + TiC + TiN and TiN + TiC + SiO 2 films were deposited on the surface of 316L austenitic stainless steel by means of physical vapor deposition (PVD). The thickness of the films was about 2-3 μm. The film is compact, oxidation-resistant, and has good adherence with the substrate below 500 deg. C. Tritium gas permeation of 316L with multiple films was examined, and it was found that the tritium permeability in 316L with a TiN + TiC + TiN film was 4-5 orders of magnitude lower, and in 316L with a TiN + TiC + SiO 2 film was 4-6 orders of magnitude lower than that in 316L with a Pd film at about 200-500 deg. C. At about 600 deg. C, the permeability of 316L with the multiple coating was 3-4 orders of magnitude lower than that in 316L with a Pd film. The result shows that the tritium permeation barrier is formed by multiple coating above 300 deg. C, and it is stable below 500 deg. C. However, the barrier is partly destroyed at about 600 deg. C because of oxidation; although this results in degradation of the barrier, it still plays a positive role. These films may be useful as coatings for the first wall, tritium blanket, and heat exchanger in fusion reactors for tritium permeation resistance

Compatibility of 316L stainless steel with tritium breeders for fusion reactors

International Nuclear Information System (INIS)

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

1986-06-01

Compatibility problems with structural materials are a concern for the choice of the tritium breeder for fusion reactors. In the frame of the European Programme on Fusion Technology, two types of blankets are considered: liquid (eutectic lithium-lead alloy at 0.68 wt % Li: 17Li83Pb) and solid (lithium aluminate or silicate) breeders. This paper is devoted to compatibility studies of 316L stainless steel with 17Li83Pb alloy and γ-LiA10 2 ceramic

48 CFR 316.770-2 - Memoranda of understanding.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Memoranda of understanding. 316.770-2 Section 316.770-2 Federal Acquisition Regulations System HEALTH AND HUMAN SERVICES CONTRACTING METHODS AND CONTRACT TYPES TYPES OF CONTRACTS Agreements 316.770-2 Memoranda of understanding. Use of a “memorandum of understanding,” which...

Service experience with AISI type 316 steel components in CEGB Midlands Region power plant

International Nuclear Information System (INIS)

Plastow, B.; Bagnall, B.I.; Yeldham, D.E.

1979-01-01

The service performance of AISI Type 316 steel components in sections up to 100 mm thick in Power Plant of the Midlands Region of the C.E.G.B. is reviewed. A comparison is drawn between the satisfactory performance of components whose dimensional stability is not critical and the difficulties experienced when rapid rates of change of temperature cause distortion in thick section components. Weldment manufacture and performance are reviewed and both are considered to be satisfactory. In general the material has performed well and the difficulties due to distortion have been overcome by imposing operating regimes which limit rates of temperature change. (author)

Deformation induced martensite in AISI 316 stainless steel

International Nuclear Information System (INIS)

Solomon, N.; Solomon, I.

2010-01-01

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, microstructure 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. (Author) 21 refs.

Duplication of 17(p11.2p11.2) in a male child with autism and severe language delay.

Science.gov (United States)

Nakamine, Alisa; Ouchanov, Leonid; Jiménez, Patricia; Manghi, Elina R; Esquivel, Marcela; Monge, Silvia; Fallas, Marietha; Burton, Barbara K; Szomju, Barbara; Elsea, Sarah H; Marshall, Christian R; Scherer, Stephen W; McInnes, L Alison

2008-03-01

Duplications of 17(p11.2p11.2) have been associated with various behavioral manifestations including attention deficits, obsessive-compulsive symptoms, autistic traits, and language delay. We are conducting a genetic study of autism and are screening all cases for submicroscopic chromosomal abnormalities, in addition to standard karyotyping, and fragile X testing. Using array-based comparative genomic hybridization analysis of data from the Affymetrix GeneChip(R) Human Mapping Array set, we detected a duplication of approximately 3.3 Mb on chromosome 17p11.2 in a male child with autism and severe expressive language delay. The duplication was confirmed by measuring the copy number of genomic DNA using quantitative polymerase chain reaction. Gene expression analyses revealed increased expression of three candidate genes for the Smith-Magenis neurobehavioral phenotype, RAI1, DRG2, and RASD1, in transformed lymphocytes from Case 81A, suggesting gene dosage effects. Our results add to a growing body of evidence suggesting that duplications of 17(p11.2p11.2) result in language delay as well as autism and related phenotypes. As Smith-Magenis syndrome is also associated with language delay, a gene involved in acquisition of language may lie within this interval. Whether a parent of origin effect, gender of the case, the presence of allelic variation, or changes in expression of genes outside the breakpoints influence the resultant phenotype remains to be determined. (c) 2007 Wiley-Liss, Inc.

Effects of simulated inflammation on the corrosion of 316L stainless steel

Energy Technology Data Exchange (ETDEWEB)

Brooks, Emily K.; Brooks, Richard P. [Department of Biomedical Engineering, State University of New York at Buffalo (United States); Ehrensberger, Mark T., E-mail: mte@buffalo.edu [Department of Biomedical Engineering, State University of New York at Buffalo (United States); Department of Orthopaedics, State University of New York at Buffalo (United States)

2017-02-01

Stainless steel alloys, including 316L, find use in orthopaedics, commonly as fracture fixation devices. Invasive procedures involved in the placement of these devices will provoke a local inflammatory response that produces hydrogen peroxide (H{sub 2}O{sub 2}) and an acidic environment surrounding the implant. This study assessed the influence of a simulated inflammatory response on the corrosion of 316L stainless steel. Samples were immersed in an electrolyte representing either normal or inflammatory physiological conditions. After 24 h of exposure, electrochemical impedance spectroscopy (EIS) and inductively coupled plasma mass spectroscopy (ICPMS) were used to evaluate differences in corrosion behavior and ion release induced by the inflammatory conditions. Scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDX) were used to evaluate surface morphology and corrosion products formed on the sample surface. Inflammatory conditions, involving the presence of H{sub 2}O{sub 2} and an acidic pH, significantly alter the corrosion processes of 316L stainless steel, promoting aggressive and localized corrosion. It is demonstrated that particular consideration should be given to 316L stainless steel implants with crevice susceptible areas (ex. screw-head/plate interface), as those areas may have an increased probability of rapid and aggressive corrosion when exposed to inflammatory conditions. - Highlights: • The corrosion of 316L exposed to simulated inflammation is examined. • Inflammation is replicated with an acidic electrolyte containing hydrogen peroxide. • Inflammatory conditions increase 316L corrosion compared to normal conditions. • Accelerated corrosion under inflammation is likely due to crevice corrosion. • Care should be taken using 316L in devices with crevice susceptible areas.

Microstructure and mechanical properties of friction welded AISI 1040/AISI 304L steels before and after electrochemical corrosion

Energy Technology Data Exchange (ETDEWEB)

Sarsilmaz, Furkan [Firat Univ., Elazig (Turkey). Dept. of Mechatronics Engineering; Kirik, Ihsan [Batman Univ. (Turkey); Ozdemir, Niyazi [Firat Univ., Elazig (Turkey)

2018-03-01

The aim of the present study is to investigate the effect of welding parameters both on the electrochemical corrosion behavior and tensile strength of pre- and post-electrochemical corrosion of friction welded dissimilar steels. The microstructural changes of AISI 1040/AISI 304L friction welded couples and also parent materials were analyzed by using scanning electron microscopy. The electrochemical behaviors of AISI1040/AISI304L joints were comparatively investigated by potentiodynamic polarization curve test and by electrochemical impedance spectra. Moreover, tensile strength experiments were carried out determining the behavior of friction welded joints of pre- and post-electrochemical corrosion and results indicated that the maximum tensile test value of the dissimilar welded pre-electrochemical corrosion was higher than those of post-electrochemical corrosion and was also very close to AISI 1040 parent material value.

Oxynitrides decorated 316L SS for potential bioimplant application

Science.gov (United States)

Saravanan Kaliaraj, Gobi; Kumar, N.

2018-03-01

Titanium oxynitride (TiON) and zirconium oxynitride (ZrON) were deposited onto 316L stainless steel (316L SS) using reactive magnetron sputtering technique. The monoclinic and cubic phase of TiON and ZrON were obtained by x-ray diffraction (XRD). Nanoindentation and wear test analysis exhibited the better mechanical properties of TiON and ZrON films. Wettability studies showed hydrophilic nature on coated films; whereas bare 316L SS substrate was least hydrophilic. Drastic reduction of bacterial adhesion (Pseudomonas aeruginosa), as well as biofilm formation, was observed in both the films at different time duration. TiON and ZrON films were exhibited excellent hemocompatibility by preventing the platelet activation. Furthermore, the coated films exhibited corrosion protection in presence and absence of hydrogen peroxide (H2O2) in artificial blood plasma (ABP) solution.

Optimization of CO2 laser cutting parameters on Austenitic type Stainless steel sheet

Science.gov (United States)

Parthiban, A.; Sathish, S.; Chandrasekaran, M.; Ravikumar, R.

2017-03-01

Thin AISI 316L stainless steel sheet widely used in sheet metal processing industries for specific applications. CO2 laser cutting is one of the most popular sheet metal cutting processes for cutting of sheets in different profile. In present work various cutting parameters such as laser power (2000 watts-4000 watts), cutting speed (3500mm/min - 5500 mm/min) and assist gas pressure (0.7 Mpa-0.9Mpa) for cutting of AISI 316L 2mm thickness stainless sheet. This experimentation was conducted based on Box-Behenken design. The aim of this work is to develop a mathematical model kerf width for straight and curved profile through response surface methodology. The developed mathematical models for straight and curved profile have been compared. The Quadratic models have the best agreement with experimental data, and also the shape of the profile a substantial role in achieving to minimize the kerf width. Finally the numerical optimization technique has been used to find out best optimum laser cutting parameter for both straight and curved profile cut.

Effect of heat treatment on workability of Cr-Ni-Mo steels

International Nuclear Information System (INIS)

Barcal, J.; Macek, K.

1988-01-01

The workability was studied of the new development generation of hardenable martensite Cr-Ni-Mo steels of the 10-10-2 and 6-11-3 types whose application is envisaged in future in nuclear engineering. Attention is paid to identification of inclusions and the phase analysis ofthe structure with respect to heat treatment and steel type. Face milling was used in the test of workability. In addition, tensile strength and impact bending strength testing was performed. The results showed that steel of the 6-11-3 type in the quenched condition was best workable. However, this steel showed a significant reduction in workability when in the hardened condition. Reduced workability can also be presumed for type 10-10-2 steel in the hardened condition when life is considered. Microstructure changes leading to softening of steel by aging had a favourable effect on workability, especially in steels of the 10-10-2 type. Hardened steels of the 6-11-3 type are recommended to be re-quenched. (Z.M.). 7 figs., 3 tabs., 9 refs

A comprehensive review on cold work of AISI D2 tool steel

Science.gov (United States)

Abdul Rahim, Mohd Aidil Shah bin; Minhat, Mohamad bin; Hussein, Nur Izan Syahriah Binti; Salleh, Mohd Shukor bin

2017-11-01

As a common material in mould and die application, AISI D2 cold work tool steel has proven to be a promising chosen material in the industries. However, challenges remain in using AISI D2 through a modified version with a considerable progress having been made in recent years. This paper provides a critical review of the original as-cast AISI D2 cold work tool steel up to the modified version. The main purpose is to develop an understanding of current modified tool steel trend; the machinability of AISI D2 (drilling, milling, turning, grinding and EDM/WEDM; and the microstructure evolution and mechanical properties of these cold work tool steels due to the presence of alloy materials in the steel matrix. The doping of rare earth alloy element, new steel fabrication processes, significant process parameter in machinability and surface treatment shows that there have been few empirical investigations into these cold work tool steel alloys. This study has discovered that cold work tool steel will remain to be explored in order to survive in the steel industries.

Influence of rare earth additions on the oxidation resistance of chromia forming alloys

International Nuclear Information System (INIS)

Pillis, Marina Fuser

1995-01-01

The addition of rare earths to alloys, either in elemental form or as surface coatings reduces the oxidation rate of chromia forming alloys. The rare earths either act as nucleation sites for surface oxides or get incorporates into the surface oxide and diffuse to oxide grain boundaries. If the latter occurs, a change in the defect structure close to the grain boundaries, probably takes place. In this manner, the rare earths inhibits the movement of chromium ions to the oxide/gas interface. The influence of rare earth additions to AISI 316, AISI 316L and Ni-20 Cr on their oxidation behavior has been studied., AISI 316+Ce, AISI 316+Y, Ni-20 Cr and Ni-20 Cr-2 Al-1 Ce were prepared by melting and AISI 316L, AISI 316L+Ce O 2 and AISI 316L+Y 2 O 3 by powder compaction. The effect of superficial deposits of rare earth oxides was also studied. The alloys were coated with rare earth oxides by high temperature conversion of the respective rare earth nitrates. Isothermal oxidation tests were carried out at 900-1100 deg C and the cyclic oxidation tests consisted of 6 cycles of 2 hours each at 900 deg C, followed by cooling to room temperature. All the tests were carried out in air. Oxidation behavior was evaluated gravimetrically. Scanning electron microscopy was used to study surface morphology. Energy dispersive analysis and X-ray diffraction techniques were used to identify oxide constituents. Overall, it has been observed that with the addition of rare earths, oxidation resistance increases by decreasing oxidation rates and increasing oxide adhesion. Addition of rare earths to AISI 316 prepared by melting resulted in rapid formation of a chromium rich oxide layered near the metal/oxide interface which reduced overall oxidation rate. The addition of Ce O 2 to AISI 316L was found to improve oxidation behavior after 10 hours at 1100 deg C and also inhibit the formation of volatile Cr O 3 . The isothermal oxidation behavior of rare earth oxide covered Ni-20 Cr at 900 deg C

Zircon coatings deposited by electrophoresis on steel 316L

International Nuclear Information System (INIS)

Espitia C, I.; Contreras G, M.E.; Bartolo P, P.; Pena, J.L.; Reyes G, J.; Martinez, L.

2005-01-01

The present research involved zirconia coatings prepared using electrophoretic deposition (EPD) on 316l stainless steel, via hydrolysis of ZrOCI 2 aqueous solution. Initially, a first zirconia thin film was obtained and treated at 400 C for consolidation. Then a second zirconia film was deposited to obtain a homogeneous and fully covered 316l stainless steel plate. The XPS analyses show that on the first zirconia film, the elements Fe, Cr, O and Zr are present. In this first film the compounds Cr 2 O 3 , Fe 2 O 3 and ZrO 2 are formed. While in the second film only the Zr and O are observed so that the surface is formed by ZrO 2 . (Author)

Thermal creep effects on 20% cold worked AISI 316 mechanical properties

International Nuclear Information System (INIS)

Duncan, D.R.

1980-09-01

The effects of thermal creep on subsequent mechanical properties of 20% cold worked AISI 316 pressurized tubes were investigated. Specimens were subjected to temperatures of 811 to 977 0 K and stresses of 86 MPa to 276 MPa. This resulted in strains up to 1.3%. Subsequent mechanical property tests included load change stress rupture tests (original test pressure increased or decreased), uniaxial tensile tests, and temperature ramp burst tests. Load change stress rupture tests were consistent with predictions from isobaric tests, and thus, consistent with the linear life fraction rule. Tests with large stress increases and tests at 866 0 K displayed a tendency for earlier than predicted failure. Tensile and temperature ramp burst tests had only slight effects on material properties (property changes were attributed to thermal recovery). The test results showed that, under the conditions of investigation, dislocation structure recovery was the most significant effect of creep. 9 figures, 5 tables

Creep tests of AISI 316 stainless steel irradiated by alpha particles of 28 MeV

International Nuclear Information System (INIS)

Segura, E.; Lucki, G.

1986-01-01

He-embrittlement effect in AISI 316 SS type throught creep tests performed with annealed and cold worked thin specimens is analized. Measurements were carried out at 700 and 750 0 C, stress of 100 MPa in vacuum better than 10 -5 torr. The He-implantations were made with the cyclotron CV-28 IPEN-CNEN/SP. Using an alpha-particle beam of 28 MeV, with concentration of 26 appm. From the valves of rupture deformation, epsilon sub(R), and rupture time, t sub(R), it was verified that he had a great effect on the operational life and ductility of this material. (Author) [pt

Evaluation of weld joints properties of 60mm thick AISI 316L for fusion reactor vacuum vessel by TIG and EB welding processes

International Nuclear Information System (INIS)

Buddu, Ramesh Kutner

2016-01-01

The present paper is focussed on the NDT examination procedures, evaluated mechanical properties; microstructure details investigated on the different welding process of Multipass TIG process (64 passes) and electron beam welding (two pass) of the AISI SS316LN plates. The characterization of mechanical properties (Tensile, Bend, Hardness and Impact) and detailed microstructure analysis have been discussed in this paper. Mechanical properties in both conditions shown higher joint efficiencies. Bend tests shown the good quality of weld and ductility behavior of the joining process. Hardening is observed in both the samples for welded zone and HAZ compared to base metal. Impact fracture results revealed the poor toughness properties for the WZ compared to HAZ and BM samples in both the cases

Investigation on the corrosion resistance of PIM 316L stainless steel in PEM fuel cell simulated environment

International Nuclear Information System (INIS)

Oliveira, Mara Cristina Lopes de; Costa, Isolda; Antunes, Renato Altobelli

2009-01-01

Bipolar plates play main functions in PEM fuel cells, accounting for the most part of the weight and cost of these devices. Powder metallurgy may be an interesting manufacturing process of these components owing to the production of large scale, complex near-net shape parts. However, corrosion processes are a major concern due to the increase of the passive film thickness on the metal surface, lowering the power output of the fuel cell. In this work, the corrosion resistance of PIM AISI 316L stainless steel specimens was evaluated in 1M H 2 SO 4 + 2 ppm HF solution at room temperature during 30 days of immersion. The electrochemical measurements comprised potentiodynamic polarization and electrochemical impedance spectroscopy. The surface morphology of the specimens was observed before and after the corrosion tests through SEM images. The material presented low corrosion current density suggesting that it is suitable to operate in the PEM fuel cell environment. (author)

Hydrothermal calcium modification of 316L stainless steel and its apatite forming ability in simulated body fluid.

Science.gov (United States)

Valanezahad, Alireza; Ishikawa, Kunio; Tsuru, Kanji; Maruta, Michito; Matsuya, Shigeki

2011-01-01

To understand the feasibility of calcium (Ca) modification of type 316L stainless steel (316L SS) surface using hydrothermal treatment, 316L SS plates were treated hydrothermally in calcium chloride (CaCl(2)) solution. X-ray photoelectron spectroscopic analysis revealed that the surface of 316L SS plate was modified with Ca after hydrothermal treatment at 200°C. And the immobilized Ca increased with CaCl(2) concentration. However no Ca-modification was occurred for 316L SS plates treated at 100°C. When Ca-modified 316L SS plate was immersed in simulated body fluid (SBF) with ion concentrations nearly equal to those of human blood plasma, low crystalline apatite was precipitated on its surface whereas no precipitate was observed on non Ca-modified 316L SS. The results obtained in the present study indicated that hydrothermal treatment at 200°C in CaCl(2) solution is useful for Ca-modification of 316L SS, and Ca-modification plays important role for apatite precipitation in SBF.

Decomposition kinetics of expanded austenite with high nitrogen contents

DEFF Research Database (Denmark)

Christiansen, Thomas; Somers, Marcel A. J.

2006-01-01

This paper addresses the decomposition kinetics of synthesized homogeneous expanded austenite formed by gaseous nitriding of stainless steel AISI 304L and AISI 316L with nitrogen contents up to 38 at.% nitrogen. Isochronal annealing experiments were carried out in both inert (N2) and reducing (H2......) atmospheres. Differential thermal analysis (DTA) and thermogravimetry were applied for identification of the decomposition reactions and X-ray diffraction analysis was applied for phase analysis. CrN precipitated upon annealing; the activation energies are 187 kJ/mol and 128 kJ/mol for AISI 316L and AISI 304L...

Correlation of yield strength with irradiation-induced microstructure in AISI 316 stainless steel

International Nuclear Information System (INIS)

Simons, R.L.; Hulbert, L.A.

1985-10-01

Improvements in the correlation of radiation-induced change in yield strength in AISI 316 stainless steel with microstructure were made by re-examining the role of short-range obstacles. Effects due to the size of the obstacles relative to their spacing and shape of the obstacles were applied. The concept of shearing the precipitates instead of bowing around them was used to explain the effects of precipitate hardening. It is concluded that large changes in yield strength may be produced in high swelling materials. Voids will dominate the hardening at high dpa. The increase in hardening will depend on the diameter of the voids even though the swelling in the material is the same. Precipitate hardening at high fluence (>15 dpa) make a significant contribution for irradiation temperatures above 500 0 C

Chemopreventive effect of chalcone derivative, L2H17, in colon cancer development

International Nuclear Information System (INIS)

Xu, Shanmei; Chen, Minxiao; Chen, Wenbo; Hui, Junguo; Ji, Jiansong; Hu, Shuping; Zhou, Jianmin; Wang, Yi; Liang, Guang

2015-01-01

Colon cancer is the third most commonly diagnosed cancer and the second leading cause of cancer mortality worldwide. Chalcone and its derivatives are reported to exhibit anti-cancer effects in several cancer cell lines, including colon cancer cells. In addition, chalcones have advantages such as poor interaction with DNA and low risk of mutagenesity. In our previous study, a group of chalcone derivatives were synthesized and exhibited strong anti-inflammatory activities. In this study, we evaluated the anti-cancer effects of the chalcone derivative, L2H17, in colon cancer cells. The cytotoxicities of L2H17 on various colon cancer cell lines were investigated by MTT and clonogenic assay. Cell cycle and apoptosis analysis were performed to evaluate the molecular mechanism of L2H17-mediated inhibition of tumor growth. Also, scratch wound and matrigel invasion experiments were performed to estimate the cell migration and invasion after L2H17 treatment. Finally, we observed the anti-colon cancer effects of L2H17 in vivo. Our data show that compound L2H17 exhibited selective cytotoxic effect on colon cancer cells, via inducing G0/G1 cell cycle arrest and apoptosis in CT26.WT cells. Furthermore, L2H17 treatment decreased cell migration and invasion of CT26.WT cells. In addition, L2H17 possessed marked anti-tumor activity in vivo. The molecular mechanism of L2H17-mediated inhibition of tumor promotion and progression were function through inactivated NF-κB and Akt signaling pathways. All these findings show that L2H17 might be a potential growth inhibitory chalcones derivative for colon cancer cells

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

Effect of multiple film on the tritium permeation property in 316L stainless steel

International Nuclear Information System (INIS)

Yao Zhenyu; Hao Jiakun; Zhou Changshan; Shan Changqi

2000-01-01

The films of TiN + TiC + TiN and TiN + TiC + SiO 2 were deposited on the surface of 316L stainless steel by physical vapor deposition technology. The characteristics of films are tested by SEM technology, it shows that the films are compact, thermal shock-resistant, oxidation-resistant and have good compatibility with bulk. the SIMS and IR analysis results show that the tritium permeation barrier is formed when TiC and SiO 2 films are annealed in hydrogen above 300 degree C. The tritium permeability in 316L with film is measured at various temperature, the results show that the tritium permeability in 316L with TiN + TiC + SiO 2 film is 4-6 orders of magnitude lower, and that in 316L with TiN + TiC + TiN film is 4-5 orders of magnitude lower than that in 316L with Pd film at about 200-600 degree C. These films may be used as the surface coating of the first wall, tritium blanket and heat exchanger in fusion reactor

Estudio de microestructura y composición de la oxidación en vapor a 700 y 750oC de los aceros austeníticos AISI 304, 316 y 317

Directory of Open Access Journals (Sweden)

José Luddey Marulanda

2013-01-01

Full Text Available Se ha investigado la oxidación de los aceros inoxidables austeníticos AISI SAE: 304, 316 y 317; a temperaturas de 700 y 750oC, en una atmósfera próxima al 100% de vapor de agua, y de 10 a 1000h de exposición. La finalidad es comprobar la calidad de los aceros austeníticos y estudiar la morfología, composición y estructura de la fases de las capas formadas en la cascarilla del óxido de las muestras por Microscopía Electrónica de Barrido (SEM, Análisis de Rayos X por Dispersión de Energía (EDAX y Difracción de Rayos X (XRD, respectivamente. Así como también, se ha realizado a diferentes tiempos un estudio sistemático de termogravimetría de las muestras oxidadas, donde se ha observado que el acero AISI 304 presentó la menor ganancia de masa y el acero AISI 316 fue el de mayor de masa respecto a los tres aceros del trabajo. Adicionalmente fue realizado un estudio teórico de simulación termodinámica de oxidación en vapor de los tres aceros, en las mismas condiciones experimentales y mediante el programa Thermo-calc. En estos aceros oxidados se han comprobado la presencia de estructuras de fases de óxidos como: Fe2O3, espinelas protectoras Fe3O4 y Cr2NiO4, y óxidos mixtos de tipo (CrxFey2O3, (Fe,Cr,Mn3O4 y Ni6MnO8. Finalmente, se discute un posible mecanismo de la formación de las capas de óxidos de las muestras ensayadas.

Process parameter optimization during EDM of AISI 316 LN stainless steel by using fuzzy based multi-objective PSO

Energy Technology Data Exchange (ETDEWEB)

Majumder, Arindam [National Institute of Technology Agartala, Tripura (India)

2013-07-15

The present contribution describes an application of a hybrid approach using fuzzy logic and particle swarm optimization (PSO) for optimizing the process parameters in the electric discharge machining (EDM) of AISI 316LN Stainless Steel. In this study, each experimentation was performed under different machining conditions of pulse current, pulse on-time, and pulse off-time. Machining performances such as MRR and EWR were evaluated. A Taguchi L9 orthogonal array was produced to plan the experimentation and the regression method was applied to model the relationship between the input factors and responses. A fuzzy model was employed to provide a fitness function to PSO by unifying the multiple responses. Finally, PSO was used to predict the optimal process parametric settings for the multi-performance optimization of the EDM operation. The experimental results confirm the feasibility of the strategy and are in good agreement with the predicted results over a wide range of machining conditions employed in the process.

Influence of enzymatic reactions on the electrochemical behavior of EN X2CrNiMo17-11-2 (AISI 316L) stainless steel in bio-corrosion: role of interfacial processes on the modification of the passive layer

International Nuclear Information System (INIS)

Landoulsi, J.

2008-01-01

The outstanding corrosion behavior of stainless steels (SS) results from the presence of thin oxide layer (some nanometers). In non sterile aqueous media, stainless steels may exhibit a non stable behavior resulting from interactions between microbial species and passive film. In fact, microorganisms can be deeply involved in the corrosion processes usually reported as Microbial Influenced Corrosion (MIC). They can induce the initiation or the acceleration of this phenomenon and they do so when organized in bio-films. From the electrochemical point of view, stainless steels showed an increase of the free corrosion potential (Ecorr) attributed to the bio-film settlement. The Eco' ennoblement was broadly reported in seawater and seems to be confirmed in fresh water according to recent findings. A considerable progress in the comprehension of MIC processes was related to the role of extracellular species, essentially enzymes. Many enzymatic reactions occurring in bio-films consist on using oxygen as electron acceptor to generate hydrogen peroxide and related species. The aim of this work is to understand the mechanisms involved in the electrochemical behavior of stainless steel according to an enzymatic approach in medium simulating fresh water. To this end, glucose oxidase was chosen to globalize aerobic activities of bio-films. Electrochemical measurements in situ and surface analysis allow the comprehension of the role and the nature of interfacial processes. Surface characterization was performed with the help of a new quantitative utilization of XPS analysis and AFM. Results show a significant evolution in term of morphology (surface organization), (ii) chemical composition (passive layer, adsorbed organic species) and (iii) chemical reaction (oxidation, dissolution, effect of enzyme). Finally, a new enzymatic system is proposed to mimic specific physicochemical conditions at the SS / bio-film interface, in particular enzymatic generation of oxidant species in diffusion limiting conditions. (author)

Corrosion resistance and in-vitro bioactivity of BaO containing Na2O-CaO-P2O5 phosphate glass-ceramic coating prepared on 316 L, duplex stainless steel 2205 and Ti6Al4V

Science.gov (United States)

Edathazhe, Akhila B.; Shashikala, H. D.

2018-03-01

The phosphate glass with composition 11Na2O-15BaO-29CaO-45P2O5 was coated on biomedical implant materials such as stainless steel 316 L, duplex stainless steel (DSS) 2205 and Ti6Al4V alloy by thermal enamelling method. The structural properties and composition of glass coated substrates were studied by x-ray diffraction (XRD), Scanning electron microscopy (SEM) and Energy dispersive x-ray spectroscopy (EDS) analysis. The coatings were partially crystalline in nature with porous structure and pore size varied from micro to nanometer range. The polarization curve was obtained for uncoated and coated substrates from electrochemical corrosion test which was conducted at 37 °C in Hank’s balanced salt solution (HBSS). The corrosion resistance of 316 L substrate increased after coating, whereas it decreased in case of DSS 2205 and Ti6Al4V. The XRD and SEM/EDS studies indicated the bioactive hydroxyapatite (HAp) layer formation on all the coated surfaces after electrochemical corrosion test, which improved the corrosion resistance. The observed electrochemical corrosion behavior can be explained based on protective HAp layer formation, composition and diffusion of ions on glass coated surfaces. The in-vitro bioactivity test was carried out at 37 °C in HBS solution for 14 days under static conditions for uncoated and coated substrates. pH and ion release rate measurements from the coated samples were conducted to substantiate the electrochemical corrosion test. The lower ion release rates of Na+ and Ca2+ from coated 316 L supported its higher electrochemical corrosion resistance among coated samples. Among the uncoated substrates, DSS showed higher electrochemical corrosion resistance. Amorphous calcium-phosphate (ACP) layer formation on all the coated substrates after in-vitro bioactivity test was confirmed by XRD, SEM/EDS and ion release measurements. The present work is a comparative study of corrosion resistance and bioactivity of glass coated and uncoated

Influence of rare earth additions on the oxidation resistance of chromia forming alloys; Influencia da adicao de terras raras sobre a resistencia a oxidacao de ligas formadoras de cromia

Energy Technology Data Exchange (ETDEWEB)

Pillis, Marina Fuser

1995-12-31

The addition of rare earths to alloys, either in elemental form or as surface coatings reduces the oxidation rate of chromia forming alloys. The rare earths either act as nucleation sites for surface oxides or get incorporates into the surface oxide and diffuse to oxide grain boundaries. If the latter occurs, a change in the defect structure close to the grain boundaries, probably takes place. In this manner, the rare earths inhibits the movement of chromium ions to the oxide/gas interface. The influence of rare earth additions to AISI 316, AISI 316L and Ni-20 Cr on their oxidation behavior has been studied., AISI 316+Ce, AISI 316+Y, Ni-20 Cr and Ni-20 Cr-2 Al-1 Ce were prepared by melting and AISI 316L, AISI 316L+Ce O{sub 2} and AISI 316L+Y{sub 2} O{sub 3} by powder compaction. The effect of superficial deposits of rare earth oxides was also studied. The alloys were coated with rare earth oxides by high temperature conversion of the respective rare earth nitrates. Isothermal oxidation tests were carried out at 900-1100 deg C and the cyclic oxidation tests consisted of 6 cycles of 2 hours each at 900 deg C, followed by cooling to room temperature. All the tests were carried out in air. Oxidation behavior was evaluated gravimetrically. Scanning electron microscopy was used to study surface morphology. Energy dispersive analysis and X-ray diffraction techniques were used to identify oxide constituents. Overall, it has been observed that with the addition of rare earths, oxidation resistance increases by decreasing oxidation rates and increasing oxide adhesion. Addition of rare earths to AISI 316 prepared by melting resulted in rapid formation of a chromium rich oxide layered near the metal/oxide interface which reduced overall oxidation rate. The addition of Ce O{sub 2} to AISI 316L was found to improve oxidation behavior after 10 hours at 1100 deg C and also inhibit the formation of volatile Cr O{sub 3}. The isothermal oxidation behavior of rare earth oxide covered

Predicción del desgaste del flanco de la herramienta de corte durante el torneado en seco de alta velocidad para piezas de acero AISI 316L en la industria minera

Directory of Open Access Journals (Sweden)

Yusimit K. Zamora-Hernández

2015-07-01

Full Text Available Se realizó un estudio experimental sobre la influencia de los parámetros de corte en el torneado del acero inoxidable AISI 316L con insertos recubiertos de TiCN, Al2O3, TiN. Un microscopio electrónico de barrido fue utilizado para medir y analizar el desgaste de las herramientas de corte. Los resultados fueron comparados utilizando el análisis de varianza y el análisis de regresión múltiple para describir la relación entre el desgaste del flanco de las herramientas de corte, el tiempo de maquinado y el avance de corte, obteniéndose las ecuaciones de los modelos ajustados. La investigación demostró el efecto significativo del avance y del tiempo de maquinado en el desgaste del flanco. El inserto de tres capas no sobrepasó el criterio de fin de vida del desgaste, mientras que el inserto de una capa sufrió un desgaste elevado para la mayor velocidad de corte. El desgaste del flanco tuvo mejor comportamiento para el avance de 0,08 mm/rev en todas las velocidades empleadas en este estudio. Los errores medios absolutos no superaron el 15 %.

Study of radiation damages in AISI 316 and 347 steels

International Nuclear Information System (INIS)

Santos, G.R. dos.

1993-03-01

The CV-28 cyclotron at IEN (Nuclear Engineering Institute) has been used to simulated, in a short time scale, uniform He concentrations produced during neutron irradiation of metals by (n, α) reactions. Helium was implanted at concentrations of 1 to 300 ppm in 100 μm thick sheet samples of AISI 316 and 347 S S by degrading a 28 MeV alpha particle beam with a rotating energy degrader. The effects of He on the mechanical properties of the steels were studied by both non-destructive (positron annihilation) and destructive tests (tensile, creep, TEM and SEM). The positron lifetime measurements of irradiated and annealed samples were used as the base to discuss the He diffusion mechanism. Activation energies of 0.34±0.04 eV for 316 S S and 0.57±0.06 eV for 347 S S, characterized a dissociative process above 650 0 C. TEM analyses have suggested the Ostwald ripening process for bubble growth over the full range of He concentrations studied. It was shown, in agreement with theoretical calculations that, by themselves the displacements produced during the helium implantation, at rate of 1.8 x 10 -3 d pa/ppm, were not sufficient to cause significant changes in ductility. However, a strong ductility loss with increasing He concentration was observed for both types of steel for tensile tests at 25 0 C, as well as in creep at 750 0 C over the range of strain (100 to 200 MPa). Finally, it was shown that charged particle simulation associated with positron annihilation techniques provides a fast, relatively low cost, and useful method to study different kinds of neutron damage in materials. (author)

Estudio de la influencia microbiológica en la corrosión de latones (UNS C68700, UNS C443 y acero inoxidable AISI 316;

Directory of Open Access Journals (Sweden)

Ohanian, Mauricio

2014-06-01

Full Text Available Microorganisms may play an important role in the corrosion process and generate conditions which affect the rate and/or the mechanism of deterioration. They become visible by the formation of biofilms: clusters of microorganisms and extracellular polymers. These biofilms affect not only the durability of the material, but also reduce the heat transfer. The present work studied the growth of aerobic and anaerobic heterotrophic microorganisms and sulfate reducing bacteria on aluminum brass (UNS C68700, admiralty brass (UNS C443 and stainless steel AISI 316 in exposure experiments held in the Bay of Montevideo (Uruguay. The influence of the biofilm growth on the corrosion behavior was studied by electrochemical techniques: polarization curves and Electrochemical Impedance Spectroscopy (EIS. The selection of the most suitable material for the exposure conditions is discussed and hypotheses of the corrosion mechanism are presented. Although stainless steel AISI 316 presented the lowest corrosion rate it showed localized deterioration.Los microorganismos influyen de manera significativa en el proceso corrosivo y generan condiciones que afectan la velocidad y/o el mecanismo de deterioro. Su presencia se manifiesta por la formación de bio-películas: conglomerados de bacterias y polímeros extracelulares. Dichas bio-películas afectan la durabilidad del material, la velocidad de flujo y la transferencia de calor. En el presente trabajo se evalúa el crecimiento de microorganismos heterótrofos aerobios, heterótrofos anaerobios y bacterias sulfato-reductoras sobre latón aluminio (UNS C68700, latón almirantazgo (UNS C443 y acero inoxidable AISI 316. Asimismo, se estudia la influencia del crecimiento de la bio-película sobre el comportamiento corrosivo mediante técnicas electroquímicas: curvas de polarización y espectroscopia de impedancia electroquímica. Las exposiciones se realizan en la Bahía de Montevideo, estuario del Río de la Plata

Mechanical properties of similar and dissimilar weldments of RAFMS and AISI 316L (N) SS prepared by electron beam welding process

Energy Technology Data Exchange (ETDEWEB)

Albert, S.K., E-mail: shaju@igcar.gov.in [Indira Gandhi Center for Atomic Research, Kalpakkam 603 102 (India); Das, C.R. [Indira Gandhi Center for Atomic Research, Kalpakkam 603 102 (India); Sam, Shiju [Institute of Plasma Research, Gandhi Nagar (India); Mastanaiah, P.; Patel, M. [Defence Research and Development Laboratory, Hyderabad (India); Bhaduri, A.K.; Jayakumar, T. [Indira Gandhi Center for Atomic Research, Kalpakkam 603 102 (India); Murthy, C.V.S. [Defence Research and Development Laboratory, Hyderabad (India); Kumar, Rajendra [Institute of Plasma Research, Gandhi Nagar (India)

2014-10-15

Highlights: • Increase of W content in RAFM steel can result in retention of delta ferrite in the EB weld of the steel. • Presence of delta ferrite seems to affect the ductile brittle transition temperature of the weld metal. • There is improper mixing of the two base metals in the fusion zone dissimilar welds of RAFM steel and austenitic stainless steel made by EB welding. - Abstract: Effect of weld metal composition on microstructure and toughness of weld metal is studied in this paper. Weld joints of reduced activation ferritic/martensitic (RAFM) steel containing 1.0 and 1.4 wt.% W were prepared using electron beam welding (EBW) process. Dissimilar weld joints between 1.0 wt.% W RAFM steel and AISI 316L (N) SS were also prepared using EBW process. The effect of post weld heat treatment (PWHT) temperatures on microstructure and mechanical properties was also studied. Microstructural observation reveals delta–ferrite in 1.4 wt.% W containing weld metal, which is absent in 1.0 wt.% W weld metal. In the case of the dissimilar weld metal, microstructure shows presence of lath martensite and retained austenite. Austenite was stable even after PWHT and its presence is attributed to high nickel (5–6 wt.%) content in the dissimilar weld metal. Hardness of RAFM steel weld metal was found to be 270–290 VHN after PWHT at 750 °C for 2 h. Impact toughness of both 1.0 and 1.4 wt.% W RAFM steel is high (>250 J) at ambient temperature. However, after PWHT, variation of toughness with temperature is more drastic for 1.4 wt.% W RAFM steel weld metal than the other. As a result, ductile brittle transition temperature (DBTT) for the 1.4 wt.% steel weld metal is close to 0 °C while that of the 1.0 wt.% W steel is close to that of the base metal (∼−80 °C)

Laser surface modification of 316 L stainless steel with bioactive hydroxyapatite.

Science.gov (United States)

Balla, Vamsi Krishna; Das, Mitun; Bose, Sreyashree; Ram, G D Janaki; Manna, Indranil

2013-12-01

Laser-engineered net shaping (LENS™), a commercial additive manufacturing process, was used to modify the surfaces of 316 L stainless steel with bioactive hydroxyapatite (HAP). The modified surfaces were characterized in terms of their microstructure, hardness and apatite forming ability. The results showed that with increase in laser energy input from 32 J/mm(2) to 59 J/mm(2) the thickness of the modified surface increased from 222±12 μm to 355±6 μm, while the average surface hardness decreased marginally from 403±18 HV0.3 to 372±8 HV0.3. Microstructural studies showed that the modified surface consisted of austenite dendrites with HAP and some reaction products primarily occurring in the inter-dendritic regions. Finally, the surface-modified 316 L samples immersed in simulated body fluids showed significantly higher apatite precipitation compared to unmodified 316 L samples. © 2013.

Tensile tests and metallography of brazed AISI 316L specimens after irradiation

International Nuclear Information System (INIS)

Groot, P.; Franconi, E.

1994-01-01

Stainless steel type 316L tensile specimens were vacuum brazed with three kinds of alloys: BNi-5, BNi-6, and BNi-7. The specimens were irradiated up to 0.7 dpa at 353 K in the High Flux Reactor at JRC Petten, the Netherlands. Tensile tests were performed at a constant displacement rate of 10 -3 s -1 at room temperature in the ECN hot cell facility. BNi-5 brazed specimens showed ductile behaviour. Necking and fractures were localized in the plate material. BNi-6 and BNi-7 brazed specimens failed brittle in the brazed zone. This was preceded by uniform deformation of the plate material. Tensile test results of irradiated specimens showed higher stresses due to radiation hardening and a reduction of the elongation of the plate material compared to the reference. SEM examination of the irradiated BNi-6 and BNi-7 fracture surfaces showed nonmetallic phases. These phases were not found in the reference specimens. ((orig.))

Effects of nitrogen and hydrogen in argon shielding gas on bead profile, delta-ferrite and nitrogen contents of the pulsed GTAW welds of AISI 316L stainless steel

Energy Technology Data Exchange (ETDEWEB)

Viyanit, Ekkarut [National Metal and Materials Technology Center (MTEC), Pathaumthani (Thailand). Failure Analysis and Surface Technology Lab; Hartung, Fritz; Lothongkum, Gobboon [Chulalongkom University, Bangkok (Thailand). Dept. of Metallurgical Engineering,; Phakpeetinan, Panyasak; Chianpairot, Amnuysak

2016-08-01

The general effects of 1, 2, 3 and 4 vol.-% nitrogen and 1, 5 and 10 vol.-% hydrogen in argon shielding gas on weld bead profile (depth/width ratio: D/W) and the δ-ferrite content of AISI 316L pulsed GTAW welds were investigated. The limits for imperfections for the quality levels of welds were based on ISO 5817 B. The plates with a thickness of 6 mm were welded at the flat position and the bead on plate. Increasing hydrogen content in argon shielding gas increases the D/W ratio. Excessive hydrogen addition to argon shielding gas will result in incompletely filled groove and excessive penetration of weld. Increasing welding speed decreases the weld-metal volume and the D/W ratios. Nitrogen addition to argon shielding gas has no effect on the D/W ratio. The addition of a mixture of nitrogen and hydrogen to argon shielding gas on the D/W ratio does not show any interaction between them. An effect on the D/W ratio can be exclusively observed as a function of hydrogen content. Increasing hydrogen content in argon shielding gas increases the δ-ferrite content of weld metal. Increasing either nitrogen content in shielding gas or welding speed decreases the δ-ferrite content of weld metal. The nitrogen addition increases the weld metal nitrogen content, however, the hydrogen addition leads to a decrease of weld metal nitrogen content.

Galvanic deposition and characterization of brushite/hydroxyapatite coatings on 316L stainless steel

Energy Technology Data Exchange (ETDEWEB)

Blanda, Giuseppe [Laboratorio di Chimica Fisica Applicata, Dipartimento di Ingegneria Chimica Gestionale Informatica Meccanica, Università di Palermo, Viale delle Scienze, 90128 Palermo (Italy); Brucato, Valerio; Pavia, Francesco Carfì; Greco, Silvia [Dipartimento di Ingegneria Civile, Ambientale, Aerospaziale, dei Materiali, Università di Palermo, Viale delle Scienze, 90128 Palermo (Italy); Piazza, Salvatore; Sunseri, Carmelo [Laboratorio di Chimica Fisica Applicata, Dipartimento di Ingegneria Chimica Gestionale Informatica Meccanica, Università di Palermo, Viale delle Scienze, 90128 Palermo (Italy); Inguanta, Rosalinda, E-mail: rosalinda.inguanta@unipa.it [Laboratorio di Chimica Fisica Applicata, Dipartimento di Ingegneria Chimica Gestionale Informatica Meccanica, Università di Palermo, Viale delle Scienze, 90128 Palermo (Italy)

2016-07-01

In this work, brushite and brushite/hydroxyapatite (BS, CaHPO{sub 4}·H{sub 2}O; HA, Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2}) coatings were deposited on 316L stainless steel (316LSS) from a solution containing Ca(NO{sub 3}){sub 2}·4H{sub 2}O and NH{sub 4}H{sub 2}PO{sub 4} by a displacement reaction based on a galvanic contact, where zinc acts as sacrificial anode. Driving force for the cementation reaction arises from the difference in the electrochemical standard potentials of two different metallic materials (316LSS and Zn) immersed in an electrolyte, so forming a galvanic contact leading to the deposition of BS/HA on nobler metal. We found that temperature and deposition time affect coating features (morphology, structure, and composition). Deposits were characterized by means of several techniques. The morphology was investigated by scanning electron microscopy, the elemental composition was obtained by X-ray energy dispersive spectroscopy, whilst the structure was identified by Raman spectroscopy and X-ray diffraction. BS was deposited at all investigated temperatures covering the 316LSS surface. At low and moderate temperature, BS coatings were compact, uniform and with good crystalline degree. On BS layers, HA crystals were obtained at 50 °C for all deposition times, while at 25 °C, its presence was revealed only after long deposition time. Electrochemical studies show remarkable improvement in corrosion resistance. - Highlights: • Brushite/hydroxyapatite coatings were obtained by a galvanic deposition method. • Galvanic deposition is simple and cheap and does not require external power supply. • Temperature is a key parameter to control composition and morphology of coatings. • Ca/P ratio changes with deposition time, from about 1 up to an optimum value of 1.7. • Compact and adherent layer covering substrate surface were obtained on 316LSS.

Galvanic deposition and characterization of brushite/hydroxyapatite coatings on 316L stainless steel

International Nuclear Information System (INIS)

Blanda, Giuseppe; Brucato, Valerio; Pavia, Francesco Carfì; Greco, Silvia; Piazza, Salvatore; Sunseri, Carmelo; Inguanta, Rosalinda

2016-01-01

In this work, brushite and brushite/hydroxyapatite (BS, CaHPO_4·H_2O; HA, Ca_1_0(PO_4)_6(OH)_2) coatings were deposited on 316L stainless steel (316LSS) from a solution containing Ca(NO_3)_2·4H_2O and NH_4H_2PO_4 by a displacement reaction based on a galvanic contact, where zinc acts as sacrificial anode. Driving force for the cementation reaction arises from the difference in the electrochemical standard potentials of two different metallic materials (316LSS and Zn) immersed in an electrolyte, so forming a galvanic contact leading to the deposition of BS/HA on nobler metal. We found that temperature and deposition time affect coating features (morphology, structure, and composition). Deposits were characterized by means of several techniques. The morphology was investigated by scanning electron microscopy, the elemental composition was obtained by X-ray energy dispersive spectroscopy, whilst the structure was identified by Raman spectroscopy and X-ray diffraction. BS was deposited at all investigated temperatures covering the 316LSS surface. At low and moderate temperature, BS coatings were compact, uniform and with good crystalline degree. On BS layers, HA crystals were obtained at 50 °C for all deposition times, while at 25 °C, its presence was revealed only after long deposition time. Electrochemical studies show remarkable improvement in corrosion resistance. - Highlights: • Brushite/hydroxyapatite coatings were obtained by a galvanic deposition method. • Galvanic deposition is simple and cheap and does not require external power supply. • Temperature is a key parameter to control composition and morphology of coatings. • Ca/P ratio changes with deposition time, from about 1 up to an optimum value of 1.7. • Compact and adherent layer covering substrate surface were obtained on 316LSS.

The influence of the martensitic transformation on the fatigue of an AISI type 316 metastable stainless steel

International Nuclear Information System (INIS)

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

The influence of the martensitic transformation on the process of pulse tension fatigue of a AISI type 316 metastable stainless steel was studied at 25 0 and 196 0 c. The fatigue tests were performed on annealed and cold worked specimens in order to separate the effects of static transformation, dynamic transformation and work hardening. The fatigue limits obtained from the corresponding Wohler curves were compared for the different test conditions. The results showed that the fatigue is not affected by the dynamically induced martensite. On the other hand the static martensite, previously induced, appears to decrease the resistance to fatigue. The reasons for these effects are discussed. (Author) [pt

Weld metal design data for 316L(N)

Energy Technology Data Exchange (ETDEWEB)

Tavassoli, A.A.F. [Commissariat a l' Energie Atoique, CEA, Saclay (France)

2007-07-01

This paper extends the ITER materials properties documentations to weld metal types 316L, 19-12-2 and 16-8-2, used for welding of Type 316L(N), i.e. the structural material retained for manufacturing of ITER main components such as the vacuum vessel. The data presented include those of the low temperature (316L) and high temperature (19-12-2) grades, as well as, the more readily available grade (16-8-2). Weld metal properties data for all three grades are collected, sorted and analyzed according to the French design and construction rules for nuclear components (RCC-MR). Particular attention is paid to the type of weld metal (e.g. wire for TIG, covered electrode for manual arc, flux wire for automatic welding), and the type and the position of welding. Design allowables are derived for each category of weld and compared with those of the base metal. The data sheets established for each physical and mechanical properties follow the presentation established for the ITER Materials Properties Handbook (MPH). They are part of the documentation that when combined with codification and inspection documents should satisfy ITER licensing needs. In most cases, the analyses performed, go beyond conventional analyses required in present international codes and pay attention to specific needs of ITER. These include, possible effects of exposures to high temperatures during various manufacturing stages e.g. HIPing, and effects of irradiation at low and medium temperatures. In general, it is noticed that all three weld metals satisfy the RCC-MR requirements, provided compositions and types of welds used correspond to those specified in RCC-MR. (orig.)

Phase transformation and hardness of SS 316 L steel cast alloy after heat treatment at high temperature

International Nuclear Information System (INIS)

Hidayat, S.; Prayitno, D. H.

2000-01-01

Heat treatment Study of SS 316 L cast alloy at high temperature was conducted. The alloy of SS 316 L was melted by arc melting furnace in argon atmosphere. Heat treatment of SS 316 L casting alloy was carried out in tube furnace at 1400 o C for period of 1/2, 1, and 2 hours. The optical microscopic characterization showed that SS 316 L cast has got dendritic micro structure with ferrite as the primary phase. After the heat treatment, the ferrite phase underwent gradual decrease followed by an increase of the austenite phase. The heat treatment process also resulted in the formation of the new grain boundary. The hardness examination revealed that for longer period of the heat treatment, the hardness of SS 316 L increased. (author)

Effects of Cr2N Precipitation on the Antibacterial Properties of AISI 430 Stainless Steel

Directory of Open Access Journals (Sweden)

Je-Kang Du

2016-03-01

Full Text Available Based on their mechanical properties and good corrosion resistance, some commercial Ni-Cr stainless steels have been widely applied as biomaterials, including the austenitic 304 stainless steel, the austenitic 316 stainless steel, the duplex 2205 stainless steel, and the ferritic 430 stainless steel. In order to reduce the occurrence of infections resulting from biomaterial implants, instruments, and medical devices, Cu2+ and Ag2+ ions have been added onto biomaterials for increasing the antibacterial properties, but they are known to damage biofilm. The occurrence of nanoparticles can also improve the antibacterial properties of biomaterials through various methods. In this study, we used Escherichia coli and analyzed the microstructures of American Iron and Steel Institute (AISI 430 stainless steel with a 0.18 mass % N alloy element. During a lower temperature aging, the microstructure of the as-quenched specimen is essentially a ferrite and martensite duplex matrix with some Cr2N precipitates formed. Additionally, the antibacterial properties of the alloy for E. coli ranged from 3% to 60%, consistent with the presence of Cr2N precipitates. When aged at a lower temperature, which resulted in nano-Cr2N precipitation, the specimen possessed the highest antibacterial activity.

Low temperature grain boundary diffusion of chromium in SUS316 and 316L stainless steels

International Nuclear Information System (INIS)

Mizouchi, Masaki; Yamazaki, Yoshihiro; Iijima, Yoshiaki; Arioka, Koji

2004-01-01

Grain boundary diffusivity of chromium is SUS316 and 316L stainless steels has been determined in the temperature range between 518 and 1173 K. The magnitudes of the grain boundary diffusivities in four kinds of specimens are in the order of the cold-worked SUS316, the solution-treated SUS316L, the solution-treated SUS316 and the sensitized SUS316. The grain boundary diffusivities in these specimens are remarkably higher than those of previous works. The activation energies for the former are 85-91 kJmol -1 , whereas those for the latter are 151-234 kJmol -1 . (author)

Nano-structure TiO2 film coating on 316L stainless steel via sol-gel technique for blood compatibility improvement

Directory of Open Access Journals (Sweden)

Mohammadreza Foruzanmehr

2014-04-01

Full Text Available   Objective(s: Titanium oxides are known to be appropriate hemocompatible materials which are suggested as coatings for blood-contacting devices. Little is known about the influence of nanometric crystal structure, layer thickness, and semiconducting characteristics of TiO2 on blood hemostasis.   Materials and Methods: Having used sol-gel dip coating method in this study, TiO2 thin films were deposited on nano-scale electro-polished stainless steel 316L with 1 to 5 nano-sized layers. Surface morphology and structure of the film were studied with X-ray diffraction and atomic force microscopy. Blood compatibility was also determined by measuring the platelet activation (CD62P expression, platelet adhesion (Scanning Electron Microscopy, and the blood clotting time on these samples. Results: The films were compact and smooth and existed mainly in the form of anatase. By increasing the number of TiO2 thin layer, clotting time greatly extended, and the population of activated platelet and P-selectine expression changed according to the surface characteristics of each layer. Conclusion: The findings revealed that stainless steel 316L coated with nano-structured TiO2 layer improved blood compatibility, in terms of both blood platelet activity and coagulation cascade, which can decrease the thrombogenicity of blood contacting devices which were made from stainless steel.

O impacto do último enxágue na citotoxicidade de produtos críticos passíveis de processamento

Directory of Open Access Journals (Sweden)

Rafael Queiroz de Souza

2015-12-01

Full Text Available RESUMO Objetivo Avaliar a citotoxicidade de produtos submetidos à contaminação desafio, limpeza baseada em procedimento operacional padrão (POP validado e enxágue final em diferentes tipos de água: de torneira, deionizada, destilada, tratada por osmose reversa e ultrapurificada. Método Estudo experimental e laboratorial. Foram utilizadas como amostras 130 cânulas de hidrodissecção, 26 por grupo experimental, caracterizados, de acordo com a água utilizada no último enxágue. As amostras foram submetidas à contaminação desafio interna e externamente por uma solução contendo 20% sangue de carneiro desfibrinado e 80% de Cloreto de Sódio a 0,9%. Em seguida, tiveram o lúmen preenchido por solução viscoelástica, permanecendo em contato com o contaminante por 50 minutos, sendo então, processadas, de acordo com um POP validado. A citotoxicidade foi avaliada pela captura do corante vital vermelho neutro. Resultados Ausência de citotoxicidade nos extratos das amostras. Conclusão As amostras não demonstraram citotoxicidade, independentemente da qualidade de água utilizada no último enxágue. Os resultados apresentados puderam ser alcançados unicamente por meio do uso de um procedimento operacional padrão de limpeza validado, baseado em literatura científica, em recomendações oficiais e na legislação relacionada.

Corrosion-induced microstructural developments in 316 stainless steel during exposure to molten Li{sub 2}BeF{sub 4}(FLiBe) salt

Energy Technology Data Exchange (ETDEWEB)

Zheng, Guiqiu, E-mail: guiqiuzheng@gmail.com [Nuclear Reactor Laboratory, Massachusetts Institute of Technology, Cambridge, MA (United States); He, Lingfeng [Idaho National Laboratory, Idaho Fall, ID (United States); Carpenter, David [Nuclear Reactor Laboratory, Massachusetts Institute of Technology, Cambridge, MA (United States); Sridharan, Kumar [Department of Engineering Physics, University of Wisconsin-Madison, Madison, WI (United States)

2016-12-15

The microstructural developments in the near-surface regions of AISI 316 stainless steel during exposure to molten Li{sub 2}BeF{sub 4} (FLiBe) salt have been investigated with the goal of using this material for the construction of the fluoride salt-cooled high-temperature reactor (FHR), a leading nuclear reactor concept for the next generation nuclear plants (NGNP). Tests were conducted in molten FLiBe salt (melting point: 459 °C) at 700 °C in graphite crucibles and 316 stainless steel crucibles for exposure duration of up to 3000 h. Corrosion-induced microstructural changes in the near-surface regions of the samples were characterized using scanning electron microscopy (SEM) in conjunction with energy dispersive x-ray spectroscopy (EDS) and electron backscatter diffraction (EBSD), and scanning transmission electron microscopy (STEM) with EDS capabilities. Intergranular corrosion attack in the near-surface regions was observed with associated Cr depletion along the grain boundaries. High-angle grain boundaries (15–180°) were particularly prone to intergranular attack and Cr depletion. The depth of attack extended to the depths of 22 μm after 3000-h exposure for the samples tested in graphite crucible, while similar exposure in 316 stainless steel crucible led to the attack depths of only about 11 μm. Testing in graphite crucibles led to the formation of nanometer-scale Mo{sub 2}C, Cr{sub 7}C{sub 3} and Al{sub 4}C{sub 3} particle phases in the near-surface regions of the material. The copious depletion of Cr in the near-surface regions induced a γ-martensite to α-ferrite phase (FeNi{sub x}) transformation. Based on the microstructural analysis, a thermal diffusion controlled corrosion model was developed and experimentally validated for predicting long-term corrosion attack depth.

Study of the Sensitization on the Grain Boundary in Austenitic Stainless Steel Aisi 316

Directory of Open Access Journals (Sweden)

Kocsisová Edina

2014-12-01

Full Text Available Intergranular corrosion (IGC is one of the major problems in austenitic stainless steels. This type of corrosion is caused by precipitation of secondary phases on grain boundaries (GB. Precipitation of the secondary phases can lead to formation of chromium depleted zones in the vicinity of grain boundaries. Mount of the sensitization of material is characterized by the degree of sensitization (DOS. Austenitic stainless steel AISI 316 as experimental material had been chosen. The samples for the study of sensitization were solution annealed on 1100 °C for 60 min followed by water quenching and then sensitization by isothermal annealing on 700 °C and 650 °C with holding time from 15 to 600 min. Transmission electron microscopy (TEM was used for identification of secondary phases. Electron backscattered diffraction (EBSD was applied for characterization of grain boundary structure as one of the factors which influences on DOS.

Measurement of carbon activity in sodium by Fe-Mn 20% alloy, and by strainless austenitic steel 304L and 316L

International Nuclear Information System (INIS)

Oberlin, C.; Saint Paul, P.; Baque, P.; Champeix, L.

1980-01-01

Precise knowledge of carbon activity in sodium used as coolant in fast breeder reactors, is essential for continuous survey of carburization-decarburization processes. Carbon activity can be periodically surveyed by measuring the carbon concentration or by hot trap like metal alloy strip placed in sodium loop. In fact, in equilibrium, activity of carbon in sodium is equal to the activity in metal alloy. Thus if the relation between concentration of carbon and it activity in the alloy is known, it is possible to estimate the activity of carbon in sodium. Materials to be used should have high solubility in carbon at the needed temperature. They should quickly attain equilibrium with sodium and they should not contain impurities that can affect the results. Materials chosen according to these criteria were Fe-Mn 20%, stainless austenitic steel AISI 304L and 316L

Stress corrosion crack growth studies on nitrogen added AISI type 316 stainless steel and its weld metal in boiling acidified sodium chloride solution using the fracture mechanics approach

Energy Technology Data Exchange (ETDEWEB)

Shaikh, H.; George, G.; Khatak, H.S. [Indira Gandhi Centre for Atomic Research, Kalpakkam (India). Div. of Metallurgy; Schneider, F.; Mummert, K. [Institut fuer Festkoerper- und Werkstofforschung Dresden e.V. (Germany). Inst. fuer Metallische Werkstoffe

2000-10-01

Compact tension specimens of nitrogen-added AISI type 316 austenitic stainless steel and its weld metal were subject to stress corrosion cracking (SCC) testing in a boiling solution containing 5 M sodium chloride + 0.15 M sodium sulphate + 2.5 ml/l hydrochloric acid solution using the constant extension rate testing (CERT) technique. The extension rate of testing was 10 microns per hour. The threshold values of stress intensify factor (K{sub ISCC}) and J-integral (J{sub ISCC}) were taken as those values of K{sub I} and J{sub I} at which about 25 microns of SCC crack growth was observed. These threshold values were about four times higher and plateau crack growth rates (PCGR) were nearly one order of magnitude lower for the base metal vis-a-vis the weld metal. Fractographic observations indicated failure by transgranular SCC (TGSCC) of austenite in both the base and weld metal. No stress-assisted dissolution of delta-ferrite or its interface with austenite, was observed. (orig.) [German] CT-Proben von Grund- und Schweissnahtwerkstoff des stickstoffhaltigen Stahles AISI 316 LN wurden Spannungsrisskorrosionstests in siedender chloridhaltiger Loesung (5 M Natriumchlorid/0,15 M Natriumsulfat/0,03 M Salzsaeure) unterzogen. Die Tests erfolgten bei konstanter Dehnrate (CERT-Test) von 10 {mu}m/h. Als Schwellwerte der Initiierung von Spannungsrisskorrosion K{sub ISCC} und I{sub ISCC} wurden die Werte des Spannungsintensitaetsfaktors K{sub I} und des J-Integrals J{sub I} ermittelt, bei denen ein Risswachstum von 25 {mu}m auftrat. Dabei wies der Grundwerkstoff 4-fach hoehere Schwellwerte K{sub ISCC} und J{sub ISCC} auf als der Schweissnahtwerkstoff. Auch die Risswachstumsraten im Plateaubereich der Risswachstumsrate-Spannungsintensitaetskruven waren am Grundwerkstoff um eine Groessenordnung geringer als am Schweissnahtwerkstoff. Die fraktorgrahischen Untersuchungen zeigten an beiden Materialien Schaedigung durch transkristalline Spannungsrisskorrosion. Eine

Cytotoxicity difference of 316L stainless steel and titanium reconstruction plate

Directory of Open Access Journals (Sweden)

Ni Putu Mira Sumarta

2011-03-01

Full Text Available Background: Pure titanium is the most biocompatible material today and used as a gold standard for metallic implants. However, stainless steel is still being used as implants because of its strength, ductility, lower price, corrosion resistant and biocompatibility. Purpose: This study was done to revealed the cytotoxicity difference between reconstruction plate made of 316L stainless steel and of commercially pure (CP titanium in baby hamster kidney-21 (BHK-21 fibroblast culture through MTT assay. Methods: Eight samples were prepared from reconstruction plates made of stainless steel type 316L grade 2 (Coen’s reconstruction plate® that had been cut into cylindrical form of 2 mm in diameter and 3 mm long. The other one were made of CP titanium (STEMA Gmbh® of 2 mm in diameter and 2,2 mm long; and had been cleaned with silica paper and ultrasonic cleaner, and sterilized in autoclave at 121° C for 20 minutes.9 Both samples were bathed into microplate well containing 50 μl of fibroblast cells with 2 x 105 density in Rosewell Park Memorial Institute-1640 (RPMI-1640 media, spinned at 30 rpm for 5 minutes. Microplate well was incubated for 24 and 48 hours in 37° C. After 24 hours, each well that will be read at 24 hour were added with 50 μl solution containing 5mg/ml MTT reagent in phosphate buffer saline (PBS solutions, then reincubated for 4 hours in CO2 10% and 37° C. Colorometric assay with MTT was used to evaluate viability of the cells population after 24 hours. Then, each well were added with 50 μl dimethyl sulfoxide (DMSO and reincubated for 5 minutes in 37° C. the wells were read using Elisa reader in 620 nm wave length. Same steps were done for the wells that will be read in 48 hours. Each data were tabulated and analyzed using independent T-test with significance of 5%. Results: This study showed that the percentage of living fibroblast after exposure to 316L stainless steel reconstruction plate was 61.58% after 24 hours and 62

In vitro biocompatibility of plasma-aided surface-modified 316L stainless steel for intracoronary stents

International Nuclear Information System (INIS)

Bayram, Cem; Denkbas, Emir Baki; Mizrak, Alpay Koray; Aktuerk, Selcuk; Kursaklioglu, Hurkan; Iyisoy, Atila; Ifran, Ahmet

2010-01-01

316L-type stainless steel is a raw material mostly used for manufacturing metallic coronary stents. The purpose of this study was to examine the chemical, wettability, cytotoxic and haemocompatibility properties of 316L stainless steel stents which were modified by plasma polymerization. Six different polymeric compounds, polyethylene glycol, 2-hydroxyethyl methacrylate, ethylenediamine, acrylic acid, hexamethyldisilane and hexamethyldisiloxane, were used in a radio frequency glow discharge plasma polymerization system. As a model antiproliferative drug, mitomycin-C was chosen for covalent coupling onto the stent surface. Modified SS 316L stents were characterized by water contact angle measurements (goniometer) and x-ray photoelectron spectroscopy. C1s binding energies showed a good correlation with the literature. Haemocompatibility tests of coated SS 316L stents showed significant latency (t-test, p < 0.05) with respect to SS 316L and control groups in each test.

Tritium transport in the water cooled Pb-17Li blanket concept of DEMO

International Nuclear Information System (INIS)

Reiter, F.; Tominetti, S.; Perujo, A.

1992-01-01

The code TIRP has been used to calculate the time dependence of tritium inventory and tritium permeation into the coolant and into the first wall boxes in the water cooled Pb-17Li blanket concept of DEMO. The calculations have been performed for the martensitic steel MANET and the austenitic steel AISI 316L as blanket structure materials, for water or helium cooling and for convective or no motion of the liquid breeder in the blanket. Tritium inventories are rather low in blankets with MANET structure and higher in those with AISI 316L structure. Tritium permeation rates are too high in both blankets. Further calculations on tritium inventory and permeation are therefore presented for blankets with TiC permeation barriers of 1 μm thickness on various surfaces of the blanket structure and for blankets with any permeation barriers in function of their thickness, tritium diffusivities, tritium surface recombination rates and atomic densities. These last calculations have been performed for a blanket with coatings on the outer surfaces of the blanket and with a tritium residence time of 10 4 s and for a blanket with coatings on both sides of the cooling tubes and stagnant Pb-17Li in the blanket. The second case for a blanket with MANET structure presents a very interesting solution for tritium recovery by permeation into and pumping from the first wall boxes. (orig.)

Early recurrence in standard-risk medulloblastoma patients with the common idic(17)(p11.2) rearrangement

Science.gov (United States)

Bien-Willner, Gabriel A.; López-Terrada, Dolores; Bhattacharjee, Meena B.; Patel, Kayuri U.; Stankiewicz, Paweł; Lupski, James R.; Pfeifer, John D.; Perry, Arie

2012-01-01

Medulloblastoma is diagnosed histologically; treatment depends on staging and age of onset. Whereas clinical factors identify a standard- and a high-risk population, these findings cannot differentiate which standard-risk patients will relapse and die. Outcome is thought to be influenced by tumor subtype and molecular alterations. Poor prognosis has been associated with isochromosome (i)17q in some but not all studies. In most instances, molecular investigations document that i17q is not a true isochromosome but rather an isodicentric chromosome, idic(17)(p11.2), with rearrangement breakpoints mapping within the REPA/REPB region on 17p11.2. This study explores the clinical utility of testing for idic(17)(p11.2) rearrangements using an assay based on fluorescent in situ hybridization (FISH). This test was applied to 58 consecutive standard- and high-risk medulloblastomas with a 5-year minimum of clinical follow-up. The presence of i17q (ie, including cases not involving the common breakpoint), idic(17)(p11.2), and histologic subtype was correlated with clinical outcome. Overall survival (OS) and disease-free survival (DFS) were consistent with literature reports. Fourteen patients (25%) had i17q, with 10 (18%) involving the common isodicentric rearrangement. The presence of i17q was associated with a poor prognosis. OS and DFS were poor in all cases with anaplasia (4), unresectable disease (7), and metastases at presentation (10); however, patients with standard-risk tumors fared better. Of these 44 cases, tumors with idic(17)(p11.2) were associated with significantly worse patient outcomes and shorter mean DFS. FISH detection of idic(17)(p11.2) may be useful for risk stratification in standard-risk patients. The presence of this abnormal chromosome is associated with early recurrence of medulloblastoma. PMID:22573308

Tensile Deformation Temperature Impact on Microstructure and Mechanical Properties of AISI 316LN Austenitic Stainless Steel

Science.gov (United States)

Xiong, Yi; He, Tiantian; Lu, Yan; Ren, Fengzhang; Volinsky, Alex A.; Cao, Wei

2018-03-01

Uniaxial tensile tests were conducted on AISI 316LN austenitic stainless steel from - 40 to 300 °C at a rate of 0.5 mm/min. Microstructure and mechanical properties of the deformed steel were investigated by optical, scanning and transmission electron microscopies, x-ray diffraction, and microhardness testing. The yield strength, ultimate tensile strength, elongation, and microhardness increase with the decrease in the test temperature. The tensile fracture morphology has the dimple rupture feature after low-temperature deformations and turns to a mixture of transgranular fracture and dimple fracture after high-temperature ones. The dominating deformation microstructure evolves from dislocation tangle/slip bands to large deformation twins/slip bands with temperature decrease. The deformation-induced martensite transformation can only be realized at low temperature, and its quantity increases with the decrease in the temperature.

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...

Hot corrosion of the ceramic composite coating Ni{sub 3}Al-Al{sub 2}O{sub 3}-Al{sub 2}O{sub 3}/MgO plasma sprayed on 316L stainless steel

Energy Technology Data Exchange (ETDEWEB)

Shirazi, Amir Khodaparast; Kiahosseini, Seyed Rahim [Islamic Azad Univ., Damghan (Iran, Islamic Republic of). Dept. of Engineering

2017-08-15

Ni{sub 3}Al-Al{sub 2}O{sub 3}-Al{sub 2}O{sub 3}/MgO three-layered coatings with thicknesses of 50, 100, and 150 μm for Al{sub 2}O{sub 3}/MgO and 100 μm for the other layers were deposited on 316L stainless steel using plasma spraying. X-ray diffraction, atomic force microscopy, furnace hot corrosion testing in the presence of a mixture of Na{sub 2}SO{sub 4} and V{sub 2}O{sub 5} corrosive salts and scanning electron microscopy were used to determine the structural, morphological and hot corrosion resistance of samples. Results revealed that the crystalline grains of MgO and Al{sub 2}O{sub 3} coating were very small. Weight loss due to hot corrosion decreased from approximately 4.267 g for 316L stainless steel without coating to 2.058 g. The samples with 150 μm outer coating showed improved resistance with the increase in outer layer thickness. Scanning electron microscopy of the coated surface revealed that the coating's resistance to hot corrosion is related to the thickness and the grain size of Al{sub 2}O{sub 3}/MgO coatings.

Influence of Ti, C and N concentration on the intergranular corrosion behaviour of AISI 316Ti and 321 stainless steels

International Nuclear Information System (INIS)

Pardo, A.; Merino, M.C.; Coy, A.E.; Viejo, F.; Carboneras, M.; Arrabal, R.

2007-01-01

Intergranular corrosion behaviour of 316Ti and 321 austenitic stainless steels has been evaluated in relation to the influence exerted by modification of Ti, C and N concentrations. For this evaluation, electrochemical measurements - double loop electrochemical potentiokinetic reactivation (DL-EPR) - were performed to produce time-temperature-sensitization (TTS) diagrams for tested materials. Transmission (TEM) and scanning electron microscopy (SEM) were used to determine the composition and nature of precipitates. The addition of Ti promotes better intergranular corrosion resistance in stainless steels. The precipitation of titanium carbides reduces the formation of chromium-rich carbides, which occurs at lower concentrations. Also, the reduction of carbon content to below 0.03 wt.% improves sensitization resistance more than does Ti content. The presence of Mo in AISI 316Ti stainless steel reduces chromium-rich carbide precipitation; the reason is that Mo increases the stability of titanium carbides and tends to replace chromium in the formation of carbides and intermetallic compounds, thus reducing the risks of chromium-depletion

Post irradiation examination of type 316 stainless steels for in-pile Oarai water loop No.2 (OWL-2)

International Nuclear Information System (INIS)

Shibata, Akira; Kimura, Tadashi; Nagata, Hiroshi; Aoyama, Masashi; Kanno, Masaru; Ohmi, Masao

2010-11-01

The Oarai water loop No.2 (OWL-2) was installed in JMTR in 1972 for the purpose of irradiation experiments of fuel element and component material for light water reactors. Type 316 stainless steels (SSs) were used for tube material of OWL-2 in the reactor. But data of mechanical properties of highly irradiated Type 316 SSs has been insufficient since OWL-2 was installed. Therefore surveillance tests of type 316 SSs which were irradiated up to 3.4x10 25 n/m 2 in fast neutron fluence (>1 MeV) were performed. Meanwhile type 316 stainless steel (SS) is widely used in JMTR such as other irradiation apparatus and irradiation capsule, and additional data of type 316 SSs irradiated higher is required. Therefore post irradiation examinations of surveillance specimens made of type 316 SSs which were irradiated up to 1.0x10 26 n/m 2 in fast neutron fluence were performed and reported in this paper. In this result of surveillance tests of type 316 SSs irradiated up to 1.0x10 26 n/m 2 , tensile strength increase with increase of Neutron fluence and total elongation decreased with increase of Neutron fluence compared to unirradiated specimens and specimens irradiated up to 3.4x10 25 n/m 2 . This tendency has good agreement with results of 10 24 - 10 25 n/m 2 in fast neutron fluence. More than 37% in total elongation was confirmed in all test conditions. It was confirmed that type 316 SS irradiated up to 1.0x10 26 n/m 2 in fast neutron fluence has enough ductility as structure material. (author)

Effects of Thermal Aging on Material Properties, Stress Corrosion Cracking, and Fracture Toughness of AISI 316L Weld Metal

Science.gov (United States)

Lucas, Timothy; Forsström, Antti; Saukkonen, Tapio; Ballinger, Ronald; Hänninen, Hannu

2016-08-01

Thermal aging and consequent embrittlement of materials are ongoing issues in cast stainless steels, as well as duplex, and high-Cr ferritic stainless steels. Spinodal decomposition is largely responsible for the well-known "748 K (475 °C) embrittlement" that results in drastic reductions in ductility and toughness in these materials. This process is also operative in welds of either cast or wrought stainless steels where δ-ferrite is present. While the embrittlement can occur after several hundred hours of aging at 748 K (475 °C), the process is also operative at lower temperatures, at the 561 K (288 °C) operating temperature of a boiling water reactor (BWR), for example, where ductility reductions have been observed after several tens of thousands of hours of exposure. An experimental program was carried out in order to understand how spinodal decomposition may affect changes in material properties in Type 316L BWR piping weld metals. The study included material characterization, nanoindentation hardness, double-loop electrochemical potentiokinetic reactivation (DL-EPR), Charpy-V, tensile, SCC crack growth, and in situ fracture toughness testing as a function of δ-ferrite content, aging time, and temperature. SCC crack growth rates of Type 316L stainless steel weld metal under simulated BWR conditions showed an approximate 2 times increase in crack growth rate over that of the unaged as-welded material. In situ fracture toughness measurements indicate that environmental exposure can result in a reduction of toughness by up to 40 pct over the corresponding at-temperature air-tested values. Material characterization results suggest that spinodal decomposition is responsible for the degradation of material properties measured in air, and that degradation of the in situ properties may be a result of hydrogen absorbed during exposure to the high-temperature water environment.

Corrosive Metabolic Activity of Desulfovibrio sp. on 316L Stainless Steel

Science.gov (United States)

Arkan, Simge; Ilhan-Sungur, Esra; Cansever, Nurhan

2016-12-01

The present study investigated the effects of chemical parameters (SO4 2-, PO4 3-, Cl-, pH) and the contents of extracellular polymeric substances (EPS) regarding the growth of Desulfovibrio sp. on the microbiologically induced corrosion of 316L stainless steel (SS). The experiments were carried out in laboratory-scaled test and control systems. 316L SS coupons were exposed to Desulfovibrio sp. culture over 720 h. The test coupons were removed at specific sampling times for enumeration of Desulfovibrio sp., determination of the corrosion rate by the weight loss measurement method and also for analysis of carbohydrate and protein in the EPS. The chemical parameters of the culture were also established. Biofilm/film formation and corrosion products on the 316L SS surfaces were investigated by scanning electron microscopy and energy-dispersive x-ray spectrometry analyses in the laboratory-scaled systems. It was found that Desulfovibrio sp. led to the corrosion of 316L SS. Both the amount of extracellular protein and chemical parameters (SO4 2- and PO4 3-) of the culture caused an increase in the corrosion of metal. There was a significantly positive relationship between the sessile and planktonic Desulfovibrio sp. counts ( p < 0.01). It was detected that the growth phases of the sessile and planktonic Desulfovibrio sp. were different from each other and the growth phases of the sessile Desulfovibrio sp. vary depending on the subspecies of Desulfovibrio sp. and the type of metal when compared with the other published studies.

Electrochemical and in vitro bioactivity of polypyrrole/ceramic nanocomposite coatings on 316L SS bio-implants.

Science.gov (United States)

Madhan Kumar, A; Nagarajan, S; Ramakrishna, Suresh; Sudhagar, P; Kang, Yong Soo; Kim, Hyongbum; Gasem, Zuhair M; Rajendran, N

2014-10-01

The present investigation describes the versatile fabrication and characterization of a novel composite coating that consists of polypyrrole (PPy) and Nb2O5 nanoparticles. Integration of the two materials is achieved by electrochemical deposition on 316L stainless steel (SS) from an aqueous solution of oxalic acid containing pyrrole and Nb2O5 nanoparticles. Fourier transform infrared spectral (FTIR) and X-ray diffraction (XRD) studies revealed that the existence of Nb2O5 nanoparticles in PPy matrix with hexagonal structure. Surface morphological analysis showed that the presence of Nb2O5 nanoparticles strongly influenced the surface nature of the nanocomposite coated 316L SS. Micro hardness results revealed the enhanced mechanical properties of PPy nanocomposite coated 316L SS due to the addition of Nb2O5 nanoparticles. The electrochemical studies were carried out using cyclic polarization and electrochemical impedance spectroscopy (EIS) measurements. In order to evaluate the biocompatibility, contact angle measurements and in vitro characterization were performed in simulated body fluid (SBF) and on MG63 osteoblast cells. The results showed that the nanocomposite coatings exhibit superior biocompatibility and enhanced corrosion protection performance over 316L SS than pure PPy coatings. Copyright © 2014 Elsevier B.V. All rights reserved.

Influence of corrosion on the morphology and structure of ZrO{sub x}N{sub y}−ZrN coatings deposited on stainless steel

Energy Technology Data Exchange (ETDEWEB)

Cubillos, G.I., E-mail: gcubillos@unal.edu.co [Departamento de Química, Grupo de Materiales y Procesos Químicos, Universidad Nacional de Colombia, Bogotá (Colombia); Romero, E., E-mail: erromerom@unal.edu.co [Departamento de Química, Grupo de Materiales y Procesos Químicos, Universidad Nacional de Colombia, Bogotá (Colombia); Alfonso, J.E. [Grupo de Ciencia de Materiales y Superficies, Departamento de Física, Universidad Nacional de Colombia, AA 14490 Bogotá (Colombia)

2016-06-15

Morphological and structural changes of zirconium nitride and oxynitride thin films (ZrO{sub x}N{sub y}/ZrN) deposited via DC magnetron sputtering on stainless steel substrates (AISI 316L, 304LS, and 2205) in a reactive N{sub 2} and N{sub 2}/O{sub 2} atmosphere mixed with argon were studied. The crystallographic structures of the films were established through X-ray diffraction (XRD). The morphology was evaluated via scanning electron microscopy (SEM) and atomic force microscopy (AFM), and the corrosion resistance was evaluated using electrochemical techniques based on linear polarization (PL). The XRD analysis showed that the films were composed of cubic ZrO{sub x}N{sub y} and monoclinic ZrO{sub 2}. The electrochemical test showed that there was corrosion because of pitting phenomena and delamination in the coating deposited on AISI 2205 and AISI 304LS substrates. For AISI 316L, the damage generated by the corrosive solution was less. On the various substrates, an increase in the films' roughness was observed after the corrosion test. - Highlights: • We study the crystallographic change of ZrOxNy thin films after corrosion. • It was evaluated the morphological change of the coating after corrosion in NaCl solution. • The ZrOxNy films grew in the cubic phase and preferentially oriented along the (222) plane. • For AISI 316L, the damage generated by the corrosive solution was less, compared with AISI 304LS and AISI 2205.

Cytocompatibility and mechanical properties of novel porous 316 L stainless steel

Energy Technology Data Exchange (ETDEWEB)

Kato, Komei, E-mail: kkato@mmc.co.jp [Mitsubishi Material Corp. 1-297 Kitabukuro-cho, Omiya-ku, Saitama, 330-8508 (Japan); Yamamoto, Akiko [Biomaterials Center, National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Ochiai, Shojiro [Department of Materials Science and Engineering, Graduate School of Engineering, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501 (Japan); Wada, Masahiro; Daigo, Yuzo [Mitsubishi Materials Corp. Advanced and Tools Company, High Performance Alloy Products Div. 476 Shimoishido-shimo, Kitamoto, Saitama 364-0023 (Japan); Kita, Koichi [Mitsubishi Materials C.M.I. Corp. Alloy Products Div. 46-1 Sempuku Susono Shizuoka-ken 410-1116 (Japan); Omori, Kenichi [Biomaterials Center, National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan)

2013-07-01

Novel 316 L stainless steel (SS) foam with 85% porosity and an open pore diameter of 70–440 μm was developed for hard tissue application. The foam sheet with a 200-μm diameter had superior cell proliferation and penetration as identified through in vitro experiments. Calcification of human osteosarcoma cells in the SS foam was observed. Multi-layered foam preparation is a potential alternative technique that satisfies multi-functional requirements such as cell penetration and binding strength to the solid metal. In tensile tests, Young's modulus and the strength of the SS foam were 4.0 GPa and 11.2 MPa respectively, which is comparable with human cancellous bone. - Highlights: • Novel 316 L stainless steel foam with 85% porosity and a pore diameter of 70–440 μm was developed. • The optimum pore diameter of the foam was 200 μm for cell proliferation and penetration. • Cell penetration in the multi-layered foam was controlled by the pore structures of the top layer. • Calcification of human osteosarcoma was confirmed in the foam and increased with incubation time. • Young's modulus and the tensile strength of the foam were comparable with human cancellous bone.

Antibacterial effects, biocompatibility and electrochemical behavior of zinc incorporated niobium oxide coating on 316L SS for biomedical applications

Science.gov (United States)

Pradeep PremKumar, K.; Duraipandy, N.; Manikantan Syamala, Kiran; Rajendran, N.

2018-01-01

In the present study, Nb2O5 (NZ0) composite coatings with various concentrations of zinc (NZ2, NZ4 & NZ6) are produced on 316L SS by sol-gel method with the aim of improving its antibacterial activity, bone formability and corrosion resistance properties. This work studied the surface characterization of NZ0, NZ2, NZ4 & NZ6 coated 316L SS by ATR-FTIR, XRD, HR-SEM with EDAX. The synthesized coatings were different in the morphological aspects, NZ0 shows mesoporous morphology whereas irregular cluster like morphology was observed for the zinc incorporated coatings. The chemical composition of the NZ0 and NZ4 composite coatings were studied by XPS and the results revealed that the zinc exist as ZnO and Nb as Nb2O5 in the coatings. The increase in the concentration of zinc in Nb2O5 increases the hydrophilic nature identified by water contact angle studies. The potentiodynamic polarization studies in simulated body fluid reveals the increase in polarization resistance with decrease in current density (icorr) and electrochemical impedance spectroscopic studies with increase in charge transfer resistance (Rct) and double layer capacitance (Qdl) were observed for NZ4 coated 316L SS. The inhibition of Staphylococcus aureus and Escherichia coli bacteria were identified for NZ4 coated 316L SS by bacterial viability studies. The NZ4 coated 316L SS showed better Osseo-integration by spreading the MG 63 osteoblast cells. The study results imply that zinc incorporated Nb2O5 (NZ4) composite coating exhibits antibacterial activity and also enhance the corrosion resistance and biocompatibility of the 316L SS.

Carburization behavior of AISI 316LN austenitic stainless steel - Experimental studies and modeling

Energy Technology Data Exchange (ETDEWEB)

Sudha, C. [Physical Metallurgy Division, Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamilnadu (India); Sivai Bharasi, N. [Corrosion Science and Technology Division, Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamilnadu (India); Anand, R. [Physical Metallurgy Division, Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamilnadu (India); Shaikh, H., E-mail: hasan@igcar.gov.i [Corrosion Science and Technology Division, Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamilnadu (India); Dayal, R.K. [Corrosion Science and Technology Division, Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamilnadu (India); Vijayalakshmi, M. [Physical Metallurgy Division, Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamilnadu (India)

2010-07-31

AISI type 316LN austenitic stainless steel was exposed to flowing sodium at 798 K for 16,000 h in the bi-metallic (BIM) sodium loop. A modified surface layer of 10 {mu}m width having a ferrite structure was detected from X-ray diffraction and electron micro probe based analysis. Beneath the modified surface layer a carburized zone of 60 {mu}m width was identified which was found to consist of M{sub 23}C{sub 6} carbides. A mathematical model based on finite difference technique was developed to predict the carburization profiles in sodium exposed austenitic stainless steel. In the computation, effect of only chromium on carbon diffusion was considered. Amount of carbon remaining in solution was determined from the solubility parameter. The predicted profile showed a reasonably good match with the experimental profile. Calculations were extended to simulate the thickness of the carburized layer after exposure to sodium for a period of 40 years. Attempt was also made to predict the carburization profiles based on equilibrium calculations using Dictra and Thermocalc which contain both thermodynamic and kinetic databases for the system under consideration.

Ultrasonic nonlinearity of AISI316 austenitic steel subjected to long-term isothermal aging

Energy Technology Data Exchange (ETDEWEB)

Gong, Won Sik; Kim, Chung Seok [Dept. of Materials Science and Engineering, Chosun University, Gwangju (Korea, Republic of)

2014-06-15

This study presents the ultrasonic nonlinearity of AISI316 austenitic stainless steels subjected to longterm isothermal aging. These steels are attractive materials for use in industrial mechanical structures because of their strength at high-temperatures and their chemical stability. The test materials were subjected to accelerated heat-treatment in an electrical furnace for a predetermined aging duration. The variations in the ultrasonic nonlinearity and microstructural damage were carefully evaluated through observation of the microstructure. The ultrasonic nonlinearity stiffly dropped after aging for up to 1000 h and, then, monotonously decreased. The polygonal shape of the initial grain structures changed to circular, especially as the annealing twins in the grains dissolved and disappeared. The delta ferrite on the grain boundaries could not be observed at 1000 h of aging, and these continuously transformed into their sigma phases. Consequently, in the intial aging period, the rapid decrease in the ultrasonic nonlinearity was caused by voids, dislocations, and twin annihilation. The continuous monotonic decrease in the ultrasonic nonlinearity after the first drop resulted from the generation of Cr{sub 23}C{sub 6} precipitates and σ phases.

A comprising steady-state creep model for the austenitic AISI 316 L(N) steel

International Nuclear Information System (INIS)

Rieth, Michael

2007-01-01

Low-stress creep data of a recently finished special long-term program now allows for much better long-term predictions of the ITER related material 316 L(N) and also enables deformation modeling for a broader stress range. The present work focuses mainly on the set-up of a steady-state creep model with help of well-known rate-equations for different deformation mechanisms. In addition, the impact of microstructure changes and precipitation formation on steady-state creep is studied. The resulting creep model consists of a summation of contributions for diffusion creep, power-law creep, and power-law breakdown. The final creep model agrees well with experimental data for temperatures between 550 and 750 deg C and for shear stresses above 30 MPa. The most important finding of this work is that for very low stresses the model predicts far higher creep rates than can be extrapolated from tests performed at the usual stress range of experimental programs

Application of Leak Before Break concept in 316LN austenitic steel pipes welded using 316L

International Nuclear Information System (INIS)

Cunto, Gabriel Giannini de

2017-01-01

This work presents a study of application of the Leak Before Break (LBB) concept, usually applied in nuclear power plants, in a pipe made from steel AISI type 316LN welded a coated electrode AISI type 316L. LBB concept is a criterion based on fracture mechanics analysis to show that a crack leak, present in a pipe, can be detected by leak detection systems, before this crack reaches a critical size that results in pipe fail. In the studied pipe, tensile tests and Ramberg-Osgood analyses were performed, as well as fracture toughness tests for obtaining the material resistance curve J-R. The tests were performed considering the base metal, weld and heat affected zone (HAZ), at the same operating temperatures of a nuclear power plant. For the mechanical properties found in these tests, load limit analyses were performed in order to determine the size of a crack which could cause a detectable leakage and the critical crack size, considering failure by plastic collapse. For the critical crack size found in the weld, which is the region that presented the lowest toughness, Integral J and tearing modulus T analyses were performed, considering failure by tearing instability. Results show a well-defined behavior between the base metal, HAZ and weld zones, where the base metal has a high toughness behavior, the weld has a low toughness behavior and the HAZ showed intermediate mechanical properties between the base metal and the weld. Using the PICEP software, the leak rate curves versus crack size and also the critical crack size were determined by considering load limit analysis. It was observed that after a certain crack size, the leak rate in base metal is much higher than for the HAZ and the weld, considering the same crack length. This occurs because in the base metal crack, it is expected that the crack grows in a more rounded form due to its higher toughness. The lowest critical crack size was found for the base metal presenting circumferential cracks. For the

[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.

Dissimilar laser welding of AISI 316L stainless steel to Ti6–Al4–6V alloy via pure vanadium interlayer

Energy Technology Data Exchange (ETDEWEB)

Tomashchuk, I., E-mail: iryna.tomashchuk@u-bourgogne.fr; Grevey, D.; Sallamand, P.

2015-01-12

Successful continuous laser joining of AISI 316L stainless steel with Ti6Al4V titanium alloy through pure vanadium interlayer has been performed. Three welding configurations were tested: one-pass welding involving all three materials and two pass and double spot welding involving creation of two melted zones separated by remaining solid vanadium. For the most relevant welds, the investigation of microstructure, phase content and mechanical properties has been carried out. In case of formation of a single melted zone, the insertion of steel elements into V-based solid solution embrittles the weld. In case of creation of two separated melted zones, the mechanical resistance of the junction is determined by annealing of remaining vanadium interlayer, which can be witnessed by observing the increase of grain size and decrease of UTS. The two pass configuration allows attain highest mechanical resistance: 367 MPa or 92% of UTS of annealed vanadium. Double spot configuration produces excessive heat supply to vanadium interlayer, which results in important decrease of tensile strength down to 72% of UTS of annealed vanadium. It was found that undesirable σ phase which forms between Fe and V is not created during the laser welding process because of high cooling rates. However, the zones whose composition corresponds to σ homogeneity range are crack-susceptible, so the best choice is to reduce the V content in steel/vanadium melted zone below σ phase formation limit. In the same time, the proportion between V and Ti in Ti6Al4V/vanadium melted zones does not influence mechanical properties as these elements form ideal solid solution.

2,2-Dinitroethene-1,1-Diamine

Czech Academy of Sciences Publication Activity Database

Šimková, Ludmila; Liška, F.; Ludvík, Jiří

2011-01-01

Roč. 15, č. 17 (2011), s. 2983-2995 ISSN 1385-2728 R&D Projects: GA ČR GAP206/11/0727; GA MŠk ME09002 Institutional research plan: CEZ:AV0Z40400503 Keywords : 1,1-diamino-2,2-dinitroethene * FOX-7 * DADNE Subject RIV: CG - Electrochemistry Impact factor: 3.064, year: 2011

Multiaxial elastoplastic cyclic loading of austenitic 316L steel

Czech Academy of Sciences Publication Activity Database

Mazánová, Veronika; Polák, Jaroslav; Škorík, Viktor; Kruml, Tomáš

2017-01-01

Roč. 11, č. 40 (2017), s. 162-169 ISSN 1971-8993 R&D Projects: GA ČR(CZ) GA13-23652S; GA MŠk LM2015069; GA MŠk(CZ) LQ1601; GA ČR GA15-08826S Institutional support: RVO:68081723 Keywords : 316L steel * Crack initiation * Cyclic stress-strain curve * Multiaxial cyclic loading Subject RIV: JL - Materials Fatigue, Friction Mechanics OBOR OECD: Audio engineering, reliability analysis

Non local approach in crystalline plasticity: study of mechanical behaviour of AISI 316LN stainless steel during low cycle fatigue

International Nuclear Information System (INIS)

Schwartz, J.

2011-01-01

If fatigue crack initiation is currently quite well understood for pure single crystals, its comprehension and prediction in cases of polycrystal alloys such as AISI 316LN stainless steel remain complicated. Experimentally our study focuses on the characterisation of the mechanical behaviour and on the study at different scales of the phenomenon leading to low cycle fatigue crack initiation in 316LN stainless steel. For straining amplitudes of?e/2 = 0,3 and 0,5%, the cyclic softening observed during testing has been related to the organisation of dislocations in band structures. These bands, formed due to the activation of slip systems having the greatest Schmid's factor, carry the most part of the deformation. Their emergence at free surfaces leads to the formation of intrusions and extrusions which help cracks initiate and spread. Numerically we worked on the mesoscopic scale, proposing a new model of crystalline plasticity. This model integrates geometrically necessary dislocations (GND) directly computed from the lattice curvature. Implemented in the finite element code Abaqus TM and Cast3m TM , it is based on single crystal finite deformations laws proposed by Peirce et al. (1983) and Teodosiu et al. (1993). Extended for polycrystals by Hoc (2001) and Erieau (2003), it has been improved by the introduction of GND (Acharya and Bassani, 2000). The simulations performed on different types of aggregates (2D/3D) have shown that taking GND into account enables:- the prediction of the grain size effect on a macroscopic and on a local scale,- a finer computation of local stress field.The influence of the elasticity and interaction matrices on the values and the evolution of the isotropic and kinematic mean stresses has been shown. The importance of boundary conditions on computed mechanical fields could also be pointed out. (author)

AFM study of surface relief evolution in 316L steel fatigued at low and high temperatures

Czech Academy of Sciences Publication Activity Database

Man, Jiří; Valtr, B.; Weidner, A.; Petrenec, Martin; Obrtlík, Karel; Polák, Jaroslav

2010-01-01

Roč. 2, č. 1 (2010), s. 1625-1633 E-ISSN 1877-7058. [Fatigue 2010. Praha, 06.06.2010-11.06.2010] R&D Projects: GA ČR GAP108/10/2371; GA AV ČR 1QS200410502; GA ČR GA106/06/1096 Institutional research plan: CEZ:AV0Z20410507 Keywords : Fatigue crack initiation * 316L steel * Persistent slip band (PSB) * Extrusion * Intrusion * Atomic force microscopy (AFM) Subject RIV: JL - Materials Fatigue, Friction Mechanics

Parameter Optimization Of Natural Hydroxyapatite/SS316l Via Metal Injection Molding (MIM)

Science.gov (United States)

Mustafa, N.; Ibrahim1, M. H. I.; Amin, A. M.; Asmawi, R.

2017-01-01

Metal injection molding (MIM) are well known as a worldwide application of powder injection molding (PIM) where as applied the shaping concept and the beneficial of plastic injection molding but develops the applications to various high performance metals and alloys, plus metal matrix composites and ceramics. This study investigates the strength of green part by using stainless steel 316L/ Natural hydroxyapatite composite as a feedstock. Stainless steel 316L (SS316L) was mixed with Natural hydroxyapatite (NHAP) by adding 40 wt. % Low Density Polyethylene and 60 %wt. Palm Stearin as a binder system at 63 wt. % powder loading consist of 90 % wt. of SS316 L and 10 wt. % NHAP prepared thru critical powder volume percentage (CPVC). Taguchi method was functional as a tool in determining the optimum green strength for Metal Injection Molding (MIM) parameters. The green strength was optimized with 4 significant injection parameter such as Injection temperature (A), Mold temperature (B), Pressure (C) and Speed (D) were selected throughout screening process. An orthogonal array of L9 (3)4 was conducted. The optimum injection parameters for highest green strength were established at A1, B2, C0 and D1 and where as calculated based on Signal to Noise Ratio.

Re-weldability tests of irradiated 316L(N) stainless steel using laser welding technique

International Nuclear Information System (INIS)

Yamada, Hirokazu; Kawamura, Hiroshi; Tsuchiya, Kunihiko; Kalinin, George; Kohno, Wataru; Morishima, Yasuo

2002-01-01

SS316L(N)-IG is the candidate material for the in-vessel and ex-vessel components of fusion reactors such as ITER (International Thermonuclear Experimental Reactor). This paper describes a study on re-weldability of un-irradiated and/or irradiated SS316L(N)-IG and the effect of helium generation on the mechanical properties of the weld joint. The laser welding process is used for re-welding of the water cooling branch pipeline repairs. It is clarified that re-welding of SS316L(N)-IG irradiated up to about 0.2 dpa (3.3 appm He) can be carried out without a serious deterioration of tensile properties due to helium accumulation. Therefore, repair of the ITER blanket cooling pipes can be performed by the laser welding process

Re-weldability tests of irradiated 316L(N) stainless steel using laser welding technique

Science.gov (United States)

Yamada, Hirokazu; Kawamura, Hiroshi; Tsuchiya, Kunihiko; Kalinin, George; Kohno, Wataru; Morishima, Yasuo

2002-12-01

SS316L(N)-IG is the candidate material for the in-vessel and ex-vessel components of fusion reactors such as ITER (International Thermonuclear Experimental Reactor). This paper describes a study on re-weldability of un-irradiated and/or irradiated SS316L(N)-IG and the effect of helium generation on the mechanical properties of the weld joint. The laser welding process is used for re-welding of the water cooling branch pipeline repairs. It is clarified that re-welding of SS316L(N)-IG irradiated up to about 0.2 dpa (3.3 appm He) can be carried out without a serious deterioration of tensile properties due to helium accumulation. Therefore, repair of the ITER blanket cooling pipes can be performed by the laser welding process.

Endurance and failure characteristics of modified Vasco X-2, CBS 600 and AISI 9310 spur gears. [aircraft construction materials

Science.gov (United States)

Townsend, D. P.; Zaretsky, E. V.

1980-01-01

Gear endurance tests and rolling-element fatigue tests were conducted to compare the performance of spur gears made from AISI 9310, CBS 600 and modified Vasco X-2 and to compare the pitting fatigue lives of these three materials. Gears manufactured from CBS 600 exhibited lives longer than those manufactured from AISI 9310. However, rolling-element fatigue tests resulted in statistically equivalent lives. Modified Vasco X-2 exhibited statistically equivalent lives to AISI 9310. CBS 600 and modified Vasco X-2 gears exhibited the potential of tooth fracture occurring at a tooth surface fatigue pit. Case carburization of all gear surfaces for the modified Vasco X-2 gears results in fracture at the tips of the gears.

The Synergistic Effect of Proteins and Reactive Oxygen Species on Electrochemical Behaviour of 316L Stainless Steel for Biomedical Applications

Science.gov (United States)

Simionescu, N.; Benea, L.; Dumitrascu, V. M.

2018-06-01

The stainless steels, especially 316L type is the most used metallic biomaterials for biomedical applications due to their good biocompatibility, low price, excellent corrosion resistance, availability, easy processing and high strength. Due to these favorable properties 316L stainless steel has become the most attractive biomaterial for dental implants, stents and orthopedic implants. However an implant material in the human body is exposed to an action effect of other molecules, including proteins (such as albumin) and reactive oxygen species (such as hydrogen peroxide - H2O2 ) produced by bacteria and immune cells. In the literature there are few studies to follow the effect of proteins and reactive oxygen species on 316L stainless steel used as implant material and are still unclear. The degree of corrosion resistance is the first criterion in the use of a metallic biomaterial in the oral or body environment. The aim of this research work is to investigate the influence of proteins (albumin) and reactive oxygen species (H2O2 ) in combination, taking into account the synergistic effect of these two factors on 316L stainless steel. Albumin is present in the body near implants and reactive oxygen species could appear in inflammatory processes as well. The study shows that the presence of albumin and reactive species influences the corrosion resistance of 316L stainless steel in biological solutions. In this research work the corrosion behavior of 316L stainless steel is analyzed by electrochemical methods such as: open circuit potential (OCP), Electrochemical Impedance Spectroscopy (EIS). It was found that, the electrochemical results are in a good agreement with micro photographs taken before and after corrosion assays. The albumin and reactive oxygen species have influence on 316L stainless steel behavior.

Study of Effect of Quenching Deformation Influenced by 17CrNiMo6 Gear Shaft of Carburization

Science.gov (United States)

Pang, Zirui; Yu, Shenjun; Xu, Jinwu

The 17CrNiMo6 steel is mainly used for the gear shaft of large modulus in many fields of heavy industry such as mining, transit, hoist, forging and so on[1]. The size of addendum circle and common normal line is changed a lot beyond the tolerance because of the long time of carburizing process and the out-of-step structural stress and thermal stress during the quenching process. And thus the posterior grinding efficiency and quality are influenced. In the paper comparison and analysis of the deformation affected by solid and hollow gear shafts were done and the methods of simulation and practice were both used. The results are as follows: the deformation of gear shaft was small before and after carburizing while that of gear shaft was large before and after quenching because of different cooling velocity, structure and hardness of each position. And the deformation of hollow was much smaller than that of solid. Therefore, if the hollow gear shaft is used, the waste of material will be decreased, and finishing cost will be reduced, and thus the technology of heat treatment will be optimized.

AFM surface imaging of AISI D2 tool steel machined by the EDM process

International Nuclear Information System (INIS)

Guu, Y.H.

2005-01-01

The surface morphology, surface roughness and micro-crack of AISI D2 tool steel machined by the electrical discharge machining (EDM) process were analyzed by means of the atomic force microscopy (AFM) technique. Experimental results indicate that the surface texture after EDM is determined by the discharge energy during processing. An excellent machined finish can be obtained by setting the machine parameters at a low pulse energy. The surface roughness and the depth of the micro-cracks were proportional to the power input. Furthermore, the AFM application yielded information about the depth of the micro-cracks is particularly important in the post treatment of AISI D2 tool steel machined by EDM

AFM surface imaging of AISI D2 tool steel machined by the EDM process

Science.gov (United States)

Guu, Y. H.

2005-04-01

The surface morphology, surface roughness and micro-crack of AISI D2 tool steel machined by the electrical discharge machining (EDM) process were analyzed by means of the atomic force microscopy (AFM) technique. Experimental results indicate that the surface texture after EDM is determined by the discharge energy during processing. An excellent machined finish can be obtained by setting the machine parameters at a low pulse energy. The surface roughness and the depth of the micro-cracks were proportional to the power input. Furthermore, the AFM application yielded information about the depth of the micro-cracks is particularly important in the post treatment of AISI D2 tool steel machined by EDM.

Proceedings of the International Congress (12th), Corrosion Control for Low-Cost Reliability, Held in Houston, Texas on September 19 -24, 1993. Volume 3B. Corrosion: Specific Issues

Science.gov (United States)

1993-09-24

de Quimica Pura y Aplicada, Monterrey N.L., 1990. No. 47. 3.- 8. Valdez, G. Guerra, J. Sampedro, N. Rosas. CORROSION, Vol. 2, No. 3, 1991, pp. 11-15...AISI 304L AND 316L STAINLESS STEELS PREPARED BY POWDER METALLURGY. E. Otero Departamento de Ciencia de Materiales Facultad de Ciencias Quimicas ...Madrid, Spain. V. Utrilla Departamento de Ciencia de Materiales Facultad de Ciencias Quimicas Universidad Complutense 28040-Madrid, Spain. E. Sfienz

Study on the effectiveness of Extreme Cold Mist MQL system on turning process of stainless steel AISI 316

Science.gov (United States)

Jamaludin, A. S.; Hosokawa, A.; Furumoto, T.; Koyano, T.; Hashimoto, Y.

2018-03-01

Cutting process of difficult-to-cut material such as stainless steel, generates immensely excessive heat, which is one of the major causes related to shortening tool life and lower quality of surface finish. It is proven that application of cutting fluid during the cutting process of difficult-to-cut material is able to improve the cutting performance, but excessive application of cutting fluid leads to another problem such as increasing processing cost and environmental hazardous pollution of workplace. In the study, Extreme Cold Mist system is designed and tested along with various Minimum Quantity Lubrication (MQL) systems on turning process of stainless steel AISI 316. In the study, it is obtained that, Extreme Cold Mist system is able to reduce cutting force up to 60N and improve the surface roughness of the machined surface significantly.

Formation of ultra-fine grained SUS316L steels by ball-milling and their mechanical properties after neutron irradiation

International Nuclear Information System (INIS)

Zheng, Y.J.; Yamasaki, T.; Fukami, T.; Terasawa, M.; Mitamura, T.

2003-01-01

In order to overcome the irradiation embrittlement in austenitic stainless steels, ultra-fine grained SUS316L steels with very fine TiC particles have been developed. The SUS316L-TiC nanocomposite powders having 1.0 to 2.0 mass% TiC were prepared by ball-milling SUS316L-TiC powder mixtures for 125 h in an argon gas atmosphere. The milled powders were consolidated by hot isostatic pressing (HIP) under a pressure of 200 MPa at temperatures between 700 and 1000 C, and the bulk materials with grain sizes between 100 and 400 nm have been produced. The possibility of using fine-grained TiC particles to pin grain boundaries and thereby maintain the ultra-fine grained structures has been discussed. In order to clarify the effects of the neutron irradiation on mechanical properties of the ultra-fine grained SUS316L steels, Vickers microhardness measurements were performed before and after the irradiation of 1.14 x 10 23 n/m 2 and 1.14 x 10 24 n/m 2 . The hardness increased with increasing the dose of the irradiation. However, these increasing rates of the ultra-fine grained steels were much smaller than those of the coarse-grained SUS316L steels having grain sizes between 13 and 50 μm. (orig.)

The influence of low oxygen and contaminated sodium environments on the fatigue behavior of solution treated AISI 316 stainless steel

Energy Technology Data Exchange (ETDEWEB)

Marshall, P [CEGB, BNL, Berkeley (United Kingdom)

1977-07-01

The influence of air and sodium environments on the fatigue properties of solution treated AISI 316 steel was studied by predictive methods and by conducting tests in air, in high temperature sodium, or following pre-exposure to sodium. The sodium environments studied included contaminated sodium or the products of sodium/water flames possibly typical of fast reactor fault conditions, and low oxygen sodium more appropriate to normal plant operation. Generally, fatigue properties were reduced by contaminated sodium or the products of sodium/water flames and improved by low oxygen sodium when compared with similar tests conducted in air. However, complex effects were observed with respect to crack initiation. The experimental results are discussed and generally follow trends predicted by physically based fatigue models. (author)

In vitro human skin permeation of endoxifen: potential for local transdermal therapy for primary prevention and carcinoma in situ of the breast

Directory of Open Access Journals (Sweden)

Lee O

2011-07-01

Full Text Available Oukseub Lee1, David Ivancic1, Robert T Chatterton Jr2, Alfred W Rademaker3, Seema A Khan11Department of Surgery, 2Department of Obstetrics/Gynecology, 3Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USAPurpose: Oral tamoxifen, a triphenylethylene (TPE, is useful for breast cancer prevention, but its adverse effects limit acceptance by women. Tamoxifen efficacy is related to its major metabolites 4-hydroxytamoxifen (4-OHT and N-desmethyl-4-hydroxytamoxifen (endoxifen [ENX]. Transdermal delivery of these to the breast may avert the toxicity of oral tamoxifen while maintaining efficacy. We evaluated the relative efficiency of skin permeation of 4-OHT and ENX in vitro, and tested oleic acid (OA as a permeation-enhancer.Methods: 4-OHT, ENX, and estradiol (E2 (0.2 mg/mL of 0.5 µCi 3H/mg were dissolved in 60% ethanol-phosphate buffer, ±OA (0.1%–5%. Permeation through EpiDermTM (Matek Corp, Ashland, MA and split-thickness human skin was calculated based on the amount of the agents recovered from the receiver fluid and skin using liquid scintillation counting over 24 hours.Results: In the EpiDerm model, the absorption of 4-OHT and ENX was 10%–11%; total penetration (TP was 26%–29% at 24 hours and was decreased by OA. In normal human skin, the absorption of 4-OHT and ENX was 0.3%; TP was 2%–4% at 24 hours. The addition of 1% OA improved the permeation of ENX significantly more than that of 4-OHT (P < 0.004; further titration of OA at 0.25%–0.5% further improved the permeation of ENX to a level similar to that of estradiol.Conclusion: The addition of OA to ENX results in a favorable rapid delivery equivalent to that of estradiol, a widely used transdermal hormone. The transdermal delivery of ENX to the breast should be further developed in preclinical and clinical studies.Keywords: endoxifen, breast cancer prevention, human skin, transdermal, oleic acid

Comparative study of high temperature oxidation behaviour in AISI 304 and AISI 439 stainless steels

Directory of Open Access Journals (Sweden)

Antônio Claret Soares Sabioni

2003-06-01

Full Text Available This work deals with a comparison of high temperature oxidation behaviour in AISI 304 austenitic and AISI 439 ferritic stainless steels. The oxidation experiments were performed between 850 and 950 °C, in oxygen and Ar (100 vpm H2. In most cases, it was formed a Cr2O3 protective scale, whose growth kinetics follows a parabolic law. The exception was for the the AISI 304 steel, at 950 °C, in oxygen atmosphere, which forms an iron oxide external layer. The oxidation resistance of the AISI 439 does not depend on the atmosphere. The AISI 304 has the same oxidation resistance in both atmospheres, at 850 °C, but at higher temperatures, its oxidation rate strongly increases in oxygen atmosphere. Concerning the performance of these steels under oxidation, our results show that the AISI 439 steel has higher oxidation resistance in oxidizing atmosphere, above 850 °C, while, in low pO2 atmosphere, the AISI 304 steel has higher oxidation resistance than the AISI 439, in all the temperature range investigated.

An experimental study of crevice corrosion behaviour of 316L stainless steel in artificial seawater

Energy Technology Data Exchange (ETDEWEB)

Cai Baoping [School of Electromechanical Engineering, China University of Petroleum, Dongying, Shandong 257061 (China); Liu Yonghong, E-mail: liuyhupc@126.co [School of Electromechanical Engineering, China University of Petroleum, Dongying, Shandong 257061 (China); Tian Xiaojie; Wang Fei; Li Hang; Ji Renjie [School of Electromechanical Engineering, China University of Petroleum, Dongying, Shandong 257061 (China)

2010-10-15

The effects of applied torque on corrosion behaviour of 316L stainless steel with crevices were investigated using the cyclic potentiodynamic polarization method. Three kinds of crevices (316L-to-polytetrafluoroethylene, 316L-to-fluoroelastomeric and 316L-to-316L) were tested in artificial seawater at 50 {sup o}C. Corroded surface morphology was also investigated using scanning electron microscopy. Results indicate similar trends in crevice corrosion susceptibility with increasing applied torque. Among the three crevices, the 316L stainless steel specimen, coupled to the 316L stainless steel crevice former, is the most susceptible to crevice corrosion.

An experimental study of crevice corrosion behaviour of 316L stainless steel in artificial seawater

International Nuclear Information System (INIS)

Cai Baoping; Liu Yonghong; Tian Xiaojie; Wang Fei; Li Hang; Ji Renjie

2010-01-01

The effects of applied torque on corrosion behaviour of 316L stainless steel with crevices were investigated using the cyclic potentiodynamic polarization method. Three kinds of crevices (316L-to-polytetrafluoroethylene, 316L-to-fluoroelastomeric and 316L-to-316L) were tested in artificial seawater at 50 o C. Corroded surface morphology was also investigated using scanning electron microscopy. Results indicate similar trends in crevice corrosion susceptibility with increasing applied torque. Among the three crevices, the 316L stainless steel specimen, coupled to the 316L stainless steel crevice former, is the most susceptible to crevice corrosion.

Optimization of multimeric human papillomavirus L2 vaccines.

Directory of Open Access Journals (Sweden)

Subhashini Jagu

Full Text Available We sought to define the protective epitopes within the amino terminus of human papillomavirus (HPV type 16 minor capsid protein L2. Passive transfer of mice with rabbit antisera to HPV16 L2 peptides 17-36, 32-51 and 65-81 provided significant protection against vaginal HPV16 challenge, whereas antisera to 47-66, 108-120 or 373-392 did not. Vaccination with L1 virus-like particles induces a high titer, but generally type-restricted neutralizing antibody response. Conversely, vaccination with L2 11-88, especially multimers thereof, induces antibodies that neutralize a broad range of papillomavirus types, albeit at lower titers than for L1 VLP. With the intent of enhancing the immunogenicity and the breadth of protection by focusing the immune response to the key protective epitopes, we designed L2 fusion proteins consisting of residues ∼11-88 of eight divergent mucosal HPV types 6, 16, 18, 31, 39, 51, 56, 73 (11-88×8 or residues ∼13-47 of fifteen HPV types (13-47×15. The 11-88×8 was significantly more immunogenic than 13-47×15 in Balb/c mice regardless of the adjuvant used, suggesting the value of including the 65-81 protective epitope in the vaccine. Since the L2 47-66 peptide antiserum failed to elicit significant protection, we generated an 11-88×8 construct deleted for this region in each subunit (11-88×8Δ. Mice were vaccinated with 11-88×8 and 11-88×8Δ to determine if deletion of this non-protective epitope enhanced the neutralizing antibody response. However, 11-88×8Δ was significantly less immunogenic than 11-88×8, and even the addition of a known T helper epitope, PADRE, to the construct (11-88×8ΔPADRE failed to recover the immunogenicity of 11-88×8 in C57BL/6 mice, suggesting that while L2 47-66 is not a critical protective or T helper epitope, it nevertheless contributes to the immunogenicity of the L2 11-88×8 multimer vaccine.

On electrical resistivity of AISI D2 steel during various stages of cryogenic treatment

Science.gov (United States)

Lomte, Sachin Vijay; Gogte, Chandrashekhar Laxman; Peshwe, Dilip

2012-06-01

The effect of dislocation densities and residual stresses is well known in tool steels. Measurement of electrical resistivity in order to monitor dislocation densities or residual stresses has seldom been used in investigating the effect of cryogenic treatment on tool steels. Monitoring residual stresses during cryogenic treatment becomes important as it is directly related to changes due to cryogenic treatment of tool steels. For high carbon high chromium (HCHC- AISI D2) steels, not only wear resistance but dimensional stability is an important issue as the steels are extensively used in dies, precision measuring instruments. This work comprises of study of measurement of electrical resistivity of AISI D2 steel at various stages of cryogenic treatment. Use of these measurements in order to assess the dimensional stability of these steels is discussed in this paper.

Effect of flowing sodium on corrosion and tensile properties of AISI type 316LN stainless steel at 823 K

Science.gov (United States)

Sivai Bharasi, N.; Thyagarajan, K.; Shaikh, H.; Balamurugan, A. K.; Bera, Santanu; Kalavathy, S.; Gurumurthy, K.; Tyagi, A. K.; Dayal, R. K.; Rajan, K. K.; Khatak, H. S.

2008-07-01

AISI type 316LN stainless steel was exposed to flowing sodium in mass transfer loop (MTL) at 823 K for 16 000 h and then examined for changes in the tensile properties due to the mass transfer and corrosion effects. Comparisons in microstructural and mechanical properties were made between annealed, thermally aged and sodium exposed materials. Microstructural examination of thermally aged and sodium exposed materials revealed precipitation of carbides at the grain boundaries. The sodium exposed samples contained a degraded layer at the surface up to a depth of around 10 μm and a surface carburized layer of about 30 μm. There was about 15% increase in yield strength and a decrease of about 20% in ductility for the sodium exposed material vis-a-vis thermally aged material and this was attributed to carburization effects and microstructural changes.

Effect of flowing sodium on corrosion and tensile properties of AISI type 316LN stainless steel at 823 K

International Nuclear Information System (INIS)

Sivai Bharasi, N.; Thyagarajan, K.; Shaikh, H.; Balamurugan, A.K.; Bera, Santanu; Kalavathy, S.; Gurumurthy, K.; Tyagi, A.K.; Dayal, R.K.; Rajan, K.K.; Khatak, H.S.

2008-01-01

AISI type 316LN stainless steel was exposed to flowing sodium in mass transfer loop (MTL) at 823 K for 16 000 h and then examined for changes in the tensile properties due to the mass transfer and corrosion effects. Comparisons in microstructural and mechanical properties were made between annealed, thermally aged and sodium exposed materials. Microstructural examination of thermally aged and sodium exposed materials revealed precipitation of carbides at the grain boundaries. The sodium exposed samples contained a degraded layer at the surface up to a depth of around 10 μm and a surface carburized layer of about 30 μm. There was about 15% increase in yield strength and a decrease of about 20% in ductility for the sodium exposed material vis-a-vis thermally aged material and this was attributed to carburization effects and microstructural changes

Human Bone Marrow-Derived Mesenchymal Cell Reactions to 316L Stainless Steel: An in Vitro Study on Cell Viability and Interleukin-6 Expression

Science.gov (United States)

Anwar, Iwan Budiwan; Santoso, Asep; Saputra, Eko; Ismail, Rifky; Jamari, J.; Van der Heide, Emile

2017-01-01

Purpose: Human bone marrow-derived mesenchymal cell (hBMC) reactions to 316L stainless steel (316L-SS) have never been evaluated. The objective of this study was to assess cell viability and interleukin-6 expression of hBMC cultures upon treatment with a 316L-SS implant. Methods: A cytotoxicity analysis was conducted with a 3-(4,5-dimethylthiazol 2-yl)-2,5-diphenyltetrazolium (MTT) assay after a period of 24, 48 and 72 hours of incubation. Expression of interleukin-6 was measured using enzyme-linked immunosorbent assay (ELISA). Results: Cell viability measurement was performed via IC50 formula. All treatment group showed a > 50 % cell viability with a range of 56,5 - 96,9 % at 24 hours, 51,8-77,3% at 48 hours and 70,1- 120 % at 72 hours. Interleukin-6 expression was downregulated subsequent to treatment with 316L-SS compared to the control group. Conclusion: We found that 316L-SS did not exhibit toxicity towards hBMC culture. PMID:28761837

Carbides crystalline structure of AISI M2 high-speed steel

International Nuclear Information System (INIS)

Serna, M.M.; Galego, E.; Rossi, J.L.

2005-01-01

The aim of this study was to identify the crystallographic structure of the extracted carbides of AISI M2 steel spray formed The structure determination of these carbides. The structure determination of these carbides is a very hard work. Since these structures were formed by atom migration it is not possible to reproduce them by a controlled process with a determined chemical composition. The solution of this problem is to obtain the carbide by chemical extraction from the steel. (Author)

Taguchi Optimization of Cutting Parameters in Turning AISI 1020 MS with M2 HSS Tool

Science.gov (United States)

Sonowal, Dharindom; Sarma, Dhrupad; Bakul Barua, Parimal; Nath, Thuleswar

2017-08-01

In this paper the effect of three cutting parameters viz. Spindle speed, Feed and Depth of Cut on surface roughness of AISI 1020 mild steel bar in turning was investigated and optimized to obtain minimum surface roughness. All the experiments are conducted on HMT LB25 lathe machine using M2 HSS cutting tool. Ranges of parameters of interest have been decided through some preliminary experimentation (One Factor At a Time experiments). Finally a combined experiment has been carried out using Taguchi’s L27 Orthogonal Array (OA) to study the main effect and interaction effect of the all three parameters. The experimental results were analyzed with raw data ANOVA (Analysis of Variance) and S/N data (Signal to Noise ratio) ANOVA. Results show that Spindle speed, Feed and Depth of Cut have significant effects on both mean and variation of surface roughness in turning AISI 1020 mild steel. Mild two factors interactions are observed among the aforesaid factors with significant effects only on the mean of the output variable. From the Taguchi parameter optimization the optimum factor combination is found to be 630 rpm spindle speed, 0.05 mm/rev feed and 1.25 mm depth of cut with estimated surface roughness 2.358 ± 0.970 µm. A confirmatory experiment was conducted with the optimum factor combination to verify the results. In the confirmatory experiment the average value of surface roughness is found to be 2.408 µm which is well within the range (0.418 µm to 4.299 µm) predicted for confirmatory experiment.

Preparation of high-performance ultrafine-grained AISI 304L stainless steel under high temperature and pressure

Directory of Open Access Journals (Sweden)

Peng Wang

2016-08-01

Full Text Available Bulk ultra-fine grained (UFG AISI 304L stainless steel with excellent mechanical properties was prepared by a high-temperature and high-pressure (HTHP method using nanocrystalline AISI 304L stainless steel powders obtained from ball milling. Samples were sintered in high-pressure conditions using the highest martensite content of AISI 304L stainless steel powders milled for 25 h. Analyses of phase composition and grain size were accomplished by X-ray diffraction and Rietveld refinement. By comparing the reverse martensite transformation under vacuum and HTHP treat, we consider that pressure can effectively promote the change in the process of transformation. Compared with the solid-solution-treated 304L, the hardness and yield strength of the samples sintered under HTHP are considerably higher. This method of preparation of UFG bulk stainless steel may be widely popularised and used to obtain UFG metallic materials with good comprehensive performance.

Reproducibility of repeated measures of deuterium substituted [11C]L-deprenyl ([11C]L-deprenyl-D2) binding in the human brain

International Nuclear Information System (INIS)

Logan, Jean; Fowler, Joanna S.; Volkow, Nora D.; Wang, Gene-Jack; MacGregor, Robert R.; Shea, Colleen

2000-01-01

The purpose of this study was to assess the reproducibility of repeated positron emission tomography (PET) measures of brain monoamine oxidase B (MAO B) using deuterium-substituted [ 11 C]L-deprenyl ([ 11 C]L-deprenyl-D2) in normal subjects and to validate the method used for estimating the kinetic constants from the irreversible 3-compartment model applied to the tracer binding. Five normal healthy subjects (age range 23-73 years) each received two PET scans with [ 11 C]L-deprenyl-D2. The time interval between scans was 7-27 days. Time-activity data from eight regions of interest and an arterial plasma input function was used to calculate λk 3 , a model term proportional to MAO B, and K 1 , the plasma to brain transfer constant that is related to blood flow. Linear (LIN) and nonlinear least-squares (NLLSQ) estimation methods were used to calculate the optimum model constants. A comparison of time-activity curves for scan 1 and scan 2 showed that the percent of change for peak uptake varied from -18.5 to 15.0% and that increases and decreases in uptake on scan 2 were associated with increases and decreases in the value of the arterial input of the tracer. Calculation of λk 3 showed a difference between scan 1 and scan 2 in the global value ranging between -6.97 and 4.5% (average -2.1±4.7%). The average percent change for eight brain regions for the five subjects was -2.84±7.07%. Values of λk 3 for scan 1 and scan 2 were highly correlated (r 2 =0.98; p 1 showed a significant correlation between scan 1 and scan 2 (r 2 =0.61; p 11 C]L-deprenyl-D2 varied between scan 1 and scan 2, driven by the differences in arterial tracer input. Application of a 3-compartment model to regional time-activity data and arterial input function yielded λk 3 values for scan 1 and scan 2 with an average difference of -2.84 ± 7.07%. Linear regression applied to values of λk 3 from the LIN and NLLSQ methods validated the use of the linear method for calculating λk 3

Microstructure, Mechanical and Corrosion Properties of Friction Stir-Processed AISI D2 Tool Steel

Science.gov (United States)

Yasavol, Noushin; Jafari, Hassan

2015-05-01

In this study, AISI D2 tool steel underwent friction stir processing (FSP). The microstructure, mechanical properties, and corrosion resistance of the FSPed materials were then evaluated. A flat WC-Co tool was used; the rotation rate of the tool varied from 400 to 800 rpm, and the travel speed was maintained constant at 385 mm/s during the process. FSP improved mechanical properties and produced ultrafine-grained surface layers in the tool steel. Mechanical properties improvement is attributed to the homogenous distribution of two types of fine (0.2-0.3 μm) and coarse (1.6 μm) carbides in duplex ferrite-martensite matrix. In addition to the refinement of the carbides, the homogenous dispersion of the particles was found to be more effective in enhancing mechanical properties at 500 rpm tool rotation rate. The improved corrosion resistance was observed and is attributed to the volume fraction of low-angle grain boundaries produced after friction stir process of the AISI D2 steel.

Estudio in vitro de la citotoxicidad y genotoxicidad de los productos liberados del acero inoxidable 316L con recubrimientos cerámicos bioactivos Cytotoxic and genotoxic study of in Vitro released products of stainless Steel 316l with bioactive ceramic Coatings

Directory of Open Access Journals (Sweden)

María Elena Márquez Fernández

2007-03-01

Full Text Available El acero inoxidable AISI 316L es el biomaterial mas utilizado para la fabricación de implantes temporales, pero presenta limitaciones para implantes permanentes debido a la liberación de iones metálicos hacia los tejidos circundantes, produciendo especies reactivas de oxígeno (ERO y daño en ADN, factores que aumentan el riesgo de aparición de tumores locales y fallas mecánicas del implante. Una estrategia utilizada para disminuir la liberación de iones es la modificación superficial de los implantes metálicos por medio de recubrimientos inorgánicos, cerámicos o vítreos, aplicados por el método sol-gel, el cual presenta una serie de ventajas comparativas con otras técnicas de deposición, como buena adherencia, aplicación sencilla, mínimos problemas de secado, bajas temperaturas de densificación y posibilidad de agregar partículas y/o grupos orgánicos que mejoran la adherencia celular al implante aumentando su biocompatibilidad. En el presente trabajo se evaluaron los efectos citotóxico por medio de la técnica MTT, y genotóxico por electroforesis en gel de células individuales (Ensayo Cometa, sobre células de la línea celular CHO, de los productos liberados en medio MEM por el acero inoxidable 316L sin recubrir, recubierto con una monocapa de vidrio de sílice (MC, o con doble capa que contiene partículas bioactivas de hidroxiapatita (HA, vidrio (V o vitrocerámico (VC, después de un periodo de 30 días. Los resultados muestran que a los 30 días de envejecimiento en medio MEM no se encuentra ningún efecto citotóxico, pero se encontró efecto genotóxico en las probetas de A y MC que no representa un peligro inminente a sistemas celulares. The stainless steel AISI 316L is the must used biomaterial for the making of temporal prosthesis, but it presents severe limitations for permanent implants due to the generation and migration of metallic ions to the surrounding peripheral tissues, which produces oxygen reactive

Effect of Ferrite Morphology on Sensitization of 316L Austenitic Stainless Steels

Energy Technology Data Exchange (ETDEWEB)

Jang, Hun; Lee, Jun Ho; Jang, Changheui [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

2013-05-15

The sensitization behaviors of L-grade SSs having predominant austenitic structure with small amount of ferrite have not been well understood. In this regard, the effect of ferrite morphology on sensitization was investigated in this study. The sensitization behaviors of three heats of 316L and 316LN SSs were investigated, Stringer type of ferrite (316L - heat A and B) showed the early sensitization by chromium depletion at ferrite. austenite interface. And, later sensitization is due to GB sensitization. On the other hand, blocky type of ferrite (316L - heat C) showed lower DOS and higher resistance to GB sensitization. It could be due to sufficient supply of chromium from relatively large ferrite phase. As a consequence, the sensitization of 316L SSs could be affected by their ferrite morphology rather than ferrite content. The sensitized region was distinguishable from results of DL-EPR tests. It can be used as an effective method for evaluation of type of sensitization.

The corrosion behaviour of austenitic and duplex stainless steels in artificial saliva with the addition of fluoride

International Nuclear Information System (INIS)

Kocijan, Aleksandra; Merl, Darja Kek; Jenko, Monika

2011-01-01

Research highlights: → The corrosion behaviour of AISI 316L and 2205 DSS in orthodontics. → The increased passive range for DSS 2205 compared to AISI 316L in artificial saliva. → Higher R p values of DSS compared to AISI 316L in artificial saliva. → The main constituent of the passive layers on DSS at the OCP in saliva was Cr-oxide. → DSS 2205 is suitable for orthodontic applications in artificial saliva. - Abstract: The evolution of the passive films on 2205 duplex stainless steel (2205 DSS) and AISI 316L stainless steel in artificial saliva, and with the addition of fluoride, was studied using electrochemical impedance spectroscopy (EIS) and potentiodynamic measurements. The extent of the passive range increased for the 2205 DSS compared to the AISI 316L in both solutions. The formation of the passive film was studied by EIS at the open-circuit potential (OCP). The passive layers were studied at the OCP by X-ray photoelectron spectroscopy (XPS). The passive films on both materials predominantly contained Cr-oxides, whereas the Fe species were markedly depleted.

The corrosion behaviour of austenitic and duplex stainless steels in artificial saliva with the addition of fluoride

Energy Technology Data Exchange (ETDEWEB)

Kocijan, Aleksandra, E-mail: Aleksandra.Kocijan@imt.s [Institute of Metals and Technology, Lepi pot 11, 1000 Ljubljana (Slovenia); Merl, Darja Kek [Jozef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia); Jenko, Monika [Institute of Metals and Technology, Lepi pot 11, 1000 Ljubljana (Slovenia)

2011-02-15

Research highlights: The corrosion behaviour of AISI 316L and 2205 DSS in orthodontics. The increased passive range for DSS 2205 compared to AISI 316L in artificial saliva. Higher R{sub p} values of DSS compared to AISI 316L in artificial saliva. The main constituent of the passive layers on DSS at the OCP in saliva was Cr-oxide. DSS 2205 is suitable for orthodontic applications in artificial saliva. - Abstract: The evolution of the passive films on 2205 duplex stainless steel (2205 DSS) and AISI 316L stainless steel in artificial saliva, and with the addition of fluoride, was studied using electrochemical impedance spectroscopy (EIS) and potentiodynamic measurements. The extent of the passive range increased for the 2205 DSS compared to the AISI 316L in both solutions. The formation of the passive film was studied by EIS at the open-circuit potential (OCP). The passive layers were studied at the OCP by X-ray photoelectron spectroscopy (XPS). The passive films on both materials predominantly contained Cr-oxides, whereas the Fe species were markedly depleted.

The influence of mechanical deformation on the irradiation creep of AISI 316 stainless steel irradiated in the EBR-II and FFTF fast reactors

International Nuclear Information System (INIS)

Garner, F.A.; Gilbert, E.R.

2007-01-01

Irradiation creep of stainless steels is thought not to be very responsive to material and environmental variables. To test this perception earlier unpublished experiments conducted in the EBR-II reactor on AISI 316 have been analyzed. While swelling is dependent on the cold-work level at 400-480 o C, the post-transient irradiation creep rate, often called the creep compliance B0, is not dependent on cold-work level. If the tube reaches pressures on reactor start-up that generate above-yield stresses in unirradiated steel, then plastic strains occur prior to significant irradiation, but the post-transient strain rate is identical to that of material that did not exceed the yield stress on start-up. It is shown that both stress-free and stress-affected swelling are isotropic and that the Soderberg relationship is maintained. At temperatures above ∼540 o C thermal creep and stored energy begin to assert themselves, with creep rates accelerating with cold-work and becoming non-linear with stress. These results are in agreement with a similar study on titanium-modified 316 steel in FFTF. (author)

A Weakest-Link Approach for Fatigue Limit of 30CrNiMo8 Steels (Preprint)

Science.gov (United States)

2011-03-01

34Application of a Weakest-Link Concept to the Fatigue Limit of the Bearing Steel Sae 52100 in a Bainitic Condition," Fatigue and Fracture of...AFRL-RX-WP-TP-2011-4206 A WEAKEST-LINK APPROACH FOR FATIGUE LIMIT OF 30CrNiMo8 STEELS (PREPRINT) S. Ekwaro-Osire and H.V. Kulkarni Texas...2011 4. TITLE AND SUBTITLE A WEAKEST-LINK APPROACH FOR FATIGUE LIMIT OF 30CrNiMo8 STEELS (PREPRINT) 5a. CONTRACT NUMBER In-house 5b. GRANT

Galvanic deposition and characterization of brushite/hydroxyapatite coatings on 316L stainless steel.

Science.gov (United States)

Blanda, Giuseppe; Brucato, Valerio; Pavia, Francesco Carfì; Greco, Silvia; Piazza, Salvatore; Sunseri, Carmelo; Inguanta, Rosalinda

2016-07-01

In this work, brushite and brushite/hydroxyapatite (BS, CaHPO4·H2O; HA, Ca10(PO4)6(OH)2) coatings were deposited on 316L stainless steel (316LSS) from a solution containing Ca(NO3)2·4H2O and NH4H2PO4 by a displacement reaction based on a galvanic contact, where zinc acts as sacrificial anode. Driving force for the cementation reaction arises from the difference in the electrochemical standard potentials of two different metallic materials (316LSS and Zn) immersed in an electrolyte, so forming a galvanic contact leading to the deposition of BS/HA on nobler metal. We found that temperature and deposition time affect coating features (morphology, structure, and composition). Deposits were characterized by means of several techniques. The morphology was investigated by scanning electron microscopy, the elemental composition was obtained by X-ray energy dispersive spectroscopy, whilst the structure was identified by Raman spectroscopy and X-ray diffraction. BS was deposited at all investigated temperatures covering the 316LSS surface. At low and moderate temperature, BS coatings were compact, uniform and with good crystalline degree. On BS layers, HA crystals were obtained at 50°C for all deposition times, while at 25°C, its presence was revealed only after long deposition time. Electrochemical studies show remarkable improvement in corrosion resistance. Copyright © 2016 Elsevier B.V. All rights reserved.

Laser surface cladding of Ti-6Al-4V on AISI 316L stainless steel for bio-implant application

CSIR Research Space (South Africa)

Kumar, A

2014-01-01

Full Text Available The present study concerns an in-depth investigation of the influence of laser surface cladding of Ti-6Al-4V on the microstructure (both the top surface, cross-section and interface), wear resistance, corrosion resistance and bio-activity of AISI...

In situ evaluation of supersolidus liquid phase sintering phenomena of stainless steel 316L: Densification and distortion

Science.gov (United States)

Bollina, Ravi

Supersolidus liquid phase sintering (SLPS) is a variant of liquid phase sintering. In SLPS, prealloyed powders are heated between the solidus and liquidus temperature of the alloy. This thesis focuses on processing of stainless steel 316L via SLPS by adding boron. Various amounts of boron were added to study the effect of boron on densification and distortion. The sintering window for water atomized 316L with 0.2% boron ranges from 1430 to 1435°C and 1225 to 1245°C for water atomized 316L with 0.8% boron. The rate of change of liquid content with temperature dVL/dt decreases from 1.5%/°C to 0.1%/°C for in increase in boron content from 0 to 0.8%, giving a wider range and better control during sintering. Further; effect of boron on mechanical properties and corrosion properties was researched. It was possible to achieve tensile strength of 476+/-21 MPa and an yield strength of 250+/-5 MPa with an elongation of 15+/-2 % in water atomized 316L with 0.8% boron. Fracture analysis indicates the presence of a brittle boride phase along the grain boundary causing intergranular fracture resulting in poor ductility. The crux of this thesis discusses the evolution of apparent viscosity and its relation to the microstructure. Beam bending viscometry was successfully used to evaluate the in situ apparent viscosity evolution of water atomized 316L with 0.2 and 0.8% boron additions. The apparent viscosity drops from 174 GPa.s at 1200°C to 4 GPa.s at 1275°C with increasing fractional liquid coverage in the water atomized 316L with 0.8% boron. The apparent viscosity calculated from bending beam and was used as an input into a finite element model (FEM) derived from constitutive equations and gives an excellent, fit between simulation and experiment. The densification behavior of boron doped stainless steel was modelled using Master Sintering Curve (MSC) (based on work of sintering) for the first time. It is proven that MSC can be used to identify change in densification rate

Effects of Si and Ti on the phase stability and swelling behavior of AISI 316 stainless steel

International Nuclear Information System (INIS)

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

1979-01-01

The swelling behavior of neutron irradiated stainless steels is strongly influenced by solute segregation and precipitation phenomena. The extent to which in-reactor swelling behavior may be simulated by heavy ion irradiation depends upon the extent to which in-reactor phase changes are reproduced; this question is addressed by comparing the precipitation behavior under neutron irradiation with behavior during 4 MeV Ni ion irradiation for AISI 316 stainless steel and a related stainless steel containing additions of titanium and silicon. The results are discussed qualitatively in terms of the effects of damage rate on solute segregation and the effects of displacement cascades on the dissolution of particles. It is shown that the partitioning of elements into various phases during irradiation is not a sufficient condition for the iniatiation of swelling in stainless steels modified with silicon and titanium. It is also necessary for helium to be generated simultaneously with the breakdown of the matrix into various phases; it is believed that helium trapping at the growing particle-matrix interface is responsible for the observed physical association between voids and precipitates. (Auth.)

Effects of Si and Ti on the phase stability and swelling behavior of AISI 316 stainless steel

International Nuclear Information System (INIS)

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

1978-01-01

Swelling behavior of neutron irradiated stainless steels is influenced by solute segregation and preciptation phenomena. The extent to which in-reactor swelling behavior may be simulated by heavy ion irradiation depends upon the extent to which in-reactor phase changes are reproduced; this question is addressed by comparing the precipitation behavior under neutron irradiation with behavior during 4 MeV Ni ion irradiation for AISI 316 stainless steel and a related stainless steel containing additions of titanium and silicon. The results are discussed qualitatively in terms of the effects of damage rate on solute segregation and the effects of displacement cascades on the dissolution of particles. It is shown that the partitioning of elements into various phases during irradiation is not a sufficient condition for the initiation of swelling in stainless steels modified with silicon and titanium. It is also necessary for helium to be generated simultaneously with the breakdown of the matrix into various phases; it is believed that helium trapping at the growing particle-matrix interface is responsible for the observed physical association between voids and precipitates

The Corrosion Behavior of Stainless Steel 316L in Novel Quaternary Eutectic Molten Salt System

Science.gov (United States)

Wang, Tao; Mantha, Divakar; Reddy, Ramana G.

2017-03-01

In this article, the corrosion behavior of stainless steel 316L in a low melting point novel LiNO3-NaNO3-KNO3-NaNO2 eutectic salt mixture was investigated at 695 K which is considered as thermally stable temperature using electrochemical and isothermal dipping methods. The passive region in the anodic polarization curve indicates the formation of protective oxides layer on the sample surface. After isothermal dipping corrosion experiments, samples were analyzed using SEM and XRD to determine the topography, corrosion products, and scale growth mechanisms. It was found that after long-term immersion in the LiNO3-NaNO3-KNO3-NaNO2 molten salt, LiFeO2, LiFe5O8, Fe3O4, (Fe, Cr)3O4 and (Fe, Ni)3O4 oxides were formed. Among these corrosion products, LiFeO2 formed a dense and protective layer which prevents the SS 316L from severe corrosion.

Second phase in steel AISI 316 tested at 8000C

International Nuclear Information System (INIS)

Silveira, V.L.A.; Monteiro, S.N.

The nature of second phases in type 316 stainless steel samples tested in creep to rupture at 800 0 C has been discussed. These phases were identified by experimental techniques completed with the available information in the literature. The role of these phases in the creep properties of the type 316 steel at 800 0 C is analysed [pt

Corrosion of 316 stainless steel in high temperature molten Li{sub 2}BeF{sub 4} (FLiBe) salt

Energy Technology Data Exchange (ETDEWEB)

Zheng, Guiqiu, E-mail: guiqiuzheng@gmail.com; Kelleher, Brian; Cao, Guoping; Anderson, Mark; Allen, Todd; Sridharan, Kumar

2015-06-15

In support of structural material development for the fluoride-salt-cooled high-temperature reactor (FHR), corrosion tests of 316 stainless steel were performed in the potential primary coolant, molten Li{sub 2}BeF{sub 4} (FLiBe) at 700 °C for an exposure duration up to 3000 h. Tests were performed in both 316 stainless steel and graphite capsules. Corrosion in both capsule materials occurred by the dissolution of chromium from the stainless steel into the salt which led to the depletion of chromium predominantly along the grain boundaries of the test samples. The samples tested in graphite capsules showed a factor of two greater depth of corrosion attack as measured in terms of chromium depletion, compared to those tested in 316 stainless steel capsules. The samples tested in graphite capsules showed the formation of Cr{sub 7}C{sub 3} particulate phases throughout the depth of the corrosion layer. Samples tested in both types of capsule materials showed the formation of MoSi{sub 2} phase due to increased activity of Mo and Si as a result of Cr depletion, and furthermore corrosion promoted the formation of a α-ferrite phase in the near-surface regions of the 316 stainless steel. Based on the corrosion tests, the corrosion attack depth in FLiBe salt was predicted as 17.1 μm/year and 31.2 μm/year for 316 stainless steel tested in 316 stainless steel and in graphite capsules respectively. It is in an acceptable range compared to the Hastelloy-N corrosion in the Molten Salt Reactor Experiment (MSRE) fuel salt.

Reducing Staphylococcus aureus biofilm formation on stainless steel 316L using functionalized self-assembled monolayers

International Nuclear Information System (INIS)

Kruszewski, Kristen M.; Nistico, Laura; Longwell, Mark J.; Hynes, Matthew J.; Maurer, Joshua A.; Hall-Stoodley, Luanne; Gawalt, Ellen S.

2013-01-01

Stainless steel 316L (SS316L) is a common material used in orthopedic implants. Bacterial colonization of the surface and subsequent biofilm development can lead to refractory infection of the implant. Since the greatest risk of infection occurs perioperatively, strategies that reduce bacterial adhesion during this time are important. As a strategy to limit bacterial adhesion and biofilm formation on SS316L, self-assembled monolayers (SAMs) were used to modify the SS316L surface. SAMs with long alkyl chains terminated with hydrophobic (− CH 3 ) or hydrophilic (oligoethylene glycol) tail groups were used to form coatings and in an orthogonal approach, SAMs were used to immobilize gentamicin or vancomycin on SS316L for the first time to form an “active” antimicrobial coating to inhibit early biofilm development. Modified SS316L surfaces were characterized using surface infrared spectroscopy, contact angles, MALDI-TOF mass spectrometry and atomic force microscopy. The ability of SAM-modified SS316L to retard biofilm development by Staphylococcus aureus was functionally tested using confocal scanning laser microscopy with COMSTAT image analysis, scanning electron microscopy and colony forming unit analysis. Neither hydrophobic nor hydrophilic SAMs reduced biofilm development. However, gentamicin-linked and vancomycin-linked SAMs significantly reduced S. aureus biofilm formation for up to 24 and 48 h, respectively. - Highlights: ► SS316L was modified with glycol terminated SAMs in order to reduce biofilm growth. ► Antibiotics gentamicin and vancomycin were immobilized on SS316L via SAMs. ► Only the antibiotic modifications reduced biofilm development on SS316L

Reducing Staphylococcus aureus biofilm formation on stainless steel 316L using functionalized self-assembled monolayers

Energy Technology Data Exchange (ETDEWEB)

Kruszewski, Kristen M., E-mail: kruszewskik@duq.edu [Duquesne University, Department of Chemistry and Biochemistry, 600 Forbes Avenue, Pittsburgh, PA 15282 (United States); Nistico, Laura, E-mail: lnistico@wpahs.org [Allegheny General Hospital, Center for Genomic Sciences, Allegheny-Singer Research Institute, 320 East North Avenue, 11th floor, South Tower, Pittsburgh, PA 15212 (United States); Longwell, Mark J., E-mail: mlongwel@wpahs.org [Allegheny General Hospital, Center for Genomic Sciences, Allegheny-Singer Research Institute, 320 East North Avenue, 11th floor, South Tower, Pittsburgh, PA 15212 (United States); Hynes, Matthew J., E-mail: mjhynes@go.wustl.edu [Washington University in St. Louis, Department of Chemistry, One Brookings Drive, St. Louis, MO 63130 (United States); Maurer, Joshua A., E-mail: maurer@wustl.edu [Washington University in St. Louis, Department of Chemistry, One Brookings Drive, St. Louis, MO 63130 (United States); Hall-Stoodley, Luanne, E-mail: L.Hall-Stoodley@soton.ac.uk [Southampton Wellcome Trust Clinical Research Facility/NIHR Respiratory BRU, University of Southampton Faculty of Medicine, Southampton General Hospital, Tremona Road, Southampton, Hampshire SO16 6YD (United Kingdom); Gawalt, Ellen S., E-mail: gawalte@duq.edu [Duquesne University, Department of Chemistry and Biochemistry, McGowan Institute for Regenerative Medicine, 600 Forbes Avenue, Pittsburgh, PA 15282 (United States)

2013-05-01

Stainless steel 316L (SS316L) is a common material used in orthopedic implants. Bacterial colonization of the surface and subsequent biofilm development can lead to refractory infection of the implant. Since the greatest risk of infection occurs perioperatively, strategies that reduce bacterial adhesion during this time are important. As a strategy to limit bacterial adhesion and biofilm formation on SS316L, self-assembled monolayers (SAMs) were used to modify the SS316L surface. SAMs with long alkyl chains terminated with hydrophobic (− CH{sub 3}) or hydrophilic (oligoethylene glycol) tail groups were used to form coatings and in an orthogonal approach, SAMs were used to immobilize gentamicin or vancomycin on SS316L for the first time to form an “active” antimicrobial coating to inhibit early biofilm development. Modified SS316L surfaces were characterized using surface infrared spectroscopy, contact angles, MALDI-TOF mass spectrometry and atomic force microscopy. The ability of SAM-modified SS316L to retard biofilm development by Staphylococcus aureus was functionally tested using confocal scanning laser microscopy with COMSTAT image analysis, scanning electron microscopy and colony forming unit analysis. Neither hydrophobic nor hydrophilic SAMs reduced biofilm development. However, gentamicin-linked and vancomycin-linked SAMs significantly reduced S. aureus biofilm formation for up to 24 and 48 h, respectively. - Highlights: ► SS316L was modified with glycol terminated SAMs in order to reduce biofilm growth. ► Antibiotics gentamicin and vancomycin were immobilized on SS316L via SAMs. ► Only the antibiotic modifications reduced biofilm development on SS316L.

Surface characteristics analysis of dry EDMed AISI D2 steel using modified tool design

Energy Technology Data Exchange (ETDEWEB)

Pragadish, N.; Kumar, M. Pradeep [Anna University, Chennai (China)

2015-04-15

A modified tool design is proposed which helps in drilling holes without any central core, and also enables the effective removal of the debris particles. Experiments were conducted on AISI D2 Steel using copper electrode as tool in both conventional EDM and dry EDM processes and the performance of both processes is compared. Experiments were designed using Taguchi's L27 orthogonal array. Discharge current (I), gap voltage (V), pulse on time (T{sub ON}), gas pressure (P) and tool rotational speed (N) were chosen as the various input parameters, and their effect on the material removal rate (MRR), surface roughness (SR), surface morphology, microstructure and elemental composition of the machined surface is analyzed. The experimental results show better surface characteristics in the surface machined under dry EDM process.

Surface characteristics analysis of dry EDMed AISI D2 steel using modified tool design

International Nuclear Information System (INIS)

Pragadish, N.; Kumar, M. Pradeep

2015-01-01

A modified tool design is proposed which helps in drilling holes without any central core, and also enables the effective removal of the debris particles. Experiments were conducted on AISI D2 Steel using copper electrode as tool in both conventional EDM and dry EDM processes and the performance of both processes is compared. Experiments were designed using Taguchi's L27 orthogonal array. Discharge current (I), gap voltage (V), pulse on time (T ON ), gas pressure (P) and tool rotational speed (N) were chosen as the various input parameters, and their effect on the material removal rate (MRR), surface roughness (SR), surface morphology, microstructure and elemental composition of the machined surface is analyzed. The experimental results show better surface characteristics in the surface machined under dry EDM process.

Microstructure, mechanical properties and chemical degradation of brazed AISI 316 stainless steel/alumina systems

International Nuclear Information System (INIS)

Paiva, O.C.; Barbosa, M.A.

2008-01-01

The main aims of the present study are simultaneously to relate the brazing parameters with: (i) the correspondent interfacial microstructure, (ii) the resultant mechanical properties and (iii) the electrochemical degradation behaviour of AISI 316 stainless steel/alumina brazed joints. Filler metals on such as Ag-26.5Cu-3Ti and Ag-34.5Cu-1.5Ti were used to produce the joints. Three different brazing temperatures (850, 900 and 950 deg. C), keeping a constant holding time of 20 min, were tested. The objective was to understand the influence of the brazing temperature on the final microstructure and properties of the joints. The mechanical properties of the metal/ceramic (M/C) joints were assessed from bond strength tests carried out using a shear solicitation loading scheme. The fracture surfaces were studied both morphologically and structurally using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction analysis (XRD). The degradation behaviour of the M/C joints was assessed by means of electrochemical techniques. It was found that using a Ag-26.5Cu-3Ti brazing alloy and a brazing temperature of 850 deg. C, produces the best results in terms of bond strength, 234 ± 18 MPa. The mechanical properties obtained could be explained on the basis of the different compounds identified on the fracture surfaces by XRD. On the other hand, the use of the Ag-34.5Cu-1.5Ti brazing alloy and a brazing temperature of 850 deg. C produces the best results in terms of corrosion rates (lower corrosion current density), 0.76 ± 0.21 μA cm -2 . Nevertheless, the joints produced at 850 deg. C using a Ag-26.5Cu-3Ti brazing alloy present the best compromise between mechanical properties and degradation behaviour, 234 ± 18 MPa and 1.26 ± 0.58 μA cm -2 , respectively. The role of Ti diffusion is fundamental in terms of the final value achieved for the M/C bond strength. On the contrary, the Ag and Cu distribution along the brazed interface seem to

The Use of Austenitic Stainless Steel versus Monel (Ni-Cu) Alloy in Pressurized Gaseous Oxygen (GOX) Life Support Systems.

Science.gov (United States)

1985-03-01

Carbon Steel AISI 1025 2. AISI 4140 3. Ductile Iron 4. 304 Stainless Steel 5. 17-4 PH Stainless Steel 6. 410 Stainless Steel 7. Lead Babbit 8. Tin Babbit...9. Inconel 718 i0. Aluminum 1100 30 6- AISI 4140 steel, all the results were negative (no ignitions). The single exception was with a sample of 4140 ...rates for austenitic stainless steel ( AISI 316), Monel (63% Ni - 34% Cu) and carbon steel (AMS 5050) tubing in this environment. 12 - 14-660 A 7

The behavior of diffusion and permeation of tritium through 316L stainless steel

International Nuclear Information System (INIS)

Changqi Shan; Aiju Wu; Qingwang Chen

1991-01-01

Results on diffusivity, solubility coefficient and permeability of tritium through palladium-plated 316 L stainless steel are described. An empirical formula for the diffusivity, the solubility coefficient and the permeability of tritium through palladium-plated 316 L stainless steel at various temperatures is presented. The influence of tritium pressure on the permeability, and the isotope effect of diffusivity of hydrogen and tritium in 316 L stainless steel is discussed. (orig.)

Pitting corrosion studies on nitrogen implanted 316L SS for biomedical applications

International Nuclear Information System (INIS)

Subbaiyan, M.; Veerabadran, K.M.; Thampi, N.S.; Kanwar Krishnan; Kamachi Mudali, U.; Dayal, R.K.

1997-01-01

Traditionally, human bone fracture and defects have been corrected using metal and alloy fixing devices. Austenitic stainless steels (such as 316L alloy studied here) are favoured because of low cost, compared to titanium alloys, ease of fabrication and fair corrosion resistance. Localized attack on 316l stainless steel, however, results in iron, chromium and nickel ions leaching into surrounding body fluids. This study reports on the successful use of nitrogen ion implantation into 316lSS to evaluate the optimum dose needed to minimise this localised attack, in a physiological saline solution. (UK)

Antibody Competition Reveals Surface Location of HPV L2 Minor Capsid Protein Residues 17-36.

Science.gov (United States)

Bywaters, Stephanie M; Brendle, Sarah A; Tossi, Kerstin P; Biryukov, Jennifer; Meyers, Craig; Christensen, Neil D

2017-11-10

The currently available nonavalent human papillomavirus (HPV) vaccine exploits the highly antigenic L1 major capsid protein to promote high-titer neutralizing antibodies, but is limited to the HPV types included in the vaccine since the responses are highly type-specific. The limited cross-protection offered by the L1 virus-like particle (VLP) vaccine warrants further investigation into cross-protective L2 epitopes. The L2 proteins are yet to be fully characterized as to their precise placement in the virion. Adding to the difficulties in localizing L2, studies have suggested that L2 epitopes are not well exposed on the surface of the mature capsid prior to cellular engagement. Using a series of competition assays between previously mapped anti-L1 monoclonal antibodies (mAbs) (H16.V5, H16.U4 and H16.7E) and novel anti-L2 mAbs, we probed the capsid surface for the location of an L2 epitope (aa17-36). The previously characterized L1 epitopes together with our competition data is consistent with a proposed L2 epitope within the canyons of pentavalent capsomers.

Cold rolled texture and microstructure in types 304 and 316L austenitic stainless steels

International Nuclear Information System (INIS)

Wasnik, D.N.; Samajdar, I.; Gopalakrishnan, I.K.; Yakhmi, J.V.; Kain, V.

2003-01-01

Two grades of austenitic stainless steel (ASS), types 304 (UNS S 30400) and 316L (UNS S 31603), were cold rolled to different reductions by unidirectional and by cross-rolling. The steels had reasonable difference in stacking fault energy (estimated respectively as 15 and 61 mJ/m 2 in types 304 and 316L) and also in starting (or pre-deformation) crystallographic texture-being relatively weak and reasonably strong in types 304 and 316L respectively. The cold rolling increased texturing in type 304, but not in type 316L ASS. The more significant effect of cold rolled texture development was in the relative increase of Brass ({011} ) against Copper ({112} ) and S ({231} ) orientations. In type 304 the increase in Brass was significant, while in type 316L the increase in Copper and S was stronger. This effect could be captured by Taylor type deformation texture simulations considering stronger twinning contributions in type 304 - for example the respective 'best-fits' (in terms of matching the changes in the volume fractions of Brass against Copper and S) were obtained by full constraint Taylor model with 1:100 and 1:10 slip:twin activities in types 304 and 316L ASS respectively. Microstructural developments during cold rolling were generalized as strain induced martensite formation and developments of dislocation substructure. The former, as estimated by vibrating sample magnetometer (VSM), increased with cold reduction, being significantly more in type 304 and was also noticeably stronger in both grades under cross-rolling. The most significant aspect of substructural developments was the formation of strain localizations. These were observed as dense dislocation walls (DDWs), micro-bands (MBs) and twin lamellar structures (TLS). The TLS contribution gained significance at higher reductions and during cross-rolling, especially in type 304. Large misorientation development and the accompanying grain splittings were always associated with such strain localizations

Intragranular cellular segregation network structure strengthening 316L stainless steel prepared by selective laser melting

Energy Technology Data Exchange (ETDEWEB)

Zhong, Yuan; Liu, Leifeng [Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, 10691 Stockholm (Sweden); Wikman, Stefan [Fusion for Energy, Torres Diagonal Litoral B3, Josep Pla 2, 08019 Barcelona (Spain); Cui, Daqing [Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, 10691 Stockholm (Sweden); Shen, Zhijian, E-mail: shen@mmk.su.se [Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, 10691 Stockholm (Sweden)

2016-03-15

A feasibility study was performed to fabricate ITER In-Vessel components by Selective Laser Melting (SLM) supported by Fusion for Energy (F4E). Almost fully dense 316L stainless steel (SS316L) components were prepared from gas-atomized powder and with optimized SLM processing parameters. Tensile tests and Charpy-V tests were carried out at 22 °C and 250 °C and the results showed that SLM SS316L fulfill the RCC-MR code. Microstructure characterization reveals the presence of hierarchical macro-, micro- and nano-structures in as-built samples that were very different from SS316L microstructures prepared by other established methods. The formation of a characteristic intragranular cellular segregation network microstructure appears to contribute to the increase of yield strength without losing ductility. Silicon oxide nano-inclusions were formed during the SLM process that generated a micro-hardness fluctuation in the building direction. The combined influence of a cellular microstructure and the nano-inclusions constraints the size of ductile dimples to nano-scale. The crack propagation is hindered by a pinning effect that improves the defect-tolerance of the SLM SS316L. This work proves that it was possible to manufacture SS316L with properties suitable for ITER First Wall panels. Further studies on irradiation properties of SLM SS316L and manufacturing of larger real-size components are needed. - Highlights: • The mechanical properties of SS316L made by selective laser melting fulfill RCC-MR. • SLM SS316L consists hierarchical structures of high heterogeneity. • Silicon rich oxide nano-inclusions are formed unexpectedly during SLM process. • Cellular structure and oxide nano-inclusions strengthen SLM SS316L.

Environmental Degradation of Dissimilar Austenitic 316L and Duplex 2205 Stainless Steels Welded Joints

Directory of Open Access Journals (Sweden)

Topolska S.

2017-12-01

Full Text Available The paper describes structure and properties of dissimilar stainless steels welded joints between duplex 2205 and austenitic 316L steels. Investigations were focused on environmentally assisted cracking of welded joints. The susceptibility to stress corrosion cracking (SCC and hydrogen embrittlement was determined in slow strain rate tests (SSRT with the strain rate of 2.2 × 10−6 s−1. Chloride-inducted SCC was determined in the 35% boiling water solution of MgCl2 environment at 125°C. Hydrogen assisted SCC tests were performed in synthetic sea water under cathodic polarization condition. It was shown that place of the lowest resistance to chloride stress corrosion cracking is heat affected zone at duplex steel side of dissimilar joins. That phenomenon was connected with undesirable structure of HAZ comprising of large fractions of ferrite grains with acicular austenite phase. Hydrogen assisted SCC tests showed significant reduction in ductility of duplex 2205 steel while austenitic 316L steel remains almost immune to degradation processes. SSR tests of dissimilar welded joints revealed a fracture in the area of austenitic steel.

Novel water-air circulation quenching process for AISI 4140 steel

Science.gov (United States)

Zheng, Liyun; Zheng, Dawei; Zhao, Lixin; Wang, Lihui; Zhang, Kai

2013-11-01

AISI 4140 steel is usually used after quenching and tempering. During the heat treatment process in industry production, there are some problems, such as quenching cracks, related to water-cooling and low hardness due to oil quenching. A water-air circulation quenching process can solve the problems of quenching cracks with water and the high cost quenching with oil, which is flammable, unsafe and not enough to obtain the required hardness. The control of the water-cooling and air-cooling time is a key factor in the process. This paper focuses on the quenching temperature, water-air cycle time and cycle index to prevent cracking for AISI 4140 steel. The optimum heat treatment parameters to achieve a good match of the strength and toughness of AISI 4140 steel were obtained by repeated adjustment of the water-air circulation quenching process parameters. The tensile strength, Charpy impact energy at -10 °C and hardness of the heat treated AISI 4140 steel after quenching and tempering were approximately 1098 MPa, 67.5 J and 316 HB, respectively.

Influence of C, N and Ti concentration on the intergranular corrosion resistance of AISI 316 Ti stainless steel

Energy Technology Data Exchange (ETDEWEB)

Pardo, A.; Merino, M.C.; Carboneras, M.; Coy, A.E.; Viejo, F.; Arrabal, R.; Munoz, J.A. [Departamento de Ciencia de Materiales, Facultad de Quimica, Universidad Complutense, 28040, Madrid (Spain)

2004-07-01

The influence of Ti, C, and N concentration on the intergranular corrosion resistance of AISI 316 Ti stainless steel has been studied. A kinetic study of the corrosion process has been carried out using gravimetric tests according to ASTM A-262 practices B and C (Streicher and Huey, respectively). The TTS diagrams were drawn as a function of alloying elements concentration (C, N and Ti). Materials characterization under several test conditions was carried out using Scanning Electron Microscopy (SEM) analysing microstructural characteristics and the attack microstructure. The chemical resistance of these steels to intergranular test was function of N, C and Ti concentration. High Ti and N concentration favoured the precipitation of TiN during the material manufacture process. N forms TiN very stable, causing the removal of Ti from the matrix and, indirectly, favouring the Cr{sub 23}C{sub 6} precipitation during the sensitization process and increasing the corrosion rate. In order to inhibit the intergranular corrosion in these materials the N and Ti concentrations must be optimised. (authors)

Influence of C, N and Ti concentration on the intergranular corrosion resistance of AISI 316 Ti stainless steel

International Nuclear Information System (INIS)

Pardo, A.; Merino, M.C.; Carboneras, M.; Coy, A.E.; Viejo, F.; Arrabal, R.; Munoz, J.A.

2004-01-01

The influence of Ti, C, and N concentration on the intergranular corrosion resistance of AISI 316 Ti stainless steel has been studied. A kinetic study of the corrosion process has been carried out using gravimetric tests according to ASTM A-262 practices B and C (Streicher and Huey, respectively). The TTS diagrams were drawn as a function of alloying elements concentration (C, N and Ti). Materials characterization under several test conditions was carried out using Scanning Electron Microscopy (SEM) analysing microstructural characteristics and the attack microstructure. The chemical resistance of these steels to intergranular test was function of N, C and Ti concentration. High Ti and N concentration favoured the precipitation of TiN during the material manufacture process. N forms TiN very stable, causing the removal of Ti from the matrix and, indirectly, favouring the Cr 23 C 6 precipitation during the sensitization process and increasing the corrosion rate. In order to inhibit the intergranular corrosion in these materials the N and Ti concentrations must be optimised. (authors)

Microstructure and Mechanical Properties of Thixowelded AISI D2 Tool Steel

Directory of Open Access Journals (Sweden)

M. N. Mohammed

2018-05-01

Full Text Available Rigid perpetual joining of materials is one of the main demands in most of the manufacturing and assembling industries. AISI D2 cold work tool steels is commonly known as non-weldable metal that a high quality joint of this kind of material can be hardly achieved and almost impossible by conventional welding. In this study, a novel thixowelding technology was proposed for joining of AISI D2 tool steel. The effect of joining temperature, holding time and post-weld heat treatment on microstructural features and mechanical properties were also investigated. Acceptable joints without defect were achieved through the welding temperature of 1300 °C, while the welding at lower temperature resulted in a series of cracks across the entire joint that led to spontaneous fracture after joining. Tensile test results showed that maximum joint tensile strength of 271 MPa was achieved at 1300 °C and 10 min holding time, which was 35% of that of D2 base metal. Meanwhile, tensile strength of the joined parts after heat treatment showed a significant improvement over the non-heat treated condition with 560 MPa, i.e., about 70% of that of the strength value of the D2 base metal. This improvement in the tensile strength attributed to the dissolution of some amounts of eutectic chromium carbides and changes in the microstructure of the matrix. The joints are fractured at the diffusion zone, and the fracture exhibits a typical brittle characteristic. The present study successfully confirmed that by avoiding dendritic microstructure, as often resulted from the fusion welding, high joining quality components obtained in the semi-solid state. These results can be obtained without complex or additional apparatuses that are used in traditional joining process.

Irradiation-induced creep in 316 and 304L stainless steels

International Nuclear Information System (INIS)

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

1977-01-01

Recent results are presented from the in-reactor creep experiments that are being conducted by Argonne National Laboratory. The experiments consist of four subassemblies that contain helium-pressurized as well as unstressed capsules of 316 and 304L stainless steels in several metallurgical conditions. Experiments are being irradiated in row 7 of the EBR-II sodium-cooled fast breeder reactor. Three of the subassemblies are being irradiated at temperatures near 400 0 C, and the fourth subassembly is being irradiated at a temperature of 550 0 C. Creep and swelling strains were determined by profilometer measurements on the full length of the capsules after each irradiation cycle. The accumulated neutron dose on the 304L capsules at 385 0 C was 45 dpa; on the 316 capsules at 400 0 C, 40 dpa; and on the 316 capsules at 550 0 C, 25 dpa. It was found that the in-reactor creep rates were linearly dependent on hoop stress, with the exception being capsules of 316 stainless steel that had been given long-term carbide aging treatment and then irradiated at 550 0 C. Those capsules exhibited much higher creep and swelling rates than their unaged counterparts. For the metallurgical conditions where significant swelling was observed (solution-annealed 304L and aged 316 stainless steels), it was found that the in-reactor creep rates were readily fit to a model that related the creep rates to accumulated swelling. Additionally, it was found that the stress-normalized creep rate for 20%-cold-worked 316 stainless steel at a temperature of 550 0 C was 1.6 times that observed at 400 0 C

Recubrimientos de aluminio-silicio realizados por deposición química de vapor en lecho fluidizado sobre el acero inoxidable AISI 316

Directory of Open Access Journals (Sweden)

José Luddey Marulanda Arevalo

2013-12-01

Full Text Available Los recubrimientos de aluminio-silicio fueron depositados sobre el acero inoxidable AISI 316 mediante deposición química de vapor en lecho fluidizado (CVD-FBR, en el rango de temperaturas de 540 a 560 ºC, utilizando un lecho formado por 2,5 g de silicio y 7,5 g de aluminio en polvo, y 90 g de lecho inerte (Alúmina, el cual se hizo fluidizar con Ar. Como gases activadores se usó una mezcla de HCl/H2, en relaciones de 1/10 a 1/16. Además, se varió el tiempo de deposición de los recubrimientos de 45 minutos a 1.5 horas, con una relación en volumen de 50% de gases activos y 50% de gases neutros. Se realizó una simulación termodinámica con la ayuda del programa informático Thermocalc, para obtener información de la posible composición y cantidad de material depositado, para las condiciones seleccionadas. En los recubrimientos se encuentran FeAl2Si, Fe2Al5 y FeAl2. Los recubrimientos aluminio-silicio fueron tratados térmicamente, para mejorar sus propiedades mecánicas y su comportamiento frente a la oxidación, por la interdifusión de los elementos de aleación, ya que el tratamiento térmico hace que el aluminio difunda hacia el substrato, y el hierro difunda hacia la superficie del recubrimiento, logrando la transformación de los compuestos anteriores en FeAl, Al2FeSi, Cr3Si, AlCrFe y AlFeNi.

XPS study of the ultrathin a-C:H films deposited onto ion beam nitrided AISI 316 steel

International Nuclear Information System (INIS)

Meskinis, S.; Andrulevicius, M.; Kopustinskas, V.; Tamulevicius, S.

2005-01-01

Effects of the steel surface treatment by nitrogen ion beam and subsequent deposition of the diamond-like carbon (hydrogenated amorphous carbon (a-C:H) and nitrogen doped hydrogenated amorphous carbon (a-CN x :H)) films were investigated by means of the X-ray photoelectron spectroscopy (XPS). Experimental results show that nitrogen ion beam treatment of the AISI 316 steel surface even at room temperature results in the formation of the Cr and Fe nitrides. Replacement of the respective metal oxides by the nitrides takes place. Formation of the C-N bonds was observed for both ultrathin a-C:H and ultrathin a-CN x :H layers deposited onto the nitrided steel. Some Fe and/or Cr nitrides still were presented at the interface after the film deposition, too. Increased adhesion between the steel substrate and hydrogenated amorphous carbon layer after the ion beam nitridation was explained by three main factors. The first two is steel surface deoxidisation/passivation by nitrogen as a result of the ion beam treatment. The third one is carbon nitride formation at the nitrided steel-hydrogenated amorphous carbon (or a-CN x :H) film interface

Additive Manufacturing of High-Performance 316L Stainless Steel Nanocomposites via Selective Laser Melting

Science.gov (United States)

AlMangour, Bandar Abdulaziz

Austenitic 316L stainless steel alloy is an attractive industrial material combining outstanding corrosion resistance, ductility, and biocompatibility, with promising structural applications and biomedical uses. However, 316L has low strength and wear resistance, limiting its high-performance applicability. Adding secondary hard nanoscale reinforcements to steel matrices, thereby forming steel-matrix nanocomposites (SMCs), can overcome these problems, improving the performance and thereby the applicability of 316L. However, SMC parts with complex-geometry cannot be easily achieved limiting its application. This can be avoided through additive manufacturing (AM) by generating layer-by-layer deposition using computer-aided design data. Expanding the range of AM-applicable materials is necessary to fulfill industrial demand. This dissertation presents the characteristics of new AM-processed high-performance 316L-matrix nanocomposites with nanoscale TiC or TiB2 reinforcements, addressing specific aspects of material design, process control and optimization, and physical metallurgy theory. The nanocomposites were prepared by high-energy ball-milling and consolidated by AM selective laser melting (SLM). Continuous and refined ring-like network structures were obtained with homogenously distributed reinforcements. Additional grain refinement occurred with reinforcement addition, attributed to nanoparticles acting as nuclei for heterogeneous nucleation. The influence of reinforcement content was first investigated; mechanical and tribological behaviors improved with increased reinforcement contents. The compressive yield strengths of composites with TiB2 or TiC reinforcements were approximately five or two times those of 316L respectively. Hot isostatic pressing post-treatment effectively eliminated major cracks and pores in SLM-fabricated components. The effects of the SLM processing parameters on the microstructure and mechanical performance were also investigated. Laser

A comparative study of creep rupture behaviour of modified 316L(N) base metal and 316L(N)/16-8-2 weldment in air and liquid sodium environments

International Nuclear Information System (INIS)

Mishra, M.P.; Mathew, M.D.; Mannan, S.L.; Rodriguez, P.; Borgstedt, H.U.

1997-01-01

Creep rupture behaviour of modified type 316L(N) stainless steel base metal and weldments prepared with 16-8-2 filler wire has been investigated in air and flowing sodium environments at 823 K. No adverse environmental effects have been noticed due to sodium on the creep rupture behaviour of these weldments for tests up to 10 000 h. Rupture lives of the weldment were higher in the sodium environment than those in air. Rupture lives of the weldments were found to be lower than those of the base metal by a factor of two to five in both air and sodium environments. Minimum creep rates were essentially the same for the weldment as well as for the base metal in both the environments, whereas rupture strain was usually lower for the weldment than that of the base metal. The reduction in area of the weldment specimens increased with increase in stress. Failures in the specimens of weldments were in the weld metal region. Microstructural studies carried out on failed weldment specimens after the creep rupture tests revealed extensive cavitation in the weld metal region in air tested specimens predominantly at the austerite/δ-ferrite interphase. However, no cavitation was observed in specimens tested in sodium. (author)

Influence of the field humiture environment on the mechanical properties of 316L stainless steel repaired with Fe314

Science.gov (United States)

Zhang, Lianzhong; Li, Dichen; Yan, Shenping; Xie, Ruidong; Qu, Hongliang

2018-04-01

The mechanical properties of 316L stainless steel repaired with Fe314 under different temperatures and humidities without inert gas protection were studied. Results indicated favorable compatibility between Fe314 and 316L stainless steel. The average yield strength, tensile strength, and sectional contraction percentage were higher in repaired samples than in 316L stainless steel, whereas the elongation rate was slightly lower. The different conditions of humiture environment on the repair sample exerted minimal influence on tensile and yield strengths. The Fe314 cladding layer was mainly composed of equiaxed grains and mixed with randomly oriented columnar crystal and tiny pores or impurities in the tissue. Results indicated that the hardness value of Fe314 cladding layer under different humiture environments ranged within 419-451.1 HV0.2. The field humiture environment also showed minimal impact on the average hardness of Fe314 cladding layers. Furthermore, 316L stainless steel can be repaired through laser cladding by using Fe314 powder without inert gas protection under different temperatures and humidity environments.

Application of Leak Before Break concept in 316LN austenitic steel pipes welded using 316L; Aplicação do conceito 1vazamento antes da falha' (Leak Before Break) em tubulações de aço 316LN soldado com metal de adição 316L

Energy Technology Data Exchange (ETDEWEB)

Cunto, Gabriel Giannini de

2017-07-01

This work presents a study of application of the Leak Before Break (LBB) concept, usually applied in nuclear power plants, in a pipe made from steel AISI type 316LN welded a coated electrode AISI type 316L. LBB concept is a criterion based on fracture mechanics analysis to show that a crack leak, present in a pipe, can be detected by leak detection systems, before this crack reaches a critical size that results in pipe fail. In the studied pipe, tensile tests and Ramberg-Osgood analyses were performed, as well as fracture toughness tests for obtaining the material resistance curve J-R. The tests were performed considering the base metal, weld and heat affected zone (HAZ), at the same operating temperatures of a nuclear power plant. For the mechanical properties found in these tests, load limit analyses were performed in order to determine the size of a crack which could cause a detectable leakage and the critical crack size, considering failure by plastic collapse. For the critical crack size found in the weld, which is the region that presented the lowest toughness, Integral J and tearing modulus T analyses were performed, considering failure by tearing instability. Results show a well-defined behavior between the base metal, HAZ and weld zones, where the base metal has a high toughness behavior, the weld has a low toughness behavior and the HAZ showed intermediate mechanical properties between the base metal and the weld. Using the PICEP software, the leak rate curves versus crack size and also the critical crack size were determined by considering load limit analysis. It was observed that after a certain crack size, the leak rate in base metal is much higher than for the HAZ and the weld, considering the same crack length. This occurs because in the base metal crack, it is expected that the crack grows in a more rounded form due to its higher toughness. The lowest critical crack size was found for the base metal presenting circumferential cracks. For the

Improvement of adhesion and barrier properties of biomedical stainless steel by deposition of YSZ coatings using RF magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Sánchez-Hernández, Z.E. [Instituto Politécnico Nacional, CICATA-Altamira, Grupo CIAMS, Km 14.5, Carretera Tampico-Puerto Industrial Altamira, C. P. 89600, Altamira, Tamps, México (Mexico); CICATA—Altamira, IPN. Grupo CIAMS, Km 14.5, Carretera Tampico-Puerto Industrial Altamira, C. P. 89600, Altamira, Tamps, México (Mexico); Domínguez-Crespo, M.A., E-mail: mdominguezc@ipn.mx [Instituto Politécnico Nacional, CICATA-Altamira, Grupo CIAMS, Km 14.5, Carretera Tampico-Puerto Industrial Altamira, C. P. 89600, Altamira, Tamps, México (Mexico); Torres-Huerta, A.M.; Onofre-Bustamante, E. [Instituto Politécnico Nacional, CICATA-Altamira, Grupo CIAMS, Km 14.5, Carretera Tampico-Puerto Industrial Altamira, C. P. 89600, Altamira, Tamps, México (Mexico); Andraca Adame, J. [Instituto Politécnico Nacional, Centro de Nanociencias Micro y Nanotecnologías, Departamento de DRX, C. P. 07300, Mexico, DF, México (Mexico); Dorantes-Rosales, H. [Instituto Politécnico Nacional, ESIQIE, Departamento de Metalurgia, C. P. 07300 Mexico, DF, México (Mexico)

2014-05-01

The AISI 316L stainless steel (SS) has been widely used in both artificial knee and hip joints in biomedical applications. In the present study, yttria stabilized zirconia (YSZ, ZrO{sub 2} + 8% Y{sub 2}O{sub 3}) films were deposited on AISI 316L SS by radio-frequency magnetron sputtering using different power densities (50–250 W) and deposition times (30–120 min) from a YSZ target. The crystallographic orientation and surface morphology were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The effects of the surface modification on the corrosion performance of AISI 316L SS were evaluated in phosphate buffered saline (PBS) solution using an electrochemical test on both the virgin and coated samples. The YSZ coatings have a (111) preferred orientation during crystal growth along the c-axis for short deposition times (30–60 min), whereas a polycrystalline structure forms during deposition times from 90 to 120 min. The corrosion protective character of the YSZ coatings depends on the crystal size and film thickness. A significant increase in adhesion and corrosion resistance by at least a factor of 46 and a higher breakdown potential were obtained for the deposited coatings at 200 W (120 min). - Highlights: • Well-formed and protective YSZ coatings were achieved on AISI 316L SS substrates. • Films grown at high power and long deposition time have polycrystalline structures. • The crystal size varies from ∼ 5 to 30 nm as both power and deposition time increased. • The differences of corrosion resistance are attributed to internal film structure.

Improvement of adhesion and barrier properties of biomedical stainless steel by deposition of YSZ coatings using RF magnetron sputtering

International Nuclear Information System (INIS)

Sánchez-Hernández, Z.E.; Domínguez-Crespo, M.A.; Torres-Huerta, A.M.; Onofre-Bustamante, E.; Andraca Adame, J.; Dorantes-Rosales, H.

2014-01-01

The AISI 316L stainless steel (SS) has been widely used in both artificial knee and hip joints in biomedical applications. In the present study, yttria stabilized zirconia (YSZ, ZrO 2 + 8% Y 2 O 3 ) films were deposited on AISI 316L SS by radio-frequency magnetron sputtering using different power densities (50–250 W) and deposition times (30–120 min) from a YSZ target. The crystallographic orientation and surface morphology were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The effects of the surface modification on the corrosion performance of AISI 316L SS were evaluated in phosphate buffered saline (PBS) solution using an electrochemical test on both the virgin and coated samples. The YSZ coatings have a (111) preferred orientation during crystal growth along the c-axis for short deposition times (30–60 min), whereas a polycrystalline structure forms during deposition times from 90 to 120 min. The corrosion protective character of the YSZ coatings depends on the crystal size and film thickness. A significant increase in adhesion and corrosion resistance by at least a factor of 46 and a higher breakdown potential were obtained for the deposited coatings at 200 W (120 min). - Highlights: • Well-formed and protective YSZ coatings were achieved on AISI 316L SS substrates. • Films grown at high power and long deposition time have polycrystalline structures. • The crystal size varies from ∼ 5 to 30 nm as both power and deposition time increased. • The differences of corrosion resistance are attributed to internal film structure

Tool life and surface roughness of ceramic cutting tool when turning AISI D2 tool steel

International Nuclear Information System (INIS)

Wan Emri Wan Abdul Rahaman

2007-01-01

The tool life of physical vapor deposition (PVD) titanium nitride (TiN) coated ceramic when turning AISI D2 tool steel of hardness 54-55 HRC was investigated. The experiments were conducted at various cutting speed and feed rate combinations with constant depth of cut and under dry cutting condition. The tool life of the cutting tool for all cutting conditions was obtained. The tool failure mode and wear mechanism were also investigated. The wear mechanism that is responsible for the wear form is abrasion and diffusion. Flank wear and crater wear are the main wear form found when turning AISI D2 grade hardened steel with 54-55 HRC using KY 4400 ceramic cutting tool. Additionally catastrophic failure is observed at cutting speed of 183 m/min and feed rate of 0.16 mm/ rev. (author)

Modelling of cyclic plasticity for austenitic stainless steels 304L, 316L, 316L(N)-IG

Energy Technology Data Exchange (ETDEWEB)

Dalla Palma, Mauro, E-mail: mauro.dallapalma@igi.cnr.it

2016-11-01

Highlights: • Stress-strain amplitudes of cyclic stress strain curves defined by design codes are provided as reference data. • A macroinstruction simulating cyclic plasticity and producing hardening parameters of constitutive models is developed. • Hardening parameters of the nonlinear Chaboche model are provided for stainless steels 316l-N, 316L, 304L at different temperatures. • Ratcheting is simulated by using the produced hardening parameters. - Abstract: The integrity assessment of structures subjected to cyclic loading must be verified with regard to cyclic type damage including time-independent fatigue and progressive deformation or ratcheting. Cyclic damage is verified simulating the material elastic-plastic loop and looking at the accumulated net plastic strain during each cycle at all points of the structure subjected to the complete time history of loadings. This work deals with the development of a numerical model producing the Chaboche hardening parameters starting from stress-strain data produced by testing of materials. Then, the total plastic strain can be simulated using the Chaboche inelastic constitutive model requested for finite element analyses. This is particularly demanding for pressure vessels, pressurised piping, boilers, and mechanical components of nuclear installations made of stainless steels. A design optimisation by iterative analyses is developed to approach the stress-strain test data with the Chaboche model. The parameters treated as design variables are the Chaboche parameters and the objective function to be minimised is a combination of the deviations from test data. The optimiser calls a macroinstruction simulating cyclic loading of a sample for different material temperatures. The numerical model can be used to produce hardening parameters of materials for inelastic finite element verifications of structures with complex joints like elbows subjected to a combination of steady sustained and cyclic loads.

Effect of post-weld heat treatment on the mechanical properties of CLAM/316L dissimilar joint

Energy Technology Data Exchange (ETDEWEB)

Zhang, Junyu [Key Laboratory of Neutronics and Radiation Safety, Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); University of Science and Technology of China, Hefei, Anhui 230027 (China); Huang, Bo [Key Laboratory of Neutronics and Radiation Safety, Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Wu, Qingsheng, E-mail: qingsheng.wu@fds.org.cn [Key Laboratory of Neutronics and Radiation Safety, Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Li, Chunjing; Huang, Qunying [Key Laboratory of Neutronics and Radiation Safety, Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei, Anhui 230031 (China)

2015-11-15

Highlights: • Dissimilar joints between CLAM and 316L steels welded by TIG were investigated. • After PWHTs, the hardening in HAZ on the CLAM steel side decreased remarkably. • Tempering at 740 °C for 2 h was considered as the preferable treatment rule. - Abstract: Dissimilar welding between China low activation martensitic (CLAM) steel and 316L austenitic stainless steel was investigated to achieve the reliable connection between test blanket modules (TBMs) and piping system in the international thermonuclear experimental reactor (ITER). The dissimilar joints were welded by tungsten inert gas (TIG) welding process with a filler material type-309. In order to stabilize the microstructure and improve the strength and toughness, post-weld heat treatments (PWHTs) of tempering at 740 °C, 780 °C and 820 °C, respectively, for 2 h were performed. The microstructure observation showed that tempering at 740 °C for 2 h was the preferable PWHT rule in this work. After the treatment, the hardening in heat affected zone (HAZ) on the CLAM steel side decreased remarkably. The tensile strength of the joint was roughly the same as that of the base metal. The impact toughness of HAZ on the CLAM steel side was 77% of that of the base metal. The absorbed energy of HAZ of 316L steel decreased by 93 J, and that of weld metal (WM) was 110 J after the treatment.

PODAAC-RSX12-L2B11

Data.gov (United States)

National Aeronautics and Space Administration — This dataset contains the RapidScat Level 2B 12.5km Version 1.1 science-quality ocean surface wind vectors. The Level 2B wind vectors are binned on a 12.5 km Wind...

Cyclic oxidation of stainless steel ferritic AISI 409, AISI 439 and AISI 441; Oxidacao ciclica dos acos inoxidaveis ferriticos AISI 409, AISI 439 e AISI 441

Energy Technology Data Exchange (ETDEWEB)

Salgado, Maria de Fatima; Santos, Diego Machado dos; Oliveira, Givanilson Brito de, E-mail: fatima.salgado@pq.cnpq.br [Universidade Estadual do Maranhao (CESC/UEMA), Caxias, MA (Brazil). Centro de Estudos Superiores; Rodrigues, Samara Clotildes Saraiva; Brandim, Ayrton de Sa [Instituto Federal do Piaui (PPGEM/IFPI), PI (Brazil); Lins, Vanessa de Freitas Cunha [Universidade Federal de Minas Gerais (IFMG), MG (Brazil)

2014-07-01

Stainless steels have many industrial applications. The cyclic oxidation of ferritic stainless steels technical and scientific importance presents, because they are less susceptible to peeling the austenitic alloys. For the purpose of investigating the behavior of these steels under thermal cycling, cyclic oxidation of AISI 409, AISI 441 and AISI 439 was carried out in a tubular furnace under two different conditions: oxidation by dipping the steel in the synthetic condensate for 10h and without oxidation immersion in the condensate, for up to 1500h at 300° C temperature. Using techniques: SEM, EDS and XRD revealed a microstructure with increased oxidation in the samples were immersed in the condensate. The oxide film remained intact during oxidation for steels 439 and 441 409 The Steel immersed in the condensate was rupture of the film after the 20th cycle of oxidation. The chemical characterization of the films allowed the identification of elements: Chromium, Iron, Aluminium and Silicon To a great extent, Cr{sub 2}O{sub 3}. (author)

Antibody Competition Reveals Surface Location of HPV L2 Minor Capsid Protein Residues 17–36

Directory of Open Access Journals (Sweden)

Stephanie M. Bywaters

2017-11-01

Full Text Available The currently available nonavalent human papillomavirus (HPV vaccine exploits the highly antigenic L1 major capsid protein to promote high-titer neutralizing antibodies, but is limited to the HPV types included in the vaccine since the responses are highly type-specific. The limited cross-protection offered by the L1 virus-like particle (VLP vaccine warrants further investigation into cross-protective L2 epitopes. The L2 proteins are yet to be fully characterized as to their precise placement in the virion. Adding to the difficulties in localizing L2, studies have suggested that L2 epitopes are not well exposed on the surface of the mature capsid prior to cellular engagement. Using a series of competition assays between previously mapped anti-L1 monoclonal antibodies (mAbs (H16.V5, H16.U4 and H16.7E and novel anti-L2 mAbs, we probed the capsid surface for the location of an L2 epitope (aa17–36. The previously characterized L1 epitopes together with our competition data is consistent with a proposed L2 epitope within the canyons of pentavalent capsomers.

Reducing Staphylococcus aureus biofilm formation on stainless steel 316L using functionalized self-assembled monolayers.

Science.gov (United States)

Kruszewski, Kristen M; Nistico, Laura; Longwell, Mark J; Hynes, Matthew J; Maurer, Joshua A; Hall-Stoodley, Luanne; Gawalt, Ellen S

2013-05-01

Stainless steel 316L (SS316L) is a common material used in orthopedic implants. Bacterial colonization of the surface and subsequent biofilm development can lead to refractory infection of the implant. Since the greatest risk of infection occurs perioperatively, strategies that reduce bacterial adhesion during this time are important. As a strategy to limit bacterial adhesion and biofilm formation on SS316L, self-assembled monolayers (SAMs) were used to modify the SS316L surface. SAMs with long alkyl chains terminated with hydrophobic (-CH3) or hydrophilic (oligoethylene glycol) tail groups were used to form coatings and in an orthogonal approach, SAMs were used to immobilize gentamicin or vancomycin on SS316L for the first time to form an "active" antimicrobial coating to inhibit early biofilm development. Modified SS316L surfaces were characterized using surface infrared spectroscopy, contact angles, MALDI-TOF mass spectrometry and atomic force microscopy. The ability of SAM-modified SS316L to retard biofilm development by Staphylococcus aureus was functionally tested using confocal scanning laser microscopy with COMSTAT image analysis, scanning electron microscopy and colony forming unit analysis. Neither hydrophobic nor hydrophilic SAMs reduced biofilm development. However, gentamicin-linked and vancomycin-linked SAMs significantly reduced S. aureus biofilm formation for up to 24 and 48 h, respectively. Copyright © 2013 Elsevier B.V. All rights reserved.

Intragranular cellular segregation network structure strengthening 316L stainless steel prepared by selective laser melting

Science.gov (United States)

Zhong, Yuan; Liu, Leifeng; Wikman, Stefan; Cui, Daqing; Shen, Zhijian

2016-03-01

A feasibility study was performed to fabricate ITER In-Vessel components by Selective Laser Melting (SLM) supported by Fusion for Energy (F4E). Almost fully dense 316L stainless steel (SS316L) components were prepared from gas-atomized powder and with optimized SLM processing parameters. Tensile tests and Charpy-V tests were carried out at 22 °C and 250 °C and the results showed that SLM SS316L fulfill the RCC-MR code. Microstructure characterization reveals the presence of hierarchical macro-, micro- and nano-structures in as-built samples that were very different from SS316L microstructures prepared by other established methods. The formation of a characteristic intragranular cellular segregation network microstructure appears to contribute to the increase of yield strength without losing ductility. Silicon oxide nano-inclusions were formed during the SLM process that generated a micro-hardness fluctuation in the building direction. The combined influence of a cellular microstructure and the nano-inclusions constraints the size of ductile dimples to nano-scale. The crack propagation is hindered by a pinning effect that improves the defect-tolerance of the SLM SS316L. This work proves that it was possible to manufacture SS316L with properties suitable for ITER First Wall panels. Further studies on irradiation properties of SLM SS316L and manufacturing of larger real-size components are needed.

Microscopic work function anisotropy and surface chemistry of 316L stainless steel using photoelectron emission microscopy

Energy Technology Data Exchange (ETDEWEB)

Barrett, N., E-mail: nick.barrett@cea.fr [CEA, IRAMIS, SPEC, LENSIS, F-91191 Gif-sur-Yvette (France); Renault, O. [CEA, LETI, Minatec Campus, F-38054 Grenoble Cedex 09 (France); Lemaître, H. [Université de Cergy-Pontoise, Rue d’Eragny, Neuville sur Oise, 95 031 Cergy-Pontoise (France); Surface Dynamics Laboratory, Institut for Fysik og Astronomi Aarhus Universitet, Ny Munkegade 120, 8000 Aarhus C (Denmark); Bonnaillie, P. [CEA, DEN, DANS, DMN, SRMP, F-91191 Gif-sur-Yvette (France); Barcelo, F. [CEA, DEN, DANS, DMN, SRMA, LA2M, F-91191 Gif-sur-Yvette (France); Miserque, F. [CEA, DEN, DANS, DPC, SCCME, LECA, F-91191 Gif-sur-Yvette (France); Wang, M.; Corbel, C. [Laboratoire des Solides Irradis, Ecole Polytechnique, route de Saclay, F-91128 Palaiseau (France)

2014-08-15

Highlights: • PEEM and EBSD study of spatial variations in local work function of 316L steel. • Correlation between work function and crystal grain orientation at the surface of 316L steel. • Spatially resolved chemistry of residual oxide layer. - Abstract: We have studied the variation in the work function of the surface of sputtered cleaned 316L stainless steel with only a very thin residual oxide surface layer as a function of grain orientation using X-ray photoelectron emission microscopy (XPEEM) and Electron Backscattering Diffraction. The grains are mainly oriented [1 1 1] and [1 0 1]. Four distinct work function values spanning a 150 meV energy window are measured. Grains oriented [1 1 1] have a higher work function than those oriented [1 0 1]. From core level XPEEM we deduce that all grain surfaces are Cr enriched and Ni depleted whereas the Cr/Fe ratio is similar for all grains. The [1 1 1] oriented grains show evidence for a Cr{sub 2}O{sub 3} surface oxide and a higher concentration of defective oxygen sites.

1,2-Dichlorohexafluoro-Cyclobutane (1,2-c-C4F6Cl2, R-316c) a Potent Ozone Depleting Substance and Greenhouse Gas: Atmospheric Loss Processes, Lifetimes, and Ozone Depletion and Global Warming Potentials for the (E) and (Z) stereoisomers

Science.gov (United States)

Papadimitriou, Vassileios C.; McGillen, Max R.; Smith, Shona C.; Jubb, Aaron M.; Portmann, Robert W.; Hall, Bradley D.; Fleming, Eric L.; Jackman, Charles H.; Burkholder, James B.

2013-01-01

The atmospheric processing of (E)- and (Z)-1,2-dichlorohexafluorocyclobutane (1,2-c-C4F6Cl2, R-316c) was examined in this work as the ozone depleting (ODP) and global warming (GWP) potentials of this proposed replacement compound are presently unknown. The predominant atmospheric loss processes and infrared absorption spectra of the R-316c isomers were measured to provide a basis to evaluate their atmospheric lifetimes and, thus, ODPs and GWPs. UV absorption spectra were measured between 184.95 to 230 nm at temperatures between 214 and 296 K and a parametrization for use in atmospheric modeling is presented. The Cl atom quantum yield in the 193 nm photolysis of R- 316c was measured to be 1.90 +/- 0.27. Hexafluorocyclobutene (c-C4F6) was determined to be a photolysis co-product with molar yields of 0.7 and 1.0 (+/-10%) for (E)- and (Z)-R-316c, respectively. The 296 K total rate coefficient for the O(1D) + R-316c reaction, i.e., O(1D) loss, was measured to be (1.56 +/- 0.11) × 10(exp -10)cu cm/ molecule/s and the reactive rate coefficient, i.e., R-316c loss, was measured to be (1.36 +/- 0.20) × 10(exp -10)cu cm/molecule/s corresponding to a approx. 88% reactive yield. Rate coefficient upper-limits for the OH and O3 reaction with R-316c were determined to be model to be 74.6 +/- 3 and 114.1 +/-10 years, respectively, where the estimated uncertainties are due solely to the uncertainty in the UV absorption spectra. Stratospheric photolysis is the predominant atmospheric loss process for both isomers with the O(1D) reaction making a minor, approx. 2% for the (E) isomer and 7% for the (Z) isomer, contribution to the total atmospheric loss. Ozone depletion potentials for (E)- and (Z)-R-316c were calculated using the 2-D model to be 0.46 and 0.54, respectively. Infrared absorption spectra for (E)- and (Z)-R-316c were measured at 296 K and used to estimate their radiative efficiencies (REs) and GWPs; 100-year time-horizon GWPs of 4160 and 5400 were obtained for (E)- and (Z

Characterization of TiC coatings on AISI 316 stainless steel limiters

International Nuclear Information System (INIS)

Brossa, F.

1984-01-01

Plasma spray and chemical vapour TiC coatings deposited on 316 SS limiters were thermally treated in conditions simulating the high pulsed heat loads predicted in fusion reactors. A 60 kV electron beam gun was used to create the energy fluxes of 0.5 - 10 kW/cm 2 for the times ranging from 3 to 500 ms. The primary damage features observed on the surface after thermal shock were microcracking, localized melt areas and exfoliation. Methods for improving the lifetime of the coatings such as steel pre-treatment or deposition of interlayers acting as a buffer in thermal expansion and as diffusion barriers were also investigated. (author)

Cyclic oxidation of stainless steel ferritic AISI 409, AISI 439 and AISI 441

International Nuclear Information System (INIS)

Salgado, Maria de Fatima; Santos, Diego Machado dos; Oliveira, Givanilson Brito de; Lins, Vanessa de Freitas Cunha

2014-01-01

Stainless steels have many industrial applications. The cyclic oxidation of ferritic stainless steels technical and scientific importance presents, because they are less susceptible to peeling the austenitic alloys. For the purpose of investigating the behavior of these steels under thermal cycling, cyclic oxidation of AISI 409, AISI 441 and AISI 439 was carried out in a tubular furnace under two different conditions: oxidation by dipping the steel in the synthetic condensate for 10h and without oxidation immersion in the condensate, for up to 1500h at 300° C temperature. Using techniques: SEM, EDS and XRD revealed a microstructure with increased oxidation in the samples were immersed in the condensate. The oxide film remained intact during oxidation for steels 439 and 441 409 The Steel immersed in the condensate was rupture of the film after the 20th cycle of oxidation. The chemical characterization of the films allowed the identification of elements: Chromium, Iron, Aluminium and Silicon To a great extent, Cr_2O_3. (author)

Evaluation of the Sensitization of 316L Stainless Steels After the Post Weld Heat Treatment

Energy Technology Data Exchange (ETDEWEB)

Lee, Junho; Jang, Changheui [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Lee, Kyoung Soo [Korea Hydro and Nuclear Power Co. Ltd., Daejeon (Korea, Republic of)

2014-05-15

It was observed that the PWSCC growth rate of alloy 182 was markedly decreased after PWHT. However, the PWHT of components made of stainless steels (SSs) would be limited because of the concerns about sensitization when they are exposed to temperature range of 500 to 800 .deg. C. Also, the sensitization of austenitic stainless steels could increase the susceptibility to intergrannular stress corrosion cracking. Therefore, the effect of PWHT on the sensitization behaviors of 316L SSs having predominant austenitic structure with small amount of ferrite was investigated to assess the applicability of PWHT to dissimilar weld area with austenitic stainless steels. The sensitization behaviors of two heats of 316L SSs with small amount of ferrite were investigated after heat treatment at 600, 650 and 700 .deg. C. Grain boundary sensitization was not observed in 316L SSs after the heat treatment at 600, 650 and 700 .deg. C up to 30 h. The increase in degree of sensitization (DOS) was caused by reduction of corrosion resistance in ferrite phase due to formation of chromium carbide and intermatallic phases during heat treatment. The DOS value of 316L SSs depended on the ferrite morphology. The stringer type of ferrite (316L-heat A) showed relatively higher DOS in comparison with 316L containing blocky type of ferrite (316L-heat B). It could be due to sufficient supplement of chromium in larger size of ferrite phase.

Evaluation of the Sensitization of 316L Stainless Steels After the Post Weld Heat Treatment

International Nuclear Information System (INIS)

Lee, Junho; Jang, Changheui; Lee, Kyoung Soo

2014-01-01

It was observed that the PWSCC growth rate of alloy 182 was markedly decreased after PWHT. However, the PWHT of components made of stainless steels (SSs) would be limited because of the concerns about sensitization when they are exposed to temperature range of 500 to 800 .deg. C. Also, the sensitization of austenitic stainless steels could increase the susceptibility to intergrannular stress corrosion cracking. Therefore, the effect of PWHT on the sensitization behaviors of 316L SSs having predominant austenitic structure with small amount of ferrite was investigated to assess the applicability of PWHT to dissimilar weld area with austenitic stainless steels. The sensitization behaviors of two heats of 316L SSs with small amount of ferrite were investigated after heat treatment at 600, 650 and 700 .deg. C. Grain boundary sensitization was not observed in 316L SSs after the heat treatment at 600, 650 and 700 .deg. C up to 30 h. The increase in degree of sensitization (DOS) was caused by reduction of corrosion resistance in ferrite phase due to formation of chromium carbide and intermatallic phases during heat treatment. The DOS value of 316L SSs depended on the ferrite morphology. The stringer type of ferrite (316L-heat A) showed relatively higher DOS in comparison with 316L containing blocky type of ferrite (316L-heat B). It could be due to sufficient supplement of chromium in larger size of ferrite phase

Sequential creep-fatigue interaction in austenitic stainless steel type 316L-SPH

International Nuclear Information System (INIS)

Tavassoli, A.A.; Mottot, M.; Petrequin, P.

1986-01-01

Influence of a prior creep or fatigue exposure on subsequent fatigue or creep properties of stainless steel type 316 L SPH has been investigated. The results obtained are used to verify the validity of time and cycle fraction rule and to obtain information on the effect of very long intermittent hold times on low cycle fatigue properties, as well as on transitory loads occurring during normal service of some structural components of LMFBR reactors. Creep and fatigue tests have been carried out at 600 0 C and under conditions yielding equal or different fatigue saturation and creep stresses. Prior creep damage levels introduced range from primary to tertiary creep, whilst those of fatigue span from 20 to 70 percent of fatigue life. In both creep-fatigue and fatigue-creep sequences in the absence of a permanent prior damage (cavitation or cracking) the subsequent resistance of 316 L-SPH to fatigue or creep is unchanged, if not improved. Thin foils prepared from the specimens confirmed these observations and showed that the dislocation substructure developed during the first mode of testing is quickly replaced by that of the second mode. Grain boundary cavitation does not occur in 316 L-SPH during creep exposures to well beyond the apparent end of secondary stage and as a result prior creep exposures up to approximately 80% of rupture life do not affect fatigue properties. Conversely, significant surface cracks were found in the prior fatigue tested specimens after above about 50% life. In the presence of such cracks the subsequent creep damage was localized at the tip of the main crack and the remaining creep life was found to be usually proportional to the effective specimen cross section. Creep and fatigue sequential damage are not necessarily additive and this type of loadings are in general less severe than the repeated creep-fatigue cycling. 17 refs.

Hydrophilic property of 316L stainless steel after treatment by atmospheric pressure corona streamer plasma using surface-sensitive analyses

Energy Technology Data Exchange (ETDEWEB)

Al-Hamarneh, Ibrahim, E-mail: hamarnehibrahim@yahoo.com [Department of Physics, Faculty of Science, Al-Balqa Applied University, Salt 19117 (Jordan); Pedrow, Patrick [School of Electrical Engineering and Computer Science, Washington State University, Pullman, WA 99164 (United States); Eskhan, Asma; Abu-Lail, Nehal [Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA 99164 (United States)

2012-10-15

Highlights: Black-Right-Pointing-Pointer Surface hydrophilic property of surgical-grade 316L stainless steel was enhanced by Ar-O{sub 2} corona streamer plasma treatment. Black-Right-Pointing-Pointer Hydrophilicity, surface morphology, roughness, and chemical composition before and after plasma treatment were evaluated. Black-Right-Pointing-Pointer Contact angle measurements and surface-sensitive analyses techniques, including XPS and AFM, were carried out. Black-Right-Pointing-Pointer Optimum plasma treatment conditions of the SS 316L surface were determined. - Abstract: Surgical-grade 316L stainless steel (SS 316L) had its surface hydrophilic property enhanced by processing in a corona streamer plasma reactor using O{sub 2} gas mixed with Ar at atmospheric pressure. Reactor excitation was 60 Hz ac high-voltage (0-10 kV{sub RMS}) applied to a multi-needle-to-grounded screen electrode configuration. The treated surface was characterized with a contact angle tester. Surface free energy (SFE) for the treated stainless steel increased measurably compared to the untreated surface. The Ar-O{sub 2} plasma was more effective in enhancing the SFE than Ar-only plasma. Optimum conditions for the plasma treatment system used in this study were obtained. X-ray photoelectron spectroscopy (XPS) characterization of the chemical composition of the treated surfaces confirms the existence of new oxygen-containing functional groups contributing to the change in the hydrophilic nature of the surface. These new functional groups were generated by surface reactions caused by reactive oxidation of substrate species. Atomic force microscopy (AFM) images were generated to investigate morphological and roughness changes on the plasma treated surfaces. The aging effect in air after treatment was also studied.

Weld defects analysis of 60 mm thick SS316L mock-ups of TIG and EB welds by ultrasonic inspection for fusion reactor vacuum vessel applications

International Nuclear Information System (INIS)

Buddu, Ramesh Kumar; Shaikh, Shamsuddin; Raole, P.M.; Sarkar, B.

2015-01-01

The present paper reports the weld quality inspections carried with 60 mm thick AISI welds of SS316L. The high thickness steel plates requirement is due to the specific applications in case of advanced fusion reactor structural components like vacuum vessel and others. Different kind welds are proposed for the thick plate joints like Tungsten Inert Gas (TIG) welding, Electron beam welding as per stringent conditions (like very low distortions and residual stresses) for the vacuum vessel fabrication. Mock-ups of laboratory scale welds are fabricated by TIG (multi-pass) and EB (double pass) process techniques and different weld quality inspections are carried by different NDT tests. The welds are examined with Liquid penetrant examination to check sub surface cracks/discontinuities towards the defects observation

Improved sensitivity of human brain MAO B measurement using deuterium substituted [{sup 11}C]L-deprenyl ([{sup 11}C]L-deprenyl-D2)

Energy Technology Data Exchange (ETDEWEB)

Fowler, J.S.; Volkow, N.D.; Wang, G.J. [Brookhaven National Laboratory, Upton, NY (United States)] [and others

1995-05-01

Post-mortem reports that human brain monoamine oxidase B (MAO B) increases in normal aging and neurodegenerative disorders due to the proliferation of MAO B-rich glial cells suggest that PET measures of MAO B may track gliosis. We have recently shown that the MAO B tracer [{sup 11}C]L-deprenyl has limited sensitivity in regions of high MAO B due to its rapid rate of trapping. This limits its utility for measuring MAO B in brain regions where MAO B is higher and/or where blood flow is low. We have recently demonstrated that [{sup 11}C]L-deprenyl-D2 has improved sensitivity in regions of high MAO B due to the deuterium isotope effect which reduces the rate of trapping. We report studies [{sup 11}C]L-deprenyl-D2 in normal human brain in 16 healthy men and women (age range 23-73) to assess tracer sensitivity, regional distribution, and reproducibility. Graphical analysis for irreversible systems was used to calculate Ki (influx constant) as an index of MAO B concentration in different brain regions. The uptake of carbon-11 in different brain regions was rapid, peaking at 5 minutes and plateauing from 30-60 minutes after an initial clearance. MAO B was highest in subcortical regions: thalamus{ge}basal ganglia>cingulate gyrus>frontal cortex=occipital cortex=cerebellum in agreement with post-mortem measurements. Ki values were highly correlated within an individual. Repeated measures at 1-4 week intervals were highly correlated (r=0.9; p=0.0001). In women (n=8: age range 23-73), Ki increased with increasing age for 8 brain regions (p < 0.04). Though men (N=8; age range 34-70) showed no correlation with age, a larger sample size is needed to adequately assess trends. In summary, the use of [{sup 11}C]L-deprenyl-D2 improves the measurement of MAO B in the human brain permitting its investigation as a positive tracer for glial cell proliferation in neurodegenerative disorders.

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.

Helium 3 precipitation in AISI 316L stainless steel induced by radioactive decay of tritium: Microstructural study of helium bubble precipitation

International Nuclear Information System (INIS)

Brass, A.M.; Chene, J.

1994-01-01

The development of the thermonuclear technology has given rise to a renewed interest in the study of the behavior of helium in metals. A great amount of work is still required for the understanding of the role of helium on the mechanical properties of structural materials for fusion technology, especially austenitic stainless steels. This article deals with the study of the influence of thermomechanical heat treatments, aging conditions (temperature and time), and helium concentration of helium bubble precipitation in a 316L austenitic steel. Helium was generated by the radioactive decay of tritium (tritium trick). Helium bubbles impede the grain growth in 316L steel aged at 1,373 K and also the recrystallization reaction at this temperature if cold working is performed prior to aging. Transmission electron microscopy (TEM) observations indicated a weak helium precipitation at 1,073 and 1,223 K, presumably due to the presence of trapping sites for tritium, and no bubble growth after aging up to 100 hours. Precipitation sites are mainly dislocations in the matrix at 1,073 K and grain boundaries and individual dislocations in the matrix at 1,223 K. The large bubble size (50 nm) observed at 1,373 K, even for short aging times (0.083), can partly be attributed to bubble dragging by dislocations toward the grain boundaries. Cold deformation prior to aging leads to a larger bubble size due to growth enhancement during recrystallization. Decreasing the helium content leads to a smaller helium bubble size and density. Tritium trapping at helium bubbles may favor helium 3 accumulation on defects such as grain boundaries, as observed by tritium autoradiography

Sliding Wear Characteristics and Corrosion Behaviour of Selective Laser Melted 316L Stainless Steel

Science.gov (United States)

Sun, Y.; Moroz, A.; Alrbaey, K.

2014-02-01

Stainless steel is one of the most popular materials used for selective laser melting (SLM) processing to produce nearly fully dense components from 3D CAD models. The tribological and corrosion properties of stainless steel components are important in many engineering applications. In this work, the wear behaviour of SLM 316L stainless steel was investigated under dry sliding conditions, and the corrosion properties were measured electrochemically in a chloride containing solution. The results show that as compared to the standard bulk 316L steel, the SLM 316L steel exhibits deteriorated dry sliding wear resistance. The wear rate of SLM steel is dependent on the vol.% porosity in the steel and by obtaining full density it is possible achieve wear resistance similar to that of the standard bulk 316L steel. In the tested chloride containing solution, the general corrosion behaviour of the SLM steel is similar to that of the standard bulk 316L steel, but the SLM steel suffers from a reduced breakdown potential and is more susceptible to pitting corrosion. Efforts have been made to correlate the obtained results with porosity in the SLM steel.

Effect of cerium and lanthanum on the microstructure and mechanical properties of AISI D2 tool steel

International Nuclear Information System (INIS)

Hamidzadeh, Mohammad Ali; Meratian, Mahmood; Saatchi, Ahmad

2013-01-01

AISI D2 tool steel has excellent wear resistance with high dimensional stability. This type of steel is suitable for making molds. This paper describes investigations into the effect of adding Ce/La on microstructure of AISI D2 type cold work tool steels obtained by means of optical microscopy, scanning electron microscopy, X-ray diffraction, energy dispersive X-ray spectrometry (EDS) and image analyzer. The results showed that after modification with Ce/La, the morphology, size and distribution of M 7 C 3 carbides change greatly. The carbide network tends to break, and all carbides are refined and distributed homogeneously in the matrix, and also reduce the size of chromium carbides and increase the dissolution of carbides during heat treatment. The results of mechanical tests show that the toughness of the alloy increased about 75% without reducing the hardness of the alloy

Characterization of 316L(N)-IG SS joint produced by hot isostatic pressing technique

International Nuclear Information System (INIS)

Nakano, J.; Miwa, Y.; Tsukada, T.; Kikuchi, M.; Kita, S.; Nemoto, Y.; Tsuji, H.; Jitsukawa, S.

2002-01-01

Type 316L(N) stainless steel of the international thermonuclear experimental reactor grade (316L(N)-IG SS) is being considered for the first wall/blanket module. Hot isostatic pressing (HIP) technique is expected for the fabrication of the module. To evaluate the integrity and susceptibility to stress corrosion cracking (SCC) of HIPed 316L(N)-IG SS, tensile tests in vacuum and slow strain rate tests in high temperature water were performed. Specimen with the HIPed joint had similar tensile properties to specimens of 316L(N)-IG SS, and did not show susceptibility to SCC in oxygenated water at 423 K. Thermally sensitized specimen was low susceptible to SCC even in the creviced condition. It is concluded that the tensile properties of HIPed SS are as high as those of the base alloy and the HIP process caused no deleterious effects

Linear Friction Welding of Dissimilar Materials 316L Stainless Steel to Zircaloy-4

Science.gov (United States)

Wanjara, P.; Naik, B. S.; Yang, Q.; Cao, X.; Gholipour, J.; Chen, D. L.

2018-02-01

In the nuclear industry, there are a number of applications where the transition of stainless steel to Zircaloy is of technological importance. However, due to the differences in their properties there are considerable challenges associated with developing a joining process that will sufficiently limit the heat input and welding time—so as to minimize the extent of interaction at the joint interface and the resulting formation of intermetallic compounds—but still render a functional metallurgical bond between these two alloys. As such, linear friction welding, a solid-state joining technology, was selected in the present study to assess the feasibility of welding 316L stainless steel to Zircaloy-4. The dissimilar alloy welds were examined to evaluate their microstructural characteristics, microhardness evolution across the joint interface, static tensile properties, and fatigue behavior. Microstructural observations revealed a central intermixed region and, on the Zircaloy-4 side, dynamically recrystallized and thermomechanically affected zones were present. By contrast, deformation on the 316L stainless steel side was limited. In the intermixed region a drastic change in the composition was observed along with a local increase in hardness, which was attributed to the presence of intermetallic compounds, such as FeZr3 and Cr2Zr. The average yield (316 MPa) and ultimate tensile (421 MPa) strengths met the minimum strength properties of Zircaloy-4, but the elongation was relatively low ( 2 pct). The tensile and fatigue fracture of the welds always occurred at the interface in the mode of partial cohesive failure.

Evaluation of micro-abrasion-corrosion on SiO2-TiO2-ZrO2 coatings synthesized by the sol-gel method

Science.gov (United States)

Bautista Ruiz, J.; Aperador, W.; Caballero Gómez, J.

2016-02-01

The medical science and the engineering, work to improve the materials used in the manufacture of joint implants, since they have a direct impact on the quality of people life. The surgical interventions are increasing worldwide with a high probability of a second or even a third intervention. Around these circumstances, it was evaluated the behaviour against microabrasion-corrosion phenomena on SiO2 TiO2 ZrO2 coatings, synthesized by the sol-gel method with concentration of the Si/Ti/Zr precursors: 10/70/20 and 10/20/70. The coatings were deposited on AISI 316 LVM stainless steel substrates. The morphological characterization of the wear was made by AFM techniques. It was observed that the coatings with higher levels of titanium have a good response to the phenomena of microabrasion-corrosion.

Deuterium permeation of amorphous alumina coating on 316L prepared by MOCVD

International Nuclear Information System (INIS)

Li Shuai; He Di; Liu Xiaopeng; Wang Shumao; Jiang Lijun

2012-01-01

Highlights: ► Deuterium permeation behavior of alumina coating by MOCVD is investigated. ► The as-prepared alumina is amorphous. ► The alumina coating is dense and well adherent to substrate. ► Deuterium permeation rate of alumina coating is 2–3 orders of magnitude lower than martensitic steels. - Abstract: The deuterium permeation behavior of the alumina coating on 316L stainless steel prepared by metal organic chemical vapor deposition (MOCVD) was investigated. The alumina coating was also characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and scanning electron microscope (SEM). It was found that the as-prepared coating consisted of amorphous alumina. This alumina coating had a dense, crack-free and homogeneous morphology. Although the alumina coating was amorphous, effective suppression of deuterium permeation was demonstrated. The deuterium permeability of the alumina coating was 51–60 times less than that of the 316L stainless steel and 153–335 times less than that of the referred low activation martensitic steels at 860–960 K.

Standard test method for electrochemical reactivation (EPR) for detecting sensitization of AISI type 304 and 304L stainless steels

CERN Document Server

American Society for Testing and Materials. Philadelphia

1994-01-01

1.1 This test method covers a laboratory procedure for conducting an electrochemical reactivation (EPR) test on AISI Type 304 and 304L (UNS No. S30400 and S30403, respectively) stainless steels. This test method can provide a nondestructive means of quantifying the degree of sensitization in these steels (1, 2, 3). This test method has found wide acceptance in studies of the effects of sensitization on intergranular corrosion and intergranular stress corrosion cracking behavior (see Terminology G15). The EPR technique has been successfully used to evaluate other stainless steels and nickel base alloys (4), but the test conditions and evaluation criteria used were modified in each case from those cited in this test method. 1.2 The values stated in SI units are to be regarded as the standard. The inch-pound units given in parentheses are for information only. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this...

Multi - pulse tea CO2 laser beam interaction with the TiN thin films

International Nuclear Information System (INIS)

Gakovic, B.; Trtica, M.; Nenadovic, T.; Pavlicevic, B.

1998-01-01

The interaction of various types of energetic beams including a laser beam with the high-hardness coatings is of great fundamental and technological interest. The Nd:YAG, excimer and CO 2 are frequently used laser beams for this purpose. The interaction of a laser beam with low thickness coatings, deposited on austenitic stainless steel, is insufficiently known in the literature. Titanium nitride (TiN) possess the excellent physico-chemical characteristics. For this reason TiN films/coatings are widely used. The purpose of this article is a consideration of the effect of TEA C0 2 laser radiation on the TiN film deposited on austenitic stainless steel substrate (AISI 316). Investigation of TiN morphological changes, after multipulse laser irradiation, shown dependence on laser fluence, number of laser pulses and the laser pulse shape. Subsequently fast heating and cooling during multi-pulse laser bombardment cause the grain growth of TiN layer. Both laser pulses (pulses with tail and tail-free pulses) produced periodical wave like structure on polished substrate material. Periodicity is observed also on AISI 316 protected with TiN layer, but only with laser pulse with tail. (author)

Preliminary microstructural examination of high and low ductility type 316 creep rupture specimens

International Nuclear Information System (INIS)

Bolton, C.J.; Cordwell, J.E.; Hooper, A.J.; Marshall, P.; Steeds, J.; Wickens, A.

1977-09-01

A preliminary report is presented dealing with the examination of creep specimens from five casts of AISI Type 316 stainless steel which ruptured with variable ductility. Specimen microstructures and attempts to identify factors responsible for high or low creep ductility are discussed. (author)

Tribological properties of CrN coatings deposited by nitro-chromizing treatment on AISI D2 steel

Energy Technology Data Exchange (ETDEWEB)

Durmaz, M., E-mail: mdurmaz@sakarya.edu.tr; Abakay, E.; Sen, U.; Sen, S. [Department of Metallurgical and Materials Engineering, Engineering Faculty, Sakarya University, Esentepe Campus, 54187 Sakarya (Turkey); Kilinc, B. [Department of Metallurgical and Materials Engineering, Institute of Arts and Sciences, Sakarya University, Esentepe Campus, 54187 Sakarya (Turkey)

2015-03-30

In this work, the wear test of uncoated and chromium nitride coated AISI D2 cold work tool steel against alumina ball realized at 0.1 m/s sliding speeds and under the loads of 2.5N, 5N and 10N. Steel samples were nitrided at 575°C for 8 h in the first step of the coating process, and then chromium nitride coating was performed thermo-reactive deposition technique (TRD) in a powder mixture consisting of ferro-chromium, ammonium chloride and alumina at 1000°C for 2 h. Nitro-chromized samples were characterized by X-Ray diffraction analysis (XRD), scanning electron microscopy (SEM), micro-hardness and ball on disk wear tests. The coating layer formed on the AISI D2 steel was compact and homogeneous. X-ray studies showed that the phase formed in the coated layer is Cr{sub 2}N. The depth of the layer was 8.15 µm. The average hardness of the layer was 2160±15 HV{sub 0.025}. For uncoated and chromium nitride materials, wear rate increased with increasing load. The results of friction coefficient and wear rate of the tested materials showed that the CrN coating presents the lowest results.

Tribological properties of CrN coatings deposited by nitro-chromizing treatment on AISI D2 steel

International Nuclear Information System (INIS)

Durmaz, M.; Abakay, E.; Sen, U.; Sen, S.; Kilinc, B.

2015-01-01

In this work, the wear test of uncoated and chromium nitride coated AISI D2 cold work tool steel against alumina ball realized at 0.1 m/s sliding speeds and under the loads of 2.5N, 5N and 10N. Steel samples were nitrided at 575°C for 8 h in the first step of the coating process, and then chromium nitride coating was performed thermo-reactive deposition technique (TRD) in a powder mixture consisting of ferro-chromium, ammonium chloride and alumina at 1000°C for 2 h. Nitro-chromized samples were characterized by X-Ray diffraction analysis (XRD), scanning electron microscopy (SEM), micro-hardness and ball on disk wear tests. The coating layer formed on the AISI D2 steel was compact and homogeneous. X-ray studies showed that the phase formed in the coated layer is Cr 2 N. The depth of the layer was 8.15 µm. The average hardness of the layer was 2160±15 HV 0.025 . For uncoated and chromium nitride materials, wear rate increased with increasing load. The results of friction coefficient and wear rate of the tested materials showed that the CrN coating presents the lowest results

Tribological properties of CrN coatings deposited by nitro-chromizing treatment on AISI D2 steel

Science.gov (United States)

Durmaz, M.; Kilinc, B.; Abakay, E.; Sen, U.; Sen, S.

2015-03-01

In this work, the wear test of uncoated and chromium nitride coated AISI D2 cold work tool steel against alumina ball realized at 0.1 m/s sliding speeds and under the loads of 2.5N, 5N and 10N. Steel samples were nitrided at 575°C for 8 h in the first step of the coating process, and then chromium nitride coating was performed thermo-reactive deposition technique (TRD) in a powder mixture consisting of ferro-chromium, ammonium chloride and alumina at 1000°C for 2 h. Nitro-chromized samples were characterized by X-Ray diffraction analysis (XRD), scanning electron microscopy (SEM), micro-hardness and ball on disk wear tests. The coating layer formed on the AISI D2 steel was compact and homogeneous. X-ray studies showed that the phase formed in the coated layer is Cr2N. The depth of the layer was 8.15 µm. The average hardness of the layer was 2160±15 HV0.025. For uncoated and chromium nitride materials, wear rate increased with increasing load. The results of friction coefficient and wear rate of the tested materials showed that the CrN coating presents the lowest results.

8 CFR 316.11 - Attachment to the Constitution; favorable disposition towards the good order and happiness.

Science.gov (United States)

2010-01-01

... disposition towards the good order and happiness. 316.11 Section 316.11 Aliens and Nationality DEPARTMENT OF... the Constitution; favorable disposition towards the good order and happiness. (a) General. An... favorably disposed toward the good order and happiness of the United States. Attachment implies a depth of...

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

International Nuclear Information System (INIS)

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

2015-01-01

The aim of this study is to evaluate the applicability of highly chemically inert titanium dioxide synthesized by ion beam implantation for corrosion protection of AISI 304 stainless steel in sodium chloride solution. More specifically, the prevention of galvanic corrosion between carbon-fiber reinforced plastic (CFRP) and AISI 304 was investigated. Corrosion performance of TiO 2 implanted AISI 304 – examined for different implantation and annealing parameters – is strongly influenced by implantation fluence. Experimental results show that a fluence of 5 × 10 16 cm −2 (Ti + ) and 1 × 10 17 cm −2 (O + ) is sufficient to prevent pitting corrosion significantly, while galvanic corrosion with CFRP can already be noticeably reduced by an implantation fluence of 5 × 10 15 cm −2 (Ti + ) and 1 × 10 16 cm −2 (O + ). Surface roughness, implantation energy and annealing at 200 °C and 400 °C show only little influence on the corrosion behavior. TEM analysis indicates the existence of stoichiometric TiO 2 inside the steel matrix for medium fluences and the formation of a separated metal oxide layer for high fluences.

Effect of cerium and lanthanum on the microstructure and mechanical properties of AISI D2 tool steel

Energy Technology Data Exchange (ETDEWEB)

Hamidzadeh, Mohammad Ali, E-mail: mahamidzadeh@yahoo.com [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Meratian, Mahmood; Saatchi, Ahmad [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)

2013-06-01

AISI D2 tool steel has excellent wear resistance with high dimensional stability. This type of steel is suitable for making molds. This paper describes investigations into the effect of adding Ce/La on microstructure of AISI D2 type cold work tool steels obtained by means of optical microscopy, scanning electron microscopy, X-ray diffraction, energy dispersive X-ray spectrometry (EDS) and image analyzer. The results showed that after modification with Ce/La, the morphology, size and distribution of M{sub 7}C{sub 3} carbides change greatly. The carbide network tends to break, and all carbides are refined and distributed homogeneously in the matrix, and also reduce the size of chromium carbides and increase the dissolution of carbides during heat treatment. The results of mechanical tests show that the toughness of the alloy increased about 75% without reducing the hardness of the alloy.

Structure/property (constitutive and dynamic strength/damage) characterization of additively manufactured 316L SS

Science.gov (United States)

Gray, G. T., III; Livescu, V.; Rigg, P. A.; Trujillo, C. P.; Cady, C. M.; Chen, S. R.; Carpenter, J. S.; Lienert, T. J.; Fensin, S.

2015-09-01

For additive manufacturing (AM), the certification and qualification paradigm needs to evolve as there exists no "ASTM-type" additive manufacturing certified process or AM-material produced specifications. Accordingly, utilization of AM materials to meet engineering applications requires quantification of the constitutive properties of these evolving materials in comparison to conventionally-manufactured metals and alloys. Cylinders of 316L SS were produced using a LENS MR-7 laser additive manufacturing system from Optomec (Albuquerque, NM) equipped with a 1kW Yb-fiber laser. The microstructure of the AM-316L SS is detailed in both the as-built condition and following heat-treatments designed to obtain full recrystallization. The constitutive behavior as a function of strain rate and temperature is presented and compared to that of nominal annealed wrought 316L SS plate. The dynamic damage evolution and failure response of all three materials was probed using flyer-plate impact driven spallation experiments at a peak stress of 4.5 GPa to examine incipient spallation response. The spall strength of AM-produced 316L SS was found to be very similar for the peak shock stress studied to that of annealed wrought or AM-316L SS following recrystallization. The damage evolution as a function of microstructure was characterized using optical metallography.

Synthesis and luminescence properties of NaAl{sub 11}O{sub 17}:Mn{sup 2+} green phosphor for white LEDs

Energy Technology Data Exchange (ETDEWEB)

Cao, Renping, E-mail: jxcrp@163.com [College of Mathematics and Physics, Jinggangshan University, Ji’an 343009 (China); Peng, Dedong; Xu, Haidong [College of Mathematics and Physics, Jinggangshan University, Ji’an 343009 (China); Jiang, Shenhua [College of pharmacology and Life Science, Jiujiang University, Jiujiang 332000 (China); Luo, Zhiyang [College of Mechanical Manufacture and Automation, Jinggangshan University, Ji’an 343009 (China); Ao, Hui [College of Mathematics and Physics, Jinggangshan University, Ji’an 343009 (China); Liu, Pan [Scientific Research Office, Jinggangshan University, Ji’an 343009 (China)

2016-10-15

Novel NaAl{sub 11}O{sub 17}:Mn{sup 2+} green phosphor is synthesized by solid-state reaction method in air. The emission band peaking at ~508 nm is observed owing to the {sup 4}T{sub 1}→{sup 6}A{sub 1}({sup 6}S) transition of Mn{sup 2+} ion, and the chromaticity coordinates are (0.0725, 0.6468). The excitation band peaking at ~360, 382, 424, 450, and 490 nm are attributed to {sup 6}A{sub 1}({sup 6}S)→{sup 4}E({sup 4}D), {sup 4}T{sub 2}({sup 4}D), [{sup 4}A{sub 1}({sup 4}G), {sup 4}E({sup 4}G)], {sup 4}T{sub 2}({sup 4}G), and {sup 4}T{sub 1}({sup 4}G) transitions of Mn{sup 2+} ion, respectively, which indicate that NaAl{sub 11}O{sub 17}:Mn{sup 2+} phosphor may be excited by (near) ultraviolet and blue LED chip. The luminous mechanism is explained by Tanabe–Sugano diagram of Mn{sup 2+} ion. The optimal Mn{sup 2+} doping concentration is ~3.5 mol%. The NaAl{sub 11}O{sub 17}:3.5%Mn{sup 2+} phosphor shows high quantum efficiency of ~67.84% with excitation 424 nm. The lifetime decreases from 6.72 to 6.0 ms with increasing Mn{sup 2+} concentration in the range of 0–4 mol%.

Comparative study of AISI M3:2 high speed steel produced through different techniques of manufacturing; Estudo comparativo de acos rapidos AISI M3:2 produzidos por diferentes processos de fabricacao

Energy Technology Data Exchange (ETDEWEB)

Araujo Filho, Oscar Olimpio de

2006-07-01

In this work AISI M3:2 high speed steels obtained through different techniques of manufacturing, submitted to the same heat treatment procedure were evaluated by measuring their mechanical properties of transverse rupture strength and hardness. Sinter 23 obtained by hot isostatic pressing (HIP), VWM3C obtained by the conventional route and a M3:2 high speed steel obtained by cold compaction of water atomized powders and vacuum sintered with and without the addition of a small quantity of carbon were evaluated after the same heat treatment procedure. The vacuum sintered M3:2 high speed steel can be an alternative to the more expensive high speed steel produced by hot isostatic pressing and with similar properties presented by the conventional one. The characterization of the vacuum sintered M3:2 high speed steel was performed by measuring the densities of the green compacts and after the sintering cycle. The sintering produced an acceptable microstructure and densities near to the theoretical. The transverse rupture strength was evaluated by means of three point bending tests and the hardness by means of Rockwell C and Vickers tests. The technique of scanning electronic microscopy (SEM) was used to evaluate the microstructure and to establish a relation with the property of transverse rupture strength. The structure was determined by means of X-ray diffraction (XRD) patterns and the retained austenite was detected to all the conditions of heat treatment. The main contribution of this work is to establish a relation between the microstructure and the mechanical property of transverse rupture strength and to evaluate the AISI M3:2 vacuum sintered high speed steel as an alternative to the similar commercial high speed steels. (author)

Role of the UGT2B17 deletion in exemestane pharmacogenetics.

Science.gov (United States)

Luo, S; Chen, G; Truica, C; Baird, C C; Leitzel, K; Lazarus, P

2018-04-01

Exemestane (EXE) is an aromatase inhibitor used for the prevention and treatment of breast cancer. The major metabolic pathway for EXE is reduction to form the active 17β-dihydro-EXE (17β-DHE) and subsequent glucuronidation to 17β-hydroxy-EXE-17-O-β-D-glucuronide (17β-DHE-Gluc) by UGT2B17. The aim of the present study was to determine the effects of UGT2B17 copy number variation on the levels of urinary and plasma 17β-DHE-Gluc and 17β-DHE in patients taking EXE. Ninety-six post-menopausal Caucasian breast cancer patients with ER+ breast tumors taking 25 mg EXE daily were recruited into this study. UGT2B17 copy number was determined by a real-time PCR copy number variant assay and the levels of EXE, 17β-DHE and 17β-DHE-Gluc were quantified by UPLC/MS in patients' urine and plasma. A 39-fold decrease (P<0.0001) in the levels of creatinine-adjusted urinary 17β-DHE-Gluc was observed among UGT2B17 (*2/*2) subjects vs subjects with the UGT2B17 (*1/*1) genotype. The plasma levels of 17β-DHE-Gluc was decreased 29-fold (P<0.0001) in subjects with the UGT2B17 (*2/*2) genotype vs subjects with UGT2B17 (*1/*1) genotype. The levels of plasma EXE-adjusted 17β-DHE was 28% higher (P=0.04) in subjects with the UGT2B17 (*2/*2) genotype vs subjects with the UGT2B17 (*1/*1) genotype. These data indicate that UGT2B17 is the major enzyme responsible for 17β-DHE-Gluc formation in vivo and that the UGT2B17 copy number variant may play a role in inter-individual variability in 17β-DHE levels in vivo.

The Interfacial Microstructure and Mechanical Properties of Diffusion-Bonded Joints of 316L Stainless Steel and the 4J29 Kovar Alloy Using Nickel as an Interlayer

Directory of Open Access Journals (Sweden)

Tingfeng Song

2016-11-01

Full Text Available 316L stainless steel (Fe–18Cr–11Ni and a Kovar (Fe–29Ni–17Co or 4J29 alloy were diffusion-bonded via vacuum hot-pressing in a temperature range of 850–950 °C with an interval of 50 °C for 120 min and at 900 °C for 180 and 240 min, under a pressure of 34.66 MPa. Interfacial microstructures of diffusion-bonded joints were characterized by optical microscopy (OM, scanning electron microscopy (SEM, X-ray diffraction (XRD, and energy dispersive spectroscopy (EDS. The inter-diffusion of the elements across the diffusion interface was revealed via electron probe microanalysis (EPMA. The mechanical properties of the joints were investigated via micro Vickers hardness and tensile strength. The results show that an Ni interlayer can serve as an effective diffusion barrier for the bonding of 316L stainless steel and the 4J29 Kovar alloy. The composition of the joints was 316L/Ni s.s (Fe–Cr–Ni/remnant Ni/Ni s.s (Fe–Co–Ni/4J29. The highest tensile strength of 504.91 MPa with an elongation of 38.75% was obtained at 900 °C for 240 min. After the width of nickel solid solution (Fe–Co–Ni sufficiently increased, failure located at the 4J29 side and the fracture surface indicated a ductile nature.

The microstructure of a small scale AISI 316 stainless steel pumped sodium loop following operation for 20,000h

International Nuclear Information System (INIS)

Charnock, W.; Gwyther, J.; Marshall, P.

1980-08-01

A small pumped loop constructed of AISI 316 stainless steel has been operated for 20,000 hrs. with a peak temperature of 635 0 C. Marked decarburisation was observed in the preheater and in the adjacent specimen chamber. No regions of significant carburisation were found. The decarburisation of the heat input areas appears to be a consequence of the large temperature difference between the hot and cold legs. In addition the steel temperatures in the hot regions are such as to allow relatively high solid state mobility of carbon. The absence of significant carburisation in other parts is attributed to the lower temperatures which leads to a gradual reduction in carbon activity over a sink area which is large in relation to that of the source. Additionally, the mobility of carbon is reduced at the lower temperatures found in the cooler regions of the loop. Tentatively applying the results to a fast reactor circuit suggests the occurrence of decarburisation in the high heat input regions ie the fuel clad, with corresponding but more widely distributed, and hence less significant, carburisation in other regions. (author)

Improved hardness of laser alloyed X12CrNiMo martensitic stainless steel

CSIR Research Space (South Africa)

Adebiyi, DI

2011-07-01

Full Text Available The improvement in hardness of X12CrNiMo martensitic stainless steel laser alloyed with 99.9% pure titanium carbide, stellite 6 and two cases of premixed ratio of titanium carbide and stellite 6 [TiC (30 wt.%)- stellite 6 (70 wt.%) and TiC (70 wt...

MRI features in 17 patients with l2 hydroxyglutaric aciduria

International Nuclear Information System (INIS)

Fourati, Héla; Ellouze, Emna; Ahmadi, Mourad; Chaari, Dhouha; Kamoun, Fatma; Hsairi, Ines; Triki, Chahnez; Mnif, Zeineb

2016-01-01

l-2-Hydroxyglutaric (l-2-HG) aciduria is a rare inherited metabolic disease usually observed in children. Patients present a very slowly progressive deterioration with cerebellar ataxia, mild or severe mental retardation, and various other clinical signs including extrapyramidal and pyramidal symptoms, and seizures Goffette et al. [1]. This leukencephalopathy was first described in 1980 Duran et al. [2]. Brain magnetic resonance imaging (MRI) demonstrates nonspecific subcortical white matter (WM) loss, cerebellar atrophy and changes in dentate nuclei and putamen Steenweg et al. [3]. The diagnosis is highlighted by increased levels of l-2-HG in body fluids such as urine and cerebrospinal fluid. The purpose of this study is to retrospectively describe the brain MRI features in l-2-HG aciduria

Oxidation Behavior of Surface-modified Stainless Steel 316LN in Supercritical-CO{sub 2} Environment

Energy Technology Data Exchange (ETDEWEB)

Kim, Sung Hwan; Heo, Jin Woo; Kim, Hyunm Yung; Jang, Chang Heui [KAIST, Daejeon (Korea, Republic of)

2016-05-15

Compared to other working fluids such as helium or nitrogen, S-CO{sub 2} offers a higher efficiency at operating temperatures of advanced reactors above 550 .deg. C. Moreover, the S-CO{sub 2} cycle is expected to have a significantly smaller footprint compared to other power conversion cycles, resulting in a broader range of applications with lower capital costs. Currently, stainless steel 316 is considered as the candidate structural material for the SFR. In comparison, it is well known that alumina (Al{sub 2}O{sub 3}) have superior oxidation and carburization resistance specifically at higher temperatures where α-Al{sub 2}O{sub 3} may form. Thus, various surface modification techniques have been applied to mostly Ni-base alloys so that a protective and continuous Al-rich oxide layer forms on the surface, conferring superior oxidation and carburization resistance. In this study, SS 316LN was deposited with Al via physical vapor deposition (PVD) method followed by heat treatment processes to develop an Al-rich layer at the surface. The specimens are to be exposed to high temperature S-CO{sub 2} environment to evaluate the oxidation and carburization resistance. Stainless steel 316LN was surface-modified to develop an Al-rich layer for improvement of oxidation behavior in S-CO{sub 2} environment. As the test temperature of 600 .deg. C is not sufficiently high for the formation of protective α-Al{sub 2}O{sub 3} formation, pre-oxidation of surface modified SS 316LN was conducted.

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

Electronic structure and mechanical properties of plasma nitrided ferrous alloys

Energy Technology Data Exchange (ETDEWEB)

Portolan, E. [Centro de Ciencias Exatas e Tecnologia, Universidade de Caxias do Sul, 95070-560 Caxias do Sul-RS (Brazil); Baumvol, I.J.R. [Centro de Ciencias Exatas e Tecnologia, Universidade de Caxias do Sul, 95070-560 Caxias do Sul-RS (Brazil); Instituto de Fisica, Universidade Federal do Rio Grande do Sul, Porto Alegre 91509-970 (Brazil); Figueroa, C.A., E-mail: cafiguer@ucs.br [Centro de Ciencias Exatas e Tecnologia, Universidade de Caxias do Sul, 95070-560 Caxias do Sul-RS (Brazil)

2009-04-15

The electronic structures of the near-surface regions of two different nitrided steels (AISI 316 and 4140) were investigated using X-ray photoelectron spectroscopy. Photoelectron groups from all main chemical elements involved were addressed for steel samples with implanted-N concentrations in the range 16-32 at.%. As the implanted-N concentrations were increased, rather contrasting behaviors were observed for the two kinds of steel. The N1s photoelectrons had spectral shifts toward lower (nitrided AISI 316) or higher (nitrided AISI 4140) binding energies, whereas the Fe2p{sub 3/2} photoelectron spectrum remains at a constant binding energy (nitrided AISI 316) or shifts toward higher binding energies (AISI 4140). These trends are discussed in terms of the metallic nitride formation and the overlapping of atomic orbitals. For nitrided AISI 316, a semi-classical approach of charge transfer between Cr and N is used to explain the experimental facts (formation of CrN), while for nitrided AISI 4140 we propose that the interaction between orbitals 4s from Fe and 2p from N promotes electrons to the conduction band increasing the electrical attraction of the N1s and Fe2p electrons in core shells (formation of FeN{sub x}). The increase in hardness of the steel upon N implantation is attributed to the localization of electrons in specific bonds, which diminishes the metallic bond character.

Electronic structure and mechanical properties of plasma nitrided ferrous alloys

Science.gov (United States)

Portolan, E.; Baumvol, I. J. R.; Figueroa, C. A.

2009-04-01

The electronic structures of the near-surface regions of two different nitrided steels (AISI 316 and 4140) were investigated using X-ray photoelectron spectroscopy. Photoelectron groups from all main chemical elements involved were addressed for steel samples with implanted-N concentrations in the range 16-32 at.%. As the implanted-N concentrations were increased, rather contrasting behaviors were observed for the two kinds of steel. The N1s photoelectrons had spectral shifts toward lower (nitrided AISI 316) or higher (nitrided AISI 4140) binding energies, whereas the Fe2p 3/2 photoelectron spectrum remains at a constant binding energy (nitrided AISI 316) or shifts toward higher binding energies (AISI 4140). These trends are discussed in terms of the metallic nitride formation and the overlapping of atomic orbitals. For nitrided AISI 316, a semi-classical approach of charge transfer between Cr and N is used to explain the experimental facts (formation of CrN), while for nitrided AISI 4140 we propose that the interaction between orbitals 4s from Fe and 2p from N promotes electrons to the conduction band increasing the electrical attraction of the N1s and Fe2p electrons in core shells (formation of FeN x). The increase in hardness of the steel upon N implantation is attributed to the localization of electrons in specific bonds, which diminishes the metallic bond character.

Electronic structure and mechanical properties of plasma nitrided ferrous alloys

International Nuclear Information System (INIS)

Portolan, E.; Baumvol, I.J.R.; Figueroa, C.A.

2009-01-01

The electronic structures of the near-surface regions of two different nitrided steels (AISI 316 and 4140) were investigated using X-ray photoelectron spectroscopy. Photoelectron groups from all main chemical elements involved were addressed for steel samples with implanted-N concentrations in the range 16-32 at.%. As the implanted-N concentrations were increased, rather contrasting behaviors were observed for the two kinds of steel. The N1s photoelectrons had spectral shifts toward lower (nitrided AISI 316) or higher (nitrided AISI 4140) binding energies, whereas the Fe2p 3/2 photoelectron spectrum remains at a constant binding energy (nitrided AISI 316) or shifts toward higher binding energies (AISI 4140). These trends are discussed in terms of the metallic nitride formation and the overlapping of atomic orbitals. For nitrided AISI 316, a semi-classical approach of charge transfer between Cr and N is used to explain the experimental facts (formation of CrN), while for nitrided AISI 4140 we propose that the interaction between orbitals 4s from Fe and 2p from N promotes electrons to the conduction band increasing the electrical attraction of the N1s and Fe2p electrons in core shells (formation of FeN x ). The increase in hardness of the steel upon N implantation is attributed to the localization of electrons in specific bonds, which diminishes the metallic bond character.

Wear and Adhesive Failure of Al2O3 Powder Coating Sprayed onto AISI H13 Tool Steel Substrate

Science.gov (United States)

Amanov, Auezhan; Pyun, Young-Sik

2016-07-01

In this study, an alumina (Al2O3) ceramic powder was sprayed onto an AISI H13 hot-work tool steel substrate that was subjected to sanding and ultrasonic nanocrystalline surface modification (UNSM) treatment processes. The significance of the UNSM technique on the adhesive failure of the Al2O3 coating and on the hardness of the substrate was investigated. The adhesive failure of the coating sprayed onto sanded and UNSM-treated substrates was investigated by a micro-scratch tester at an incremental load. It was found, based on the obtained results, that the coating sprayed onto the UNSM-treated substrate exhibited a better resistance to adhesive failure in comparison with that of the coating sprayed onto the sanded substrate. Dry friction and wear property of the coatings sprayed onto the sanded and UNSM-treated substrates were assessed by means of a ball-on-disk tribometer against an AISI 52100 steel ball. It was demonstrated that the UNSM technique controllably improved the adhesive failure of the Al2O3 coating, where the critical load was improved by about 31%. Thus, it is expected that the application of the UNSM technique to an AISI H13 tool steel substrate prior to coating may delay the adhesive failure and improve the sticking between the coating and the substrate thanks to the modified and hardened surface.

Structure/property (constitutive and dynamic strength/damage characterization of additively manufactured 316L SS

Directory of Open Access Journals (Sweden)

Gray III G.T.

2015-01-01

Full Text Available For additive manufacturing (AM, the certification and qualification paradigm needs to evolve as there exists no “ASTM-type” additive manufacturing certified process or AM-material produced specifications. Accordingly, utilization of AM materials to meet engineering applications requires quantification of the constitutive properties of these evolving materials in comparison to conventionally-manufactured metals and alloys. Cylinders of 316L SS were produced using a LENS MR-7 laser additive manufacturing system from Optomec (Albuquerque, NM equipped with a 1kW Yb-fiber laser. The microstructure of the AM-316L SS is detailed in both the as-built condition and following heat-treatments designed to obtain full recrystallization. The constitutive behavior as a function of strain rate and temperature is presented and compared to that of nominal annealed wrought 316L SS plate. The dynamic damage evolution and failure response of all three materials was probed using flyer-plate impact driven spallation experiments at a peak stress of 4.5 GPa to examine incipient spallation response. The spall strength of AM-produced 316L SS was found to be very similar for the peak shock stress studied to that of annealed wrought or AM-316L SS following recrystallization. The damage evolution as a function of microstructure was characterized using optical metallography.

Characterization of mechanical properties and electrochemical behaviour in a Hank´s solution of 316L/Cr1-xAlxN system

International Nuclear Information System (INIS)

Osorio, D M; Caicedo, J C; Zambrano, G; Aperador, W; Benitez-Castro, A M; Giraldo-Betancur, A L; Muñoz-Saldaña, J; Yañez-Limón, J M; Sanchez, O

2017-01-01

Cr 1-x Al x N hard coatings were successfully deposited by R.F. reactive magnetron co-sputtering in an Ar/N2 gas mixture using chromium and aluminium targets on 316L stainless steel substrates. Crystallographic orientations associated to the Cr 1-x Al x N FCC based in the conjugate complex of CrN and w-AlN phases, with ao=4.18Å lattice parameter for the ternary Cr 1-x Al x N compound were identified by X-Ray diffraction. The thickness and roughness of the deposited coatings are 1.00±0.05nm and 2.65±0.6nm, respectively. The mechanical properties were determined by nanoindentation leading to a hardness of 27.8±2.6GPa and elastic modulus of 346GPa. The corrosion resistance of the coated 316L/Cr 1-x Al x N system under simulated body fluid (SBF, Hank’s solution) was determined via electrochemical impedance spectroscopy. A reduction in the corrosion rate of 99% in relation to uncoated 316L stainless steel substrate was found by Tafel. Thus, these coatings seem to be excellent candidates to be used in biomedical applications. (paper)

Precipitation in AISI 316L(N) during creep tests at 550 and 600 °C up to 10 years

Science.gov (United States)

Padilha, A. F.; Escriba, D. M.; Materna-Morris, E.; Rieth, M.; Klimenkov, M.

2007-05-01

The precipitation behaviour in the gauge lengths and in the heads of initially solution annealed type 316L(N) austenitic stainless steel specimens tested in creep at 550 and 600 °C for periods of up to 85 000 h has been studied using several metallographic techniques. Three phases were detected: M 23C 6, Laves, and sigma phase. The volume fraction of the precipitated sigma phase was significantly higher than that of carbides and the Laves phase. M 23C 6 carbide precipitation occurred very rapidly and was followed by the sigma and Laves phases formation in the delta ferrite islands. Sigma and Laves phases precipitated at grain boundaries after longer times. Two different mechanisms of sigma phase precipitation have been proposed, one for delta ferrite decomposition and another for grain boundary precipitation. Small quantities of the Laves phase were detected in delta ferrite, at grain boundaries and inside the grains.

Magnetic excitations in Ho2Co17 and Ho2Fe17

International Nuclear Information System (INIS)

Clausen, K.N.

1981-01-01

The low energy part ( 2 Co 17 and Ho 2 Fe 17 have been measured along the three high symmetry directions at a temperature of 4.2 K, using the inelastic neutron scattering technique. The resulting magnon dispersion relations have been interpreted using linear spin wave theory with a Hamiltonian including single ion crystal field anisotropy and isotropic exchange between spatially well localized spins. The R 2 T 17 structure contains two different Ho sites, with the same point symmetry, and from the spin wave results it was concluded that the crystal field anisotropy of the two Ho sites in both Ho 2 Co 17 and Ho 2 Fe 17 were identical. The deduced crystal field parameters for Ho 2 Fe 17 were slightly larger than for Ho 2 Co 17 , and the parameters were of the same order of magnitude as for pure Ho. For Ho 2 Fe 17 the Fe-Fe exchange was found to be anisotropic, and for both compounds the magnetic ordering temperatures of 1178 K for Ho 2 Co 17 and 335 K for Ho 2 Fe 17 were determined by the strong positive 3d-3d exchange. (Auth.)

The passive oxide films growth on 316L stainless steel in borate buffer solution measured by real-time spectroscopic ellipsometry

Energy Technology Data Exchange (ETDEWEB)

Xu, Haisong; Wang, Lu; Sun, Dongbai [National Center for Materials Service Safety (NCMS), University of Science and Technology Beijing, Beijing 100083 (China); Yu, Hongying, E-mail: hyyu@ustb.edu.cn [Institute of Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083 (China)

2015-10-01

Highlights: • The optical properties of passive oxide films on 316L stainless steel were studied. • The thickness of the oxide films (1.5–2.6 nm) increased linearly with the potentials. • The growth of passive film followed high electric field ion conduction model. • Selective solubility of oxide induced compositional change of passive film. - Abstract: Passive film growth on 316L stainless steel was investigated in borate buffer electrolyte (pH = 9.1) by real-time spectroscopic ellipsometry (SE) and the composition was estimated by X-ray photoelectron spectroscopy (XPS). Anodic passivation of 316L SS was carried out in the potential range from 0 V{sub SCE} to 0.9 V{sub SCE}, after potentiostatic polarization for 1800s, the current density decayed from 10{sup −2} A cm{sup −2} to 10{sup −6} A cm{sup −2}. The passive film thickness was simulated from Frenel and Drude reflection equations, the average complex refractive index was assumed to be N = 2.3 − j0.445. The estimated thickness increased linearly with potential from 1.5 nm at 0 V to 2.6 nm at 0.8 V. The growth of passive film followed high electric field ion conduction model. The passive film mainly contained the oxide/hydroxide of iron and chromium. The selective solubility of oxide in passive film explained the change of iron and chromium content at different potentials. Few nickel and molybdenum also contributed to the passive film with a constant content.

Corrosion kinetics of 316L stainless steel bipolar plate with chromiumcarbide coating in simulated PEMFC cathodic environment

Directory of Open Access Journals (Sweden)

N.B. Huang

Full Text Available Stainless steel with chromium carbide coating is an ideal candidate for bipolar plates. However, the coating still cannot resist the corrosion of a proton exchange membrane fuel cell (PEMFC environment. In this work, the corrosion kinetics of 316L stainless steel with chromium carbide is investigated in simulated PEMFC cathodic environment by combining electrochemical tests with morphology and microstructure analysis. SEM results reveal that the steel’s surface is completely coated by Cr and chromium carbide but there are pinholes in the coating. After the coated 316L stainless steel is polarized, the diffraction peak of Fe oxide is found. EIS results indicate that the capacitive resistance and the reaction resistance first slowly decrease (2–32 h and then increase. The potentiostatic transient curve declines sharply within 2000 s and then decreases slightly. The pinholes, which exist in the coating, result in pitting corrosion. The corrosion kinetics of the coated 316L stainless steel are modeled and accords the following equation: i0 = 7.6341t−0.5, with the corrosion rate controlled by ion migration in the pinholes. Keywords: PEMFC, Metal bipolar plate, Chromium carbide coating, Corrosion kinetics, Pitting corrosion

Microstructure and local texture evolution by plasma nitriding in a 316L austenitic stainless steel and consequences on its fatigue durability

International Nuclear Information System (INIS)

Stinville, Jean-Charles

2010-01-01

The present study concerns the surface and mechanical properties induced by specific low temperature (∼400 C) plasma nitriding of an AISI 316L austenitic stainless steel largely used for structural component in nuclear and chemical industries. It focuses especially on its influence on the fatigue durability. The great advantages of this plasma nitriding process are to produce thick nitrided layers with a high concentration of nitrogen atoms in solid solution into the material and to preserve the stainless character of the substrate. As a consequence a new phase named expanded austenite or γ N phase is formed and the lattice expansion associated with the high supersaturation of interstitial nitrogen atoms results in residual compressive stresses at the surface that exceed 2 GPa. The surface is then strongly modified as a result of complex effects including some crystallographic plane rotation, plasticity and damage in some grains depending on their orientation. The considerable increase of hardness and wear resistance produced by plasma nitriding of austenitic stainless steels is now well documented but there are practically no data on the influence on fatigue properties. Series of fatigue tests in air at room temperature carried out in the low cycle fatigue range show a significant improvement of the fatigue life. The results are discussed especially taking into account the compressive residual stresses induced by the nitrided layer. (authors)

A Study on Structural, Corrosion, and Sensitization Behavior of Ultrafine and Coarse Grain 316 Stainless Steel Processed by Multiaxial Forging and Heat Treatment

Science.gov (United States)

Kiahosseini, Seyed Rahim; Mohammadi Baygi, Seyyed Javad; Khalaj, Gholamreza; Khoshakhlagh, Ali; Samadipour, Razieh

2018-01-01

Cubic specimens from AISI 316 stainless steel were multiaxially forged to 15 passes and annealed at 1200 °C for 1, 2, and 3 h and finally sensitized at 700 °C for 24 h. Examination of samples indicated that the hardness of the annealed samples was reduced from 153 to 110, 81, and 74 HV for as-received sample and under 1, 2, and 3 h of annealing, and increased from 245 to 288 HV for samples forged at 3 and 7 passes. However, no significant changes were observed in a large number of passes and at about 300 HV. Degree of sensitization of samples was increased to approximately 27.3% at 3-h annealing but reduced to 1.23% by 15 passes of MF. The potentiodynamic polarization test shows that the breakdown potentials decreased with annealing time from 0.6 to - 102 (mV/SCE) for as-received and 3-h annealed specimen. These potentials increased to approximately - 16.5 mV with the increase in MF passes to 15. These observations indicated that the chromium carbide deposition affects Cr-depleted zone, which can subsequently affect the degree of sensitization and pitting corrosion resistance of AISI 316 austenitic stainless steel.

Recovery in cold-worked alloy under pressure: example of AISI 316 stainless steel

Energy Technology Data Exchange (ETDEWEB)

Yousuf, M; Sahu, P C; Raghunathan, V S; Govinda Rajan, K

1986-06-01

In this paper we report the behaviour of defects under high pressure in severely cold-deformed 316 stainless steel. In situ electrical resistivity measurements indicate a minimum in the reduced resistivity ratio at 2 GPa associated with a characteristic relaxation time of 500 + - 5 sec. Microhardness data on pressure-treated and recovered samples are consistent with the electrical resistivity behaviour. X-ray powder diffraction rings indicate sharpening beyond 2 GPa. The decrease in the full width at half maximum (FWHM) of the strongest ring is about 2% at pressures beyond 2 GPa. Transmission electron microscopy reveals that samples pressure treated beyond 2 GPa have a polygonized dislocation structure. This is in sharp contrast to the tangled dislocation structure observed in the cold-worked samples. The experimental results suggest a recovery stage in cold-worked stainless steel at 2 GPa. We propose that the recovery process is activated through an enhanced vacancy concentration caused by deformation, a pressure-induced vacancy-dislocation interaction and consequently a pressure-assisted dislocation mobility leading to polygonization.

Characterization of laser metal deposited 316L stainless steel

CSIR Research Space (South Africa)

Bayode, A

2016-06-01

Full Text Available investigates the effects of laser power on the structural integrity, microstructure and microhardness of laser deposited 316L stainless steel. The result showed that the laser power has much influence on the evolving microstructure and microhardness...

Common variation at 3q26.2, 6p21.33, 17p11.2 and 22q13.1 influences multiple myeloma risk

Science.gov (United States)

Broderick, Peter; Chen, Bowang; Johnson, David C; Försti, Asta; Vijayakrishnan, Jayaram; Migliorini, Gabriele; Dobbins, Sara E; Holroyd, Amy; Hose, Dirk; Walker, Brian A; Davies, Faith E; Gregory, Walter A; Jackson, Graham H; Irving, Julie A; Pratt, Guy; Fegan, Chris; Fenton, James AL; Neben, Kai; Hoffmann, Per; Nöthen, Markus M; Mühleisen, Thomas W; Eisele, Lewin; Ross, Fiona M; Straka, Christian; Einsele, Hermann; Langer, Christian; Dörner, Elisabeth; Allan, James M; Jauch, Anna; Morgan, Gareth J; Hemminki, Kari; Houlston, Richard S; Goldschmidt, Hartmut

2016-01-01

To identify variants for multiple myeloma risk, we conducted a genome-wide association study with validation in additional series totaling 4,692 cases and 10,990 controls. We identified four risk loci at 3q26.2 (rs10936599, P=8.70x10-14), 6p21.33 (rs2285803, PSORS1C2; P= 9.67x10-11), 17p11.2 (rs4273077, TNFRSF13B; P=7.67x10-9) and 22q13.1 (rs877529, CBX7; P=7.63x10-16). These data provide further evidence for genetic susceptibility to this B-cell hematological malignancy and insight into the biological basis of predisposition. PMID:23955597

Curie temperature rising by fluorination for Sm2Fe17

Directory of Open Access Journals (Sweden)

Matahiro Komuro

2013-02-01

Full Text Available Fluorine atoms can be introduced to Sm2Fe17 using XeF2 below 423 K. The resulting fluorinated Sm2Fe17 powders have ferromagnetic phases containing Sm2Fe17FY1(01<1, Sm2Fe17FY2 (12<4, Sm2Fe17, and α-Fe. The unit cell for Sm2Fe17 is elongated by the fluorination. The largest unit cell volume among the rhombohedral Sm2Fe17 compounds is 83.8 nm3, which is 5.8% larger than Sm2Fe17. The rhombohedral Sm2Fe17 with the largest unit cell volume is dissociated above 873 K, and fluorination increases Curie temperature from 403 K for Sm2Fe17 to 675 K. This increase can be explained by the magneto-volume effect.

Stress corrosion cracking behavior of annealed and cold worked 316L stainless steel in supercritical water

Energy Technology Data Exchange (ETDEWEB)

Sáez-Maderuelo, A., E-mail: alberto.saez@ciemat.es; Gómez-Briceño, D.

2016-10-15

Highlights: • The alloy 316L is susceptible to stress corrosion cracking in supercritical water. • The susceptibility of alloy 316L increases with temperature and plastic deformation. • Dynamic strain ageing processes may be active in the material. - Abstract: The supercritical water reactor (SCWR) is one of the more promising designs considered by the Generation IV International Forum due to its high thermal efficiency and improving security. To build this reactor, standardized structural materials used in light water reactors (LWR), like austenitic stainless steels, have been proposed. These kind of materials have shown an optimum behavior to stress corrosion cracking (SCC) under LWR conditions except when they are cold worked. It is known that physicochemical properties of water change sharply with pressure and temperature inside of the supercritical region. Owing to this situation, there are several doubts about the behavior of candidate materials like austenitic stainless steel 316L to SCC in the SCWR conditions. In this work, alloy 316L was studied in deaerated SCW at two different temperatures (400 °C and 500 °C) and at 25 MPa in order to determine how changes in this variable influence the resistance of this material to SCC. The influence of plastic deformation in the behavior of alloy 316L to SCC in SCW was also studied at both temperatures. Results obtained from these tests have shown that alloy 316L is susceptible to SCC in supercritical water reactor conditions where the susceptibility of this alloy increases with temperature. Moreover, prior plastic deformation of 316L SS increased its susceptibility to environmental cracking in SCW.

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

Energy Technology Data Exchange (ETDEWEB)

Hartwig, A.; Decker, M.; Klein, O.; Karl, H., E-mail: helmut.karl@physik.uni-augsburg.de

2015-12-15

The aim of this study is to evaluate the applicability of highly chemically inert titanium dioxide synthesized by ion beam implantation for corrosion protection of AISI 304 stainless steel in sodium chloride solution. More specifically, the prevention of galvanic corrosion between carbon-fiber reinforced plastic (CFRP) and AISI 304 was investigated. Corrosion performance of TiO{sub 2} implanted AISI 304 – examined for different implantation and annealing parameters – is strongly influenced by implantation fluence. Experimental results show that a fluence of 5 × 10{sup 16} cm{sup −2} (Ti{sup +}) and 1 × 10{sup 17} cm{sup −2} (O{sup +}) is sufficient to prevent pitting corrosion significantly, while galvanic corrosion with CFRP can already be noticeably reduced by an implantation fluence of 5 × 10{sup 15} cm{sup −2} (Ti{sup +}) and 1 × 10{sup 16} cm{sup −2} (O{sup +}). Surface roughness, implantation energy and annealing at 200 °C and 400 °C show only little influence on the corrosion behavior. TEM analysis indicates the existence of stoichiometric TiO{sub 2} inside the steel matrix for medium fluences and the formation of a separated metal oxide layer for high fluences.

Non-equilibrium grain boundary segregation of boron in austenitic stainless steel - IV. Precipitation behaviour and distribution of elements at grain boundaries

International Nuclear Information System (INIS)

Karlsson, L.; Norden, H.

1988-01-01

The distribution of elements and the precipitation behaviour at grain boundaries have been studied in boron containing AISI 316L and ''Mo-free AISI 316L'' type austenitic stainless steels. A combination of microanalytical techniques was used to study the boundary regions after cooling at 0.29-530 0 C/s from 800, 1075 or 1250 0 C. Tetragonal M/sub 2/B, M/sub 5/B/sub 3/ and M/sub 3/B/sub 2/, all rich in Fe, Cr and Mo, precipitated in the ''high B'' (40 ppm) AISI 316L steel whereas orthorhombic M/sub 2/B, rich in Cr and Fe was found in the ''Mo-free steel'' with 23 ppm B. In the ''high B steel'' a thin (<2nm), continuous layer, containing B, Cr, Mo and Fe and having a stoichiometry of typically M/sub 9/B, formed at boundaries after cooling at intermediate cooling rates. For both types of steels a boundary zone was found, after all heat treatments, with a composition differing significantly from the bulk composition. The differences were most marked after cooling at intermediate cooling rates. In both types of steel boundary depletion of Cr and enrichment of B and C occurred. It was found that non-equilibrium grain boundary segregation of boron can affect the precipitation behaviour by making the boundary composition enter a new phase field ''Non-equilibrium phases'' might also form. The synergistic effect of B and Mo on the boundary composition and precipitation behaviour, and the observed indications of C non-equilibrium segregation are discussed

Experimental and Simulation Analysis of Hot Isostatic Pressing of Gas Atomized Stainless Steel 316L Powder Compacts

International Nuclear Information System (INIS)

Lin, Dongguo; Park, Seong Jin; Ha, Sangyul; Shin, Youngho; Park, Dong Yong; Chung, Sung Taek; Bollina, Ravi; See, Seongkyu

2016-01-01

In this work, both experimental and numerical studies were conducted to investigate the densification behavior of stainless steel 316L (STS 316L) powders during hot isostatic pressing (HIP), and to characterize the mechanical properties of HIPed specimens. The HIP experiments were conducted with gas atomized STS 316L powders with spherical particle shapes under controlled pressure and temperature conditions. The mechanical properties of HIPed samples were determined based on a series of tensile tests, and the results were compared to a reference STS 316L sample prepared by the conventional process, i.e., extrusion and annealing process. Corresponding microstructures before and after tensile tests were observed using scanning electron microscopy and their relationships to the mechanical properties were addressed. Furthermore, a finite element simulation based on the power-law creep model was carried out to predict the density distribution and overall shape change of the STS316L powder compact during HIP process, which agreed well with the experimental results.

Experimental and Simulation Analysis of Hot Isostatic Pressing of Gas Atomized Stainless Steel 316L Powder Compacts

Energy Technology Data Exchange (ETDEWEB)

Lin, Dongguo; Park, Seong Jin [Pohang University of Science and Technology, Pohang (Korea, Republic of); Ha, Sangyul [Samsung Electro-Mechanics, Suwon (Korea, Republic of); Shin, Youngho [Doosan Heavy Industries and Construction Co., Ltd., Changwon (Korea, Republic of); Park, Dong Yong [Korea Institute of Energy Research, Daejeon (Korea, Republic of); Chung, Sung Taek [CetaTech Inc., Sacheon (Korea, Republic of); Bollina, Ravi [Bahadurpally Jeedimetla, Hyderabad (India); See, Seongkyu [POSCO, Pohang (Korea, Republic of)

2016-10-15

In this work, both experimental and numerical studies were conducted to investigate the densification behavior of stainless steel 316L (STS 316L) powders during hot isostatic pressing (HIP), and to characterize the mechanical properties of HIPed specimens. The HIP experiments were conducted with gas atomized STS 316L powders with spherical particle shapes under controlled pressure and temperature conditions. The mechanical properties of HIPed samples were determined based on a series of tensile tests, and the results were compared to a reference STS 316L sample prepared by the conventional process, i.e., extrusion and annealing process. Corresponding microstructures before and after tensile tests were observed using scanning electron microscopy and their relationships to the mechanical properties were addressed. Furthermore, a finite element simulation based on the power-law creep model was carried out to predict the density distribution and overall shape change of the STS316L powder compact during HIP process, which agreed well with the experimental results.

Microstructure of Au-ion irradiated 316L and FeNiCr austenitic stainless steels

Energy Technology Data Exchange (ETDEWEB)

Jublot-Leclerc, S., E-mail: stephanie.jublot-leclerc@csnsm.in2p3.fr [CSNSM, Univ Paris-Sud, CNRS, Université Paris Saclay, 91405 Orsay (France); Li, X. [CSNSM, Univ Paris-Sud, CNRS, Université Paris Saclay, 91405 Orsay (France); Legras, L.; Lescoat, M.-L. [EDF R& D, Groupe Métallurgie, Les Renardières, 77818 Moret sur Loing (France); Fortuna, F.; Gentils, A. [CSNSM, Univ Paris-Sud, CNRS, Université Paris Saclay, 91405 Orsay (France)

2016-11-15

Thin foils of 316L were irradiated in situ in a Transmission Electron Microscope with 4 MeV Au ions at 450 °C and 550 °C. Similar irradiations were performed at 450 °C in FeNiCr. The void and dislocation microstructure of 316L is found to depend strongly on temperature. At 450 °C, a dense network of dislocation lines is observed in situ to grow from black dot defects by absorption of other black dots and interstitial clusters whilst no Frank loops are detected. At 550 °C, no such network is observed but large Frank loops and perfect loops whose sudden appearance is concomitant with a strong increase in void density as a result of a strong coupling between voids and dislocations. Moreover, differences in both alloys microstructure show the major role played by the minor constituents of 316L, increasing the stacking fault formation energy, and possibly leading to significant differences in swelling behaviour. - Highlights: • 316L and FeNiCr were ion irradiated in situ in a TEM at elevated temperature. • The minor constituents of 316L play a major role in the resulting microstructure. • A dense network of dislocations develops in both alloys from black dot defects. • The nucleation and growth of voids and dislocations are strongly correlated. • The Frank loop mean size saturates at similar dpa values as in neutron irradiation.

Onco-miR-24 regulates cell growth and apoptosis by targeting BCL2L11 in gastric cancer

Directory of Open Access Journals (Sweden)

Haiyang Zhang

2016-01-01

Full Text Available ABSTRACT Gastric cancer is one of the most common malignancies worldwide; however, the molecular mechanism in tumorigenesis still needs exploration. BCL2L11 belongs to the BCL-2 family, and acts as a central regulator of the intrinsic apoptotic cascade and mediates cell apoptosis. Although miRNAs have been reported to be involved in each stage of cancer development, the role of miR-24 in GC has not been reported yet. In the present study, miR-24 was found to be up-regulated while the expression of BCL2L11 was inhibited in tumor tissues of GC. Studies from both in vitro and in vivo shown that miR-24 regulates BCL2L11 expression by directly binding with 3′UTR of mRNA, thus promoting cell growth, migration while inhibiting cell apoptosis. Therefore, miR-24 is a novel onco-miRNA that can be potential drug targets for future clinical use.

Attenuation of the in vitro neurotoxicity of 316L SS by graphene oxide surface coating

International Nuclear Information System (INIS)

Tasnim, Nishat; Kumar, Alok; Joddar, Binata

2017-01-01

A persistent theme in biomaterials research comprises of surface engineering and modification of bare metallic substrates for improved cellular response and biocompatibility. Graphene Oxide (GO), a derivative of graphene, has outstanding chemical and mechanical properties; its large surface to volume ratio, ease of surface modification and processing make GO an attractive coating material. GO-coatings have been extensively studied as biosensors. Further owing to its surface nano-architecture, GO-coated surfaces promote cell adhesion and growth, making it suitable for tissue engineering applications. The need to improve the long-term durability and therapeutic effectiveness of commercially available bare 316L stainless steel (SS) surfaces led us to adopt a polymer-free approach which is cost-effective and scalable. GO was immobilized on to 316L SS utilizing amide linkage, to generate a strongly adherent uniform coating with surface roughness. GO-coated 316L SS surfaces showed increased hydrophilicity and biocompatibility with SHSY-5Y neuronal cells, which proliferated well and showed decreased reactive oxygen species (ROS) expression. In contrast, cells did not adhere to bare uncoated 316L SS meshes nor maintain viability when cultured in the vicinity of bare meshes. Therefore the combination of the improved surface properties and biocompatibility implies that GO-coating can be utilized to overcome pertinent limitations of bare metallic 316L SS implant surfaces, especially SS neural electrodes. Also, the procedure for making GO-based protective coatings can be applied to numerous other implants where the development of such protective films is necessary. - Highlights: • GO was immobilized on to 316L SS utilizing carbodiimide chemistry to generate a strong adherent uniform nano coating. • GO-modified surfaces showed increased hydrophilicity and biocompatibility with SH5YSY cells cultured atop these surfaces. • Proliferation and alignment of the cells with the

Attenuation of the in vitro neurotoxicity of 316L SS by graphene oxide surface coating

Energy Technology Data Exchange (ETDEWEB)

Tasnim, Nishat; Kumar, Alok; Joddar, Binata, E-mail: bjoddar@utep.edu

2017-04-01

A persistent theme in biomaterials research comprises of surface engineering and modification of bare metallic substrates for improved cellular response and biocompatibility. Graphene Oxide (GO), a derivative of graphene, has outstanding chemical and mechanical properties; its large surface to volume ratio, ease of surface modification and processing make GO an attractive coating material. GO-coatings have been extensively studied as biosensors. Further owing to its surface nano-architecture, GO-coated surfaces promote cell adhesion and growth, making it suitable for tissue engineering applications. The need to improve the long-term durability and therapeutic effectiveness of commercially available bare 316L stainless steel (SS) surfaces led us to adopt a polymer-free approach which is cost-effective and scalable. GO was immobilized on to 316L SS utilizing amide linkage, to generate a strongly adherent uniform coating with surface roughness. GO-coated 316L SS surfaces showed increased hydrophilicity and biocompatibility with SHSY-5Y neuronal cells, which proliferated well and showed decreased reactive oxygen species (ROS) expression. In contrast, cells did not adhere to bare uncoated 316L SS meshes nor maintain viability when cultured in the vicinity of bare meshes. Therefore the combination of the improved surface properties and biocompatibility implies that GO-coating can be utilized to overcome pertinent limitations of bare metallic 316L SS implant surfaces, especially SS neural electrodes. Also, the procedure for making GO-based protective coatings can be applied to numerous other implants where the development of such protective films is necessary. - Highlights: • GO was immobilized on to 316L SS utilizing carbodiimide chemistry to generate a strong adherent uniform nano coating. • GO-modified surfaces showed increased hydrophilicity and biocompatibility with SH5YSY cells cultured atop these surfaces. • Proliferation and alignment of the cells with the

Tensile Stress-Strain Results for 304L and 316L Stainless-Steel Plate at Temperature

International Nuclear Information System (INIS)

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

2007-01-01

The Idaho National Laboratory (INL) is conducting moderate strain rate (10 to 200 per second) research on stainless steel materials in support of the Department of Energy's (DOE) National Spent Nuclear Fuel Program (NSNFP). For this research, strain rate effects are characterized by comparison to quasi-static tensile test results. Considerable tensile testing has been conducted resulting in the generation of a large amount of basic material data expressed as engineering and true stress-strain curves. The purpose of this paper is to present the results of quasi-static tensile testing of 304/304L and 316/316L stainless steels in order to add to the existing data pool for these materials and make the data more readily available to other researchers, engineers, and interested parties. Standard tensile testing of round specimens in accordance with ASTM procedure A 370-03a were conducted on 304L and 316L stainless-steel plate materials at temperatures ranging from -20 F to 600 F. Two plate thicknesses, eight material heats, and both base and weld metal were tested. Material yield strength, Young's modulus, ultimate strength, ultimate strain, failure strength and failure strain were determined, engineering and true stress-strain curves to failure were developed, and comparisons to ASME Code minimums were made. The procedures used during testing and the typical results obtained are described in this paper

Martensitic transformation in 304L and 316L types stainless steels cathodically hydrogen charged

International Nuclear Information System (INIS)

Minkovitz, E.; Eliezer, D.

1984-01-01

This paper reports a TEM study on the role of phase transitions at the crack tip in 304L and 316L types stainless steels cathodically hydrogen charged in the absence of any eternally applied forces. The possible role of α prime and epsilon martensite phases in the fracture mechanism is discussed

Production of stable superhydrophilic surfaces on 316L steel by simultaneous laser texturing and SiO2 deposition

Science.gov (United States)

Rajab, Fatema H.; Liu, Zhu; Li, Lin

2018-01-01

Superhydrophilic surfaces with liquid contact angles of less than 5 ° have attracted much interest in practical applications including self-cleaning, cell manipulation, adhesion enhancement, anti-fogging, fluid flow control and evaporative cooling. Standard laser metal texturing method often result in unstable wetting characteristics, i.e. changing from super hydrophilic to hydrophobic in a few days or weeks. In this paper, a simple one step method is reported for fabricating a stable superhydrophilic metallic surface that lasted for at least 6 months. Here, 316L stainless steel substrates were textured using a nanosecond laser with in-situ SiO2 deposition. Morphology and chemistry of laser-textured surfaces were characterised using SEM, XRD, XPS and an optical 3D profiler. Static wettability analysis was carried out over a period of 6 months after the laser treatment. The effect of surface roughness on wettability was also studied. Results showed that the wettability of the textured surfaces could be controlled by changing the scanning speed of laser beam and number of passes. The main reason for the realisation of the stable superhydrophilic surface is the combination of the melted glass particles mainly Si and O with that of stainless steel in the micro-textured patterns. This study presents a useful method

5,11,17,23-Tetra-tert-butyl-25,26,27,28-tetrapropynyloxy-2,8,14,20-tetrathiacalix[4]arene

Directory of Open Access Journals (Sweden)

Xiang-Gao Meng

2009-12-01

Full Text Available The title compound [systematic name: 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetrapropynyloxy-2,8,14,20-tetrathiacalix[4]arene], C52H56O4S4, is an alkylated product bearing four propyne groups at the lower rim of a 5,11,17,23-tetra-tert-butyl-tetrathiacalix[4]arene. The molecule is located on a crystallographic twofold rotation axis, running through two S atoms and perpendicular to the long axis of the molecule. The four propyne groups, located in an alternate fashion above and below the mean plane of the four S atoms, are almost parallel to the calixarene long axis. The dihedral angle between the two crystallographically independent benzene rings is 86.77 (14°. Two tert-butyl groups are disordered over two positions with site occupancies of 0.59 (2 and 0.41 (2.

Sintering and Microstructures of SUS 316L Powder Produced by 3D Printing Process

Directory of Open Access Journals (Sweden)

Kim W.J.

2017-06-01

Full Text Available Selective laser sintering (SLS is a type of laminating sintering technique, using CO2 laser with (metal, polymer, and ceramic powders. In this result, the flake SUS 316L was used to achieve a high porous product, and compare to spherical type. After SLS, the porosity of flake-type sample with 34% was quite higher than that of the spherical-type one that had only 11%. The surface roughness of the flake SLS sample were also investigated in both inner and surface parts. The results show that the deviation of the roughness of the surface part is about 64.40μm, while that of the internal one was about 117.65μm, which presents the containing of high porosity in the uneven surfaces. With the process using spherical powder, the sample was quite dense, however, some initial particles still remained as a result of less energy received at the beneath of the processing layer.

Weldability of dissimilar joint between F82H and SUS316L under fiber laser welding

Energy Technology Data Exchange (ETDEWEB)

Serizawa, Hisashi [Joining and Welding Research Institute, Osaka University, 11-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan); Mori, Daiki; Shirai, Yuma; Ogiwara, Hiroyuki; Mori, Hiroaki [Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan)

2013-10-15

Highlights: • The microstructure of F82H/SUS316L dissimilar joint can be divided into four regions. • In the case without beam position shift, hardness of WM cannot be reduced by PWHT. • The fiber laser welding would be applicable for constructing the dissimilar joint. -- Abstract: As one of the high beam quality heat sources, 4 kW fiber laser was applied for joining between reduced activation ferritic/martensitic steel, F82H and SUS316L austenitic stainless steel, and the microstructural analyses and Vickers hardness measurements were carried out before and after post-weld heat treatment (PWHT). The microstructure of joint can be divided into four regions which are base metal of F82H, heat affected zone (HAZ) in F82H, weld metal (WM) and base metal of SUS316L. Also, it is revealed that the high-power fiber laser can be employed for constructing butt joint between F82H and SUS316L by applying PWHT and shifting the laser beam position to SUS316L, where the distance between the contact face and beam should be set as a range from radius to diameter of laser beam.

Weldability of dissimilar joint between F82H and SUS316L under fiber laser welding

International Nuclear Information System (INIS)

Serizawa, Hisashi; Mori, Daiki; Shirai, Yuma; Ogiwara, Hiroyuki; Mori, Hiroaki

2013-01-01

Highlights: • The microstructure of F82H/SUS316L dissimilar joint can be divided into four regions. • In the case without beam position shift, hardness of WM cannot be reduced by PWHT. • The fiber laser welding would be applicable for constructing the dissimilar joint. -- Abstract: As one of the high beam quality heat sources, 4 kW fiber laser was applied for joining between reduced activation ferritic/martensitic steel, F82H and SUS316L austenitic stainless steel, and the microstructural analyses and Vickers hardness measurements were carried out before and after post-weld heat treatment (PWHT). The microstructure of joint can be divided into four regions which are base metal of F82H, heat affected zone (HAZ) in F82H, weld metal (WM) and base metal of SUS316L. Also, it is revealed that the high-power fiber laser can be employed for constructing butt joint between F82H and SUS316L by applying PWHT and shifting the laser beam position to SUS316L, where the distance between the contact face and beam should be set as a range from radius to diameter of laser beam

High temperature oxidation behavior of austenitic stainless steel AISI 304 in steam of nanofluids contain nanoparticle ZrO2

International Nuclear Information System (INIS)

Prajitno, Djoko Hadi; Syarif, Dani Gustaman

2014-01-01

The objective of this study is to evaluate high temperature oxidation behavior of austenitic stainless steel SS 304 in steam of nanofluids contain nanoparticle ZrO 2 . The oxidation was performed at high temperatures ranging from 600 to 800°C. The oxidation time was 60 minutes. After oxidation the surface of the samples was analyzed by different methods including, optical microscope, scanning electron microscope (SEM) and X-ray diffraction (XRD). X-ray diffraction examination show that the oxide scale formed during oxidation of stainless steel AISI 304 alloys is dominated by iron oxide, Fe 2 O 3 . Minor element such as Cr 2 O 3 is also appeared in the diffraction pattern. Characterization by optical microscope showed that cross section microstructure of stainless steel changed after oxidized with the oxide scale on the surface stainless steels. SEM and x-ray diffraction examination show that the oxide of ZrO 2 appeared on the surface of stainless steel. Kinetic rate of oxidation of austenite stainless steel AISI 304 showed that increasing oxidation temperature and time will increase oxidation rate

Ion nitriding in 316=L stainless steel

International Nuclear Information System (INIS)

Rojas-Calderon, E.L.

1989-01-01

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

Effects of composition on the in-reactor creep of AISI 316

International Nuclear Information System (INIS)

Bates, J.F.; Gilbert, E.R.

1979-08-01

In-reactor tests designed to provide information on the relationship between compositional variations and irradiation-induced swelling and creep have achieved an exposure of 4.6 x 10 22 n/cm 2 (E > 0.1 MeV) at 450 0 C. Postirradiation diametral measurements of pressurized tube specimens have indicated that irradiation-induced creep of 316 stainless steel can be modified by compositional variations of minor alloying elements. There is a general trend for specimens with higher swelling to exhibit higher creep. Silicon, phosphorus and molybdenum all retard in-reactor creep and inhibit irradiation-induced swelling as well. However, the relationship between creep and swelling is strongly composition dependent. The data suggest that carbon and nitrogen act synergistically the major influence being the nitrogen concentration. The irradiation-induced creep is insensitive to cobalt variations to the fluences investigated

Influence of temperature and grain size on the tensile ductility of AISI 316 stainless steel

International Nuclear Information System (INIS)

Mannan, S.L.; Samuel, K.G.; Rodriguez, P.

1985-01-01

The influence of tmeperature and grain size on the tensile ductility of AISI 316 stainless steel has been examined in the temperature range 300-1223 K for specimens with grain sizes varying from 0.025 to 0.650 mm at a nominal strain rate of 3 X 10 -4 s -1 . The percentage total elongation and reduction in area at fracture show minimum ductility at an intermediate temperature, and the temperature corresponding to this ductility minimum has been found to increase with increase in grain size. The total elongation is found to decrease with increase in grain size at high temperatures where failures are essentially intergranular in nature. At 300 K, both uniform and total elongation increase with increase in grain size and then show a small decrease for a very coarse grain size. The high ductility observed at low temperatures (300 K) is consistent with the observation of characteristic dimples associated with transgranular ductile fracture. The ductility minimum with respect to temperature is associated with the occurrence of intergranular fracture, as evidenced by optical and scanning electron microscopy. The present results support the suggestion that the ductility minimum coincides with the maximum amount of grain boundary sliding; at temperatures beyond the ductility minimum, grain boundary separation by cavitation is retarded by the occurrence of grain boundary migration, as evidenced by the grain boundary cusps. In tests conducted at various strain rates in the range 10 -3 -10 -6 s -1 at 873 K the ductility was found to decrease with decreasing strain rate, emphasizing the increased importance of grain boundary sliding at lower strain rates. (Auth.)

Swelling, mechanical properties, and microstructure of Type 316 stainless steel at fusion reactor damage levels

International Nuclear Information System (INIS)

Horak, J.A.; Bloom, E.E.; Grossbeck, M.L.; Maziasz, P.J.; Stiegler, J.O.; Wiffen, F.W.

1979-01-01

Alloys such as AISI 316 stainless steel exhibit more swelling and larger decreases in ductility when irradiated to produce fusion reactor He and dpa levels than at fast reactor He and dpa levels. For T approx. 0 C to ensure adequate ductility for long-term service

Effect of silicon ion implantation upon the structure and corrosion resistance of the surface layer of stainless steel 316L, Vitalium and titanium alloy Ti6Al14V

International Nuclear Information System (INIS)

Baszkiewicz, J.; Kaminski, M.; Krupa, D.; Kozubowski, J.; Barcz, A.; Gawlik, A.; Jagielski, J.

1995-01-01

Samples of 316L stainless steel, Vitalium and Ti6A14V titanium alloy have been implanted with doses of 1.5, 3, and 4.5 x 10 17 Si + /cm 2 . Transmission electron microscopy shows that during ion implantation amorphous layers are formed. When samples of titanium alloy were implanted with a dose of 0.5 x 10 17 Si + /cm 2 , the implanted layer consisted of a dispersion of fine silicide crystallites instead of being amorphous. The corrosion resistance was analyzed by electrochemical techniques in 0.9% NaCl at the temperature of 37 C. The increase of corrosion resistance has been observed as a result of structural modifications of the surface layer. (author). 7 refs, 4 tabs

Corrosion protection of AISI 1018 steel using Co-doped TiO_2/polypyrrole nanocomposites in 3.5% NaCl solution

International Nuclear Information System (INIS)

Ladan, Magaji; Basirun, Wan Jeffrey; Kazi, Salim Newaz; Rahman, Fariza Abdul

2017-01-01

A polypyrrole nanocomposites (PPy NTCs) have been effectively synthesized in the presence of TiO_2 and Co-doped TiO_2 nanoparticles (NPs) by an in situ chemical oxidative polymerization. Field Emission Scanning Electron Microscopy and Transmission Electron Microscopy revealed a tube shape structure of the PPy. The TEM results confirmed that the nanocomposite size of Co-doped TiO_2/PPy NTCs was smaller than TiO_2/PPy NTCs thereby increasing the interaction between the PPy nanotube and the AISI steel surface. The corrosion performance of the coatings was evaluated by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization measurements in 3.5% NaCl solution. The EIS results show that the log |Z| of AISI 1018 coated with Co-doped TiO_2/PPy NTCs and TiO_2/PPy NTCs reached about 8.2 and 6.0 respectively after 30 days of exposure in 3.5% NaCl solution. This is likely due to the increased surface area of the PPy synthesized in the presence of Co-doped TiO_2 NPs. The EIS results are confirmed by the potentiodynamic polarization and open circuit potential values of the Co-doped TiO_2/PPy which indicated little changes between 1 and 30 days of exposure which confirms the protection ability of this coating. . It is evident that the presence of Co-doped TiO_2 NPs can enhance the resistance against corrosion at the steel/electrolyte interface. - Highlights: • Polymerization of pyrrole monomer in the presence of Co-doped TiO_2 decreases the size of the polypyrrole nanotube (PPy NT). • The corrosion protection increases with the increase in PPy NT dispersion. • The corrosion resistance of steel coated with Co-doped TiO_2/PPy NTCs is considerably higher. • TiO_2/PPy with Co doping reduces the charge transfer across the electrolyte/AISI 1018 steel interface.

Electrochemical impedance spectrometry using Inconel 690, zircaloy 4, 316Ti steel, 17-4-PH, UR52N et URSB8. Simulation in tritiated water. Tome 2

International Nuclear Information System (INIS)

Bellanger, G.

1994-11-01

The redox potential of 3 H 2 O, as well as the corrosion potentials in this medium are found, abnormally, in the trans-passive region. This is completely different from behavior in the chemical industry or in the water in nuclear powers. With such behavior, there will be breakdowns of the protective oxide layers, and in the presence of chloride there will be immediate pitting. Polarization and electrochemical impedance spectrometry curves are presented and discussed. These curves make it possible to ascertain the corrosion domains and to compare the kinetics of different stainless steel alloys. These corrosion kinetics and the corrosion potentials provide a classification of the steels studied here: Inconel 690, zircaloy 4, 316 Ti steel, 17-4-PH, UR52N et URSB8. From the results it can be concluded that URSB8 has the best corrosion resistance. (author). 13 refs., 522 figs., tabs

Screening for strains with 11α-hydroxylase activity for 17α-hydroxy progesterone biotransformation.

Science.gov (United States)

Gao, Qian; Qiao, Yuqian; Shen, Yanbing; Wang, Min; Wang, Xibo; Liu, Yang

2017-08-01

Various corticosteroids are prepared by using 11α,17α-diOH-progesterone (11α,17α-diOH-PROG) as an important intermediate and raw material. Hence, strains that can improve the yields of 11α,17α-diOH-PROG should be screened. Cunninghamella elegans CICC40250 was singled out from five common 11α hydroxylation strains. The reaction parameters of 11α,17α-diOH-PROG production were also investigated. C. elegans CICC40250 could efficiently catalyze the hydroxylation of 17α-hydroxy progesterone (17α-OH-PROG) at C-11α position. This strain could also effectively convert 11α,17α-diOH-PROG at high substrate concentrations (up to 30g/L). After the coenzyme precursor glucose was added, the rate of 11α,17α-diOH-PROG formation reached 84.2%, which was 11.4% higher than that of the control group. Our study established a simple and feasible mechanism to increase 11α,17α-diOH-PROG production levels. This mechanism involves C. elegans CICC40250 that can be efficiently applied to induce the biotransformation of 17α-OH-PROG with a hydroxylation biocatalytic ability. Copyright © 2017. Published by Elsevier Inc.

Characterization of coatings and the low cycle fatigue behaviour of 316L

International Nuclear Information System (INIS)

Groot, P.; Horsten, M.G.; Tjoa, G.L.

1993-03-01

In the framework of the European Fusion Technology Programme ECN participates in a NET task PSM-8 'Coatings and Surface Effects on Stainless Steel 316L'. High emissivity coatings were developed for enhanced heat transfer from graphite tiles to a Stainless Steel First Wall. Four candidate materials, Cr 2 O 3 , Black Cr, Al 2 O 3 /TiO 2 and TiC were tested as candidate high emissivity coatings. These coatings were manufactured by atmospheric and vacuum plasma spraying technique and the Black Chromium coatings were manufactured by a galvanic coating technique. The tests included total emissivity measurements and Low Cycle Fatigue (LCF) experiments. The total emissivity of two TiC coatings at 525 K appeared to be 0.62 and 0.64. The total emissivity of the TiC and 5 wt% TiO 2 /Al 2 O 3 coating was about 0.7. (orig.)

Microestrutura de uma Solda Dissimilar entre o Aço Inoxidável Ferrítico AISI 410S e o Aço Inoxidável Austenítico AISI 304L Soldado pelo Processo FSW

Directory of Open Access Journals (Sweden)

Tathiane Caminha Andrade

2015-12-01

Full Text Available Resumo O presente trabalho visa investigar a microestrutura formada na soldagem dissimilar entre chapas de aços inoxidáveis ferríticos AISI 410S e aços inoxidáveis austeníticos AISI 304L pelo processo friction stir welding. A soldagem foi realizada com o ajuste dos seguintes parâmetros: rotação 450 rpm; velocidade de soldagem de 1,0 mm/s; e força axial 40 kN. O aço AISI 410S foi posicionado no lado de avanço enquanto que o aço AISI 304L foi posicionado no lado de retrocesso. A análise consistiu de preparação metalográfica e caracterização microestrutural por microscopia ótica e microscopia eletrônica de varredura. Para o aço AISI 410S foi observada a formação de martensita associada com ferrita na zona de mistura (ZM, zona termomecanicamente afetada (ZTMA e na zona afetada pelo calor (ZAC. As características do processo de soldagem FSW resultaram num refino de grão para o aço inoxidável ferrítico, posicionado no lado de avanço, tanto na ZM quanto nas ZTMA e ZAC. O mesmo comportamento não foi observado para o lado austenítico.

Research of a fracture criterion for ductile metals. Application to austenitic stainless steels

International Nuclear Information System (INIS)

Chavaillard, J.P.

1984-01-01

Elasto-plastic Fracture Mechanics has been used when plasticity spreads over the ligament or the whole specimen. Then, the theoretic basis of the J-Integral breaks down; the value obtained with the J-Integral's definitions is a still usable parameter. The Crack - Opening - Displacement, COD, also is still a measure of the singularity's severity in the crack-tip surrounding (whom description is not necessary). These observations stem from many experiments conducted on traction specimens, with central or lateral cracks, and shape factor ranging from 0.2 to 0.8, width 40 or 80mm, thickness 10mm; extracted from the transverse direction of Z1 NCDU 25 20 and Z2 CND 17 13 (AISI 316 L) steel plates. The experiment did not fulfil ASTM's size requirement. Critical values of J and COD obtained here (in plane stress), from interrumpted tests or not, are practically independent of shape factor and geometry. They are very similar to the published values (AISI 316 L, 304). The net section stress in the ligament, in tension, is not a fracture parameter because it depends on width. The integral definition of J has been computed by a finite difference program analysing deformed grids in surface. These values are practically path independent here, they are in good agreement with those obtained by the compliance method [fr

Comparison among creep rupture strength extrapolation methods with application to data for AISI 316 SS from Italy, France, U.K. and F.R.G

International Nuclear Information System (INIS)

Brunori, G.; Cappellato, S.; Vacchiano, S.; Guglielmi, F.

1982-01-01

Inside Activity 3 ''Materials'' of WGCS, the member states UK and FRG have developed a work regarding extrapolation methods for creep data. This work has been done by comparising extrapolation methods in use in their countries by applying them to creep rupture strength data on AISI 316 SS obtained in UK and FRG. This work has been issued on April 1978 and the Community has dealed it to all Activity 3 Members. Italy, in the figure of NIRA S.p.A., has received, from the European Community a contract to extend the work to Italian and French data, using extrapolation methods currently in use in Italy. The work should deal with the following points: - Collect of Italian experimental data; - Chemical analysis on Italian Specimen; - Comparison among Italian experimental data with French, FRG and UK data; - Description of extrapolation methods in use in Italy; - Application of these extrapolation methods to Italian, French, British and Germany data; - Extensions of a Final Report

Effect of heat treatment on mechanical properties and microstructure of selective laser melting 316L stainless steel

Science.gov (United States)

Kamariah, M. S. I. N.; Harun, W. S. W.; Khalil, N. Z.; Ahmad, F.; Ismail, M. H.; Sharif, S.

2017-10-01

Selective Laser Melting (SLM) has been one of the preferred Additive Manufacturing process to fabricate parts due to its merits in terms of design freedom, lower material waste and faster production when compare to the conventional manufacturing processes. However, due to the thermal gradient experienced during the process, the parts are exposed to the residual stress that leads to parts distortion. This work presents the effect of heat treatments on the micro-hardness of 316L stainless steel parts. In current study, SLM has been employed to fabricate 316L stainless steel compacts. Different heat treatments of 650°C, 950°C, and 1100°C for 2 hours were applied on the compacts. Hardness test were performed on the as-built and heat-treated compacts. The relationship between the microstructures and micro-hardness were discussed in this paper. The results revealed that the micro-hardness of the as-built compacts is between 209.0 and 212.2 HV, which is much higher than the heattreated compacts.