WorldWideScience

Sample records for type 310s stainless

  1. The oxidation of Type 310S stainless steel in mixed gases at elevated temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, J.S. [Clemson Univ., SC (United States). Dept. of Mechanical Engineering; Cavin, O.B.; DeVan, J.H. [Oak Ridge National Lab., TN (United States)

    1992-04-01

    Sheet specimens of Type 310S stainless steel were exposed to air as well as to ``lean`` and ``rich`` sulfidizing atmospheres at temperatures near 900{degrees}C to determine the relationships that exist between the scale structure, the rate of reaction, and the stresses generated during exposure. One goal of this experimental research program was to examine how these factors might be related to the breakdown of protective scales in sulfidizing atmospheres. It was found that the scales formed in air and the ``lean`` atmosphere are protective and non-spalling while those formed in the ``rich`` atmosphere spall, initially react at rates 1000 times greater than counterparts in less aggressive atmospheres, and later exhibit a ``breakaway``-type rapid reaction. Only those scales formed in air provide the cooperative, tractive interfacial forces required to produce uniform dilatation and deformation of the substrate. However, evidence exists for at least localized stresses in all of the scales examined.

  2. The oxidation of Type 310S stainless steel in mixed gases at elevated temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, J.S. (Clemson Univ., SC (United States). Dept. of Mechanical Engineering); Cavin, O.B.; DeVan, J.H. (Oak Ridge National Lab., TN (United States))

    1992-04-01

    Sheet specimens of Type 310S stainless steel were exposed to air as well as to lean'' and rich'' sulfidizing atmospheres at temperatures near 900{degrees}C to determine the relationships that exist between the scale structure, the rate of reaction, and the stresses generated during exposure. One goal of this experimental research program was to examine how these factors might be related to the breakdown of protective scales in sulfidizing atmospheres. It was found that the scales formed in air and the lean'' atmosphere are protective and non-spalling while those formed in the rich'' atmosphere spall, initially react at rates 1000 times greater than counterparts in less aggressive atmospheres, and later exhibit a breakaway''-type rapid reaction. Only those scales formed in air provide the cooperative, tractive interfacial forces required to produce uniform dilatation and deformation of the substrate. However, evidence exists for at least localized stresses in all of the scales examined.

  3. Stress Corrosion Cracking Behaviour of Dissimilar Welding of AISI 310S Austenitic Stainless Steel to 2304 Duplex Stainless Steel

    Directory of Open Access Journals (Sweden)

    Thiago AmaroVicente

    2018-03-01

    Full Text Available The influence of the weld metal chemistry on the stress corrosion cracking (SCC susceptibility of dissimilar weldments between 310S austenitic stainless steel and 2304 duplex steels was investigated by constant load tests and microstructural examination. Two filler metals (E309L and E2209 were used to produce fusion zones of different chemical compositions. The SCC results showed that the heat affected zone (HAZ on the 2304 base metal side of the weldments was the most susceptible region to SCC for both filler metals tested. The SCC results also showed that the weldments with 2209 duplex steel filler metal presented the best SCC resistance when compared to the weldments with E309L filler metal. The lower SCC resistance of the dissimilar joint with 309L austenitic steel filler metal may be attributed to (1 the presence of brittle chi/sigma phase in the HAZ on the 2304 base metal, which produced SC cracks in this region and (2 the presence of a semi-continuous delta-ferrite network in the fusion zone which favored the nucleation and propagation of SC cracks from the fusion zone to HAZ of the 2304 stainless steel. Thus, the SC cracks from the fusion zone associated with the SC cracks of 2304 HAZ decreased considerably the time-of-fracture on this region, where the fracture occurred. Although the dissimilar weldment with E2209 filler metal also presented SC cracks in the HAZ on the 2304 side, it did not present the delta ferrite network in the fusion zone due to its chemical composition. Fractography analyses showed that the mixed fracture mode was predominant for both filler metals used.

  4. High temperature and stress corrosion cracking of 310S austenitic stainless steel in wet chloride corrosive environment

    Directory of Open Access Journals (Sweden)

    T. Pornpibunsompop

    2018-01-01

    Full Text Available High temperature corrosion and stress corrosion cracking of 310S austenitic stainless steel in wet chloride environment at a high temperature was investigated. The result showed that high temperature corrosion products mostly consisted of ferrous oxides and chromium oxides. Chloride ions attacked a chromium passive film and strongly reacted with iron and chromium. As a result of metal chlorides being volatized, tunnel of pores inside corrosion layer existed. Intergranular stress corrosion cracking was observed. The oxide originated on surface could act as a crack initiator and a crack propagation would progress along grain boundaries and particularly along tunnel of pores.

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

    International Nuclear Information System (INIS)

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

    1993-01-01

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

  6. Stress Corrosion Cracking of Type 304 Stainless Steel

    National Research Council Canada - National Science Library

    Louthan, M

    1964-01-01

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

  7. Fatigue crack nucleation of type 316LN stainless steel

    International Nuclear Information System (INIS)

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

    2000-01-01

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

  8. Internal frictions of austenitic stainless steels at low temperature

    Science.gov (United States)

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

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

  9. High cycle fatigue of Type 422 stainless steel

    International Nuclear Information System (INIS)

    Soo, P.; Chow, J.G.Y.; Sabatini, R.L.

    1978-01-01

    High cycle fatigue testing has been carried out on Type 422 stainless steel to determine the performance of cyclically stressed disks and blades in the main and auxiliary HTGR helium circulators. Tests were performed at 316, 482, and 538 0 C (600, 900, and 1000 0 F) in air for the fully reversible and mean load conditions. Goodman's analysis is shown to be valid in predicting failure at 316 0 C (600 0 F), marginally valid at 482 0 C (900 0 F), and probably invalid at 538 0 C (1000 0 F). Metallographic analyses were conducted to characterize the nature of failure for the temperatures and loading conditions investigated

  10. Stress relaxation characteristics of type 304 stainless steel

    International Nuclear Information System (INIS)

    Manjoine, M.J.

    1975-01-01

    The stress relaxation of type 304 stainless steel below 900 0 F (482 0 C) is practically time independent after 100 h and has a maximum of about 18 per cent. The per cent relaxation decreases with increasing degree of cold work and with decreasing stress. Above 900 0 F the per cent relaxation increases with time, temperature, and cold work. The initial stress can also be increased for cold work materials so that the remaining stress can be maintained at a higher value even up to 1200 0 F (649 0 C). Time-temperature parameters are practical to correlate and extrapolate the data in the higher temperature range. (author)

  11. Deformation in type 304 austenitic stainless steel. Final report

    International Nuclear Information System (INIS)

    Kumar, V.; Mukherjee, S.; Huang, F.H.; Li, C.Y.

    1979-12-01

    Extensive experimental and theoretical work on Type 304 stainless steel to demonstrate the applicability of a state variable approach in materials testing and in stress analysis are reported. The state variable approach adopted has been shown recently to be able to describe the deformation properties of a variety of materials accurately with constitutive equations in the form of mechanical equation of state. It has been shown that the effort required in materials testing to determine the parameters of the constitutive equations is considerably less compared to that required for equations based on the traditional approach. During the course of the work a set of constitutive equations based on state variables for Type 304 stainless steel were established with all the required parameters determined experimentally. Numerical codes for uniaxial deformation and for bending of a beam were developed and used to predict the results of component testing. The code predictions were found to agree well with experimental data. The same constitutive equations were also incorporated into two versions of NONFIN, a finite element stress analysis code; one for Honeywell Computers and the other for IBM Computers. Both versions ran successfully and economically

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-05-15

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

  13. Assessment of tensile and creep data for types 304 and 316 stainless steel

    International Nuclear Information System (INIS)

    Sikka, V.K.; Booker, M.K.

    1976-01-01

    Austenitic stainless steels of types 304 and 316 are prime construction materials for nuclear fast breeder reactors and will be used in the temperature range where elevated-temperature, tensile, creep, and fatigue properties are required to calculate the design stress limits. This report examines the possible variations in such properties, using data from several sources including data from Japan and the United Kingdom. United States data were shown to contain the largest variations in both tensile and creep properties, with Japanese data the least. For a given country no distinction could be made in variations in tensile properties of types 304 and 316 stainless steels, but variations in standard error of estimate for all creep properties analyzed were significantly lower for type 316 stainless steel than corresponding variations in creep properties of type 304 stainless steel. The data from each of these countries showed the same creep rupture strength (at 10 4 h) for type 316 stainless steel; this was not true for the type 304 stainless steel. Results of the analysis performed in this paper showed that the U.S. and foreign data on types 304 and 316 stainless steels could possibly be combined for the determination of design stress intensity limits

  14. In-service inspection for assessment of weld degradation in SS 310S reduction retort

    International Nuclear Information System (INIS)

    Murthy, C.H.V.S.; Naik, Kalpana; Yadav, M.K.; Lakshmi, K.S.; Kapoor, Komal

    2015-01-01

    Austenitic stainless steel AISI 310S is used as the material of construction for Reduction retorts. SS 310S is selected for its ease of fabrication, corrosion and elevated temperature (around 850ÚC) properties. Matching welding consumables (E 310/ER 310) are used for welding of longitudinal and circumferential joints during fabrication of these retorts. The high temperatures applied during both welding and service, significantly affect the microstructure and properties of the weldment. During operation, these retorts are subjected to highly corrosive chloride environment in addition to high temperature. The middle zone operating temperature is 600ÚC to 700Ú C and undergoes inter granular stress corrosion attack (IGSCC) from inside and oxidation on outside surface. The bottom zone operating temperature is 800ÚC to 850ÚC and undergoes IGSCC and weld degradation. The retort is operated at an internal pressure of 5 psig and carries a tensile load of around 6 tons at 850ÚC. Hence these reduction retorts are subjected to in-service inspection (visual inspection and radiography of hot zone welds) after 40 runs and thereafter at regular frequencies to assess the healthiness of the weld joints. During In-service inspection (ISI), in retorts which were welded with ER 310 filler wire, many cracks were observed in the weld between shell and dished end. Inspection of welds during service was carried out using digital radiography by using a panoramic X-ray exposure. In order to find out the cause for the weld degradation and linear defects formation and propagation, failure analysis of the retorts was taken up. The observations in the failure analysis were correlated with the fabrication history, operating data and in-service inspection data. With this the mechanisms of weld degradation were identified and recommendations were made to improve the life of the retorts. The use of E 310 Mo welding consumables, modification of process conditions and fabrication procedures

  15. Diffusionless bonding of aluminum to type 304 stainless steel

    International Nuclear Information System (INIS)

    Watson, R.D.

    1963-03-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-09-06

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

  17. Influence of silver additions to type 316 stainless steels on bacterial inhibition, mechanical properties, and corrosion resistance

    DEFF Research Database (Denmark)

    Chiang, Wen-Chi; Tseng, I-Sheng; Møller, Per

    2010-01-01

    techniques. The microstructure of these 316 stainless steels was examined, and the influences of silver additions to 316 stainless steels on bacterial inhibition, mechanical properties, and corrosion resistance were investigated. This study suggested that silver-bearing 316 stainless steels could be used......Bacterial contamination is a major concern in many areas. In this study, silver was added to type 316 stainless steels in order to obtain an expected bacteria inhibiting property to reduce the occurrence of bacterial contamination. Silver-bearing 316 stainless steels were prepared by vacuum melting...

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

    Science.gov (United States)

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

    2008-11-01

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

  19. The Underground Corrosion of Selected Type 300 Stainless Steels After 34 Years

    International Nuclear Information System (INIS)

    Yoder, T.S.; Adler Flitton, M.K.

    2009-01-01

    Recently, interest in long-term underground corrosion has greatly increased because of the ongoing need to dispose of nuclear waste. Additionally, the Nuclear Waste Policy Act of 1982 requires disposal of high-level nuclear waste in an underground repository. Current contaminant release and transport models use limited available short-term underground corrosion rates when considering container and waste form degradation. Consequently, the resulting models oversimplify the complex mechanisms of underground metal corrosion. The complexity of stainless steel corrosion mechanisms and the processes by which corrosion products migrate from their source are not well depicted by a corrosion rate based on general attack. The research presented here is the analysis of austenitic stainless steels after 33 and a half years of burial. In this research, the corrosion specimens were analyzed using applicable ASTM standards as well as microscopic and X-ray examination to determine the mechanisms of underground stainless steel corrosion. As presented, the differences in the corrosion mechanisms vary with the type of stainless steel and the treatment of the samples. The uniqueness of the long sampling time allows for further understanding of the actual stainless steel corrosion mechanisms, and when applied back into predictive models, will assist in reduction of the uncertainty in parameters for predicting long-term fate and transport

  20. The Underground Corrosion of Selected Type 300 Stainless Steels After 34 Years

    Energy Technology Data Exchange (ETDEWEB)

    T. S. Yoder; M. K. Adler Flitton

    2009-03-01

    Recently, interest in long-term underground corrosion has greatly increased because of the ongoing need to dispose of nuclear waste. Additionally, the Nuclear Waste Policy Act of 1982 requires disposal of high-level nuclear waste in an underground repository. Current contaminant release and transport models use limited available short-term underground corrosion rates when considering container and waste form degradation. Consequently, the resulting models oversimplify the complex mechanisms of underground metal corrosion. The complexity of stainless steel corrosion mechanisms and the processes by which corrosion products migrate from their source are not well depicted by a corrosion rate based on general attack. The research presented here is the analysis of austenitic stainless steels after 33½ years of burial. In this research, the corrosion specimens were analyzed using applicable ASTM standards as well as microscopic and X-ray examination to determine the mechanisms of underground stainless steel corrosion. As presented, the differences in the corrosion mechanisms vary with the type of stainless steel and the treatment of the samples. The uniqueness of the long sampling time allows for further understanding of the actual stainless steel corrosion mechanisms, and when applied back into predictive models, will assist in reduction of the uncertainty in parameters for predicting long-term fate and transport.

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

    International Nuclear Information System (INIS)

    Caskey, G.R. Jr.

    1980-01-01

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

  2. Influence of silver additions to type 316 stainless steels on bacterial inhibition, mechanical properties, and corrosion resistance

    DEFF Research Database (Denmark)

    Chiang, Wen-Chi; Tseng, I-Sheng; Møller, Per

    2010-01-01

    Bacterial contamination is a major concern in many areas. In this study, silver was added to type 316 stainless steels in order to obtain an expected bacteria inhibiting property to reduce the occurrence of bacterial contamination. Silver-bearing 316 stainless steels were prepared by vacuum melting...... techniques. The microstructure of these 316 stainless steels was examined, and the influences of silver additions to 316 stainless steels on bacterial inhibition, mechanical properties, and corrosion resistance were investigated. This study suggested that silver-bearing 316 stainless steels could be used...... in areas where hygiene is a major requirement. The possible mechanisms of silver dissolution from the surfaces of silver-bearing 316 stainless steels were also discussed in this report....

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

    International Nuclear Information System (INIS)

    Rozenak, P.; Eliezer, D.

    1984-01-01

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

  4. Cold work effects: a compilation of data for types 304 and 316 stainless steel

    International Nuclear Information System (INIS)

    Moen, R.A.; Duncan, D.R.

    1976-03-01

    Effects of cold working on the mechanical properties of Types 304 and 316 stainless steel are tabulated, illustrated, and summarized. The properties covered are those that affect the setting of Code allowable stresses. Effects on other properties that indirectly affect the utilization of cold worked materials are also discussed. The report provides in summary the basis for formulating guidelines or rules to govern the use of cold worked materials in various types of components and construction

  5. Design-relevant mechanical properties of 316-type stainless steels for superconducting magnets

    Energy Technology Data Exchange (ETDEWEB)

    Tobler, R.L.; Nishimura, A.; Yamamoto, J.

    1996-08-01

    Worldwide interest in austenitic alloys for structural applications in superconducting magnets has led to an expanded database for the 316-type stainless steels. We review the cryogenic mechanical properties of wrought, cast, and welded steels at liquid helium temperature (4 K), focussing on aspects of material behavior relevant to magnet design. Fracture mechanics parameters essential to structural reliability assessments are presented, including strength, toughness, and fatigue parameters that are critical for some component designs. (author). 105 refs.

  6. Design-relevant mechanical properties of 316-type stainless steels for superconducting magnets

    International Nuclear Information System (INIS)

    Tobler, R.L.; Nishimura, A.; Yamamoto, J.

    1996-08-01

    Worldwide interest in austenitic alloys for structural applications in superconducting magnets has led to an expanded database for the 316-type stainless steels. We review the cryogenic mechanical properties of wrought, cast, and welded steels at liquid helium temperature (4 K), focussing on aspects of material behavior relevant to magnet design. Fracture mechanics parameters essential to structural reliability assessments are presented, including strength, toughness, and fatigue parameters that are critical for some component designs. (author). 105 refs

  7. Influence of the welding process choice on the pitting corrosion resistance of 304 L type stainless steels

    International Nuclear Information System (INIS)

    Carbonell, L.

    2002-01-01

    This document gives indications and information on process and welding parameters optimization to improve the pitting corrosion resistance of 304 L type stainless steels, used in industrial piping. (A.L.B.)

  8. Preplastic strain effect on chromium carbides precipitation of type 316 stainless steel during high-temperature ageing

    International Nuclear Information System (INIS)

    Mao, X.; Zhao, W.

    1992-01-01

    Long exposure of Type 316 stainless steel to elevated temperature (400-900 o C) is known to cause high-temperature embrittlement due to chromium carbides and σ-phase precipitating in grain boundaries. Numerous investigations have been published on the mechanical properties and microstructure changes occurring during such exposure. However, no investigations exist on the preplastic deformation effect on chromium carbide precipitation in the grain matrix and grain boundary during high-temperature ageing of Type 316 stainless steel and then its effects on the room-temperature tensile properties. Since the stainless steel sometimes is deformed before use at high temperatures, it is necessary to study the preplastic strain effect of the stainless steel on the microstructure change and mechanical property change during high-temperature exposure. The purpose of the present investigation was to carry out such a study. The conclusions reached are as follows. First, chromium carbides are precipitated in deformation lines (slip lines) and then the amount of chromium carbides precipitation in the grain boundary is relatively reduced in predeformed stainless steel after ageing. Secondly, plastic strain pretreatments of and subsequent ageing treatments of Type 316 stainless steel can improve its tensile ductility. Finally, secondary cracking of aged stainless steel occurs in a normal tensile test. The secondary cracking can be reduced by adding preplastic strain into the material. (Author)

  9. The effect on the impact properties of type 304 stainless steel

    International Nuclear Information System (INIS)

    Diaz-Sanchez, A. del C.

    1990-01-01

    The relationship between the degree of sensitization and the corrosion resistance of austenitic stainless steel has been reported since long time, however this relationship does not account for all the experimental results reported on the literature. The present work was developed in order to establish the effect of time and temperature in the degree of sensitization in stainless steel type 304 at short treatment times (up to 6 hrs.) in the range of 450-850 o C. The maximum amount of degree of sensitization was found at 650 o C and the mechanical properties were in direct relationship to the amount of carbides at the grain boundary. For lower temperatures an abnormal mechanical behavior was found, and it is explained by means of precipitation kinetics which induces the intragranular carbide formation. Diffusion phenomena observed in higher temperature were attributed to deterioration of mechanical properties. (Author)

  10. Inertia and friction welding of aluminum alloy 1100 to type 316 stainless steel

    International Nuclear Information System (INIS)

    Perkins, M.A.

    1979-01-01

    The inertia and friction-welding processes were evaluated for joining aluminum alloy 1100-H14 and Type 316 vacuum-induction melted, vacuum-arc remelted (VIM VAR) stainless steel. While both processes consistently produced joints in which the strength exceeded the strength of the aluminum base metal, 100 percent bonding was not reliably achieved with inertia welding. The deficiency points out the need for development of nondestructive testing techniques for this type of joint. Additionally, solid-state volume diffusion did not appear to be a satisfactory explanation for the inertia and friction-welding bonding mechanism

  11. Relationship between microstructure and fracture types in a UNS S32205 duplex stainless steel

    Directory of Open Access Journals (Sweden)

    Maria Victoria Biezma

    2013-01-01

    Full Text Available Duplex stainless steels are susceptible to the formation of sigma phase at high temperature which could potentially be responsible for catastrophic service failure of components. Thermal treatments were applied to duplex stainless steels in order to promote the precipitation of different fractions of sigma phase into a ferrite-austenite microstructure. Quantitative image analysis was employed to characterize the microstructure and Charpy impact tests were used in order to evaluate the mechanical degradation caused by sigma phase presence. The fracture morphology of the Charpy test specimens were thoroughly observed in SEM, looking for a correlation between the microstructure and the fracture types in UNS S32205 duplex stainless steel. The main conclusion is the strong embrittlement effect of sigma phase since it is possible to observe a transition from transgranular fracture to intergranular fracture as increases the percentage of sigma phase. Thus, the mixed modes of fracture are predominant in the present study with high dependence on sigma phase percentages obtained by different thermal treatments.

  12. Microstructure and phase identification in type 304 stainless steel-zirconium alloys

    International Nuclear Information System (INIS)

    Abraham, D.P.; McDeavitt, S.M.; Park, J.

    1996-01-01

    Stainless steel-zirconium alloys have been developed at Argonne National Laboratory to contain radioactive metal isotopes isolated from spent nuclear fuel. This article discusses the various phases that are formed in as-cast alloys of type 304 stainless steel and zirconium that contain up to 92 wt pct Zr. Microstructural characterization was performed by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS), and crystal structure information was obtained by X-ray diffraction. Type 304SS-Zr alloys with 5 and 10 wt pct Zr have a three-phase microstructure--austenite, ferrite, and the Laves intermetallic, Zr(Fe,Cr,Ni) 2+x , whereas alloys with 15, 20, and 30 wt pct Zr contain only two phases--ferrite and Zr(Fe,Cr,Ni) 2+x . Alloys with 45 to 67 wt pct Zr contain a mixture of Zr(Fe,Cr,Ni) 2+x and Zr 2 (Ni,Fe), whereas alloys with 83 and 92 wt pct Zr contain three phases--α-Zr, Zr 2 (Ni,Fe), and Zr(Fe,Cr,Ni) 2+x . Fe 3 Zr-type and Zr 3 Fe-type phases were not observed in the type 304SS-Zr alloys. The changes in alloy microstructure with zirconium content have been correlated to the Fe-Zr binary phase diagram

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

    International Nuclear Information System (INIS)

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

    1984-01-01

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

  14. Fracture toughness and stress relief response of irradiated Type 347/348 stainless steel

    International Nuclear Information System (INIS)

    Haggag, F.M.

    1985-01-01

    A test program has experimentally determined: (1) The fracture toughness of Type 347/348 stainless steel (SS) specimens with high values of irradiation fluence (2.3 to 4.8 x 10 22 n/cm 2 , E > 1.0 MeV) and experiencing different levels of irradiation creep (0.0, 0.6, 1.1, 1.8%), (2) the effect of thermal stress relief on fracture toughness recovery for the highly irradiated material, and (3) the mechanisms associated with fracture toughness recovery due to thermal stress relief. The postirradiation fracture toughness tests and tensile tests were conducted at 427 0 C

  15. Determination of internal state variables and constitutive modeling for Type 316 stainless steel

    International Nuclear Information System (INIS)

    Taguchi, Kosei; Uno, Tetsuro

    1993-01-01

    The purpose of this study is to develop an approach for unified constitutive modeling based on experimentally determined back stress and overstress. Back stress and overstress were experimentally determined for Type 316 stainless steel at 600deg C, by analyzing the unloading curve for the stress-strain response of cyclic strain tests. The result has indicated that the cyclic strain hardening behavior is mainly caused by hardening in the back stress. A phenomenological unified constitutive model in which the back stress and drag stress are taken as the internal state variables is proposed, and has been shown that this model is able to simulate the cyclic inelastic behavior. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1976-01-01

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

  17. Growth of creep life of type-347H austenitic stainless steel by micro-alloying elements

    International Nuclear Information System (INIS)

    Research highlights: → B, Ce and N can improve the creep life significantly at high temperature. → The precipitate of B element at the grain boundaries can improve the creep life. → The removing O through Ce provided the steel with longer creep life. → N increased the creep life by stabilizing austenite and solid solution strengthening. - Abstract: The creep life of type-347H austenitic stainless steel modified with B, Ce and N was measured, and microstructures were analyzed by optical microscope, X-ray diffraction, scanning electron microscope and transmission electron microscope equipped with energy dispersive spectroscopy. The results indicate that B, Ce and N can improve the creep life significantly at high temperature. The growth of creep life was mainly due to the precipitate of B in the elemental form at the grain boundaries and the removing O through Ce. N addition made for solid solution strengthening and effectively suppressed the precipitate of δ-ferrite at high temperature. The micro-alloying elements have a beneficial effect on creep life of type-347H austenitic stainless steel at high temperature.

  18. Mechanical properties of type 316 stainless steel materials after irradiation at 5150C and 5850C

    International Nuclear Information System (INIS)

    Blackburn, L.D.; Greenslade, D.L.; Ward, A.L.

    1981-04-01

    Three different heats of type 316 SS base metal plate metals and three different weld metals produced by shielded metal arc, submerged arc, and gas tungsten arc processes with type 316 SS filler metal were used in the Gas-Cooled Fast Reactor (GCFR) Structural Materials Irradiation Experiment. Pre-irradiation strength and ductility properties over the range 24 0 C to 650 0 C were very similar for the three base metal heats and were within the expected range for this alloy. The three welds showed variations in strength and ductility before irradiation, but properties were generally within the range of previous experience for austenitic stainless steel welds. Weld metals showed higher yield strength but lower uniform and total elongations than those of base metal

  19. High temperature interaction between Zircaloy-4 and stainless steel type 304

    International Nuclear Information System (INIS)

    Nagase, Fumihisa; Otomo, Takashi; Uetsuka, Hiroshi

    2001-03-01

    The chemical interactions between Zircaloy-4 and stainless steel type 304 were investigated in the temperature range from 1273 to 1573 K to obtain the basic information on the melt progress in the fuel bundle during an LWR severe accident. Reaction layers were formed at the contact interface and grew as the temperature and the time increase. The Zircaloy was preferentially dissolved by the reaction. The SEM/EDX analyses showed that the main process of the reaction was diffusion of Fe, Cr and Ni into the Zircaloy which resulted in the formation of a Zr-rich eutectic through the tested temperature range. Reaction rates for decrease in the materials thickness were evaluated and the reaction generally obeyed a parabolic rate law. The reaction rate constant was determined at every examined temperature and Arrhenius type rate equations were estimated for the temperature range. (author)

  20. Topological characterization of static strain aging of type AISI 304 austenitic stainless steel

    International Nuclear Information System (INIS)

    Monteiro, S.N.; Miranda, P.E.V. de

    1981-01-01

    Static strain aging of type AISI 304 austenitic stainless steel was studied from room temperature up to 623K by conducting tests in which the load was held approximately constant. The aging times varied between 10s and 100h, using a plastic pre-deformation of 9%. The static strain aging of 304 steel furnished an activation energy of 23.800 cal/mol. This implies that vacancies play an important role on the aging process. The curve of the variation of the discontinuous yielding with aging time presented different stages, to which specific mathematical expressions were developed. These facts permited the conclusion that Snock type mechanisms are responsible for the aging in such conditions. (Author) [pt

  1. Corrosion behavior induced by LiCl-KCl in type 304 and 316 stainless steel and copper at low temperature

    Directory of Open Access Journals (Sweden)

    Jee-Hyung Sim

    2017-06-01

    Full Text Available The corrosion behavior of stainless steel (304 and 316 type and copper induced by LiCl-KCl at low temperatures in the presence of sufficient oxygen and moisture was investigated through a series of experiments (at 30°C, 40°C, 60°C, and 80°C for 24 hours, 48 hours, 72 hours, and 96 hours. The specimens not coated on one side with an aqueous solution saturated with LiCl-KCl experienced no corrosion at any temperature, not even when the test duration exceeded 96 hours. Stainless steel exposed to LiCl-KCl experienced almost no corrosion below 40°C, but pitting corrosion was observed at temperatures above 60°C. As the duration of the experiment was increased, the rate of corrosion accelerated in proportion to the temperature. The 316 type stainless steel exhibited better corrosion resistance than did the 304 type. In the case of copper, the rate of corrosion accelerated in proportion to the duration and temperature but, unlike the case of stainless steel, the corrosion was more general. As a result, the extent of copper corrosion was about three times that of stainless steel.

  2. Using transmission Kikuchi diffraction to study intergranular stress corrosion cracking in type 316 stainless steels.

    Science.gov (United States)

    Meisnar, Martina; Vilalta-Clemente, Arantxa; Gholinia, Ali; Moody, Michael; Wilkinson, Angus J; Huin, Nicolas; Lozano-Perez, Sergio

    2015-08-01

    Transmission Kikuchi diffraction (TKD), also known as transmission-electron backscatter diffraction (t-EBSD) is a novel method for orientation mapping of electron transparent transmission electron microscopy specimen in the scanning electron microscope and has been utilized for stress corrosion cracking characterization of type 316 stainless steels. The main advantage of TKD is a significantly higher spatial resolution compared to the conventional EBSD due to the smaller interaction volume of the incident beam with the specimen. Two 316 stainless steel specimen, tested for stress corrosion cracking in hydrogenated and oxygenated pressurized water reactor chemistry, were characterized via TKD. The results include inverse pole figure (IPFZ) maps, image quality maps and misorientation maps, all acquired in very short time (crack with respect to the grain boundary, deformation bands, twinning and slip. Furthermore, TKD has been used to measure the grain boundary misorientation and establish a gauge for quantifying plastic deformation at the crack tip and other regions in the surrounding matrix. Both grain boundary migration and slip transfer have been detected as well. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Influence of applied stress on swelling behavior in Type 304 stainless steel

    International Nuclear Information System (INIS)

    Igata, N.; Fujihira, T.; Kohno, Y.; Tsunakawa, M.

    1984-01-01

    The swelling behavior of Type 304 stainless steel during stress application was investigated by means of electron irradiation using a high-voltage electron microscope (HVEM). The dose dependence of swelling under stress is similar to the linearafter-incubation swelling scheme of other electron irradiation studies. The effect of applied stress on the swelling characteristics appeared through the control of incubation regime of swelling rather than of the swelling rate. The incubation dose first increases, then decreases, and increases again with increasing applied stress. The prominent finding in this study, based on the advantage of HVEM in situ observation, is that the saturated void density is equal to the number density of interstitial dislocation loops observed in the early stage of irradiation. Essentially, applied stress affects the loop nucleation process. The dislocation loop density then affects the incubation dose of swelling through its control of dislocation behavior and the saturation dose of dislocation density

  4. Inhibition of intergranular stress corrosion cracking of sensitized type 304 stainless steel. Annual report

    International Nuclear Information System (INIS)

    Brown, B.F.

    1977-01-01

    The effectiveness of various inhibitors in mitigating stress corrosion cracking of stainless steel in hot aqueous environment was evaluated. The inhibitors studied were of three types: poly-oxy-anions, organic competitive absorbers, and simple cations; the corrosive medium was 4M NaCl acidified with H 2 SO 4 to ph of about 2.3. The following conclusions were reached: pH does not affect cracking kinetics in a sensitive way; cracking time is highly dependent on chloride concentrations; poly-oxy-anions do not perform well; organics offer some possibilities as inhibitors; cationic additives can have effects varying from trivial to total suppression of cracking--behavior is both cation and concentration dependent. 2 figures, 5 tables

  5. The effect of pre-aging on the creep behaviour of type 321 stainless steel

    International Nuclear Information System (INIS)

    Snowden, K.U.; Stathers, P.A.; Hughes, D.S.

    1983-01-01

    An investigation was made of the influence of prior thermal treatment on the creep behaviour and microstructure of type 321 stainless steel. The material was pre-aged at 750 deg C in vacuum for periods up to approx. 10 3 hours and subsequently creep tested in air at 650 deg C and a stress of 200 MPa. Pre-aging increased the creep rate and the ductility, and decreased the time to failure and the activation energy for creep. Over the aging period examined, the increase in creep rate was proportional to (aging time)sup(0.61). Electron microscopy suggested that the increased creep rate was associated with the growth of precipitates at triple junctions, along grain boundaries and within grains. (author)

  6. The Effect of Calcium Treatment on Pitting Corrosion of Type 316L Austenitic Stainless steel

    International Nuclear Information System (INIS)

    Lee, Yong Heon; LeeSoo Chan; Kim, Yong Hwan; Kim, Hee San

    2001-01-01

    Pitting in chloride containing aqueous solution occurs mainly on manganese sulphide. Adding a slight amount of Ca as an alloying element prevents the MnS formation, since Ca is a stronger sulphide former than Mn. In this work, calcium treated Type 316L austenitic stainless steels have been investigated electrochemically to evaluate the effect of modified inclusions on pitting corrosion. Staircase polarization measurements were performed in 3.5% NaCl solution, where the occurrence of pits in materials caused current spikes. During staircase polarization test, steels with calcium treatment show low and discontinuous current spikes while those without calcium treatment show high and continuous current spikes. The results show that calcium treatment in Ca/S ratio of 1 ∼ 2 leads to an increase in the pitting potential of several hundred mV. A relationship between the calcium treatment and pit initiation sites was described

  7. Surface effects induced by cathodic hydrogenation in type AISI 304 stainless steel

    International Nuclear Information System (INIS)

    Silva, T.C.V.

    1984-08-01

    Cathodic hydrogen charging of type AISI 304 stainless steel modified its austenitic structure, giving rise to the formation of two new martensitic phases and the appearance of cracks, in most cases delayed. As electrolyte a 1 N H 2 S O 4 solution containing As 2 O 3 was employed. The cathodic hydrogenation was carries out at room temperature. The transformed phases were identified with black and white and coloured metallographic techniques, as well as by X-ray diffraction. The effect of cathodic hydrogenation in samples uniaxially tensile tested with constant nominal strain rate was investigated. It was concluded that the number of cracks per unit surface area changes with hydrogenation conditions and that hydrogen should be present for the embrittlement to occur. (author)

  8. Fatigue crack growth studies on type 304LN stainless steel straight pipes

    International Nuclear Information System (INIS)

    Raghava, G.

    2016-01-01

    Fatigue crack initiation and growth rate studies in different exposure and loading conditions were carried out on 26 straight pipes made of Type 304LN stainless steel, which is a widely used steel in nuclear power plant piping components. The pipe dimensions were in two categories: 170 mm OD, 15 mm thickness and 324 mm OD, 28 mm thickness. The specimens contained pre-existing flaws in the form of part-through notch in one of the following locations: base metal, heat affected zone and weld metal. Notch length varied from 7.0 mm to 127.0 mm and notch depth varied from 3.0 mm to 10.9 mm. Twenty one specimens were tested under four point bending in air environment, three under four point bending in water environment; and two under combined torsion and bending in air environment. This paper presents details of the experimental investigations and the results of the studies. (author)

  9. Corrosion Behavior of Aqua-Blasted and Laser-Engraved Type 316L Stainless Steel

    Science.gov (United States)

    Krawczyk, B.; Cook, P.; Hobbs, J.; Engelberg, D. L.

    2017-12-01

    The effect of aqua blasting and laser engraving on surface microstructure development, residual stress and corrosion resistance of type 316L stainless steel has been investigated. Aqua blasting resulted in a deformed near-surface microstructure containing compressive residual stresses. Subsequent laser engraving produced a surface layer with tensile residual stresses reaching to a depth of 200 microns. Changes of surface roughness topography were accompanied by the development of a thick oxide/hydroxide film after laser engraving. The atmospheric corrosion behavior of all surfaces with MgCl2-laden droplets was compared to their electrochemical response in 1M NaCl and 0.7 M HCl aqueous solutions. The measured total volume loss after atmospheric corrosion testing was similar for all investigated surface conditions. Laser-engraved surface exhibited the smallest number of corrosion sites, but the largest mean corrosion depth.

  10. Creep deformation and rupture behavior of type 304/308 stainless steel structural weldments

    International Nuclear Information System (INIS)

    McAfee, W.J.; Richardson, M.; Sartory, W.K.

    1977-01-01

    The creep deformation and rupture of type 304/308 stainless steel structural weldments at 593 0 C (1100 0 F) was experimentally investigated to study the comparative behavior of the base metal and weld metal constituents. The tests were conducted in support of ORNL's program to develop high-temperature structural design methods applicable to liquid-metal fast breeder reactor (LMFBR) system components that operate in the creep range. The specimens used were thin-walled, right circular cylinders capped with either flat or hemispherical heads and tested under internal gas pressure. Circumferential welds were located in different regions of the cylinder or head and, with one exception, were geometrically duplicated by all base metal regions in companion specimens. Results are presented on the comparative deformation and rupture behavior of selected points in the base metal and weldment regions of the different specimens and on the overall surface strains for selected specimens

  11. Influence of nitrogen alloying on hydrogen embrittlement in AISI 304-type stainless steels

    Science.gov (United States)

    Hannula, Simo-Pekka; Hänninen, Hannu; Tähtinen, Seppo

    1984-12-01

    Hydrogen embrittlement of AISI 304-type austenitic stainless steels has been studied with special emphasis on the effects of the nitrogen content of the steels. Hydrogen charging was found to degrade the mechanical properties of all the steels studied, as measured by a tensile test. The fracture surfaces of hydrogen charged specimens were brittle cleavage-like whereas the uncharged specimens showed ductile, dimpled fracture. In sensitized materials transgranular cleavage mode of fracture was replaced by an intergranular mode of fracture and the losses of mechanical properties were higher. Nitrogen alloying decreased the hydrogen-induced losses of mechanical properties by increasing the stability of austenite. In sensitized steels the stability of austenite and nitrogen content were found to have only a minor effect on hydrogen embrittlement, except when sensitization had caused α'-martensite transformation at the grain boundaries.

  12. Behavior of Type 316 stainless steel under simulated fusion reactor irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Wiffen, F.W.; Maziasz, P.J.; Bloom, E.E.; Stiegler, J.O.; Grossbeck, M.L.

    1978-05-01

    Fusion reactor irradiation response in alloys containing nickel can be simulated in thermal-spectrum fission reactors, where displacement damage is produced by the high-energy neutrons and helium is produced by the capture of two thermal neutrons in the reactions: /sup 58/Ni + n ..-->.. /sup 59/Ni + ..gamma..; /sup 59/Ni + n ..-->.. /sup 56/Fe + ..cap alpha... Examination of type 316 stainless steel specimens irradiated in HFIR has shown that swelling due to cavity formation and degradation of mechanical properties are more severe than can be predicted from fast reactor irradiations, where the helium contents produced are far too low to simulate fusion reactor service. Swelling values are greater and the temperature dependence of swelling is different than in the fast reactor case.

  13. Effect of Neutron Irradiation on Fatigue Crack Propagation in Types 304 and 316 Stainless Steels at High Temperature.

    Science.gov (United States)

    The resistance of pre- and postirradiated AISI Types 304 and 316 stainless steels to fatigue crack propagation was determined at 800 and 1100F (427...and 593C) using the fracture mechanics approach. The effect of irradiation on the fatigue resistance of these steels was dependent upon test temperature and irradiation conditions. (Author)

  14. High temperature vapor pressures of stainless steel type 1.4970 and of some other pure metals from laser evaporation

    International Nuclear Information System (INIS)

    Bober, M.; Singer, J.

    1984-10-01

    For the safety analysis of nuclear reactors vapor pressure data of stainless steel are required up to temperatures exceeding 4000 K. In analogy to the classic boiling point method a new technique was developed to measure the high-temperature vapor pressures of stainless steel and other metals from laser vaporization. A fast pyrometer, an ion current probe and an image converter camera are used to detect incipient boiling from the time-temperature curve. The saturated-vapor pressure curves of stainless steel (Type 1.4970), being a cladding material of the SNR 300 breeder reactor, and of molybdenum are experimentally determined in the temperature ranges of 2800-3900 K and 4500-5200 K, respectively. The normal boiling points of iron, nickel, titanium, vanadium and zirconium are verified. Besides, spectral emissivity values of the liquid metals are measured at the pyrometer wavelengths of 752 nm and/or 940 nm. (orig.) [de

  15. The effects of N+ implantation on the wear and friction of type 304 and 15-5 PH stainless steels

    International Nuclear Information System (INIS)

    Yost, F.G.; Picraux, S.T.; Follstaedt, D.M.; Pope, L.E.; Knapp, J.A.

    1983-01-01

    Ion implantation of N + into mechanically polished type 304 and 15-5 PH stainless steels was studied to determine its effect on dry wear and friction behavior. Implantation of 4.0 X 10 17 N + cm -2 at 50 keV yielded a depth profile with a peak concentration of about 45 at.% at a depth of 70 nm which dropped to about 10 at.% at 120 nm. Wear and friction were studied in an unlubricated pin-on-disc configuration using type 304 and 440C stainless steel pins. Both N + -implanted steels exhibited reduced wear at low loads but no significant reduction in the coefficient of friction was found. At the lowest normal load studied (12.3 gf), the average maximum wear depth of the implanted 15-5 PH stainless steel disc (about 0.1 μm) was reduced to approximately 10% of that for the corresponding unimplanted pin-on-disc pair after 1000 cycles. At normal loads of 50 gf or above (corresponding to hertzian stresses of 1160 MPa or higher) all beneficial effects were gone. Vacuum heat treatment at 923 K for 1.8 ks of an identically implanted type 304 stainless steel specimen eradicated the beneficial effects of the nitrogen implantation. The N + -implanted discs show similar reductions in wear to discs implanted with titanium and carbon, but the N + -implanted discs do not exhibit the reductions in the coefficient of friction seen with the discs implanted with titanium and carbon. (Auth.)

  16. Evaluation of the onset of tertiary creep for types 304 and 316 stainless steels

    International Nuclear Information System (INIS)

    Staerk, E.; Picker, C.; Felsen, M.F.

    1989-01-01

    Austenitic stainless steels Types 304 and 316 are used for LMFBR components. Although at high temperature many codes base the allowable stress on the stress rupture strength, some recent codes eg ASME Code Case N47 and RCC-MR also take account of the onset of tertiary creep. In order to examine this latter aspect creep deformation data on Type 304 and Type 316 steel have been collected and analysed. The ratio time to onset of tertiary creep against the time to rupture has been analysed as a function of temperature. At temperatures below 750 0 C the ratio is found to decrease slightly with increasing temperature. Monkman Grant and Lambda relationships have also been investigated. In relation to the ASME S t allowable stress criteria it is shown that below 600 0 C the allowable stress is likely to be governed by the stress rupture strength rather than the onset of tertiary creep criterion. Recommendations are given concerning the determination of the onset of tertiary creep, the fitting of the Leyda/Rowe relationship and a method to compute the maximum allowable stress S t from equation describing the time-temperature dependency of the three constituents of S t

  17. Fundamental distribution of stress corrosion crack depth on Type 316L stainless steels induced by creviced bent beam test

    International Nuclear Information System (INIS)

    Miyahara, Yuichi; Miura, Yasufumi; Kako, Kenji

    2014-01-01

    The creviced bent beam (CBB) test has been applied for many materials such as nickel base alloys and low carbon austenitic stainless steels. For sensitized austenitic stainless steels, fundamental distribution of crack depth induced by CBB tests was evaluated to establish SCC initiation model and lifetime prediction method. On the other hand, there are a few studies about distribution of crack depth on low carbon austenitic stainless steels. In this study, statistical analysis of crack depth was conducted in Type 316L stainless steels after CBB tests. The results are summarized as follows, (1) Distribution of grain boundary depth designated as distance from surface to triple point of grain boundary fit lognormal probability distribution and exponential probability distribution. (2) Distribution of crack depth approaches lognormal or exponential probability distribution with passage of test duration. Distribution of plastic strain on the specimen surface is not affect to type of crack depth distribution. (3) Inflection or bent point appears on the probability plot at depth of the median of grain boundary depth distribution. (4) Less than median of grain boundary depth, distribution of crack depth is identical to grain boundary depth distribution. More than median + standard deviation of grain boundary depth, crack depth distribution is described by the exponential distribution. (author)

  18. Effects of fluoride and other halogen ions on the external stress corrosion cracking of Type 304 austenitic stainless steel

    International Nuclear Information System (INIS)

    Whorlow, K.M.; Hutto, F.B. Jr.

    1997-07-01

    The drip procedure from the Standard Test Method for Evaluating the Influence of Thermal Insulation on External Stress Corrosion Cracking Tendency of Austenitic Stainless Steel (ASTM C 692-95a) was used to research the effect of halogens and inhibitors on the External Stress Corrosion Cracking (ESCC) of Type 304 stainless steel as it applies to Nuclear Regulatory Commission Regulatory Guide 1.36, Nonmetallic Thermal Insulation for Austenitic Stainless Steel. The solutions used in this research were prepared using pure chemical reagents to simulate the halogens and inhibitors found in insulation extraction solutions. The results indicated that sodium silicate compounds that were higher in sodium were more effective for preventing chloride-induced ESCC in Type 304 austenitic stainless steel. Potassium silicate (all-silicate inhibitor) was not as effective as sodium silicate. Limited testing with sodium hydroxide (all-sodium inhibitor) indicated that it may be effective as an inhibitor. Fluoride, bromide, and iodide caused minimal ESCC which could be effectively inhibited by sodium silicate. The addition of fluoride to the chloride/sodium silicate systems at the threshold of ESCC appeared to have no synergistic effect on ESCC. The mass ratio of sodium + silicate (mg/kg) to chloride (mg/kg) at the lower end of the NRC RG 1.36 Acceptability Curve was not sufficient to prevent ESCC using the methods of this research

  19. 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

  20. Development of nuclear grade type 316 stainless steel for BWR pipings

    International Nuclear Information System (INIS)

    Kowaka, Masamichi; Nagano, Hiroo; Yoshikawa, Kunihiko; Miura, Minoru; Ota, Kunio.

    1981-01-01

    The countermeasures were established against the grain boundary stress corrosion cracking in the heat-affected zone of 304 stainless steel pipings used for recirculating system and others of BWRs. Sumitomo Metal Industries, Ltd. has engaged in the development of the stainless steel having excellent resistance to stress corrosion cracking, substituting for 304 stainless steel. In order to prevent stainless steel from becoming sensitive to the grain boundary stress corrosion cracking, the reduction of carbon content, or the addition of the elements stabilizing carbon in steel are conceivable. 316 L stainless steel was selected as the base for development, because it is a low carbon steel (C <= 0.03%) and contains Mo effective for improving the pitting corrosion resistance and restricting the steel to become sensitive. The requirements for the piping materials for BWRs are the resistance to stress corrosion cracking in high temperature, high pressure water, excellent strength and weldability, and the possibility of the commercial production of pipes. For the purpose of developing 316 stainless steel pipes, the effects of Mo and trace elements on the stress corrosion cracking resistance, the effects of C, N and grain size on the strength, and the effect of N on the weldability were examined, and the composition design of 316 stainless steel for atomic energy use was carried out. The result is given. (Kako, I.)

  1. Dresden 1 Radiation Level Reduction Program. Intergranular corrosion tests of sensitized Type-304 stainless steel in Dow NS-1, and stress corrosion cracking tests of Type-304 stainless steel and carbon and low alloy steels in Dow copper rinse solution

    International Nuclear Information System (INIS)

    Walker, W.L.

    1978-09-01

    Corrosion tests were performed to evaluate the extent of intergranular attack on sensitized Type-304 stainless steel by a proprietary Dow Chemical solvent, NS-1, which is to be used in the chemical cleaning of the Dresden 1 primary system. In addition, tests were performed to evaluate stress corrosion cracking of sensitized Type-304 stainless steel and post-weld heat-treated ASTM A336-F1, A302-B, and A106-B carbon and low alloy steels in a solution to be used to remove residual metallic copper from the Dresden 1 primary system surfaces following the chemical cleaning. No evidence of deleterious corrosion was observed in either set of tests

  2. Effect of Different Types of Toothpaste on the Frictional Resistance Between Orthodontic Stainless Steel Brackets and Wires

    Science.gov (United States)

    Hosseinzadeh Nik, Tahereh; Hooshmand, Tabassom

    2017-01-01

    Objectives: The purpose of this study was to investigate the effect of different types of toothpaste on the frictional resistance between stainless steel brackets and archwires. Materials and Methods: Ninety stainless steel orthodontic brackets with stainless steel wires were bonded to bovine teeth and were divided into 6 groups for application of the following toothpastes: Colgate® Total® Advanced Whitening, Colgate® Total® Pro Gum Health, Colgate® Anticavity, Ortho.Kin®, and Sunstar GUM® Ortho toothpastes. No toothpaste was applied in the control group. Each group was brushed by a brushing machine with the use of the designated solution for 4.5 minutes. The frictional force was measured in a universal testing machine with a crosshead speed of 10 mm/minute over a 5-mm archwire. Data were analyzed using one-way analysis of variance (ANOVA) at the 0.05 significance level. Results: The frictional resistance values of Ortho.Kin® and GUM® Ortho toothpastes and the control group were not significantly different (P>0.05). However, there were significant differences between the frictional resistance values of Colgate® Total® Pro Gum Health and Colgate® Anticavity toothpastes with that of the control group (Porthodontic toothpastes did not increase the frictional resistance between the orthodontic stainless steel brackets and wires. PMID:29296113

  3. Critical pitting temperature for Type 254 SMO stainless steel in chloride solutions

    International Nuclear Information System (INIS)

    Abd El Meguid, E.A.; Abd El Latif, A.A.

    2007-01-01

    The variation with time of the open circuit potential of high molybdenum containing stainless steel (Type 254 SMO) was measured in 4% sodium chloride solution in the temperatures range 30-100 deg. C. The plot of steady state potentials as function of temperature showed an inflection at 50 deg. C, attributed to the decrease of oxygen solubility in test solution above 50 deg. C. Potentiodynamic cycling anodic polarization technique was used to determine the critical pitting potential (E pit ) and the critical protection potential (E prot ) of the steel in 4-30% NaCl solutions at temperatures between 30 and 100 deg. C. By plotting the two values versus solution temperature, the corresponding critical pitting (CPT) and the critical protection (CPrT) temperatures were determined. Both parameters decreased with increasing chloride content. Above the CPT, E pit and E prot decreased linearly with log[Cl - ]. The addition of bromide ions to the solution shifted both E pit and E prot towards positive values. In 4% NaCl, E pit increased linearly with pH in the range 1-10. The combined effect of chloride ion concentration and pH on the morphology of the pits was examined by scanning electron microscopy (SEM) following potentiodynamic cycling anodic polarization

  4. Thermomechanical history measurements on Type 304L stainless steel pipe girth welds

    International Nuclear Information System (INIS)

    Li, Ming; Atteridge, D.G.; Anderson, W.E.; Turpin, R.; West, S.L.

    1993-01-01

    Thermal and strain histories were recorded for three 40-cm-diameter (16 inch), Type 304L stainless steel (SS), schedule 40 (1.27 cm thickness) pipe girth welds. Two weld groove preparations were standard V grooves while the third was a narrow groove configuration. The welding parameters for the three pipe welds simulated expected field practice as closely as possible. The narrow gap weld was completed in four continuous passes while the other two welds required six and nine (discontinuous) passes, due to the use of different weld wire diameters. Thermomechanical history measurements were taken on the inner counterbore surface, encompassing the weld centerline and heat-affected zone (HAZ), as well as 10 cm of inner counterbore surface on either side of the weld centerline; a total of 47 data acquisition instruments were used for each weld. These instruments monitored: (1) weld shrinkages parallel to the pipe axis; (2) surface temperatures; (3) surface strains parallel to weld centerline; and (4) radial deformations. Results show that the weld and HAZ experienced cyclic deformation in the radial direction during welding, indicating that the final residual stress distribution in multi-pass pipe weldments is not axisymmetric. Measured radial and axial deformations were smaller for the narrow gap groove than for the standard V grooves, suggesting that the narrow gap groove weldment may have lower residual stress levels than the standard V groove weldments. This study provides the experimental database and a guideline for further computational modeling work

  5. Effect of Element Diffusion Through Metallic Networks During Oxidation of Type 321 Stainless Steel

    Science.gov (United States)

    Zeng, Z.; Natesan, K.; Cai, Z.; Gosztola, D.; Cook, R.; Hiller, J.

    2014-04-01

    A detailed study was conducted on localized oxidation on Type 321 stainless steel (321ss) using synchrotron x-ray nanobeam analysis along with Raman microscopy. The results showed the presence of metallic nanonetworks in the oxide scales, which plays an important role in the continued oxidation of the alloy at 750 °C. A mechanism is proposed to explain the rapid oxidation of 321ss in complex gaseous environments at elevated temperature. Neutral metal atoms could diffuse outward, and carbon atoms could diffuse inward through the metallic nanonetworks in oxide layers. Alternately, diffusion tunnels can dramatically affect the phase composition of the oxide scales. Since the diffusion rate of neutral metal and carbon atoms through the metallic nanonetworks can be much faster than the diffusion of cations through Cr2O3, the metallic nanonetwork provides a path through the protective Cr2O3 layer for the rapid outward diffusion of metallic chromium and iron atoms to the nonprotective spinel layer. This diffusion process affects the solid-state reaction near the alloy-oxide boundary, and a dense Cr2O3 protective layer does not form. The classic stable structure of the oxide scales, with a dense Cr2O3 layer at the bottom, is damaged by the rapid diffusion through the tunnel at the reaction front, resulting in locally accelerated oxidation. This process can subsequently lead to "breakaway" oxidation and catastrophic failure of the alloy.

  6. Statistical analysis of elevated-temperature, strain-controlled fatigue data on Type 304 stainless steel

    International Nuclear Information System (INIS)

    Diercks, D.R.; Raske, D.T.

    1976-01-01

    The available elevated-temperature, strain-controlled, uniaxial fatigue data on Type 304 stainless steel (435 data points) are summarized, and variables that influence cyclic life are divided into first- and second-order categories. The first-order variables, which include strain range, strain rate, temperature, and tensile hold time, were used in a multivariable regression analysis to describe the observed variation in fatigue life. Goodness of fit with respect to these variables as well as the appropriateness of the transformations employed are discussed. Confidence intervals are estimated, and a comparison with the ASME Boiler and Pressure Vessel Code Case 1592 creep-fatigue design curve is made for a particular set of conditions. The second-order variables include the laboratories at which the data were generated, the different heats from which the test specimens were fabricated, and the heat treatments that preceded testing. These variables were statistically analyzed to determine their effect on fatigue life. The results are discussed, and the heats and heat treatments that are most resistant to fatigue damage under these loading and environmental conditions are identified

  7. Acoustic emission characteristics of stress corrosion cracks in a type 304 stainless steel tube

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Woong Gi; Bae, Seung Gi; Lee, Bo Young [School of Aerospace and Mechanical Engineering, Korea Aerospace University, Goyang (Korea, Republic of); Kim, Jae Seong [Center for Robot Technology and Manufacturing, Institute for Advanced Engineering, Yongin (Korea, Republic of); Kang, Sung Sik [Dept. of Nuclear Safety Research, Daejeon (Korea, Republic of); Kwag, Nog Won [Ultrasonic Division, RM910, Byucksan Digital Valley II, Seoul (Korea, Republic of)

    2015-06-15

    Acoustic emission (AE) is one of the promising methods for detecting the formation of stress corrosion cracks (SCCs) in laboratory tests. This method has the advantage of online inspection. Some studies have been conducted to investigate the characteristics of AE parameters during SCC propagation. However, it is difficult to classify the distinct features of SCC behavior. Because the previous studies were performed on slow strain rate test or compact tension specimens, it is difficult to make certain correlations between AE signals and actual SCC behavior in real tube-type specimens. In this study, the specimen was a AISI 304 stainless steel tube widely applied in the nuclear industry, and an accelerated test was conducted at high temperature and pressure with a corrosive environmental condition. The study result indicated that intense AE signals were mainly detected in the elastic deformation region, and a good correlation was observed between AE activity and crack growth. By contrast, the behavior of accumulated counts was divided into four regions. According to the waveform analysis, a specific waveform pattern was observed during SCC development. It is suggested that AE can be used to detect and monitor SCC initiation and propagation in actual tubes.

  8. Acoustic emission characteristics of stress corrosion cracks in a type 304 stainless steel tube

    Directory of Open Access Journals (Sweden)

    Woonggi Hwang

    2015-06-01

    Full Text Available Acoustic emission (AE is one of the promising methods for detecting the formation of stress corrosion cracks (SCCs in laboratory tests. This method has the advantage of online inspection. Some studies have been conducted to investigate the characteristics of AE parameters during SCC propagation. However, it is difficult to classify the distinct features of SCC behavior. Because the previous studies were performed on slow strain rate test or compact tension specimens, it is difficult to make certain correlations between AE signals and actual SCC behavior in real tube-type specimens. In this study, the specimen was a AISI 304 stainless steel tube widely applied in the nuclear industry, and an accelerated test was conducted at high temperature and pressure with a corrosive environmental condition. The study result indicated that intense AE signals were mainly detected in the elastic deformation region, and a good correlation was observed between AE activity and crack growth. By contrast, the behavior of accumulated counts was divided into four regions. According to the waveform analysis, a specific waveform pattern was observed during SCC development. It is suggested that AE can be used to detect and monitor SCC initiation and propagation in actual tubes.

  9. Optimization of control parameters for SR in EDM injection flushing type on stainless steel 304 workpiece

    International Nuclear Information System (INIS)

    Reza, M S; Yusoff, A R; Shaharun, M A

    2012-01-01

    The operating control parameters of injection flushing type of electrical discharge machining process on stainless steel 304 workpiece with copper tools are being optimized according to its individual machining characteristic i.e. surface roughness (SR). Higher SR during EDM machining process results for poor surface integrity of the workpiece. Hence, the quality characteristic for SR is set to lower-the-better to achieve the optimum surface integrity. Taguchi method has been used for the construction, layout and analysis of the experiment for each of the machining characteristic for the SR. The use of Taguchi method in the experiment saves a lot of time and cost of machining the experiment samples. Therefore, an L18 Orthogonal array which was the fundamental component in the statistical design of experiments has been used to plan the experiments and Analysis of Variance (ANOVA) is used to determine the optimum machining parameters for this machining characteristic. The control parameters selected for this optimization experiments are polarity, pulse on duration, discharge current, discharge voltage, machining depth, machining diameter and dielectric liquid pressure. The result had shown that the lower the machining diameter, the lower will be the SR.

  10. Electrochemical and SEM study on Type 254 SMO stainless steel in chloride solutions

    International Nuclear Information System (INIS)

    Abd El Meguid, E.A.; Abd El Latif, A.A.

    2004-01-01

    An investigation was conducted to examine the critical crevice potential (E crev ) and the critical protection potential (E prot ) for Type 254 SMO stainless steel in 4% NaCl solution by using potentiodynamic cyclic anodic polarization (PCAP) technique at temperature ranging from 30 to 90 deg. C. The critical crevice temperature (CCT) and the critical crevice protection temperature (T prot ) were determined by plotting the values of breakdown potential and E prot versus solution temperature, respectively. The values of CCT and T prot were recorded at the abrupt transition with increasing the temperature from transpassive corrosion to crevice corrosion and were found to be at 55 and 52 deg. C, respectively. Above CCT (70 deg. C) the following points were recorded. The E crev and E prot decreased linearly with log [Cl - ]. The addition of bromide ions to chloride ions at a fixed halide content of 4% increased both E crev and E prot . The E crev value in 4% NaCl increased linearly with increasing pH in the range 1-10. The addition of 0.5 M bicarbonate ions to 4% NaCl completely removed the crevices effect while increasing the addition of sulphate ions to 4% NaCl increased both of E crev and E prot . The morphology of the crevice corrosion produced on the steel surface was examined by scanning electron microscope (SEM) after PCAP treatment under different test conditions

  11. Tensile stress corrosion cracking of type 304 stainless steel irradiated to very high dose

    Energy Technology Data Exchange (ETDEWEB)

    Chung, H. M.; Ruther, W. E.; Strain, R. V.; Shack, W. J.

    2001-09-01

    Certain safety-related core internal structural components of light water reactors, usually fabricated from Type 304 or 316 austenitic stainless steels (SSs), accumulate very high levels of irradiation damage (20--100 displacement per atom or dpa) by the end of life. The data bases and mechanistic understanding of, the degradation of such highly irradiated components, however, are not well established. A key question is the nature of irradiation-assisted intergranular cracking at very high dose, i.e., is it purely mechanical failure or is it stress-commotion cracking? In this work, hot-cell tests and microstructural characterization were performed on Type 304 SS from the hexagonal fuel can of the decommissioned EBR-11 reactor after irradiation to {approximately}50 dpa at {approximately}370 C. Slow-strain-rate tensile tests were conducted at 289 C in air and in water at several levels of electrochemical potential (ECP), and microstructural characteristics were analyzed by scanning and transmission electron microcopies. The material deformed significantly by twinning and exhibited surprisingly high ductility in air, but was susceptible to severe intergranular stress corrosion cracking (IGSCC) at high ECP. Low levels of dissolved O and ECP were effective in suppressing the susceptibility of the heavily irradiated material to IGSCC, indicating that the stress corrosion process associated with irradiation-induced grain-boundary Cr depletion, rather than purely mechanical separation of grain boundaries, plays the dominant role. However, although IGSCC was suppressed, the material was susceptible to dislocation channeling at low ECP, and this susceptibility led to poor work-hardening capability and low ductility.

  12. 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.

  13. Microstructure of rapidly solidified Al2O3-dispersion-strengthened Type 316 stainless steel

    International Nuclear Information System (INIS)

    Megusar, J.; Arnberg, L.; Vander Sande, J.B.; Grant, N.J.

    1981-01-01

    An aluminum oxide dispersion strengthened 316 stainless steel was developed by surface oxidation. Surface oxidation was chosen as a preferred method in order to minimize formation of less stable chromium oxides. Ultra low C+N 316 stainless steel was alloyed with 1 wt % Al, rapidly solidified to produce fine powders and attrited to approximately 0.5 μm thick flakes to provide for surface oxidation. Oxide particles in the extruded material were identified mostly as Al oxides. In the preirradiated condition, oxide dispersion retarded crystallization and grain growth and had an effect on room temperature tensile properties. These structural modifications are expected to have an effect on the swelling resistance, structure stability and high temperature strength of austenitic stainless steels

  14. Determination of susceptibility to intergranular corrosion of stainless steels type X5CrNi18-10 in field

    Directory of Open Access Journals (Sweden)

    Bore V. Jegdic

    2016-12-01

    Full Text Available In this paper, the DL EPR method (electrochemical potentiokinetic reactivation with double loop was modified and used to study the susceptibility to intergranular corrosion and stress corrosion cracking of a stainless steel type X5CrNi18-10. The tests were performed in a special electrochemical cell, with the electrolyte in the gel form. Modified DL EPR method is characterized by simple and high accuracy measurements as well as repeatability of the test results. The indicator of susceptibility to intergranular corrosion (Qr/QpGBA obtained by modified DL EPR method is in a very good agreement with the same indicator obtained by standard DL EPR method. The modified DL EPR method is quantitative and highly selective method. Small differences in the susceptibility of the stainless steel type CrNi18-10 to intergranular corrosion and stress corrosion cracking can be determined. Test results can be obtained in a short time. The cost of tests performed by modified DL EPR method is much lower than the cost of tests by conventional chemical methods. Modified DL EPR method can be applied in the field on the stainless steels constructions.

  15. Effect of applied stress on chloride induced external stress corrosion cracking of type 304 stainless steel in air atmosphere

    International Nuclear Information System (INIS)

    Hayashibara, Hitoshi; Mayuzumi, Masami; Mizutani, Yoshihiro; Tani, Jun-ichi

    2006-01-01

    Austenitic stainless steels (SS) are widely used in various components of chemical plants, nuclear power plants, etc, because of the superior mechanical property and general corrosion resistance. However, it is also well known that austenitic stainless steels are susceptible to localized corrosion in the environments containing chloride ions, and several equipment in the plants built in coastal area has been suffering from chloride induced external stress corrosion cracking (ESCC). Hence, for the establishment of the countermeasures it is very important to clarify the factors governing ESCC process from the view points of stress, material and environmental conditions. The purpose of this study is to investigate the effect of applied stress on ESCC of type 304 stainless steel. ESCC tests were conducted on type 304 SS specimens, which were fabricated from a cold rolled plate, by a uniaxial constant load method using springs. After loading, droplets of synthetic sea water were put on the gage section of specimen and dried, and then the specimens were placed in a chamber with a constant temperature of 353 K and a relative humidity of 35%. The test specimens after the test were observed by a scanning electron microscope to measure the crack length and depth. No clear difference was found in the maximum values of the average crack propagation rate (crack depth divided by test time) among the applied stress conditions. In addition, most of ESCC were initiated from the bottom or periphery of pits under the low applied stress condition (0.5σ 0.2 ). (author)

  16. Substructures developed during creep and cyclic tests of type 304 stainless steel (heat 9T2796)

    Energy Technology Data Exchange (ETDEWEB)

    Swindeman, R.W.; Bhargava, R.K.; Sikka, V.K.; Moteff, J.

    1977-09-01

    Substructures developed in tested specimens of a reference heat of type 304 stainless steel (heat 9T2796) are examined. Data include dislocation densities, cell and subgrain sizes, and carbide precipitate sizes. Testing conditions range for temperatures from 482 to 649/sup 0/C, for stresses from 28 to 241 MPa, and for times from 4 to 15,000 hr. As expected, it is observed that temperature, stress, and time have strong influences on substructure. The change in the dislocation density is too small to measure for conditions which produce less than 1 percent monotonic strain. No cells form, and the major alteration of substructure is the precipitation of M/sub 23/C/sub 6/ carbides on grain boundaries, on twin boundaries, and on some dislocations. At stresses ranging from 69 to 172 MPa and at temperatures ranging from 482 to 593/sup 0/C, the dislocation density increases with increasing stress and is generally higher than expected from studies made at higher temperatures. Dislocations are arranged in fine networks stabilized by carbides. At stresses above 172 MPa and temperatures to 649/sup 0/C, the dislocation density is too great to measure. Cells develop which are finer in size than cells developed at similar stresses but at higher temperatures. Dislocation densities and cell sizes for cyclic specimens are comparable to data for creep-tested specimens. On the basis of the observed substructures, recommendations are made regarding further studies which would assist in the development of constitutive equations for high-temperature inelastic analysis of reactor components.

  17. Effect of stress during neutron irradiation on the microstructure of type 316 stainless steel

    International Nuclear Information System (INIS)

    Brager, H.R.; Garner, F.A.; Guthrie, G.L.

    1976-04-01

    A transmission electron microscopy (TEM) examination was performed on solution annealed and 20 percent cold-worked Type 316 stainless steel specimens stressed during irradiation at 500 0 C in EBR-II. Hoop stress levels ranged from 0 to 327 MN/m 2 (47,300 psi) and fluences between 2.0 and 3.0 x 10 22 n/cm 2 (E greater than 0.1 MeV). Data confirm that applied tensile stresses enhance swelling in the solution annealed steel. The number densities of both voids and Frank loops were sensitive to the stress environment. Total swelling in the annealed material increased with stress, but not in direct proportion to the increased void nucleation. While the effect of cold working was to suppress swelling, the nucleation and growth of Frank loops was unaffected by the cold worked microstructure. The individual planar loop densities within any one specimen were quite sensitive to the magnitude of the stress component normal to the loop plane, while the total loop number density was sensitive to a smaller degree of the magnitude of the hydrostatic stress level. The number and size distribution of the loop populations were unaffected by the planar shear stress components, but the mean loop sizes were found to be limited by the probability of loop intersection with dislocations and loops. The stress dependence of void and loop densities allowed determination of the critical nuclei sizes, approximately sixteen vacancies for voids and six atoms for loops. Many observations were made on the probable creep mechanisms. Both dislocation and void microstructures evolved in a consistent stress-dependent manner, giving support to models which predict a coupling of the swelling and irradiation creep phenomena through the stress environment. 13 figures, 3 tables

  18. Intergranular crack propagation rates in sensitized Type 304 stainless steel in an oxygenated water environment

    International Nuclear Information System (INIS)

    Park, J.Y.; Shack, W.J.

    1983-01-01

    Intergranular stress-corrosion crack (IGSCC) propagation rates were measured in three heats of sensitized Type 304 stainless steel (SS) as a function of applied load and sensitization in high-purity water with 8 ppM. Active-loading tests yielded IGSCC propagation rates ranging from approx. 2 x 10 -10 to 1 x 10 -9 m/s (approx. 2 x 10 -5 to 2 x 10 -4 in./h) over the range of stress intensities from 25 to 46 MPa√m (22 to 41 ksi√in.). If the dependence of propagation rate on stress intensity is assumed to follow a power law, a least-squares fit of data yields (da/dt) = 1.23 x 10 -8 K 2 42 (in./h) for K in ksi√in. Deflection-controlled tests on standard 12.7-mm-thick compact tension specimens yielded IGSCC propagation rates from 7 x 10 -12 to 2 x 10 -10 m/s (10 -6 to 2 x 10 -5 in./h) at effective average stress intensities in the range 21 to 26 MPa√m (19 to 24 ksi√in.). Crack lengths were determined by compilance measurements using in-situ high-temperature clip gage or LVDT methods, optical metallography on the side faces of the specimen, and fractography of the cracked surface after completion of the tests. The optical metallography measurements did not provide useful estimates of crack lengths, because large variations in IGSCC propagation across the thickness of the specimens occurred. The effects of the degree of sensitization on the IGSCC propagation rate are obscured by the data scatter. However, it seems clear that these variables do not lead to order-of-magnitude changes in the crack propagation rate

  19. Evaluation on Safety of Stainless Steels in Chemical Decontamination Process with Immersion Type of Reactor Coolant Pump for Nuclear Reactor

    International Nuclear Information System (INIS)

    Kim, Seong Jong; Han, Min Su; Jang, Seok Ki; Kim, Ki Joon

    2011-01-01

    Due to commercialization of nuclear power, most countries have taken interest in decontamination process of nuclear power plant and tried to develop a optimum process. Because open literature of the decontamination process are rare, it is hard to obtain skills on decontamination of foreign country and it is necessarily to develop proper chemical decontamination process system in Korea. In this study, applicable possibility in chemical decontamination for reactor coolant pump (RCP) was investigated for the various stainless steels. The stainless steel (STS) 304 showed the best electrochemical properties for corrosion resistance and the lowest weight loss ratio in chemical decontamination process with immersion type than other materials. However, the pitting corrosion was generated in both STS 415 and STS 431 with the increasing numbers of cycle. The intergranular corrosion in STS 431 was sporadically observed. The sizes of their pitting corrosion also increased with increasing cycle numbers

  20. Articles comprising ferritic stainless steels

    Science.gov (United States)

    Rakowski, James M.

    2016-06-28

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

  1. 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

  2. Formation Mechanism of Spinel-Type Inclusions in High-Alloyed Stainless Steel Melts

    Science.gov (United States)

    Park, Joo Hyun

    2007-08-01

    Fundamental thermodynamics of the relationship between high-alloyed stainless steel melts (Fe-20 mass pct Cr-13 mass pct Ni-3 mass pct Si) and the inclusions were investigated. The formation mechanism of the inclusions containing the spinel crystals was developed based on the experimental results and from the compositions of the inclusions in the steel samples taken during plant operations. The molar content of alumina in the inclusions was found to be linearly proportional to the increase of aluminum content, indicating that the inclusions could contain alumina even with less than about 200 ppm aluminum in the steel melt, e.g., steel melts that were mainly deoxidized by silicon. Furthermore, the composition of the inclusions is shown to be a function of the activity of the deoxidizers such as aluminum and silicon in the steel melt. From the analysis of the plant samples, it was found that the contents of MgO and Al2O3 in the calcium silicate type inclusions increased continuously as the steel melt transfers from the argon oxygen decarburization (AOD) converter to the tundish. This composition change in the inclusions originated from the reduction of MgO and Al2O3 in the slags or refractories by silicon in the steel melt. Increases of MgO and Al2O3 contents were prominent in tundish samples, and thus, the spinel phase could be crystallized in the calcium silicate inclusion matrix in the tundish; and finally the spinel crystals grew during cooling of the steel melt through the continuous casting (CC) mold and in the slabs. On the other hand, manganese silicate type inclusions containing chromium oxide were observed after tapping of the molten steel to the ladle. The MnO and Cr2O3 in these inclusions was initially reduced by silicon in the steel melt in the ladle treatment (LT) process, followed by further reduction by aluminum through the LT to the CC mold. The fractions of inclusions containing spinel crystals in cast slabs were negligible at the alumina content of

  3. Effect of Different Types of Toothpaste on the Frictional Resistance between Orthodontic Stainless Steel Brackets and Wires

    Directory of Open Access Journals (Sweden)

    Tahereh Hosseinzadeh Nik

    2017-12-01

    Full Text Available Objectives: The purpose of this study was to investigate the effect of different types of toothpaste on the frictional resistance between stainless steel brackets and archwires.Materials and Methods: Ninety stainless steel orthodontic brackets with stainless steel wires were bonded to bovine teeth and were divided into 6 groups for application of the following toothpastes: Colgate® Total® Advanced Whitening, Colgate® Total® Pro Gum Health, Colgate® Anticavity, Ortho.Kin®, and Sunstar GUM® Ortho toothpastes. No toothpaste was applied in the control group. Each group was brushed by a brushing machine with the use of the designated solution for 4.5 minutes. The frictional force was measured in a universal testing machine with a crosshead speed of 10 mm/minute over a 5-mm archwire. Data were analyzed using one-way analysis of variance (ANOVA at the 0.05 significance level.Results: The frictional resistance values of Ortho.Kin® and GUM® Ortho toothpastes and the control group were not significantly different (P>0.05. However, there were significant differences between the frictional resistance values of Colgate® Total® Pro Gum Health and Colgate® Anticavity toothpastes with that of the control group (P<0.05. The highest and lowest frictional resistance values were related to Colgate® Total® Pro Gum Health toothpaste and the control group, respectively.Conclusions: Among the evaluated toothpastes, the orthodontic toothpastes did not increase the frictional resistance between the orthodontic stainless steel brackets and wires.

  4. Fatigue-crack growth behavior of Type 347 stainless steels under simulated PWR water conditions

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Seokmin; Min, Ki-Deuk; Yoon, Ji-Hyun; Kim, Min-Chul; Lee, Bong-Sang [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    Fatigue crack growth rate (FCGR) curve of stainless steel exists in ASME code section XI, but it is still not considering the environmental effects. The longer time nuclear power plant is operated, the more the environmental degradation issues of materials pop up. There are some researches on fatigue crack growth rate of S304 and S316, but researches of FCGR of S347 used in Korea nuclear power plant are insufficient. In this study, the FCGR of S347 stainless steel was evaluated in the PWR high temperature water conditions. The FCGRs of S347 stainless steel under pressurized-water conditions were measured by using compact-tension (CT) specimens at different levels of dissolved oxygen (DO) and frequency. 1. FCGRs of SS347 were slower than that in ASME XI and environmental effect did not occur when frequency was higher than 1Hz. 2. Fatigue crack growth is accelerated by corrosion fatigue and it is more severe when frequency is slower than 0.1Hz. 3. Increase of crack tip opening time increased corrosion fatigue and it deteriorated environmental fatigue properties.

  5. Hydrogen embrittlement of type 410 stainless steel in sodium chloride, sodium sulfate, and sodium hydroxide environments at 90 C

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Rodriguez, J.G.; Salinas-Bravo, V.M. [Inst. de Investigaciones Electricas, Cuernavaca (Mexico). Dept. Fisico Quimica Aplicada; Martinez-Villafane, A. [Centro de Investigaciones en Materiales Avanzados Leon Tolstoi, Chihuahua (Mexico)

    1997-06-01

    Susceptibility of martensitic type 410 (UNS S41000) stainless steel (SS) to environmental cracking was evaluated at 90 C in concentrated sodium chloride, sodium sulfate and sodium hydroxide solutions, all of which are environments related to steam turbine conditions, using the slow strain rate testing (SSRT) technique. In NaCl, the effects of solution pH, concentration, and anodic and cathodic polarization were investigated. Tests were supplemented by detailed electron fractography and hydrogen permeation measurements. A clear correlation was found between the degree of embrittlement and the amount of hydrogen permeating the steel, suggesting a hydrogen-induced cracking mechanism.

  6. Deformation effects on the development of grain boundary chronium depletion (sensitization) in type 316 austenitic stainless steels

    International Nuclear Information System (INIS)

    Atteridge, D.G.; Wood, W.E.; Advani, A.H.; Bruemmer, S.M.

    1990-01-01

    Deformation induces an acceleration in the kinetics and reduction in the thermodynamic barrier to carbide precipitation and grain boundary chromium depletion (GBCD) development of a high carbon Type 316 stainless steel (SS). This was observed in a study on strain effects on GBCD (or sensitization) development in the range of 575 degree C to 775 degree C. Grain boundary chromium depletion behavior of SS was examined using the indirect electrochemical potentiokinetic reactivation (EPR) test and supported by studies on carbide precipitation using transmission electron microscopy (TEM). 99 refs., 84 figs., 9 tabs

  7. 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

  8. The Effect of Wire Dimension, Type and Thickness of Coating Layer on Friction of Coated Stainless-Steel Arch Wires

    Directory of Open Access Journals (Sweden)

    Ahmed Abdulhussain Abbas

    2018-03-01

    Full Text Available Background/Purpose: Esthetic coated arch wires are the desired types to match esthetic brackets in the clinical orthodontics, but the presence of coating layer is greatly affect friction during sliding mechanics. The aims of this study were to evaluate the effect of total wire dimension with the type and thickness of coating layer on friction of coated stainless-steel wires. Methods: The sample of this study consisted of 140 segments of coated stainless-steel arch wires involving two wire dimensions (0.016 × 0.022 inch and 0.019 × 0.025 inch. The samples were supplied from seven companies (DB, RMO, TP, DANY, G&H, Highland and Hubit and the uncoated control samples were supplied from IOS company. Wire dimensions and thickness of coating layer were measured by the metallurgical light incident microscope and the static frictional force was measured using pulling the wire through set of ceramic brackets by the universal testing machine. The data were then statistically analyzed using ANOVA tests. Results: Generally measured wire dimensions do not match the stated dimensions by the manufacturer. The frictional forces of coated wires differ from uncoated control being higher in the labially coated wires and lesser in the fully Teflon coated wires owing to differences in the wire dimension, thickness of coating layer, and physical properties of coating materials. Conclusion: when tested in vitro, Teflon fully coated wires produce the least amount of friction.

  9. In situ X-ray diffraction of surface oxide on type 430 stainless steel in breakaway condition using synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Saeki, Isao, E-mail: isaos@mmm.muroran-it.ac.jp [Department of Materials Science and Engineering, Muroran Institute of Technology, 27-1 Mizumoto, Muroran, Hokkaido 050-8585 (Japan); Sugiyama, Yusuke [Graduate School of Engineering, Muroran Institute of Technology, 27-1 Mizumoto, Muroran, Hokkaido 050-8585 (Japan); Hayashi, Shigenari; Yamauchi, Akira [Graduate School of Engineering, Hokkaido University, Kita 13 Nishi 8, Kita-ku, Sapporo, Hokkaido 006-8628 (Japan); Doi, Takashi; Nishiyama, Yoshitaka [Corporate R and D Laboratories, Sumitomo Metals Industries Ltd., 1-8 Fuso-cho, Amagasaki, Hyogo 660-0891 (Japan); Kyo, Shoji [Power Engineering R and D Centre, Kansai Electric Power Co., Inc., 3-11-20 Wakaoji, Amagasaki, Hyogo 661-0794 (Japan); Suzuki, Shigeru [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan); Sato, Masugu [Japan Synchrotron Radiation Research Institute, 1-1-1 Koto, Sayo-cho, Hyogo 679-5198 (Japan); Fujimoto, Shinji [Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan)

    2012-02-15

    Highlights: Black-Right-Pointing-Pointer Breakaway studied with Synchrotron radiation X-ray. Black-Right-Pointing-Pointer Local equilibria between phases established during high-temperature oxidation. Black-Right-Pointing-Pointer Chemical failure model well describes the breakaway. - Abstract: Changes in the crystal structure of type 430 stainless steel and the oxides on its surface were studied in situ at 1373 K using a high-intensity synchrotron X-ray source provided by SPring-8 in Japan. The surface of the steel was initially covered with Cr{sub 2}O{sub 3}, which was then converted to FeCr{sub 2}O{sub 4}, and finally Fe{sub 3}O{sub 4} and Fe{sub 2}O{sub 3} formed on it. These results indicated that the reason for the breakaway oxidation in type 430 stainless steel is Cr depletion beneath Cr{sub 2}O{sub 3} layer and the subsequent ionisation of Fe, not the simple mechanical failure of Cr{sub 2}O{sub 3}.

  10. The microstructure of type 304 stainless steel implanted with titanium and carbon and its relation to friction and wear tests

    International Nuclear Information System (INIS)

    Follstaedt, D.M.; Pope, L.E.; Knapp, J.A.; Picraux, S.T.; Yost, F.G.

    1983-01-01

    The authors have used transmission electron microscopy to examine the microstructure of type 304 stainless steel which was ion implanted with high doses (2 X 10 17 atoms cm -2 ) of titanium and carbon. It is found that the resulting surface alloy is an amorphous phase similar to that observed when pure iron is identically implanted. This result is important for identifying the mechanisms by which the coefficient of friction and the wear depth are reduced in unlubricated pin-on-disc tests of type 304 stainless steel implanted with titanium and carbon. The effect of temperature on the amorphous alloy during annealing in the microscope has also been examined. It is found that devitrification begins after 15 min at 500 0 C and that the alloy fully crystallizes into f.c.c., b.c.c. and TiC phases after 15 min at 650 0 C. A comparison of mechanical test results from devitrified specimens with results from amorphous specimens demonstrates that the reduction in the coefficient of friction correlates with the presence of the amorphous layer, whereas the reduction in the wear depth is obtained for both amorphous and crystalline alloys. (Auth.)

  11. Aspects of plasma arc cutting process in the AISI 321 type stainless steel

    International Nuclear Information System (INIS)

    Souza Barros, I. de.

    1985-01-01

    Some aspects of plasma arc cutting process in the AISI321 stainless steel, used in nuclear industry, are analysed. The maximum values of the velocity of cutting and, the minimum quantity of energy per unit of length necesary for the plasma were determined. The localization of irregularities in the cut surface in function of the velocity of cutting was investigated. The cut surfaces were evaluated by surface roughness, using as measurement parameter, the distance between the sharpest salience and the deepest reentrance of the sample profile. The width of layer from thermal action of the plasma was influenced by the velocity of cutting. (Author) [pt

  12. Decontamination of Stainless Steel SS 304 Type with Pressurized CO2 Solid

    International Nuclear Information System (INIS)

    Sutoto

    2007-01-01

    The abrasive decontamination of the stainless steel valve using 12 bar pressurized CO 2 solid has been done. Experiment activities was performed in the HOT CELL facility with variation of blasting time 15, 30, 45 and 60 seconds. The result of experiment shown that the operation of abrasive decontamination during 45 seconds gives the decreasing of the equipment radiation dose rate from 460 to 200 mRem/h and decontamination factor 1.35. The secondary waste from decontamination activities was treated by filtration method using HEPA filter and activated carbon filter. (author)

  13. On the high cycle fatigue behavior of a type 304L stainless steel at room temperature

    International Nuclear Information System (INIS)

    Vincent, Ludovic; Le Roux, Jean-Christophe; Taheri, Said

    2012-01-01

    An extensive study of the uniaxial cyclic material behavior of an AISI 304L austenitic stainless steel is proposed in the high cycle regime and in constant amplitude loadings. More particularly, the effect on the material behavior and lifetime of a mean axial stress is evaluated imposing either a stress or a strain amplitude. Almost no effect is observed on the stress fatigue curve while a reduction of about 30% is obtained on the strain fatigue curve in the endurance regime. It appears that a stress amplitude fatigue parameter or a Smith-Watson-Topper parameter predict accurately such differences based on the material behavior at maximum cyclic softening. (authors)

  14. Nickel and chromium ion release from stainless steel bracket on immersion various types of mouthwashes

    Science.gov (United States)

    Mihardjanti, M.; Ismah, N.; Purwanegara, M. K.

    2017-08-01

    The stainless steel bracket is widely used in orthodontics because of its mechanical properties, strength, and good biocompatibility. However, under certain conditions, it can be susceptible to corrosion. Studies have reported that the release of nickel and chromium ions because of corrosion can cause allergic reactions in some individuals and are mutagenic. The condition of the oral environment can lead to corrosion, and one factor that can alter the oral environment is mouthwash. The aim of this study was to measure the nickel and chromium ions released from stainless steel brackets when immersed in mouthwash and aquadest. The objects consisted of four groups of 17 maxillary premolar brackets with .022 slots. Each group was immersed in a different mouthwash and aquadest and incubated at 37 °C for 30 days. After 30 days of immersion, the released ions were measured using the ICP-MS (Inductively Coupled Plasma-Mass Spectrometer). For statistical analysis, both the Kruskal-Wallis and Mann-Whitney tests were used. The results showed differences among the four groups in the nickel ions released (p World Health Organization.

  15. Swelling and microstructural development in path A PCA and type 316 stainless steel irradiated in HFIR to about 22 dpa

    International Nuclear Information System (INIS)

    Maziasz, P.J.; Braski, D.N.

    1983-01-01

    Irradiation of several microstructural variants of PCA and 20%-cold-worked N-lot type 316 stainess steel (CW 316) in HFIR to about 10 dpa produced no visible cavities at 300 0 C, bubbles at 400 0 C, and varying distributions of bubbles and voids at 500 and 600 0 C. The PCA-B1 swells the most and CW 316 (N-lot) the least at 600 0 C. Irradiations have been extended to about 22 dpa. The PCA-Al swells 0.06%/dpa at 600 0 C but at a much lower rate at 500 0 C. The PCA-A3 shows the lowest swelling at 600 0 C, about the half the swelling rate of type 316 stainless steel

  16. Effects of laser surface melting on the pitting resistance of sensitized nitrogen-bearing type 316L stainless steel

    International Nuclear Information System (INIS)

    Kamachi Mudali, U.; Pujar, M.G.; Dayal, R.K.

    1998-01-01

    Austenitic stainless steels (SS) form a major part of the structural materials for fast reactors because of their excellent mechanical properties at high temperatures and good corrosion resistance in general. Here, laser surface melting of sensitized nitrogen-bearing type 316L austenitic stainless steel was carried out using a pulsed ruby laser. The sensitization heat treatment was carried out at 923 K for 50, 200, 1,000, and 2,500 h, and the sensitized microstructure was classified according to ASTM A 262 practice A. The degree of sensitization was assessed by the electrochemical potentiokinetic reactivation (EPR) test. The critical pitting potentials of as-sensitized as well as sensitized-laser melted specimens were determined by potentiodynamic anodic polarization method in a medium containing 0.5 M NaCl and 0.5 M H 2 SO 4 at room temperature. Results indicated that upon laser melting the pitting resistance increased significantly. This increase was attributed to the elimination of the sensitized heterogeneous microstructure by laser melting. The microscopic examination of the pitted specimens showed only micropits that developed at the interfaces of oxide/sulfide inclusions of titanium and matrix

  17. 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...

  18. An assessment of Raman spectroscopy to detect iodine deposited on thin oxide films formed on Type 316 stainless steel

    International Nuclear Information System (INIS)

    Allen, G.C.; Tyler, J.W.

    1989-04-01

    Iodine-131 is one of the most important volatile fission product elements with respect to radiobiological impact, and the characterisation of its chemical state and distribution on reactor surfaces is required for reactor safety assessments. To this end, duplicate samples of Type 316 (17%Cr/12%Ni) stainless steel oxidised in Co 2 /CH 3 I gas mixtures and previously characterised using X-ray photoelectron spectroscopy have been examined using Raman spectroscopy. The aim is to improve our understanding of the way in which iodine is distributed throughout the oxide scale and to identify its chemical state. In this report we present Raman spectra recorded from a series of stainless steel specimens together with spectra recorded from a number of standard iodine compounds. It is demonstrated that the technique is well suited as a fingerprint method of species identification, can differentiate between the chemical state of iodine as iodide and iodate and can analyse thin oxide films (5-50 nm). Identification of iodine deposits in these oxide films at concentrations of ≤1 At% was not achieved however, there being insufficient iodine present to distinguish any peaks present from the background signal. It is concluded that local concentrations of iodine in oxide inclusions of different composition/morphology on the steel surface does not occur to any extent. (author)

  19. Corrosion of path A PCA, type 316 stainless steel and Fe-12 Cr-1 MoVW steel in flowing lithium

    International Nuclear Information System (INIS)

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

    1983-01-01

    Results from lithium thermal-convection loop (TCL) experiments with the path A prime candidate alloy (PCA), type 316 stainless steel, and Fe-12 Cr-1 MoVW are presented. The short-term ( 0 C yielded the same dissolution rate as the steady-state value for nickel-depleted type 316 stainless steel. Significant weight losses were measured in the cold leg of this loop, and they appeared to be related to chromium depletion (possibly as a result of impurity reactions)

  20. Shallow-Land Buriable PCA-type austenitic stainless steel for fusion application

    International Nuclear Information System (INIS)

    Zucchetti, M.

    1991-01-01

    Neutron-induced activity in the PCA (Primary Candidate Alloy) austenitic stainless steel is examined, when used for first-wall components in a DEMO fusion reactor. Some low-activity definitions, based on different waste management and disposal concepts, are introduced. Activity in the PCA is so high that any recycling of the irradiated material can be excluded. Disposal of PCA radioactive wastes in Shallow-Land Buriable (SLB) is prevented as well. Mo, Nb and some impurity elements have to be removed or limited, in order to reduce the radioactivity of the PCA. Possible low-activity versions of the PCA are introduced (PCA-la); they meet the requirements for SLB and may also be recycled under certain conditions. (author)

  1. Evaluation of weight loss of stainless steels in supercritical water

    International Nuclear Information System (INIS)

    Maruno, Yusaku; Kaneda, Junya; Kasahara, Shigeki; Saito, Norihisa; Shikama, Tatsuo; Matsui, Hideki

    2009-01-01

    The supercritical water-cooled reactor (SCWR) is one of the Generation IV nuclear systems. According to a planned design for the SCWR, the temperature of the main steam is supposed to be 560degC and the surface temperature of the fuel cladding, which has a thickness of only 0.45 mm, is supposed to reach 700degC. General corrosion is one of the most critical issues for designing the fuel cladding when taking these temperature conditions into account. Therefore, the general corrosive behavior of candidate cladding materials under the SCWR conditions needs to be evaluated. In particular, from the viewpoint of a safe-life design for the SCWR, it is necessary to evaluate the amount of weight loss, which reflects the corrosion resistance, under the SCWR conditions before selecting the most promising materials for the fuel claddings. This paper reports on the weight loss of Type304, Type316L, Type310S, 12Cr-1Mo-1WVNb, modified Type316L, and modified Type310S under 500, 550, and 600degC supercritical water conditions. After the corrosion tests were finished, the oxide film from the specimen was removed using molten lithium. The weight loss was measured as the difference in weight of the same specimen before and after the corrosion test without the oxide film. The results showed that the weight loss increased along with the test temperature. On the basis of the Arrhenius equation, a linear relationship was observed between the weight loss and the reciprocal of the temperature. Type310S and modified Type310S had a smaller weight loss than Type316L, Type304, and 12Cr-1Mo-1WVNb. In addition, the weight loss of these candidate materials at 700degC during 50000h was extrapolated by the Arrhenius equation. Meanwhile, the reduced thicknesses of Type310S and modified Type310S were estimated as 45 μm or less, which is 10% or less of the thickness of the fuel claddings. Based on the above results, Type310S and modified Type310S were the most promising alloys for the fuel cladding

  2. Evaluation of AISI Type 304 stainless steel as a suitable surface material for evaluating the efficacy of peracetic acid-based disinfectants against Clostridium difficile spores.

    Science.gov (United States)

    Black, Elaine; Owens, Krista; Staub, Richard; Li, Junzhong; Mills, Kristen; Valenstein, Justin; Hilgren, John

    2017-01-01

    Disinfectants play an important role in controlling microbial contamination on hard surfaces in hospitals. The effectiveness of disinfectants in real life can be predicted by laboratory tests that measure killing of microbes on carriers. The modified Quantitative Disk Carrier Test (QCT-2) is a standard laboratory method that employs American Iron and Steel Institute (AISI) Type 430 stainless steel carriers to measure hospital disinfectant efficacy against Clostridium difficile spores. The formation of a rust-colored precipitate was observed on Type 430 carriers when testing a peracetic acid (PAA)-based disinfectant with the QCT-2 method. It was hypothesized that the precipitate was indicative of corrosion of the Type 430 carrier, and that corrosion could impact efficacy results. The objective of this study was to compare the suitability of AISI Type 430 to Type 304 stainless steel carriers for evaluating PAA-based disinfectants using the QCT-2 method. Type 304 is more corrosion-resistant than Type 430, is ubiquitous in healthcare environments, and is used in other standard methods. Suitability of the carriers was evaluated by comparing their impacts on efficacy results and PAA degradation rates. In efficacy tests with 1376 ppm PAA, reductions of C. difficile spores after 5, 7 and 10 minutes on Type 430 carriers were at least about 1.5 log10 lower than reductions on Type 304 carriers. In conditions simulating a QCT-2 test, PAA concentration with Type 430 carriers was reduced by approximately 80% in 10 minutes, whereas PAA concentration in the presence of Type 304 carriers remained stable. Elemental analyses of residues on each carrier type after efficacy testing were indicative of corrosion on the Type 430 carrier. Use of Type 430 stainless steel carriers for measuring the efficacy of PAA-based disinfectants should be avoided as it can lead to an underestimation of real life sporicidal efficacy. Type 304 stainless steel carriers are recommended as a suitable

  3. Evaluation of AISI Type 304 stainless steel as a suitable surface material for evaluating the efficacy of peracetic acid-based disinfectants against Clostridium difficile spores.

    Directory of Open Access Journals (Sweden)

    Elaine Black

    Full Text Available Disinfectants play an important role in controlling microbial contamination on hard surfaces in hospitals. The effectiveness of disinfectants in real life can be predicted by laboratory tests that measure killing of microbes on carriers. The modified Quantitative Disk Carrier Test (QCT-2 is a standard laboratory method that employs American Iron and Steel Institute (AISI Type 430 stainless steel carriers to measure hospital disinfectant efficacy against Clostridium difficile spores. The formation of a rust-colored precipitate was observed on Type 430 carriers when testing a peracetic acid (PAA-based disinfectant with the QCT-2 method. It was hypothesized that the precipitate was indicative of corrosion of the Type 430 carrier, and that corrosion could impact efficacy results. The objective of this study was to compare the suitability of AISI Type 430 to Type 304 stainless steel carriers for evaluating PAA-based disinfectants using the QCT-2 method. Type 304 is more corrosion-resistant than Type 430, is ubiquitous in healthcare environments, and is used in other standard methods. Suitability of the carriers was evaluated by comparing their impacts on efficacy results and PAA degradation rates. In efficacy tests with 1376 ppm PAA, reductions of C. difficile spores after 5, 7 and 10 minutes on Type 430 carriers were at least about 1.5 log10 lower than reductions on Type 304 carriers. In conditions simulating a QCT-2 test, PAA concentration with Type 430 carriers was reduced by approximately 80% in 10 minutes, whereas PAA concentration in the presence of Type 304 carriers remained stable. Elemental analyses of residues on each carrier type after efficacy testing were indicative of corrosion on the Type 430 carrier. Use of Type 430 stainless steel carriers for measuring the efficacy of PAA-based disinfectants should be avoided as it can lead to an underestimation of real life sporicidal efficacy. Type 304 stainless steel carriers are recommended as a

  4. Void formation in cold-worked type 316 stainless steel irradiated with 1-MeV protons

    International Nuclear Information System (INIS)

    Keefer, D.W.; Pard, A.G.

    1974-01-01

    Cold-worked Type 316 stainless steel was irradiated at 500 and 600 0 C with 1-MeV protons. The dependence of void formation on displacement damage, irradiation temperature, and microstructure was studied by transmission electron microscopy. Cold working delays the onset of swelling and reduces it, via a reduction in void size, at both irradiation temperatures. Inhomogeneity in the cold-worked microstructure leads to inhomogeneity in the disposition of voids. Swelling at 600 is greater than at 500 0 C; the voids are less numerous but larger at the higher temperature. No change in the cold-worked microstructure can be detected by transmission electron microscopy after 500 0 C irradiation to 23 displacements per atom. Irradiation to a comparable damage level at 600 0 C results in almost complete elimination of the cold-worked microstructure. Comparison of the results is made with data from reactor irradiation experiments

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

    Energy Technology Data Exchange (ETDEWEB)

    Sivai Bharasi, N. [Corrosion Science and Technology Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamil Nadu (India)], E-mail: sivai@igcar.gov.in; Thyagarajan, K.; Shaikh, H. [Corrosion Science and Technology Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamil Nadu (India); Balamurugan, A.K. [Materials Science Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamil Nadu (India); Bera, Santanu [Water and Steam Chemistry Division, Bhabha Atomic Research Centre, Kalpakkam 603 102, Tamil Nadu (India); Kalavathy, S. [Materials Science Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamil Nadu (India); Gurumurthy, K. [Fast Reactor Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamil Nadu (India); Tyagi, A.K. [Materials Science Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamil Nadu (India); Dayal, R.K. [Corrosion Science and Technology Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamil Nadu (India); Rajan, K.K. [Fast Reactor Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamil Nadu (India); Khatak, H.S. [Corrosion Science and Technology Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamil Nadu (India)

    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 {mu}m and a surface carburized layer of about 30 {mu}m. 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.

  6. The influences of sulphur and phosphorus additions on the creep cavitation characteristics in type 304 stainless steels

    International Nuclear Information System (INIS)

    Jun Hwa Hong; Soo Woo Nam; Sun Pil Choi

    1986-01-01

    The effects of impurities on creep cavitation characteristics in type 304 stainless steels with and without additions of sulphur and/or phosphorus have been studied using four experimental heats. Over a limited range of stress at 1000 K, the change in size distribution of creep cavities and carbide precipitates, and the level of impurity segregation with the amount of addition have been investigated. It is found that phosphorus accelerates the nucleation of creep cavities, but retards the growth of them. However, sulphur had little effect on both nucleation and growth of the cavities. It has also been found that ageing prior to testing inhibits creep cavitation. The effects of impurities on cavitation are analysed and discussed from the viewpoint of the change in the segregation of impurities and the precipitation of carbides due to impurity additions. (author)

  7. Improving pitting corrosion resistance of type 304 austenitic stainless steel pipe weldments using purging gases with low amounts of oxygen

    International Nuclear Information System (INIS)

    Huang, W.; Paciej, R.; Link, L.; Mckeown, M.

    1993-01-01

    Pitting corrosion on the welded joints of water pipe lines may cause the shut down of nuclear power plants. The susceptibility to pitting corrosion is usually increased by high temperature oxidation during welding. In this study, an attempt was made to improve the pitting corrosion resistance of type 304 austenitic stainless steel pipe weldments by reducing the oxygen level in the purging gases. The pitting corrosion resistance of the as-received weldments was determined using stepwise cyclic polarization in aqueous solution containing chloride ions. It was found that relatively high oxygen levels (1-2%) in the purging gases caused severe high temperature oxidation, resulting in a non-uniform, porous, cracked, and thick surface oxide layer on the fusion and heat affected zones on the root pass of the pipe weldments. This high temperature oxidation also created a non-uniform distribution of chromium in the surface oxide layer, which, in turn, caused preferential pitting in the chromium depleted areas

  8. Creep and rupture behavior of weld-deposited Type 16-8-2 stainless steel at 5930C

    International Nuclear Information System (INIS)

    Ward, A.L.; Blackburn, L.D.

    1976-03-01

    The creep and rupture behavior of weld-deposited Type 16-8-2 stainless steel at 593 0 C was investigated over the time range from 3.6 x 10 4 s to 2.5 x 10 7 s. Equations relating stress to the time to rupture, the time to the onset of tertiary creep, and the time to produce a given creep strain were obtained. The experimental results indicate that the control of welding parameters (e.g. current, voltage and travel speed) within reasonable ranges can yield weld deposits with consistent time-dependent properties. Limited data suggest that high temperature (1065 0 C) post-weld annealing significantly alters only the flow curve for plastic deformation, while long-term thermal exposure at an intermediate temperature (565 0 C) produces only minor changes in either the plastic deformation or creep behavior of the weld materials

  9. Application of Strainrange Partitioning to the prediction of creep-fatigue lives of AISI Types 304 and 316 stainless steel

    Science.gov (United States)

    Saltsman, J. F.; Halford, G. R.

    1977-01-01

    As a demonstration of the predictive capabilities of the method of Strainrange Partitioning, published high-temperature, low cycle, creep-fatigue test results on AISI Types 304 and 316 stainless steel were analyzed and calculated cyclic lives compared with observed lives. Predicted lives agreed with observed lives within factors of two for 76 percent, factors of three for 93 percent, and factors of four for 98 percent of the laboratory tests analyzed. Agreement between observed and predicted lives is judged satisfactory considering that the data are associated with a number of variables (two alloys, several heats and heat treatments, a range of temperatures, different testing techniques, etc.) that are not directly accounted for in the calculations.

  10. Effect of nitrogen on the creep-fatigue behaviors of type 316L(N) stainless steel

    International Nuclear Information System (INIS)

    Kim, Dae Whan; Kim, Woo Gon; Ryu, Woo Seog

    2001-01-01

    Creep-fatigue tests including hold time of 10 minute at the maximum tensile strain were conducted for type 316(N) stainless steels containing different nitrogen content of 0.04 and 0.10 wt% at 600 .deg. C and 2x10 -3 /sec in air atmosphere. Creep-fatigue life was decreased with the hold time but was increased with the addition of nitrogen. Fracture modes were intergranular regardless of nitrogen content. Dislocation structures were changed from cell to planar with the addition of nitrogen. Carbides (M 23 C 6 ) were precipitated at grain boundaries and acted as the site for cavitation. Carbides were continuous in the low nitrogen content steel but discontinuous in high nitrogen content steel. The increase of creep-fatigue life with the addition of nitrogen is attributed to the distribution of carbides at grain boundaries rather than the change of dislocation structures

  11. Improvement of solidification cracking susceptibility of electron beam weld metal of fully austenitic type 316 stainless steel

    International Nuclear Information System (INIS)

    Nakao, Yoshikuni; Katsu, Shinichiro

    1986-01-01

    The effect of rare earth metals (REM) addition on the solidification cracking susceptibility of electron beam weld metals in fully austenitic Type 316 stainless steel was researched. The cracking susceptibility of this steel is put in order by REM and P or (P + S) content. Adding proper content of REM (about 0.25 % REM for 0.025 % P steel) is effective to improve the cracking susceptibility of this steel. However, the cracking susceptibility of this steel is deteriorated again by adding excess content of REM (about 0.37 % REM for 0.025 % P steel). Free P and S atoms being fixed as phosphides, oxyphosphides, sulfides and oxysulfides by REM atoms is the main reason why the cracking susceptibility of this steel is improved by adding REM. (author)

  12. Creep-life prediction and standard error analysis of type 316LN stainless steel by time-temperature parametric methods

    International Nuclear Information System (INIS)

    Kim, Woo Gon; Ryu, Woo Seog; Yoon, Song Nam; Yi, Won

    2005-01-01

    A number of creep rupture data for type 316LN stainless steel were collected through literature survey or experimental data produced in KAERI. Using these data, polynomial equations for predicting creep life were obtained by Larson-Miller (L-M), Orr-Sherby-Dorn (O-S-D) and Manson-Haferd (M-H) parameters using Time-Temperature Parametric (TTP) methods. Standard Error of Estimate (SEE) values for the each parameter was obtained with different temperatures through the statistical process of the creep data. The results of L-M, O-S-D and M-H methods showed good creep-life prediction, but M-H method showed better agreement than L-M and O-S-D methods. Especially, it was found that SEE values of M-H method at 700 .deg. C were lower than that of L-M and O-S-D methods

  13. Analysis of microstructure constitution and electrochemical characteristics of pitting corrosion in AISI 316-L type stainless steel modified by niobium

    International Nuclear Information System (INIS)

    Assis, O.B.G. de.

    1986-01-01

    The viability of total or partial substitution of molybdenum by niobium in stainless steel type AISI 316-L was studied. It was analysed the effects caused on the microstructural constitution and the electrochemical characteristics in the formation and stability of superficial oxide films grown on acid chloride solution. The electrochemical parameters were obtained on the potential kinetic polarization curves for two different scanning rates, as well the alloys dissolution rate by the measure of the variation in pitting density current (I p ) on time at a constant potential of + 300 mV (ECS). It was established the characteristics of niobium as stabilizer element of the passive film through inhibition of pitting propagation by the formation of re passivation oxides in the broken sites or actives points in the film. (author)

  14. External stress-corrosion cracking of a 1.22-m-diameter type 316 stainless steel air valve

    Science.gov (United States)

    Moore, Thomas J.; Telesman, Jack; Moore, Allan S.; Johnson, Dereck F.; Kuivinen, David E.

    1993-01-01

    An investigation was conducted to determine the cause of the failure of a massive AISI Type 316 stainless steel valve which controlled combustion air to a jet engine test facility. Several through-the-wall cracks were present near welded joints in the valve skirt. The valve had been in outdoor service for 18 years. Samples were taken in the cracked regions for metallographic and chemical analyses. Insulating material and sources of water mist in the vicinity of the failed valve were analyzed for chlorides. A scanning electron microscope was used to determine whether foreign elements were present in a crack. On the basis of the information generated, the failure was characterized as external stress-corrosion cracking. The cracking resulted from a combination of residual tensile stress from welding and the presence of aqueous chlorides. Recommended countermeasures are included.

  15. 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...

  16. Influence of dynamical ion mixing of crystalline aluminium and nickel coatings on the fatigue behaviour of a 316L-type stainless steel

    International Nuclear Information System (INIS)

    Villechaise, P.; Mendez, J.; Violan, P.; Riviere, J.P.

    1991-01-01

    New techniques of dynamical ion mixing have been applied to the improvement of fatigue resistance of metallic materials. Such techniques involve a deposition method combined with simultaneous ion implantation. In this way, well adherent cyrstalline coatings of pure Al and Ni, 0.5 μm thick, have been deposited on a 316L-type austenitic stainless steel substrate. It has been shown that such coatings lead to a substantial increase in the fatigue lifetime of the stainless steel at room temperature, which is associated with important modifications in surface damage processes. (orig.)

  17. Effect of pre-hardening on the lifetime of type 304L austenitic stainless steels

    International Nuclear Information System (INIS)

    Kpodekon, C.

    2010-01-01

    This study deals with the effect of the loading history on the cyclic behavior and the fatigue life of two kinds (THYSSEN and CLI) of 304L stainless steel at room temperature. The experiments have been performed using two specimens' categories. The first one (virgin) has been submitted to only classical fatigue tests while in the second category, prior to the fatigue test, the specimen is subjected to a pre-hardening process under either monotonic or cyclic strain control. Cyclic softening followed by cyclic hardening are observed for the virgin specimens while only cyclic softening is exhibited by the pre-hardened specimens. The obtained results show that fatigue life is strongly influenced by the pre-hardening: it seems beneficial under stress control but detrimental under strain control, even in the presence of a compressive mean stress. The results are discussed regarding the cyclic evolution of the elastic modulus as well as the isotropic and kinematic parts of the strain hardening, and strain energy density per cycle, in different configurations: with or without prehardening,stress or strain control. (author)

  18. Fatigue resistance, debonding force, and failure type of fiber-reinforced composite, polyethylene ribbon-reinforced, and braided stainless steel wire lingual retainers in vitro

    NARCIS (Netherlands)

    Foek, Dave Lie Sam; Yetkiner, Enver; Ozcan, Mutlu

    Objective: To analyze the fatigue resistance, debonding force, and failure type of fiber-reinforced composite, polyethylene ribbon-reinforced, and braided stainless steel wire lingual retainers in vitro. Methods: Roots of human mandibular central incisors were covered with silicone, mimicking the

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

    International Nuclear Information System (INIS)

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

    1996-01-01

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

  20. Weak effect of metal type and ica genes on staphylococcal infection of titanium and stainless steel implants.

    Science.gov (United States)

    Hudetz, D; Ursic Hudetz, S; Harris, L G; Luginbühl, R; Friederich, N F; Landmann, R

    2008-12-01

    Currently, ica is considered to be the major operon responsible for staphylococcal biofilm. The effect of biofilm on susceptibility to staphylococcal infection of different implant materials in vivo is unclear. The interaction of ica-positive (wild-type (WT)) and ica-negative (ica(-)) Staphylococcus aureus and Staphylococcus epidermidis strains with titanium and both smooth and rough stainless steel surfaces was studied by scanning electron microscopy in vitro and in a mouse tissue cage model during 2 weeks following perioperative or postoperative inoculation in vivo. In vitro, WT S. epidermidis adhered equally and more strongly than did WT S. aureus to all materials. Both WT strains, but not ica(-) strains, showed multilayered biofilm. In vivo, 300 CFUs of WT and ica(-)S. aureus led, in all metal cages, to an infection with a high level of planktonic CFUs and only 0.89% adherent CFUs after 8 days. In contrast, 10(6) CFUs of the WT and ica(-) strains were required for postoperative infection with S. epidermidis. In all metal types, planktonic numbers of S. epidermidis dropped to titanium cages adherent WT bacteria survived in higher numbers than ica(-) bacteria. In conclusion, the metal played a minor role in susceptibility to and persistence of staphylococcal infection; the presence of ica genes had a strong effect on biofilm in vitro and a weak effect in vivo; and S. epidermidis was more pathogenic when introduced during implantation than after implantation.

  1. Radiation effects on low-cycle fatigue and tensile properties of aisi type 304 stainless steel at 298 K

    International Nuclear Information System (INIS)

    Vries, M.I. de; Tjoa, G.L.; Elen, J.D.

    1977-11-01

    Mechanisms were studied on the effect of neutron damage on low-cycle fatigue and tensile properties at room temperature on stainless steel aisi type 304. Samples were irradiated in the HFR at Petten to a fast fluence of 5.10 24 n.m -2 (E > 0.1 MeV) at 333 K followed by mechanical testing at room temperature. The low temperature irradiation caused irradiation hardening: the 0.2 yield stress increased from a value of 230 MN.m -2 for the unirradiated material to a lower yield point value of 540 MN.m -2 . Irradiation had no significant effect on fatigue life. The loop type damage was removed by glide dislocations resulting in cyclic softening. Dislocation substructures were observed after fatigue testing: cell structures were more pronounced to failure after fatigue testing, the higher the applied strain ranges. The formation of fatigue cracks at the surface of the specimens was observed in a series of specimens exposed to an increasing number of fatigue cycles. The tensile properties after fatigue loading and measured at the strain rate epsilon of 1 s -1 were found to be closely related to prior cyclic softening or hardening and to the development of large fatigue cracks

  2. Visualization of Hydrogen Diffusion in a Hydrogen-Enhanced Fatigue Crack Growth in Type 304 Stainless Steel

    Science.gov (United States)

    Matsunaga, Hisao; Noda, Hiroshi

    2011-09-01

    To study the influence of hydrogen on the fatigue strength of AISI type 304 metastable austenitic stainless steel, specimens were cathodically charged with hydrogen. Using tension-compression fatigue tests, the behavior of fatigue crack growth from a small drill hole in the hydrogen-charged specimen was compared with that of noncharged specimen. Hydrogen charging led to a marked increase in the crack growth rate. Typical characteristics of hydrogen effect were observed in the slip band morphology and fatigue striation. To elucidate the behavior of hydrogen diffusion microscopically in the fatigue process, the hydrogen emission from the specimens was visualized using the hydrogen microprint technique (HMT). In the hydrogen-charged specimen, hydrogen emissions were mainly observed in the vicinity of the fatigue crack. Comparison between the HMT image and the etched microstructure image revealed that the slip bands worked as a pathway for hydrogen to move preferentially. Hydrogen-charging resulted in a significant change in the phase transformation behavior in the fatigue process. In the noncharged specimen, a massive type α' martensite was observed in the vicinity of the fatigue crack. On the other hand, in the hydrogen-charged specimen, large amounts of ɛ martensite and a smaller amount of α' martensite were observed along the slip bands. The results indicated that solute hydrogen facilitated the ɛ martensitic transformation in the fatigue process. Comparison between the results of HMT and EBSD inferred that martensitic transformations as well as plastic deformation itself can enhance the mobility of hydrogen.

  3. Statistical study by digitalized image analysis of pitting corrosion of an AISI 304 type stainless steel in chloride environment

    International Nuclear Information System (INIS)

    Lacome, Isabelle

    1994-01-01

    This research thesis addresses the pitting corrosion of an AISI 304-type stainless steel in chloride environment, a phenomenon which is generally considered as comprising two main steps: pit initiation with local degradation of the passive film, and pit growth. By using a technique of analysis of digitalized images, the process is observed in situ and both steps are monitored. A statistical study of the initiation of all the noticed pits is performed. After a bibliographical survey on the pitting corrosion process, its mechanisms and the influence of different parameters, the author presents the studied material and the experimental methods, reports the investigation of the pitting corrosion process in potentiostatic mode over a wide range of potentials in order to study all the types of pits, discusses the influence of potential on pit initiation and growth, reports the study of the influence of hydrodynamic conditions and of ageing in solution on the different parameters, reports the analysis of passive films by photoelectron spectroscopy, and the study of the influence of an inhibitor (molybdate ions) on both steps of pitting corrosion [fr

  4. Long-term creep and creep-rupture behavior of Types 304 and 316 stainless steel, Type 316 casting material (CF8M), and 2 1/4 Cr-1 Mo steel. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Brinkman, C R; Booker, M K; Sikka, V K; McCoy, H E

    1986-06-01

    Final results of long-term creep and creep-rupture tests are compiled and summarized for a number of structural materials evaluated in support of the Liquid Metal Reactor program. These materials include type 304 stainless steel (tested to 13.4 years), type 316 stainless steel (tested to 8.2 years), CF8M or type 316 stainless casting (tested to 2.5 years), and 2 1/4 Cr-1 Mo steel (tested to 6.5 years). Creep curves of all materials evaluated, representative metallography, and hardness data taken subsequent to testing are also included. Comparisons are made between predictions made several years ago with preliminary creep and creep-rupture data and final results obtained under this program.

  5. The effect of retentive groove, sandblasting and cement type on the retentive strength of stainless steel crowns in primary second molars--an in vitro comparative study.

    Science.gov (United States)

    Veerabadhran, M M; Reddy, V; Nayak, U A; Rao, A P; Sundaram, M A

    2012-01-01

    This in vitro study was conducted to find out the effect of retentive groove, sand blasting and cement type on the retentive strength of stainless steel crowns in primary second molars. Thirty-two extracted intact human maxillary and mandibular primary second molars were embedded in aluminum blocks utilizing autopolymerising acrylic resin. After tooth preparation, the 3M stainless steel crown was adjusted to the prepared tooth. Then weldable buccal tubes were welded on the buccal and lingual surfaces of each crown as an attachment for the testing machine. A full factorial design matrix for four factors (retentive groove placement on the tooth, cement type, sandblasting and primary second molar) at two levels each was developed and the study was conducted as dictated by the matrix. The lower and upper limits for each factor were without and with retentive groove placement on the tooth, GIC and RMGIC, without and with sandblasting of crown, maxillary and mandibular second primary molar. For those teeth for which the design matrix dictated groove placement, the retentive groove was placed on the middle third of the buccal surface of the tooth horizontally and for those crowns for which sandblasting of the crowns are to be done, sandblasting was done with aluminium oxide with a particle size of 250 mm. The crowns were luted with either GIC or RMGIC, as dictated by the design matrix. Then the retentive strength of each sample was evaluated by means of an universal testing machine. The obtained data was analyzed using ANOVA for statistical analysis of the data and 't'- tests for pairwise comparison. The mean retentive strength in kg/cm 2 stainless steel crowns luted with RMGIC was 19.361 and the mean retentive strength of stainless steel crowns luted with GIC was 15.964 kg/cm 2 with a mean difference of 3.397 kg/cm 2 and was statistically significant. The mean retentive strength in kg/cm 2 of stainless steel crowns, which was not sandblasted, was 18.880 and which was

  6. The effect of retentive groove, sandblasting and cement type on the retentive strength of stainless steel crowns in primary second molars - An in vitro comparative study

    Directory of Open Access Journals (Sweden)

    M M Veerabadhran

    2012-01-01

    Full Text Available Purpose: This in vitro study was conducted to find out the effect of retentive groove, sand blasting and cement type on the retentive strength of stainless steel crowns in primary second molars. Materials and Methods: Thirty-two extracted intact human maxillary and mandibular primary second molars were embedded in aluminum blocks utilizing autopolymerising acrylic resin. After tooth preparation, the 3M stainless steel crown was adjusted to the prepared tooth. Then weldable buccal tubes were welded on the buccal and lingual surfaces of each crown as an attachment for the testing machine. A full factorial design matrix for four factors (retentive groove placement on the tooth, cement type, sandblasting and primary second molar at two levels each was developed and the study was conducted as dictated by the matrix. The lower and upper limits for each factor were without and with retentive groove placement on the tooth, GIC and RMGIC, without and with sandblasting of crown, maxillary and mandibular second primary molar. For those teeth for which the design matrix dictated groove placement, the retentive groove was placed on the middle third of the buccal surface of the tooth horizontally and for those crowns for which sandblasting of the crowns are to be done, sandblasting was done with aluminium oxide with a particle size of 250 mm. The crowns were luted with either GIC or RMGIC, as dictated by the design matrix. Then the retentive strength of each sample was evaluated by means of an universal testing machine. The obtained data was analyzed using ANOVA for statistical analysis of the data and ′t′- tests for pairwise comparison. Results: The mean retentive strength in kg/cm 2 stainless steel crowns luted with RMGIC was 19.361 and the mean retentive strength of stainless steel crowns luted with GIC was 15.964 kg/cm 2 with a mean difference of 3.397 kg/cm 2 and was statistically significant. The mean retentive strength in kg/cm 2 of stainless steel

  7. Critical potentials for pitting and crevice corrosion of type 304 stainless steel in NaCl solution at 423 K

    International Nuclear Information System (INIS)

    Yashiro, Hitoshi; Koshiyama, Shinichi; Tanno, Kazuo

    1991-01-01

    Critical potentials for pitting (E pit ) and crevice corrosion (E crev ) for type 304 stainless steel have been determined from long-term steady polarization tests in deaerated NaCl solutions as a function of NaCl concentration at 423 K. E pit and E crev were expressed by the conventional form: E=A-Blog[Cl - ], where A and B in volt vs. SHE were -0.19 and 0.15 for E pit and -0.20 and 0.10 for E crev , respectively. The comparison of E pit with pitting potential (E' pit ) and repassivation potential (E R,pit ), which were repeatedly determined from stepwise cyclic polarization tests, showed that E R,pit distributed less nobly than E pit especially at lower NaCl concentrations and that E pit could be described as a lower limit of Weibull's distribution function for E' pit . The similar analysis for crevice corrosion showed that the noblest value of E R,crev for its dependency on corrosion extent corresponded to E crev but the distribution in E' crev at different concentrations of NaCl could not be described by the Weibull's function with an identical shape parameter. (author)

  8. Study of tensile test behavior of austenitic stainless steel type 347 seamless thin-walled tubes in cold worked condition

    Energy Technology Data Exchange (ETDEWEB)

    Terui, Clarice, E-mail: clarice.terui@marinha.mil.br [Centro Tecnológico da Marinha em São Paulo (CINA/CTMSP), Iperó, SP (Brazil). Centro Industrial Nuclear da Marinha; Lima, Nelson B. de, E-mail: nblima@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNE-SP), Sao Paulo, SP (Brazil)

    2017-07-01

    These austenitic stainless steel type 347 seamless thin-walled tubes are potential candidates to be used in fuel elements of nuclear power plants (as PWR - Pressurized Water Reactor). So, their metallurgical condition and mechanical properties, as the tensile strength and yield strength, normally are very restrict in demanding project and design requirements. Several full size tensile tests at room temperature and high temperature (315 deg C) were performed in these seamless tubes in cold-worked condition. The results of specified tensile and yield strengths were achieved but the elongation of the tube, in the geometry of the component, could not be measured at high temperature due to unconventional mode of rupture (helical mode without separation of parts). The average value of elongation was obtained from stress-strain curves of hot tensile tests and was around 5%. The results obtained in this research show that this behavior of the full size tensile test samples of thin-walled tube (wall thickness less than 0.5 mm) in high temperature (315°C) is due to the combination of the manufacturing process, the material (crystallographic structure and chemical composition) and the final geometry of the component. In other words, the strong crystallographic texture of material induced by tube drawing process in addition with the geometry of the component are responsible for the behavior in hot uniaxial tensile tests. (author)

  9. The effect of NO3- and OH- ions on the laser ablation of Cs+ ion on Type 304 stainless steel

    International Nuclear Information System (INIS)

    Hui-Jun Won; Jei-Kwon Moon; Chong-Hun Jung; Kune-Woo Lee; Jae-Hyuk Hyun

    2011-01-01

    Type 304 stainless steel specimens artificially contaminated with CsCl solution were treated with KOH solution and KNO 3 solution, respectively. Cs + ion removal tests by a Q-switched Nd:YAG laser at 1064 nm at a given fluence of 57.3 J/cm 2 were performed. The surface morphology and the relative atomic mole ratio of the specimen surface were investigated by SEM and EPMA. The order of Cs + ion removal efficiency of laser was no-treatment 3 during the 42 shots. From the investigation of XPS peaks around 532.7 and 292.9 eV, KNO 3 on a surface of specimen was found to be fully decomposed during the laser irradiation. It was suggested that Cs 2 O particulates formed by the reaction between the reactive oxygen generated from the nitrate ion and Cs + ion on the metal surface could be easily suspended. For the KOH system, FeOOH was formed during the laser irradiation and it changed into Fe 2 O 3 . It was also suggested that Cs 2 O particulates were formed by the reaction between the reactive oxygen generated from the decomposition of K 2 O and Cs + ion on the metal surface. (author)

  10. The application of neutron diffraction to a study of phases in type 316 stainless steel weld metals

    International Nuclear Information System (INIS)

    Slattery, G.F.; Windsor, C.G.

    1983-01-01

    Neutron diffraction techniques have been utilised to study the phases in type 316 austenitic stainless steel weld metal, both in the as-welded condition and after stress-relieving and ageing heat-treatments. The amounts of the principal crystallographic phases present in bulk specimens have been measured. Two compositions of weld metal were selected to provide a 'low' (6%) and 'high' (16%) initial ferrite level and the subsequent volume fractions of transformation products were measured after heat-treatment. Some retained ferrite was observed in all the heat-treated specimens, ranging from 4% for specimens of both initial ferrite levels treated at 625 0 C for 1000 h, to around 1% for the specimens treated at 850 0 C for 6 h. The high initial ferrite specimen produced 0.9% of sigma phase after the 850 0 C treatment and 0.2% sigma after the 625 0 C treatment. The low initial ferrite specimen produced 1.5% M 23 C 6 carbide after both heat-treatments. The results compare well with previous findings on similar samples of weld metal using optical and electron microscopy. (orig.)

  11. Effect of chemical compositions and heat treatment on IGSCC resistance for strain hardened low carbon austenitic stainless steels in oxygenated water

    International Nuclear Information System (INIS)

    Yonezawa, T.; Kanasaki, H.; Fujimoto, K.; Taneike, M.; Ooki, S.; Sueishi, Y.; Tezuka, H.; Takamori, K.; Suzuki, S.

    2011-01-01

    In order to develop the highly resistant alternative materials to intergranular stress corrosion cracking (IGSCC) for the non-sensitized and strain hardened low carbon austenitic stainless steel in oxygenated water, the effects of chemical compositions and heat treatment conditions on the IGSCC resistance and stacking fault energy (SFE) values were studied for 33 laboratory melted steels and commercial type 310S stainless steel. The IGSCC resistance for test materials was compared by the maximum crack length, average crack length and cracked area in fatigue pre-cracked CT specimens after SCC test in oxygenated high temperature water. SFE values for these test materials were measured by the transmission electron microscopy on the width of isolated extended dislocations under g-3g weak beam condition for thin foils taken from the test materials, in this study. From these experiments, the effects of the chromium, molybdenum, nitrogen, silicon and manganese contents on the SCC resistance for non-aged materials were not so pronounced in this study. It is strongly suggested that the SFE value is a key parameter for the IGSCC resistance of the aged or non-aged and strain hardened low carbon austenitic stainless steels. (authors)

  12. The Structure and Properties of Diffusion Assisted Bonded Joints in 17-4 PH, Type 347, 15-5 PH and Nitronic 40 Stainless Steels

    Science.gov (United States)

    Wigley, D. A.

    1981-01-01

    Diffusion assisted bonds are formed in 17-4 PH, 15-5 PH, type 347 and Nitronic 40 stainless steels using electrodeposited copper as the bonding agent. The bonds are analyzed by conventional metallographic, electron microprobe analysis, and scanning electron microscopic techniques as well as Charpy V-notch impact tests at temperatures of 77 and 300 K. Results are discussed in terms of a postulated model for the bonding process.

  13. Evaluation of AISI Type 304 stainless steel as a suitable surface material for evaluating the efficacy of peracetic acid-based disinfectants against Clostridium difficile spores

    OpenAIRE

    Black, Elaine; Owens, Krista; Staub, Richard; Li, Junzhong; Mills, Kristen; Valenstein, Justin; Hilgren, John

    2017-01-01

    Disinfectants play an important role in controlling microbial contamination on hard surfaces in hospitals. The effectiveness of disinfectants in real life can be predicted by laboratory tests that measure killing of microbes on carriers. The modified Quantitative Disk Carrier Test (QCT-2) is a standard laboratory method that employs American Iron and Steel Institute (AISI) Type 430 stainless steel carriers to measure hospital disinfectant efficacy against Clostridium difficile spores. The for...

  14. Tensile and stress corrosion cracking properties of type 304 stainless steel irradiated to a very high dose

    International Nuclear Information System (INIS)

    Chung, H.M.; Strain, R.V.; Shack, W.J.

    2001-01-01

    Certain safety-related core internal structural components of light water reactors, usually fabricated from Type 304 or 316 austenitic stainless steels (SSs), accumulate very high levels of irradiation damage (20-100 displacement per atom or dpa) by the end of life. Our databases and mechanistic understanding of the degradation of such highly irradiated components, however, are not well established. A key question is the nature of irradiation-assisted intergranular cracking at very high doses, i.e. is it purely mechanical failure or is it stress-corrosion cracking? In this work, hot-cell tests and microstructural characterization were performed on Type 304 SS from the hexagonal fuel can of the decommissioned EBR-II reactor after irradiation to ∼50 dpa at ∼370 deg. C. Slow-strain-rate tensile tests were conducted at 289 degree sign C in air and in water at several levels of electrochemical potential (ECP), and microstructural characteristics were analyzed by scanning and transmission electron microscopies. The material deformed significantly by twinning and exhibited surprisingly high ductility in air, but was susceptible to severe intergranular stress corrosion cracking (IGSCC) at high ECP. Low levels of dissolved O and ECP were effective in suppressing the susceptibility of the heavily irradiated material to IGSCC, indicating that the stress corrosion process associated with irradiation-induced grain-boundary Cr depletion, rather than purely mechanical separation of grain boundaries, plays the dominant role. However, although IGSCC was suppressed, the material was susceptible to dislocation channeling at a low ECP, and this susceptibility led to a poor work-hardening capability and low ductility

  15. Intergranular stress corrosion cracking of type 304 stainless steels treated with inhibitive chemicals in high temperature pure water

    Energy Technology Data Exchange (ETDEWEB)

    Yeh, T.K. [Nuclear Science and Technology Development Center, National Tsing-Hua Univ. Taiwan (China); Lee, M.Y.; Tsai, C.H. [Department of Engineering and System Science, National Tsing-Hua Univ. Taiwan (China)

    2002-07-01

    Electrochemical potentiodynamic polarizations, electrochemical corrosion potential (ECP) measurements and slow strain rate tensile (SSRT) tests were conducted to investigate the intergranular stress corrosion cracking (IGSCC) characteristics of Type 304 stainless steels treated with inhibitive chemicals in simulated boiling water reactor (BWR) environments. A number of thermally sensitized specimens were prepared and were pre-oxidized in a 288 C environment with the presence of 300 ppb dissolved oxygen for 360 hours. Most of the specimens were then treated with various chemicals including powdered zirconium oxide (ZrO{sub 2}), powdered titanium oxide (TiO{sub 2}), and zirconyl nitrate [ZrO(NO{sub 3}){sub 2}] via static immersion at 90 C, 150 C, and 200 C. Test environments were specifically designed in a circulation loop to create a dissolved oxygen concentration of 300 ppb. Test results showed that the corrosion current densities of all treated specimens were lower than that of the untreated, pre-oxidized specimen at ambient temperature in a solution mixed with 1 mM K{sub 3}Fe(CN){sub 6} and 1 mM K{sub 4}Fe(CN){sub 6}. The ECPs of the treated specimens could be lower or higher than that of the pre-oxidized one at 288 C, depending upon the type of treating chemical and the treating temperature. In addition, IGSCC was observed on all specimens (treated or untreated) in the same environment. However, the untreated specimen exhibited lower elongation, shorter failure time, and more secondary cracks on the side surfaces. It was therefore suggested that inhibitive chemicals such as ZrO{sub 2}, TiO{sub 2}, and ZrO(NO{sub 3}){sub 2} did provide a certain degree of enhancement in improving the mechanical behavior of the treated specimens and in prolonging the IGSCC initiation time. (authors)

  16. Effects of helium content of microstructural development in Type 316 stainless steel under neutron irradiation

    International Nuclear Information System (INIS)

    Maziasz, P.J.

    1985-11-01

    This work investigated the sensitivity of microstructural evolution, particularly precipitate development, to increased helium content during thermal aging and during neutron irradiation. Helium (110 at. ppM) was cold preinjected into solution annealed (SA) DO-heat type 316 stainess steel (316) via cyclotron irradiation. These specimens were then exposed side by side with uninjected samples. Continuous helium generation was increased considerably relative to EBR-II irradiation by irradiation in HFIR. Data were obtained from quantitative analytical electron microscopy (AEM) in thin foils and on extraction replicas. 480 refs., 86 figs., 19 tabs

  17. Effects of helium content of microstructural development in Type 316 stainless steel under neutron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Maziasz, P.J.

    1985-11-01

    This work investigated the sensitivity of microstructural evolution, particularly precipitate development, to increased helium content during thermal aging and during neutron irradiation. Helium (110 at. ppM) was cold preinjected into solution annealed (SA) DO-heat type 316 stainess steel (316) via cyclotron irradiation. These specimens were then exposed side by side with uninjected samples. Continuous helium generation was increased considerably relative to EBR-II irradiation by irradiation in HFIR. Data were obtained from quantitative analytical electron microscopy (AEM) in thin foils and on extraction replicas. 480 refs., 86 figs., 19 tabs.

  18. Susceptibility to stress corrosion in stainless steels type AISI 321 and 12X18H10T used in PWR type reactors (WWER)

    International Nuclear Information System (INIS)

    Matadamas C, N.

    1995-01-01

    Titanium stabilized stainless steels have been utilized in sovietic pressurized water reactors (VVER) for avoid the susceptibility to Intergranular Corrosion (IGC) present in other austenitic stainless steels. However the Intergranular Corrosion resistance of this kind of materials has been questioned because of Intergranular Stress Corrosion Cracking failures (IGSCC) have been reported. This paper study the electrochemical behavior of the AISI 321 stainless steel in a H 3 BO 3 Solution contaminated with chlorides and its susceptibility to Intergranular Corrosion.Electrochemical prediction diagrams of the stainless steels AISI 321 and 12X18H10T (sovietic) sensitized (600 Centigrade, 3 h.) were compared. Cylindrical and conical samples were used in Slow Strain Rate Tests (SSRT), to determine the susceptibility to Stress Corrosion Cracking (SCC) in AISI 321 and 12X18H10T stainless steels. The results obtained showed that the temperature of the solution is a very important factor to detect this susceptibility. Fractography studies on the fracture surfaces of the samples obtained in the SSRT at high temperature were realized. Corrosion velocities of both AISI 321 and 12X18H10T stainless steels were determined using conical samples in the CERT system at high temperature. E.D.A.X. analysis was employed in both AISI 321 and 12X18H10T stainless steels in order to explain the degree of sensitization. (Author)

  19. Effect of sensitization on the mechanical properties of type 304 L stainless steel

    International Nuclear Information System (INIS)

    Vargas Mendoza, L.F.

    1990-01-01

    The sensitization is a corrosion cause that it has studied broadly in the austenitic steels; however its relations don't knowed very well, into the sensitization and the steel's mechanical properties. Wherefore, the objectives of this work was to study the mechanical properties, in tension of austenitic steel with different levels of sensitization. The material utilized was a 304 L steel of standard composition AISI. The samples were sensitized at 450, 650 and 850 Centigrade degree, by short expositions, following by a temper in water. After this treatment, the tension test tubes were carried to rupture at low deformation velocity. The sensitization was evaluated by the method of Akashi EPR cyclic polarization. The sensitization distribution was analyzed by optical metallography in color and the fracture surface were studied by sweeping electronic microscopy. The distribution and length of the carbides were the factor that control the mechanic behavior of materials. At 450 Centigrade, the border of the grain its founded free of carbides, also for the longest times of exposition, but the particles are presented as fine precipitates in the grain interior, with this is increased the mechanical properties by the internal interactions of hardness or oldness types. At 650 Centigrade the frontiers show a dense distribution of fine carbides. These precipitates are interacting with the borders grain, increasing lightly the mechanical properties of steel. At 850 Centigrade, were formed discontinued carbides that not affect the mechanical behavior, but whether the fracture; the resistance is reduced and the ductility is increased although to impose the thermic effect of treatment. (Author)

  20. Assessment of susceptibility of Type 304 stainless steel to intergranular stress corrosion cracking in simulated Savannah River Reactor environments

    International Nuclear Information System (INIS)

    Ondrejcin, R.S.; Caskey, C.R. Jr.

    1989-01-01

    Intergranular stress corrosion cracking (IGSCC) of Type 304 stainless steel rate tests (CERT) of specimens machined was evaluated by constant extension from Savannah River Plant (SRP) decontaminated process water piping. Results from 12 preliminary CERT tests verified that IGSCC occurred over a wide range of simulated SRP envirorments. 73 specimens were tested in two statistical experimental designs of the central composite class. In one design, testing was done in environments containing hydrogen peroxide; in the other design, hydrogen peroxide was omitted but oxygen was added to the environment. Prediction equations relating IGSCC to temperature and environmental variables were formulated. Temperature was the most important independent variable. IGSCC was severe at 100 to 120C and a threshold temperature between 40C and 55C was identified below which IGSCC did not occur. In environments containing hydrogen peroxide, as in SRP operation, a reduction in chloride concentration from 30 to 2 ppB also significantly reduced IGSCC. Reduction in sulfate concentration from 50 to 7 ppB was effective in reducing IGSCC provided the chloride concentration was 30 ppB or less and temperature was 95C or higher. Presence of hydrogen peroxide in the environment increased IGSCC except when chloride concentration was 11 ppB or less. Actual concentrations of hydrogen peroxide, oxygen and carbon dioxide did not affect IGSCC. Large positive ECP values (+450 to +750 mV Standard Hydrogen Electrode (SHE)) in simulated SRP environments containing hydrogen peroxide and were good agreement with ECP measurements made in SRP reactors, indicating that the simulated environments are representative of SRP reactor environments. Overall CERT results suggest that the most effective method to reduce IGSCC is to reduce chloride and sulfate concentrations

  1. Effect of welding process, type of electrode and electrode core diameter on the tensile property of 304L austenitic stainless steel

    Directory of Open Access Journals (Sweden)

    Akinlabi OYETUNJI

    2014-11-01

    Full Text Available The effect of welding process, type of electrode and electrode core diameter on the tensile property of AISI 304L Austenitic Stainless Steel (ASS was studied. The tensile strength property of ASS welded samples was evaluated. Prepared samples of the ASS were welded under these three various variables. Tensile test was then carried out on the welded samples. It was found that the reduction in ultimate tensile strength (UTS of the butt joint samples increases with increase in core diameter of the electrode. Also, the best electrode for welding 304L ASS is 308L stainless steel-core electrode of 3.2 mm core diameter. It is recommended that the findings of this work can be applied in the chemical, food and oil industries where 304L ASS are predominantly used.

  2. The Effect of Surface Roughness on the Corrosion Properties of Type AISI 304 Stainless Steel in Diluted NaCl and Urban Rain Solution

    Science.gov (United States)

    Leban, Mirjam Bajt; Mikyška, Črt; Kosec, Tadeja; Markoli, Boštjan; Kovač, Janez

    2014-05-01

    Due to their good corrosion resistance, favorable mechanical properties, and reasonable price regarding their excellent properties, austenitic stainless steels have, over recent decades, become one of the alloys that are increasingly used in civil engineering and building, as well as for specific architectural purposes. Architects often design stainless steel exterior elements with higher surface roughnesses, which are not resistant to corrosion processes. The aim of this work was to investigate the influence of different types of surface finishes to stainless steel of quality AISI 304 on the corrosion properties of this steel. In order to achieve this goal, electrochemical tests were performed on different surface finishes in two different environments: in an NaCl aqueous solution, and in simulated urban rain which contained no chlorides. In addition to the electrochemical methods used, surface roughness was also measured, and XPS surface analyses were performed. The results of the investigation showed that surface roughness affects the growth of the passive layer in urban rain significantly; however, the growth of such a film is retarded in the case of the NaCl aqueous solution. Based on the results of the performed analyses, it was found that, in the NaCl solution, the pitting potential depended strongly upon the surface roughness and the surface finish, but this was not true for the samples tested in urban rain.

  3. Some observations on the carburization of type 316 stainless steel foil in a low carbon activity sodium environment

    International Nuclear Information System (INIS)

    Thorley, A.W.; Jeffcoat, P.J.

    1982-01-01

    Work currently being undertaken to establish the equilibrium composition of carbides which form in stainless steel foils during their exposure to low carbon activity sodium environment is described. The time it takes the carbon to reach equilibrium during exposure to sodium of different carbon activity is discussed. The lowest carbon activity measureable in test loops where the sodium is just above carburizing to stainless steel is reported. Analytical techniques are used to determine the composition of the carbide and the austenite matrix and hence estimate the carbon activity of the equilibrium structure. This provides a comparison with carbon activity values determined by alternative methods such as the Harwell Carbon Meter and nickel tab techniques

  4. Preliminary microstructural characterization by transmission electron microscopy of 14 MeV neutron irradiated type 316 stainless steel

    International Nuclear Information System (INIS)

    Echer, C.J.

    1977-01-01

    Substantial changes in the mechanical properties of 316 stainless steel were observed after neutron irradiation (phi/sub t/ = 2.3 x 10 21 n/m 2 and E = 14 MeV) at 25 0 C. Comparison of microstructures of the unirradiated and neutron irradiated materials were evaluated using transmission electron microscopy. Evidence of small defect clusters in the irradiated material was found. These findings are consistent with other investigators also evaluating low dose irradiations

  5. Computational simulation of the microstructure of irradiation damaged regions for the plate type fuel of UO2 microspheres dispersed in stainless steel matrix

    International Nuclear Information System (INIS)

    Reis, S.C. dos; Lage, A.F.; Braga, D.; Ferraz, W.B.

    2006-01-01

    Plate type fuel elements have high efficiency of thermal transference what benefits the heat flux with high rates of power output. In reactor cores, fuel elements, in general, are subject to a high neutrons flux, high working temperatures, severe corrosion conditions, direct interference of fission products that result from nuclear reactions and radiation interaction-matter. For plate type fuels composed of ceramic particles dispersed in metallic matrix, one can observe the damage regions that arise due to the interaction fission products in the metallic matrix. Aiming at evaluating the extension of the damage regions in function of the particles and its diameters, in this paper, computational geometric simulations structure of plate type fuel cores, composed of UO 2 microspheres dispersed in stainless steel in several fractions of volume and diameters were carried out. The results of the simulations were exported to AutoCAD R where it was possible its visualization and analysis. (author)

  6. Behavior of the elements in the mechanically alloyed and cast ferritic steels and a type 316 stainless steel in a flowing sodium environment

    International Nuclear Information System (INIS)

    Suzuki, T.; Mutoh, I.

    1988-01-01

    Sodium corrosion behavior of a mechanically alloyed ferritic steel, dispersion-strengthened with addition of Y 2 0 3 and Ti, two kinds of melted/cast ferritic steels and a Type 316 stainless steel was examined by using a non-isothermal sodium loop system, constructed of another Type 316 stainless steel, with a direct resistance electrical heater. The sodium conditions were 675 0 C, 4.0 m/s in velocity and 1-2 ppm oxygen concentration and a cumulative exposure time of the specimens was about 3000 h. The absorption of Ni and selective dissolution of Cr played an important role in the corrosion of the mechanically alloyed ferritic steel as in the case of the cast ferritic steels. However, the region of Ni absorption and Cr diminution was deeper than that of the cast ferritic steels. Peculiar finding for the mechanically alloyed ferritic steel was the corroded surface with irregularly shaped protuberance, that might be related with formation of sodium titanate, and the absorption of carbon and nitrogen to form carbide and nitride of titanium. It seems that these facts resulted in the irregular weight loss of the specimens, which depended on the downstream position and the cumulative exposure time. However, the tensile properties of the mechanically alloyed ferritic steel did not noticeably change by the sodium exposure

  7. Effect of Heat Treatment on Low Temperature Toughness of Reduced Pressure Electron Beam Weld Metal of Type 316L Stainless Steel

    International Nuclear Information System (INIS)

    Nakagawa, H.; Fujii, H.; Tamura, M.

    2006-01-01

    Austenitic stainless steels are considered to be the candidate materials for liquid hydrogen vessels and the related equipments, and those welding parts that require high toughness at cryogenic temperature. The authors have found that the weld metal of Type 316L stainless steel processed by reduced pressure electron beam (RPEB) welding has high toughness at cryogenic temperature, which is considered to be due to the single-pass welding process without reheating effect accompanied by multi-pass welding process.In this work, the effect of heat treatment on low temperature toughness of the RPEB weld metal of Type 316L was investigated by Charpy impact test at 77K. The absorbed energy decreased with higher temperature and longer holding time of heat treatment. The remarkable drop in the absorbed energy was found with heat treatment at 1073K for 2 hours, which is as low as that of conventional multi-pass weld metal such as tungsten inert gas welding. The observations of fracture surface and microstructure revealed that the decrease in the absorbed energy with heat treatment resulted from the precipitation of intermetallic compounds near delta-ferrite phase

  8. Effect of heat and mechanical treatments on the microstructure of type Z6 CNDT 17.13 phosphorus containing, titanium stabilized austenitic stainless steels

    International Nuclear Information System (INIS)

    Gandit, M.

    1987-06-01

    The heterogeneities in composition resulting from hot transformation are eliminated by high temperature heat treatments. Phosphorus additions to this type of stainless steel does not affect significantly the homogeneity in composition. A significant lowering of the recrystallisaton temperature results from cold working. In addition, the precipitation of minute titanium crystals is promoted as well as that of phosphorus at temperatures between 500 and 600oC. At concentrations in excess of 0.1 %, phosphorus precipitation induces a significant change in the crystal lattice. At high concentrations, phosphorus precipitates upon show heating or cooling (rate below 100 deg C/min) requiring a high temperature heat treatment to revert to solution (above 1000 deg C). This type of steel is chosen for fuel cans of LMFBR reactors [fr

  9. Investigation of Local Hydrogen Distribution Around Fatigue Crack Tip of a Type 304 Stainless Steel with Secondary Ion Mass Spectrometry and Hydrogen Micro-Print Technique

    Science.gov (United States)

    Kawamoto, Kyohei; Oda, Yasuji; Noguchi, Hiroshi; Fujii, Hideki; Izumi, Takahiro; Itoh, Goroh

    In order to establish an appropriate method for measuring the local hydrogen content distribution around a fatigue crack tip in austenitic stainless steels, secondary ion mass spectrometry (SIMS) and the hydrogen micro-print technique (HMPT) were applied to a fatigue crack in a type 304 stainless steel fatigued in a hydrogen gas environment. The main results in this study are as follows. In the SIMS method, it is visualized that a high content of hydrogen exists in the plastic zone at a fatigue crack tip propagated in hydrogen gas, compared to that on a smooth area fatigued in hydrogen, though there is a measurement error based on false detection due to the edge effect regarding hydrogen in water vapor on the fatigue crack surface. On the other hand, hydrogen in the plastic zone is difficult to detect by HMPT. This is attributed to the difficulty for hydrogen atoms to be emitted from the sample in this case. To detect hydrogen, it is necessary to sputter the atoms forcibly. In addition, it is considered that to analyze the local hydrogen distribution around a fatigue crack tip with SIMS not only qualitatively but also quantitatively, reduction of the false detection due to the edge effect is necessary.

  10. The separate roles of subgrains and forest dislocations in the isotropic hardening of type 304 stainless steel

    International Nuclear Information System (INIS)

    Kassner, M.E.; Miller, A.K.; Sherby, O.D.

    1982-01-01

    Tests on 304 stainless steel were conducted involving first warm working in torsion, then cold working in torsion, and finally measurement of the elevated-temperature yield strength in compression. These tests permitted separation of the effects of subgrain size and forest dislocation density on the isotropic part of the flow stress. Forest dislocation strengthening appears to dominate in this material. Th results are best fitted by a root-mean-square summation of strength terms representing the contributions of solutes, forest dislocations, and subgrain boundaries. The same equation successfully predicts the flow stress during elevated-temperature transient deformation (under both constant strain rate and variable strain rate) from the transient dislocation substructure

  11. Microstructural, Micro-hardness and Sensitization Evaluation in HAZ of Type 316L Stainless Steel Joint with Narrow Gap Welds

    Energy Technology Data Exchange (ETDEWEB)

    Islam, Faisal Shafiqul; Jang, Changheui [KAIST, Daejeon (Korea, Republic of); Kang, Shi Chull [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2015-10-15

    From Micro-hardness measurement HAZ zone was found approximately 1-1.5 mm in NGW and DL-EPR test confirmed that 316L NGW HAZ was not susceptible to sensitization as DOS <1% according to sensitization criteria based on reference. In nuclear power plants 316L stainless steels are commonly used material for their metallurgical stability, high corrosion resistance, and good creep and ductility properties at elevated temperatures. Welding zone considered as the weakest and failure initiation source of the components. For safety and economy of nuclear power plants accurate and dependable structural integrity assessment of main components like pressure vessels and piping are need as it joined by different welding process. In similar and dissimilar metal weld it has been observed that weld microstructure cause the variation of mechanical properties through the thickness direction. In the Heat Affected Zone (HAZ) relative to the fusion line face a unique thermal experience during welding.

  12. Determination of Susceptibility to Intergranular Corrosion of UNS 31803 Type Duplex Stainless Steel by Electrochemical Reactivation Method: A Comparative Study

    Directory of Open Access Journals (Sweden)

    Mehmet Emin Arıkan

    2012-01-01

    Full Text Available In the present study as in our previous studies (Arikan and Doruk, 2008 and Arikan et al., 2012, similar specimens taken from a hot rolled cylindrical duplex stainless steel (DSS bar with 22% Cr grade were solution annealed at 1050°C and then aged at 800∘C from 100 to 31622 min for sensitization treatment. Double loop electrochemical potentiodynamic reactivation and standard weight loss immersion acid tests were conducted. The solution annealed samples were found unsensitized. The samples aged for 100 min were less sensitized whereas samples aged for 316 min and more time were sensitized. The degree of sensitization (DOS can be attributed to higher contribution of chromium and molybdenum depleted areas that result from intermetallic phases. However, especially the samples aged from 3162 to 31622 min have revealed chromium replenishment. Consequently, the degree of sensitization was lowered in comparison to the results obtained in previous studies.

  13. Determination of Susceptibility to Intergranular Corrosion of UNS 31803 Type Duplex Stainless Steel by Electrochemical Reactivation Method

    Directory of Open Access Journals (Sweden)

    Mehmet Emin Arıkan

    2012-01-01

    Full Text Available Specimens taken from a hot-rolled cylindrical duplex stainless steel (DSS bar with 22% Cr grade were solution annealed at 1050∘C and then aged at 725∘C from 100 to 31622 min for sensitization treatment. Double loop electrochemical potentiodynamic reactivation and standard weight loss immersion acid tests were conducted. The solution-annealed samples were found unsensitized. Those samples aged for 100 and 316 min were less sensitized whereas samples aged for 1000 min and especially those aged for 3162, 10000, and 31622 min were heavily sensitized. The degree of sensitization (DOS can be attributed to higher contribution of chromium- and molybdenum-depleted areas resulting from intermetallic phases.

  14. Corrosion and passivation behavior of various stainless steels in libr solution used in absorption-type refrigeration system

    International Nuclear Information System (INIS)

    Shahid, M.

    2007-01-01

    Various structural materials have been suggested for the refrigeration units to combat high corrosiveness of the absorbent. The corrosion behavior of three grades of austenitic stainless steels, have been investigated in lithium bromide (LiBr) solutions, using electrochemical techniques. Potentiodynamic E- log-i curves, potential-time scans and polarization resistance diagrams obtained by using three-electrode system connected to a computerized Gamry at the rate framework, have been used to analyze their corrosion and passivation behavior in various concentrations of LiBr i.e. commercial LiBr (850 g/J solution containing chromate inhibitor), 400 g/l LiBr and 700 g/J LiBr solutions, at room temperature. Relatively higher corrosion current was observed in SS304 exposed to inhibitor-free electrolyte compared to inhibited commercial solution. Inhibitor proved to be more efficient in case of AISI 304 as it showed significantly higher corrosion rate in un-inhibited solutions. (author)

  15. In Vitro Retentive Effect of Groove, Sandblasting, and Cement Type on Stainless Steel Crowns in Primary Molars.

    Science.gov (United States)

    Pathak, Sidhant; Shashibhushan, K K; Bharath, K P; Poornima, P; Reddy, V V Subba

    2015-01-01

    The purpose of this study was to evaluate and compare the effect of placing vertical grooves, sandblasting, and luting cements on the retention of stainless steel crowns (SSCs). Eighty extracted primary molars were mounted in acrylic blocks. Specimens were divided into Group 1 (RelyX U200) and Group 2 (Smart Cem2). Teeth in each group were further subdivided into Subgroup A (no vertical grooves and no sandblasting), Subgroup B (vertical grooves), Subgroup C (sandblasting of crowns), and Subgroup D (vertical grooves and sandblasting of crowns). After cementation, SSCs were pulled off using a universal testing machine. One-way analysis of variance was used for statistical analyses. In Groups 1 and 2, the highest retentive strengths were found in Subgroup D (1,124 and 783 kPa, respectively), followed by Subgroup C (1,066 and 748 kPa, respectively), Subgroup A (762 and 356 kPa, respectively), and Subgroup B (743 and 314 kPa, respectively). Retentive strength in Group one was significantly higher than in Group two; Subgroups A and B were significantly lower than C and D. RelyX U200 showed higher retentive strength than Smart Cem2. Sandblasting increased the retention strength, whereas a vertical groove had no significant effect on retention.

  16. Effect of Sandblasting and Type of Cement on the Bond Strength of Molar Bands on Stainless Steel Crowns.

    Science.gov (United States)

    Bawazir, Omar A; Elaraby, Alaa; Alshamrani, Hamed; Salama, Fouad S

    2015-01-01

    The purposes of this study were to: (1) compare the bond strength of molar bands cemented to stainless steel crowns (SSCs) using glass ionomer cement (GIC), resin-modified glass ionomer cement (RMGIC), or polycarboxylate cement (PXC); and (2) assess the influence of sandblasting molar bands on the mean bond strength between the band and the SSC. Sixty SSCs and 60 molar bands were used. The inner surfaces of 30 molar bands were roughened by sandblasting prior to cementation. The bond strength was measured after dislodging the SSC using a push-out test. In the nonsandblasted group, a significant difference was observed between PXC and RMGIC (P >.04). In the sandblasted group, a significant difference was observed between PXC and RMGIC (P >.02), while there was only a marginal difference between GIC and RMGIC (P >.05). The sandblasted group exhibited superior bond strength overall. However, the only significant improvement was observed for GIC (P >.03). PXC showed the highest bond strength of molar bands to SSCs, while RMGIC showed the lowest. Sandblasting the inner surface of bands enhanced the bond strength of different cements.

  17. Effects of pre-cold work on the intergranular corrosion in HAZ of type 304 austenitic stainless steel

    International Nuclear Information System (INIS)

    Choi, S.P.; Hong, J.H.; Chi, S.W.

    1981-01-01

    The annealed specimens and the 10% cold-worked specimens have been welded and the base metal, the HAZ, and the weld metal of each specimen have been cut to measure the corrosion rates according to Practice A through Practice E of ASTM A 262. It is obtained that the corrosion rates of the base metal, the HAZ, and the weld metal in the 65 % boiling nitric acid were 12.11 mpy, 40.25 mpy, and 10.55 mpy respectively for the annealed specimens and 435.21 mpy, 480.72 mpy, and 10.55 mpy respectively for the 10% cold-worked specimens and the HAZ measured from the fusion line of the weld was extended from 4mm to 7mm for the annealed specimens and from 3mm to 6.8mm for the 10% cold-worked specimens in the case of 3.5mm-thick specimens and 25 +-5 KJ/inch of heat input. It has been confirmed through the experiments that: 1. The cold work has an effect reducing sensitization in the HAZ since the ratio of corrosion rate of the HAZ to the base metal of the 10% cold-worked specimens is smaller than that of the annealed specimens. 2. The results can be explained not by the Cr-depletion theory and the electro-chemical theory but by the strain theory, and 3. The sensitization tests of ASTM A 262 can be a method to judge the quality of the austenitic stainless steels

  18. Plating on stainless steel alloys

    International Nuclear Information System (INIS)

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

    1981-01-01

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

  19. Role of environmental variables on the stress corrosion cracking of sensitized AISI type 304 stainless steel (SS304) in thiosulfate solutions

    Science.gov (United States)

    Roychowdhury, S.; Ghosal, S. K.; de, P. K.

    2004-10-01

    The stress corrosion cracking (SCC) behavior of sensitized AISI type 304 stainless steel (SS304) has been studied in dilute thiosulfate solutions as a function of thiosulfate concentrations and applied potentials. The susceptibility to SCC was observed to increase with thiosulfate concentrations and applied potentials. The addition of boric acid produced the reverse effect. A critical potential was found to exist, below which no SCC took place. Potential fluctuations, as recorded in the tests under open circuit conditions, appeared to be correlated with crack initiation and propagation during SCC. Current fluctuations observed in the controlled potential tests also gave indications of crack nucleation; however, at higher applied potentials such fluctuations were absent. The formation and presence of martensite in the specimens seemed to have a minor role in the overall SCC process. The aggressiveness of the thiosulfate concentration was also an important factor in determining the degree of susceptibility to SCC. The results obtained in the slow strain rate tests under open circuit as well as under potential-controlled conditions suggested a film ruptureanodic dissolution type of mechanism operative during SCC of sensitized SS304 in thiosulfate solutions.

  20. Void swelling and phase stability in different heats of cold-drawn type 1.4970 stainless steel after heavy-ion irradiation

    International Nuclear Information System (INIS)

    Vaidya, W.V.; Knoblauch, G.; Ehrlich, K.

    1982-01-01

    The present investigations were undertaken with the aim to understand, to what extent variations of the tube fabrication parameters and slight modifications in the chemical composition might influence the swelling behaviour of Type 1.4970 stainless steel. The parameters varied were: Variations in the manufacturing parameters for coldworked tubes (type and degree of drawing, solution-annealing temperature and thermomechanical treatments), and variations in minor elements (C, Ti, Mo) within the specified range of chemical composition. In addition, the Si-content and the Ti/C ratio - the so-called stabilization - were changed within a broader range. The samples were irradiated with 46 MeV-Ni-ions to 64 dpa at 575 0 C and swelling as well as austenite stability, formation of precipitates and other microstructural changes were investigated by TEM. Though the austenite was stable under irradiation with respect to ferrite/martensite-transformation, the cold-drawn alloys showed a tendency to recrystallize during irradiation and exhibited lean precipitation. With respect to swelling, the only parameter that substantially reduced it, was the high Si addition; otherwise the alloys were practically insensitive to changes in the investigated parameters. These results are discussed in terms of the radiation-induced recrystallization and the high Si-effect, both of which are found to be beneficial in reducing swelling. (orig.)

  1. Ductile fracture behavior of 6-inch diameter type 304 stainless steel and STS 42 carbon steel piping containing a through-wall or part-through crack

    International Nuclear Information System (INIS)

    Shibata, Katsuyuki; Ohba, Toshihiro; Kawamura, Takaichi; Miyazono, Shohachiro; Kaneko, Tadashi; Yokoyama, Norio.

    1986-05-01

    The double ended guillotine break philosophy in the design base accident of the nuclear power plant is considered to be overly conservative from the view point of piping design. Through the past experiences and developments of the fabrication, inspection, and operation of nuclear power plants, it has been recognized that the Leak-Before-Break (LBB) concept can be justified in the LWR pressure boundary pipings. In order to verify the LBB concept, extensive experimental and theoretical works are being conducted in many countries. Furthermore, a revised piping design standard, in which LBB concept is introduced, is under preparation in Japan, U.S.A., and European countries. At JAERI, a research program to investigate the unstable ductile fracture behavior of LWR piping under bending load has been carried out as a part of the LBB verification researches since 1983. This report summarizes the result of the ductile fracture tests conducted at room temperature in 1983 and 84. The 6-inch diameter pipes of type 304 stainless steel and STS 42 carbon steel pipe with a through-wall or part-through crack were tested under bending load with low or high compliance condition at room temperature. Pipe fracture data were obtained from the test as regards to load- displacement curve, crack extension, net section stress, J-resistance curve, and so on. Besides, the influence of the compliance on the fracture behavior was examined. Discussions are performed on the ductile pipe fracture criterion, flaw evaluation criterion, and LBB evaluation method. (author)

  2. Effect of Oxygen Content Upon the Microstructural and Mechanical Properties of Type 316L Austenitic Stainless Steel Manufactured by Hot Isostatic Pressing

    Science.gov (United States)

    Cooper, Adam J.; Cooper, Norman I.; Dhers, Jean; Sherry, Andrew H.

    2016-09-01

    Although hot isostatic pressing (HIP) has been shown to demonstrate significant advances over more conventional manufacture routes, it is important to appreciate and quantify the detrimental effects of oxygen involvement during the HIP manufacture process on the microstructural and material properties of the resulting component. This paper quantifies the effects of oxygen content on the microstructure and Charpy impact properties of HIP'd austenitic stainless steel, through combination of detailed metallographic examination and mechanical testing on HIP'd Type 316L steel containing different concentrations (100 to 190 ppm) of oxygen. Micron-scale pores were visible in the microstructure of the HIP'd materials postmetallographic preparation, which result from the removal of nonmetallic oxide inclusions during metallographic preparation. The area fraction of the resulting pores is shown to correlate with the oxygen concentration which influences the Charpy impact toughness over the temperature range of 77 K to 573 K (-196 °C to 300 °C), and demonstrates the influence of oxygen involved during the HIP manufacture process on Charpy toughness. The same test procedures and microstructural analyses were performed on commercially available forged 316L. This showed comparatively fewer inclusions and exhibited higher Charpy impact toughness over the tested temperature range.

  3. Applicability of repassivation potential for long-term prediction of localized corrosion of Alloy 825 and type 316L stainless steel

    International Nuclear Information System (INIS)

    Sridhar, N.; Cragnolino, G.A.

    1993-01-01

    Repassivation potential (E rp ) was investigated for use as a parameter in the long-term prediction of pitting resistance of two Fe-Ni-Cr-Mo alloys that are candidate materials for high-level nuclear waste containers. This potential was found to be independent of the extent of prior pit growth for alloy 825 (UNS N08825) and type 316 L (UNS S31603) stainless steel (SS). Repassivation potential decreased by an increase in backward scan rate after pits were grown under potentiostatic conditions. This was related to the effect of potential on repassivation time. The corrosion potential (E corr ) in simulated pit-crevice solutions increased with a decrease in pH and was independent of chloride (CL - ) concentration even to the point of depassivation. The depassivation pH (pH D ) was independent of Cl - concentration and increased slightly with an increase in temperature. The relationship between repassivation potential and E corr in simulated pit solutions was discussed. It was hypothesized that the repassivation potential for shallow pits was related to the time-dependent alteration of solution composition inside the pits and that the repassivation potential for deep pits was related to E corr of the depassivated metal inside the pit modified by the ohmic potential drop in the pit

  4. Topographical, microstructural and chemical effects of simulated high heat flux on the corrosion of Type 316 stainless steel in flowing sodium

    International Nuclear Information System (INIS)

    Bagnall, C.; Shiels, S.A.; Orbon, S.J.

    1976-01-01

    Earlier work, performed in sodium test facilities around the world, have produced corrosion data for Type 316 SS which has been used to estimate metal loss rates from the core of a liquid metal fast breeder reactor. Practical difficulties precluded evaluation of the influence on corrosion of irradiation, a high heat flux and the high axial temperature gradient the latter produces. Downstream effects in isothermal regions were, however, documented in some tests. This paper presents recent results of corrosion experiments conducted in a test facility designed to produce a temperature rise in the fluid equivalent to a heat flux in the primary heater of about 0.5 x10 6 Btu/(h-ft 2 ). The axial temperature gradient was such that the sodium temperature was increased over a distance of three feet from 820F at the inlet, to 1360F at the outlet. The secondary ion mass spectrometer, the electron probe microanalyzer, the scanning electron microscope, and the optical microscope were used individually to characterize the various compositional, topographical and structural changes that occurred in the stainless steel as a result of the sodium exposure. Several important effects attributable to the high axial temperature gradient were noted. The collective results presented provide a clarified picture of material reaction to this environment and permit a more meaningful prediction of the behavior of critical components within the core of a liquid metal fast breeder reactor. (Auth.)

  5. Topographical, microstructural, and chemical effects of simulated high heat flux on the corrosion of Type 316 stainless steel in flowing sodium

    International Nuclear Information System (INIS)

    Bagnall, C.; Shiels, S.A.; Orbon, S.J.

    1976-01-01

    Earlier work, performed in sodium test facilities around the world, have produced corrosion data for Type 306 SS which has been used to estimate metal loss rates from the core of a LMFBR. Practical difficulties precluded evaluation of the influence on corrosion of irradiation, a high heat flux and the high axial temperature gradient the latter produces. Downstream effects in isothermal regions were, however, documented in some tests. This paper presents recent results of corrosion experiments conducted in a test facility designed to produce a temperature rise in the fluid equivalent to a heat flux in the primary heater of about 0.5 x 10 6 Btu/(h-ft 2 ). The axial temperature gradient was such that the sodium temperature was increased over a distance of three feet from 820F at the inlet, to 1360F at the outlet. The secondary ion mass spectrometer, electron probe microanalyzer, scanning electron microscope, and optical microscope were used individually to characterize the various compositional, topographical, and structural changes that occurred in the stainless steel as a result of the sodium exposure. Several important effects attributable to the high axial temperature gradient were noted

  6. Contribution of solution pH and buffer capacity to suppress intergranular stress corrosion cracking of sensitized type 304 stainless steel at 95 C

    International Nuclear Information System (INIS)

    Zhang, S.; Shibata, T.; Haruna, T.

    1999-01-01

    Controlling pH of high-temperature water to ∼pH 7 at 300 C by adding lithium hydroxide (LiOH) into the coolant system of a pressurized water reactor (PWR) successfully has been mitigating the corrosion of PWR component materials. The effects of solution pH and buffer capacity on intergranular stress corrosion cracking (IGSCC) of sensitized type 304 stainless steel ([SS] UNS S30400) was examined at 95 C by slow strain rate technique (SSRT) with an in-situ cracking observation system. It was found that an increase in solution pH or buffer capacity increased crack initiation time and decreased mean crack initiation frequency, but exerted almost no effect on crack propagation. This inhibition effect on IGSCC initiation was explained as resulting from a retarding effect of solution pH and buffer capacity on the decrease in pH at crack nuclei caused by the hydrolysis of metal ions dissolved when the passive film was ruptured by strain in SSRT

  7. A Comparative Study of the Shear and Tensile Bond Strength using three types of Direct Bonding Adhesives on Stainless Steel Brackets - An In Vitro Study.

    Science.gov (United States)

    Sunilkumar, P; Patil, Chandrashekhara; H, Baswaraj; Putturaj, Kt; Sangolgi, Vijaykumar C; Jayasudha, K

    2013-08-01

    The purpose of this study was to compare the shear and tensile bond strength of three adhesive systems with increasing concentrations of filler for bonding brackets. The study was carried out on 120 extracted human premolars; randomly divided into six groups, three groups for shear bond strength & three for tensile bond strength, each subgroup consisting of 20 teeth; using light cured adhesive systems: Group 1: FORTIFY Unfilled, (unfilled penetrating resin) Group 2: ALITEF Low Filled (filler load 58% by weight) Group 3: PYRAMID Highly Filled (filler load greater than 80% by weight) with metal brackets (TP 256-650. TP orthodontic inc. Po.box 73,La Porte 46350,USA). The findings showed that in vitro tensile bond strength and shear bond strength of PYRAMID [9.88/11.46 MPa resp.] is significantly greater than ALITEFLO[5.34/9.50 MPa resp.] and FORTIFY [2.65/5.39 MPa resp.]. Using the same bracket and force mode but different adhesive filler concentrations revealed increased shear and tensile bond strength with increased filler concentration. How to cite this article: Kumar PS, Patil C, Hullal B, Putturaj KT, Sangolgi VC, Jayasudha K. A Comparative Study of the Shear and Tensile Bond Strength using three types of Direct Bonding Adhesives on Stainless Steel Brackets - An In Vitro Study. J Int Oral Health 2013; 5(4):26-29.

  8. Scale-up protein separation on stainless steel wide bore toroidal columns in the type-J counter-current chromatography.

    Science.gov (United States)

    Guan, Yue Hugh; Hewitson, Peter; van den Heuvel, Remco N A M; Zhao, Yan; Siebers, Rick P G; Zhuang, Ying-Ping; Sutherland, Ian

    2015-12-11

    Manufacturing high-value added biotech biopharmaceutical products (e.g. therapeutic proteins) requires quick-to-develop, GMP-compliant, easy-to-scale and cost effective preparatory chromatography technologies. In this work, we describe the construction and testing of a set of 5-mm inner diameter stainless steel toroidal columns for use on commercially available preparatory scale synchronous J-type counter-current chromatography (CCC) machinery. We used a 20.2m long column with an aqueous two-phase system containing 14% (w/w) PEG1000 and 14% (w/w) potassium phosphate at pH 7, and tested a sample loading of 5% column volume and a mobile phase flow rate of 20ml/min. We then satisfactorily demonstrated the potential for a weekly protein separation and preparation throughput of ca. 11g based on a normal weekly routine for separating a pair of model proteins by making five stacked injections on a single portion of stationary phase with no stripping. Compared to our previous 1.6mm bore PTFE toroidal column, the present columns enlarged the nominal column processing throughput by nearly 10. For an ideal model protein injection modality, we observed a scaling up factor of at least 21. The 2 scales of protein separation and purification steps were realized on the same commercial CCC device. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. The stress corrosion cracking of heavily sensitized type 316 stainless steel in water in the temperature range 50-100oC

    International Nuclear Information System (INIS)

    Congleton, J.; Sui, G.

    1992-01-01

    The susceptibility to stress corrosion cracking of a Type 316 stainless steel tubing material which had been sensitized in a steam generating rig operated at temperatures from 502 to 533 o C was assessed using the slow strain rate technique. The experiments were performed in de-aerated and in oxygenated water with and without chloride additions and in the temperature range 50-100 o C. The material was susceptible to stress corrosion cracking and to mechanically induced cracking during dynamic straining. Susceptibility to stress corrosion cracking increased with increasing temperature and with increasing oxygen and chloride contents. Cracking occurred with greater than 200 ppb oxygen present even when the chloride content was less than 5 ppb. The maximum allowable oxygen content decreased further when the chloride content was increased. The maximum chloride content for immunity to stress corrosion cracking was 5 ppm even when less than 5 ppb oxygen was present in the water. The severe susceptibility of the material was caused by the complicated metallurgical state of the inner tube surface, but cracking could be prevented by appropriate potentiostatic control. (author)

  10. Weldability of Stainless Steels

    International Nuclear Information System (INIS)

    Saida, Kazuyoshi

    2010-01-01

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

  11. Thermophysical properties of stainless steels

    International Nuclear Information System (INIS)

    Kim, C.S.

    1975-09-01

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

  12. Utilization of aluminum to obtaining a duplex type stainless steel using high energy ball milling; Obtencao de um aco inoxidavel de estrutura duplex do sistema FeMnAl processado por moagem de alta energia

    Energy Technology Data Exchange (ETDEWEB)

    Pavlak, I.E.; Cintho, O.M., E-mail: eng.igorpavlak@yahoo.com.b [Universidade Estadual de Ponta Grossa (UEPG), PR (Brazil); Capocchi, J.D.T. [Universidade de Sao Paulo (USP), SP (Brazil)

    2010-07-01

    The obtaining of stainless steel using aluminum in its composition - FeMnAl system, has been researches subject since the sixties, by good mechanical properties and resistance to oxidation presented, when compared with conventional FeNiCr stainless steel system. In another point, the aluminum and manganese are low cost then traditional elements. This work, metallic powders of iron, manganese and pure aluminum, were processed in a Spex type high-energy ball mill in nitrogen atmosphere. The milling products were compressed into pastille form and sintered under inert atmosphere. The final products were characterized by optical and electronic microscopy and microhardness test. The metallographic analysis shows a typical austenite and ferrite duplex type microstructure. The presence of these phases was confirmed according X ray diffraction analysis. (author)

  13. Experiments on 18-8 stainless steels exposed to liquid lithium. I. 1,100-hour corrosion tests in lithium of 400, 500 and 6000C in natural circulation type testing apparatus

    International Nuclear Information System (INIS)

    Nihei, I.; Sumiya, I.; Fukaya, Y.; Yamazaki, Y.

    The Japan Atomic Energy Research Institute has planned and started to carry out a series of experiments concerning fusion reactor materials. This report gives the results of the first experiments. The first test materials selected were 18-8 stainless steels, and the experiments were designed to test their behavior when exposed to liquid lithium. Natural circulation type corrosion testing devices (pots) were used as the testing apparatus, and the tests were conducted with lithium temperatures up to 600 0 C

  14. Study of a particular type of intercrystalline cracking under stress at 7000C in austenitic stainless steels

    International Nuclear Information System (INIS)

    Bonnet, F.; Biscondi, M.

    1977-01-01

    Rupture under internal stresses at about 700 0 C, by propagation of an intergranular crack of great length, was first observed by Hodierne on extruded tubes made of stabilized austenitic steels. This phenomenon occurs in very particular thermomechanical conditions. It was reproduced by hot tension on various grades of industrial or synthetic steels, stabilized or not. Precipitation does not play the main role. A general interpretation is given which lies on concentration of stresses at the triple nodes due to intergranular slipping. Then, these observations can be explained, specially the existence of a critical tension velocity. The presence of some oligoelements in very low quantities clearly increases this type of brittleness [fr

  15. The Effect of Laser Type and Power on the Efficiency of Industrial Cutting of Mild and Stainless Steels

    OpenAIRE

    Pocorni, Jetro; Petring, Dirk; Powell, John; Deichsel, Eckard; Kaplan, Alexander

    2016-01-01

    This paper investigates the effect of material type, material thickness, laser wavelength and laser power on the efficiency of the cutting process for industrial state-of-the-art cutting machines. The cutting efficiency is defined in its most basic terms: as the area of cut edge created per Joule of laser energy. This fundamental measure is useful in producing a direct comparison between the efficiency of fiber and CO2 lasers when cutting any material. It is well known that the efficiency of ...

  16. Special stainless steels for sea water service

    International Nuclear Information System (INIS)

    Tomaselli, A.C.

    1983-01-01

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

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

    International Nuclear Information System (INIS)

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

    2000-01-01

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

  18. Compositional depth profiles of the type 316 stainless steel undergone the corrosion in liquid lithium using laser-induced breakdown spectroscopy

    Science.gov (United States)

    Li, Ying; Ke, Chuan; Liu, Xiang; Gou, Fujun; Duan, Xuru; Zhao, Yong

    2017-12-01

    Liquid metal lithium cause severe corrosion on the surface of metal structure material that used in the blanket and first wall of fusion device. Fast and accurate compositional depth profile measurement for the boundary layer of the corroded specimen will reveal the clues for the understanding and evaluation of the liquid lithium corrosion process as well as the involved corrosion mechanism. In this work, the feasibility of laser-induced breakdown spectroscopy for the compositional depth profile analysis of type 316 stainless steel which was corroded by liquid lithium in certain conditions was demonstrated. High sensitivity of LIBS was revealed especially for the corrosion medium Li in addition to the matrix elements of Fe, Cr, Ni and Mn by the spectral analysis of the plasma emission. Compositional depth profile analysis for the concerned elements which related to corrosion was carried out on the surface of the corroded specimen. Based on the verified local thermodynamic equilibrium shot-by-shot along the depth profile, the matrix effect was evaluated as negligible by the extracted physical parameter of the plasmas generated by each laser pulse in the longitudinal depth profile. In addition, the emission line intensity ratios were introduced to further reduce the impact on the emission line intensity variations arise from the strong inhomogeneities on the corroded surface. Compositional depth profiles for the matrix elements of Fe, Cr, Ni, Mn and the corrosion medium Li were constructed with their measured relative emission line intensities. The distribution and correlations of the concerned elements in depth profile may indicate the clues to the complicated process of composition diffusion and mass transfer. The results obtained demonstrate the potentiality of LIBS as an effective technique to perform spectrochemical measurement in the research fields of liquid metal lithium corrosion.

  19. 77 FR 60673 - Drawn Stainless Steel Sinks From the People's Republic of China: Antidumping Duty Investigation

    Science.gov (United States)

    2012-10-04

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

  20. Anelasticity in austenitic stainless steel

    International Nuclear Information System (INIS)

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

  1. Materials Reliability Program: Environmental Fatigue Testing of Type 304L Stainless Steel U-Bends in Simulated PWR Primary Water (MRP-137)

    Energy Technology Data Exchange (ETDEWEB)

    R.Kilian

    2004-12-01

    Laboratory data generated in the past decade indicate a significant reduction in component fatigue life when reactor water environmental effects are experimentally simulated. However, these laboratory data have not been supported by nuclear power plant component operating experience. In recent comprehensive review of laboratory, component and structural test data performed through the EPRI Materials Reliability Program, flow rate was identified as a critical variable that was generally not considered in laboratory studies but applicable in plant operating environments. Available data for carbon/low-alloy steel piping components suggest that high flow is beneficial regarding the effects of a reactor water environment. Similar information is lacking for stainless steel piping materials. This report documents progress made to date in an extensive testing program underway to evaluate the effects of flow rate on the corrosion fatigue of 304L stainless steel under simulated PWR primary water environmental conditions.

  2. Materials Reliability Program: Environmental Fatigue Testing of Type 304L Stainless Steel U-Bends in Simulated PWR Primary Water (MRP-137)

    International Nuclear Information System (INIS)

    Kilian, R.

    2004-01-01

    Laboratory data generated in the past decade indicate a significant reduction in component fatigue life when reactor water environmental effects are experimentally simulated. However, these laboratory data have not been supported by nuclear power plant component operating experience. In recent comprehensive review of laboratory, component and structural test data performed through the EPRI Materials Reliability Program, flow rate was identified as a critical variable that was generally not considered in laboratory studies but applicable in plant operating environments. Available data for carbon/low-alloy steel piping components suggest that high flow is beneficial regarding the effects of a reactor water environment. Similar information is lacking for stainless steel piping materials. This report documents progress made to date in an extensive testing program underway to evaluate the effects of flow rate on the corrosion fatigue of 304L stainless steel under simulated PWR primary water environmental conditions

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

    Science.gov (United States)

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

    2014-01-01

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

  4. Accelerated corrosion of stainless steels with the presence of molten carbonates below 923 K

    International Nuclear Information System (INIS)

    Ota, Ken-ichiro; Toda, Katsuya; Mitsushima, Shigenori; Kamiya, Nobuyuki

    2002-01-01

    The high-temperature corrosion of stainless steels (SUS316L and SUS310S) in the presence of lithium-potassium eutectic carbonate and lithium-sodium eutectic carbonate has been studied by thermogravimetry and the metal consumption method under a carbon dioxide-oxygen atmosphere in the temperature range of 773-1123 K. Although the corrosion of SUS310S obeyed the parabolic rate law for all reaction conditions, the corrosion of SUS316L significantly depended on the reaction conditions. At or above 923 K, the corrosion of SUS316L obeyed the parabolic rate law, even with a carbonate coating. The corrosion rates were accelerated during the initial period of corrosion tests below 923 K, especially around 823 K with a lithium-sodium carbonates coating. The initial accelerated corrosion was a local corrosion, which produced through holes in the metal specimens, and occurred more clearly at higher carbon dioxide partial pressures with the lithium-sodium carbonate coating than with the lithium-potassium carbonate coating. (author)

  5. Aging degradation of cast stainless steel

    International Nuclear Information System (INIS)

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

    1985-10-01

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

  6. Ferritic stainless steels: corrosion resistance + economy

    International Nuclear Information System (INIS)

    Remus, A.L.

    1976-01-01

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

  7. Chromium-Makes stainless steel stainless

    Science.gov (United States)

    Kropschot, S.J.; Doebrich, Jeff

    2010-01-01

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

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

    Science.gov (United States)

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

    2013-07-01

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

  9. Stress corrosion inhibitors for type 18-10 stainless steels with low carbon content in hot and concentrated solutions of MgCl2. Study of some inorganic iodides

    International Nuclear Information System (INIS)

    Pinard, J.-L.

    1974-01-01

    Stress corrosion inhibitors for type Z2CN18-10 austenitic stainless steels with low carbon content in a solution of Cl 2 Mg at 105 deg C were investigated. It was established that iodides are the most adequate corrosion inhibitors because they react simultaneously upon the three main components of the alloy (Fe, Ni, Cr). A difference of behavior between I 2 Mg and the other iodides was observed (in electrochemistry and in simple stress corrosion experiments) and the influence of the metallic cation associated to I - was studied. The formation of the superficial film and the phenomena liable to occur at the interface film-corrosive solution were examined: film growth in MgCl 2 ; influence of certain substances added to the solution. A mechanism of inhibition by I - is suggested. It is similar to the mechanism proposed by BERGEN for the stress corrosion cracking by Cl - [fr

  10. Study of the stress corrosion cracking susceptibility of type 304 austenitic stainless steel in aqueous solution of MgCl2 at 1250C using the slow - strain - rate technique

    International Nuclear Information System (INIS)

    Heck, N.C.

    1981-01-01

    A study has been made of the stress corrosion cracking susceptibility of type 304 austenitic stainless steel mainly in aqueous solution of MgCl 2 at 125 0 C using the slow strain-rate technique. A system is built up of a tensile test machine and the peripheric equipment. The efficacy of this system has been tested by running experiments for determination of critical potentials in MgCl 2 with or without aditions of NaNO 3 . Critical potentials are found to be between -145 and -160 mV sub(H) for pure MgCl 2 and between -90 and -100 mV sub(H) for MgCl 2 plus 2,5% NaNO 3 . Comparing these results with others of constant load tests, good agreement is found. (Author) [pt

  11. Influence of molybdenum on the high-temperature mechanical resistance especially creep resistance around 7000C of 18-14 type stainless steels

    International Nuclear Information System (INIS)

    Ben Marzouk, M.T.

    1977-06-01

    The influence of molybdenum on the mechanical properties under traction, the creep parameters, sub-structure and diffusion parameters of iron in stainless steels was investigated. Between 20 0 C and 800 0 C molybdenum has no significant effect on the elastic limit, breaking load or consolidation coefficient but increases the distributed elongation between 500 0 C and 800 0 C; its influence is greatest at 700 0 C. Addition of molybdenum reduces the creep rate at high temperature from the start of the test up to breaking point. In the temperature range studied, 600 0 C to 900 0 C, its influence is greatest at 600 0 C, decreases as the temperature rises and disappears at 900 0 C. Addition of 2% molybdenum increases the activation energy from 72 kcal/mole to 88 kcal/mole. At 700 0 C molybdenum hardly affects the precipitation and structure of dislocations but delays healing processes. Between 1000 0 C and 1300 0 C molybdenum has no effect on the iron diffusion coefficient: Q=68.7kcal/mole, D 0 =1.3cm 2 /s. The influence of Mo on the creep resistance of austenitic steels between 600 0 C and 900 0 C does not seem to be due to precipitation but to a solid solution effect, which could be a decrease in the diffusion coefficient of iron below 900 0 C [fr

  12. Post irradiation fatigue tests of type 316 LN stainless steel. Final report for the ITER Task T511, Subtask 1. European Technology Programme Task GB5-T217

    Energy Technology Data Exchange (ETDEWEB)

    Norring, K.; Koenig, M

    2002-01-01

    The main objective of this Subtask was to estimate the corrosion fatigue behaviour of 316L Stainless Steel (SS) and SS/SS joints, and to check among others the influence of irradiation. Joints were produced by solid Hot Isostatic Pressure (HIP) and powder HIP. Conventional material was used for comparison. The specimens were supplied by EFDA and were irradiated to 4 dpa in Dimitrovgrad (Russia). All specimens were tested at 150 deg C in hydrogenated high purity water. Testing was performed with a stepwise decrease in {delta}K keeping K{sub max} constant. The crack growth rates of irradiated as well as unirradiated specimens tested earlier are of the same magnitude, around 2x10{sup -5} mm/cycle at {delta}K= 18 MPa{radical}m. Thus, irradiation does not seem to enhance the fatigue crack growth rate, at least not up to irradiation levels of 4 dpa. But it is worth noting that the exponents in the da/dN versus {delta}K equation, also known as Paris' law, seems to fall within two areas, either around 3.5 or just below 2. Both Powder HIPed and Solid HIPed specimens are found in both groups. The reason for this is not evident. The fracture surfaces of the specimens show typical fatigue appearance.

  13. Microstructural characterization of stainless steel 17-4 PH used in the control element of PWR-Type reactors submitted to different heat treatments

    International Nuclear Information System (INIS)

    Ferreira, Douglas F.A.; Rezende, Renato P.; Turcarelli, Tiago

    2017-01-01

    The Control Element is a set of mechanical components of pressurized water cooled nuclear reactors (PWR), with the function of modifying the reactivity of the nucleus by insertion and withdrawal of neutron absorptive rod, in order to change the flow of neutrons (power) to the necessary and desired levels. The control element also has a safety function when there is a need to have negative reactivity available to shut down the reactor in normal operating or accident situations. In this situation, the control element descends instantly and inserts the rods with absorptive material into the fuel element thus shutting down the reactor. The control element consists of control rods, which carry the neutron absorption material and is supported by the spider, pin, spring and spring retainer assembly. The control element has some components that need to have high resistance to impacts when the safety function is activated, so the material of this component must have high mechanical strength and toughness. One of the materials in which can be specified for this application is martensitic stainless steel 17- 4PH (UNS 17400). This steel, when subjected to the aging heat treatment, has its mechanical properties altered due to the precipitation of dispersed intermetallic compounds in the matrix. In all heat treatments performed the predominant microstructure is lath martensite. The heat treatment of the 620 °C / 4 h presented lower hardness when compared to the other treatments and when increase time and temperature the material presents Nb precipitates that increase the hardness. (author)

  14. Effect of welding processes and joint configuration on the residual stresses and distortion in type 316 LN stainless steel weld joints

    International Nuclear Information System (INIS)

    Vasantharaja, P.; Vasudevan, M.; Palanichamy, P.

    2012-01-01

    Fabrication by welding introduces significant residual stresses in the welded structure/component due to non-uniform heat distribution during heating and cooling cycle. To control, reduce, or beneficially redistribute the residual stresses in weld joints, the stress distribution needs to be known. In the present study, weld joints of 16 mm thick 316LN stainless steel were made by multi-pass TIG, A-TIG welding and combination of TIG and A-TIG welding processes with various joint configurations. While V-groove edge preparation was required for making multi-pass TIG weld joint, square-edge preparation was sufficient for making A-TIG weld joint. Ultrasonic nondestructive technique based on the critically refracted longitudinal waves (LCR waves) has been used for the quantitative surface/sub-surface residual stress measurements in the weld joints. Distortion measurements were carried out before and after welding using height gauge. A-TIG weld joint was found to exhibit significant reduction in tensile residual stresses and distortion in comparison to that of other joints. (author)

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

    International Nuclear Information System (INIS)

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

    1995-01-01

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

  16. High Nitrogen Stainless Steel

    Science.gov (United States)

    2011-07-19

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

  17. Solidification behavior of austenitic stainless steel filler metals

    International Nuclear Information System (INIS)

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

    1980-02-01

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

  18. Hydrogen effects in stainless steel

    International Nuclear Information System (INIS)

    Caskey, G.R. Jr.

    1983-01-01

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

  19. Stainless super p-branes

    International Nuclear Information System (INIS)

    Lue, H.; Pope, C.N.; Sezgin, E.; Stelle, K.S.

    1995-01-01

    The elementary and solitonic supersymmetric p-brane solutions to supergravity theories form families related by dimensional reduction, each headed by a maximal ('stainless') member that cannot be isotropically dimensionally oxidized into higher dimensions. We find several new families, headed by stainless solutions in various dimensions D≤9. In some cases, these occur with dimensions (D,p) that coincide with those of descendants of known families, but since the new solutions are stainless, they are necessarily distinct. The new stainless supersymmetric solutions include a 6-brane and a 5-brane in D=9, a string in D=5, and particles in all dimensions 5≤D≤9. (orig.)

  20. Pitting corrosion resistant austenite stainless steel

    Science.gov (United States)

    van Rooyen, D.; Bandy, R.

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

  1. Fatigue fracture modes of a stainless steel

    International Nuclear Information System (INIS)

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

    1977-01-01

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

  2. Self-welding evaluation of type 304 and A286 stainless steel in the temperature range 800/sup 0/-1140/sup 0/F in flowing sodium

    Energy Technology Data Exchange (ETDEWEB)

    Chang, J.Y.; Flagella, P.N.; Schrock, S.L.

    1976-01-01

    This paper covers two material combinations, Type 304 SS vs Type 304 SS and Type 304 SS vs A286, tested at temperatures from 800 to 1140/sup 0/F for time periods up to six months in flowing sodium. Contact stresses ranged from 2 to 30 ksi on contact areas for 0.63 to 1.00 in./sup 2/. Tests were performed in either tensile or shear modes on the flat-on-flat samples. Surface morphologies of the sample before and after the test were presented. Self-welding of Type 304 SS was significant at temperatures above 1080/sup 0/F while no self-welding was detected at 800/sup 0/F. Sliding friction coefficient (..mu..) data for a Type 304 SS couple at 800/sup 0/F under compressive stresses from 2000 to 30,000 psi in sodium could be correlated quite accurately by W/sigma = 0.08e/sup 9..mu../, where W is the waviness height in microinches and sigma is the compressive stress in kilo-pound per square inch. One self-weld couple of Type 304 SS/Type 304 SS exposed at 1080/sup 0/F for 3 months was not separated but rather removed intact from the test apparatus and examined in cross-section. Scanning electron micrographs of the contacted area revealed that portions of the original interface were no longer discernible. (auth)

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

    Science.gov (United States)

    2016-06-01

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

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

    Science.gov (United States)

    Peralta, Stephen

    2010-01-01

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

  5. Plasma spot welding of ferritic stainless steels

    International Nuclear Information System (INIS)

    Lesnjak, A.; Tusek, J.

    2002-01-01

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

  6. Evolution of stainless steels in nuclear industry

    International Nuclear Information System (INIS)

    Tavassoli, Farhad

    2010-01-01

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

  7. A study on the behaviour of stress-corrosion crack initiation and propagation of type 304 stainless steel in aqueous 35wt% MgCl2 solution by electrical potential method

    International Nuclear Information System (INIS)

    Choi, Jung Kyo; Pyun, Su Il; Rhee, Woo Bong

    1988-01-01

    The behaviour of stress corrosion(SC) crack initiation and propagation of Type 304 stainless steel in 35 wt% MgCl 2 has been studied as a function of temperature and applied stress at the applied electrochemical potential of -106mV SHE by using electrical potential method. In the present study, the electrical potential method allows to differentiate the incubation period from the propagation period for SC crack. The optical microscopy revealed that the pit is a primary source of SC crack initiation under the applied stress lower than yield strength. SC crack initiation stage is composed of three steps; 1) pit initiation, 2) pit growth to critical size, and 3) crack propagation in the lateral and the through-thickness directions. The portion of anodic dissolution trenches to pits as sites of SC crack initiation increased with applied stress higher than yield strength. The activation energy of the electrochemical reaction contribution to the SC crack initiation and the energy of the stress contribution to the SC crack initiation under 212MPa are evaluated to be 30.5 kJ/mol and 14.0 kJ/mol, respectively. The fractography of SC crack propagation showed the transition of fracture mode from fully transgranular mode to the mixed zone with intergranular mode in the interior of the specimen. The intergranular portion is nearly independent of temperature, however it increases with the applied stress. (Author)

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

    Science.gov (United States)

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

    1994-10-01

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

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

    International Nuclear Information System (INIS)

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

    2004-01-01

    Boron containing stainless steels are used in the nuclear industry for applications such as spent fuel storage, control rods and shielding. It was of interest to compare the corrosion resistance of three borated stainless steels with standard austenitic alloy materials such as type 304 and 316 stainless steels. Tests were conducted in three simulated concentrated ground waters at 90 C. Results show that the borated stainless were less resistant to corrosion than the witness austenitic materials. An acidic concentrated ground water was more aggressive than an alkaline concentrated ground water

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

    International Nuclear Information System (INIS)

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

    1991-01-01

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

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

    International Nuclear Information System (INIS)

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

    1997-04-01

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

  12. Effects of microstructure on ultrasonic examination of stainless steel

    International Nuclear Information System (INIS)

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

    1976-01-01

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

  13. A final report on the performance achieved by non-destructive testing of defective butt welds in 50mm thick Type 316 stainless steel

    International Nuclear Information System (INIS)

    Ford, J.; Hudgell, R.J.

    1987-03-01

    This report concludes a programme of work started approximately eight years ago to fabricate deliberately defective austenitic downhand welds in 50 mm thick Type 316 plate and then to examine them non-destructively under ideal laboratory conditions. After completing and reporting the Non-Destructive Testing (NDT), the specimens were subjected to detailed metallography to locate, identify and size all the planned and unplanned flaws in the welds. The report gives the final analysis of this exercise on the relative merits of X-radiography, pulse echo ultrasonics and the time-of-flight technique for the detection, location and sizing of weld flaws. It was found that X-radiography and pulse echo ultrasonics were the best techniques for flaw detection but neither technique was reliable for flaw sizing. The time-of-flight technique provided accurate sizing data but the location of the flaws had to be known to identify the diffracted signals from the extremities of the flaws due to the poor signal to noise ratio. Observations are also reported on the fabrication of deliberately defective austenitic welds for use as reference specimens in the FR programme. (author)

  14. The development of a type B(U) transport container design in cast and forged stainless steel for the transport of immobilised intermediate level waste

    Energy Technology Data Exchange (ETDEWEB)

    Sievwright, B. [United Kingdom Nirex Ltd, Harwell (United Kingdom); Dixon, P. [RWE NUKEM, Harwell (United Kingdom); Tso, C.F. [Ove Arup and Partners, London (United Kingdom)

    2004-07-01

    United Kingdom Nirex Limited (Nirex) is responsible for providing the United Kingdom with safe, environmentally sound and publicly acceptable options for the long-term management of radioactive materials. This includes intermediate level (ILW) and some low level (LLW) wastes. As part of its role Nirex has defined standards and specifications for the conditioning and packaging of these wastes, and carries out assessments of packaging proposals to ensure compatibility with the requirements for future phases of waste management. In order to facilitate this process and to provide a basis for the production of waste package specifications, Nirex has developed the Phased Disposal Concept, and produced a suite of underpinning safety and performance assessments. It has also undertaken work to assess the compatibility of its waste packaging specifications with other waste management options. The Phased Disposal Concept continues to be developed and updated to incorporate issues arising from dialogue with stakeholders, including members of the public; future changes arising from Government policy, legislation and regulations; information from waste producers, and the results from on-going research and development. One of the documents describing the Phased Disposal Concept is the Generic Transport System Design (GTSD). The GTSD outlines the range of waste packages to be transported and disposed of, and describes the design of the transport system needed to transport wastes from their sites of production or storage to a centralised phased disposal facility site. It also describes a range of re-usable transport containers which could be used to transport those waste packages, which require Type B standards for transport, through the public domain. This paper describes the development to date of such a design of reusable transport container, known as the SWTC-285, the Standard Waste Transport Container (SWTC) with 285 mm of shielding.

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

    International Nuclear Information System (INIS)

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

    1980-01-01

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

  16. Effects of neutron irradiation on tensile and creep properties of stainless steels

    International Nuclear Information System (INIS)

    Miyaji, Noriko; Abe, Yasuhiro; Asayama, Tai; Aoto, Kazumi; Ukai, Shigeharu

    1997-01-01

    In order to investigate the effects of neutron irradiation on the creep and tensile properties of stainless steels, post-irradiation tests were made on the specimens of FBR grade type 316 stainless steel (316FR) and type 304 stainless steel. The post-irradiation tensile tests showed that the fracture elongation of both 316FR and type 304 stainless steel decreased and the 0.2% proof strength increased by irradiation. These phenomena are related to the point defect accumulation due to neutron irradiation. The post-irradiation creep test of 316FR demonstrated that the time to rupture decreased to between 1/3 and 1/5 of the unirradiated one, and this reduction is smaller than that of type 304 stainless steels under the same irradiation and test conditions. The creep property degradation of type 304 stainless steel due to the irradiation is caused by accumulation of helium bubbles at the grain boundaries. As for 316FR, it is considered that beyond the neutron exposure level of 0.3dpa a growth of phosphide caused a decrease in solution hardening and accumulation of helium bubbles at the grain boundaries. It is concluded that the reduction ratio of time to rupture for both 316FR and type 304 stainless steels after irradiation became larger than 1/30, which is the lower limit of the reduction ratio for the 'Monju' FBR. (author)

  17. Diamond deposition on siliconized stainless steel

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  18. Alternativa de protección contra la corrosión del acero AISI 310S mediante recubrimiento de aluminio bajo condiciones de platos separadores en celdas de combustible de carbonatos fundidos

    Directory of Open Access Journals (Sweden)

    R. Orozco-Cruz

    2016-01-01

    Full Text Available Introducción: La celda de combustible de carbonatos fundidos (MCFC, por sus siglas en inglés convencional opera a 650°C. Consiste de un cátodo de NiO poroso y litiado, una mezcla eutéctica de carbonato de litio (Li2CO3 y carbonato de potasio (K2CO3 fundido en una matriz electrolitica de óxido de aluminio litiado (LiAlO2 y un ánodo poroso de Ni. Los platos separadores entre cada celda presentan problemas de corrosión. Ante eso, un acero inoxidable AISI 310S con recubrimiento fue estudiado en condiciones de un plato separador en una MCFC. Método: Se utilizó un acero inoxidable AISI 310S como sustrato (muestra A, aplicándole un recubrimiento de Al con (B y sin tratamiento térmico (C. Fueron expuestos en carbonatos fundidos (62 mol% Li2CO3 -38 mol% K2CO3 a 650 °C en crisoles de alúmina. El comportamiento electroquímico fue estudiado mediante la técnica de Espectroscopía de Impedancia Electroquimica (EIS. Para el análisis de los diagramas de impedancia, se utilizó el software de simulación “Boukamp Equivalent Circuit”. La sección transversal de las muestras corroídas fue caracterizada mediante Microscopía Electrónica de Barrido (SEM, por sus siglas en inglés y los productos formados por Difracción de rayos X (XRD, por sus siglas en inglés. Resultados: Los diagramas de EIS presentan aumentos y disminuciones en los semicírculos formados a altas frecuencias indicativo de disolución de la capa externa, aumento y disminución de la resistencia de esta última así como el posible rompimiento de ella. La técnica de XRD presentó fases LiFeO2, LiCrO2, -LiAlO2 y -LiAlO2 así como fases intermetálicas para las distintas condiciones de la muestra. De la misma manera, los análisis de SEM presentaron los espesores de cada una de las capas formadas. Discusión o Conclusión: En la muestra A, se formaron capas de LiFeO2 y LiCrO2 después de 200 horas de exposición. La capa de LiCrO2 aumenta por la difusión de Li hacia el

  19. Study of cyclic oxidation for stainless steels AISI 309 T 253 M A, with low additions of cerium

    International Nuclear Information System (INIS)

    Velazquez F, G.L.; Martinez, M.; Ruiz, A.

    1998-01-01

    It has been detected that the addition of small amounts (<1%) of the so called 'reactive elements' such as Cerium to Fe-Cr alloys that was utilized in oxidating environment at high temperatures improving its resistance to oxidation under isothermal and cyclic conditions. In this work, it was evaluated the behavior under cyclic oxidation conditions for an austenitic stainless steel at chromium-nickel (253MA) with cerium addition, and comparing it with the AISI 310S austenitic stainless steel. The cyclic oxidation essays consist of five cycles by 24 hours each one, following of a cooling in air until ambient temperature from the temperatures of 850, 900 and 950 Centigrade, registering the gain mass of the specimen at end of each cycle. In order to this were prepared samples with dimensions of 20 mm. x 10 mm. x 1 mm. Later to the oxidation essays was evaluated the morphology of the corrosion products layer by scanning electron microscopy. The present phases were identified by X-ray diffraction and by chemical microanalysis by Dispersive energy (EDAX). The results obtained show that the steel with cerium addition, presents a higher adherence and resistance to the spalling noting that the cerium promotes the casting anchor of the oxides layer to matrix and by reducing the grain size of the layer improving its plasticity. Additionally the cerium promotes the preferential oxidation of the forming elements of protective layers like the chromium. (Author)

  20. Antibacterial effect of silver nanofilm modified stainless steel surface

    Science.gov (United States)

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

    2015-03-01

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

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

    Science.gov (United States)

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

    2018-03-01

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

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

    Directory of Open Access Journals (Sweden)

    Udomdej Pakdee

    2017-01-01

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

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

    Science.gov (United States)

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

    2004-11-01

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

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

    International Nuclear Information System (INIS)

    Zamora R, L.

    1994-01-01

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

  5. Evaluation of stainless steel reinforcement construction project

    Science.gov (United States)

    2003-02-01

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

  6. Martensite transformations influence in austenite stainless steel fractures

    International Nuclear Information System (INIS)

    Fonseca, H.; Monteiro, S.N.

    1976-07-01

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

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

    Directory of Open Access Journals (Sweden)

    M. Sapieta

    2017-01-01

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

  8. Phase transformations evaluation on a UNS S31803 duplex stainless steel based on nondestructive testing

    Energy Technology Data Exchange (ETDEWEB)

    Macedo Silva, Edgard de, E-mail: edgard@cefetpb.edu.br [Centro federal de Educacao Tecnologica da Paraiba (CEFET PB), Area da Industria, Avenida 1o de Maio, 720 - 58015-430 - Joao Pessoa/PB (Brazil); Costa de Albuquerque, Victor Hugo, E-mail: victor.albuquerque@fe.up.pt [Universidade Federal da Paraiba (UFPB), Departamento de Engenharia Mecanica (DEM), Cidade Universitaria, S/N - 58059-900 - Joao Pessoa/PB (Brazil); Pereira Leite, Josinaldo, E-mail: josinaldo@ct.ufpb.br [Universidade Federal da Paraiba (UFPB), Departamento de Engenharia Mecanica (DEM), Cidade Universitaria, S/N - 58059-900 - Joao Pessoa/PB (Brazil); Gomes Varela, Antonio Carlos, E-mail: varela@cefetpb.edu.br [Universidade Federal da Paraiba (UFPB), Departamento de Engenharia Mecanica (DEM), Cidade Universitaria, S/N - 58059-900 - Joao Pessoa/PB (Brazil); Pinho de Moura, Elineudo, E-mail: elineudo@pq.cnpq.br [Universidade Federal do Ceara (UFC), Departamento de Engenharia Metalurgica e de Materiais, Campus do Pici, Bloco 715, 60455-760 - Fortaleza/CE (Brazil); Tavares, Joao Manuel R.S., E-mail: tavares@fe.up.pt [Faculdade de Engenharia da Universidade do Porto (FEUP), Departamento de Engenharia Mecanica e Gestao Industrial (DEMEGI)/Instituto de Engenharia Mecanica e Gestao Industrial - INEGI, Rua Dr. Roberto Frias, s/n, 4200-465 Porto (Portugal)

    2009-08-15

    Duplex stainless steel presents special mechanical properties such as, for example, mechanical and corrosion strength, becoming competitive in relation to the other types of stainless steel. One of the great problems of duplex stainless steel microstructural changes study is related to embrittlement above 300 deg. C, with the precipitation of the {alpha}' phase occurring over the ferritic microstructure. Aiming to characterise embrittlement of duplex stainless steel, hardening kinetics, from 425 to 475 deg. C, was analysed through the speed of sound, Charpy impact energy, X-ray diffraction, hardness and microscopy parameters. The presence of two hardening stages, detected through the speed of sound, was observed, one being of brittle characteristic and the other ductile. Moreover, the speed of sound showed a direct correlation with the material's hardness. Thus, it is concluded that the speed of sound is a promising nondestructive parameter to follow-up embrittlement in duplex stainless steel.

  9. Phase transformations evaluation on a UNS S31803 duplex stainless steel based on nondestructive testing

    International Nuclear Information System (INIS)

    Macedo Silva, Edgard de; Costa de Albuquerque, Victor Hugo; Pereira Leite, Josinaldo; Gomes Varela, Antonio Carlos; Pinho de Moura, Elineudo; Tavares, Joao Manuel R.S.

    2009-01-01

    Duplex stainless steel presents special mechanical properties such as, for example, mechanical and corrosion strength, becoming competitive in relation to the other types of stainless steel. One of the great problems of duplex stainless steel microstructural changes study is related to embrittlement above 300 deg. C, with the precipitation of the α' phase occurring over the ferritic microstructure. Aiming to characterise embrittlement of duplex stainless steel, hardening kinetics, from 425 to 475 deg. C, was analysed through the speed of sound, Charpy impact energy, X-ray diffraction, hardness and microscopy parameters. The presence of two hardening stages, detected through the speed of sound, was observed, one being of brittle characteristic and the other ductile. Moreover, the speed of sound showed a direct correlation with the material's hardness. Thus, it is concluded that the speed of sound is a promising nondestructive parameter to follow-up embrittlement in duplex stainless steel.

  10. Effects of fast neutron irradiation on the fracture behavior of stainless steel

    International Nuclear Information System (INIS)

    Huang, F.H.; Fish, R.L.

    1982-03-01

    In designing against premature fracture, the characteristics of materials must be measured and design criteria developed. The reduction in ductility for irradiated stainless steels has been observed, but little work has been conducted on evaluating the effects of notches on these materials. A reduction in notch ductility has been investigated in Charpy-V impact tests of irradiated Type 304 and Type 316 stainless steel; in irradiated Type 304 stainless steel, notch effects were not observed at 232 and 317 0 C, but as the test temperature was increased from 538 to 593 0 C, the material irradiated to a fluence of 3 X 10 22 n/cm 2 exhibited a notch weakening. Recently, similar experiments were performed on irradiated 20% cold worked Type 316 stainless steel to determine the effects of irradiation on the fracture behavior of this alloy

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

    Digital Repository Service at National Institute of Oceanography (India)

    PrabhaDevi; Wagh, A.B.

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

  12. Microstructure and wear resistance of spray-formed supermartensitic stainless steel

    Directory of Open Access Journals (Sweden)

    Guilherme Zepon

    2013-06-01

    Full Text Available Since the early 90's the oil industry has been encouraging the development of corrosion and wear resistant alloys for onshore and offshore pipeline applications. In this context supermartensitic stainless steel was introduced to replace the more expensive duplex stainless steel for tubing applications. Despite the outstanding corrosion resistance of stainless steels, their wear resistance is of concern. Some authors reported obtaining material processed by spray forming, such as ferritic stainless steel, superduplex stainless steel modified with boron, and iron-based amorphous alloys, which presented high wear resistance while maintaining the corrosion performance1,2. The addition of boron to iron-based alloys promotes the formation of hard boride particles (M2B type which improve their wear resistances3-9. This work aimed to study the microstructure and wear resistance of supermartensitic stainless steel modified with 0.3 wt. (% and 0.7 wt. (% processed by spray forming (SF-SMSS 0.3%B and SF-SMSS 0.7%B, respectively. These boron contents were selected in order to improve the wear resistance of supermartensitic stainless steel through the formation of uniformly distributed borides maintaining the characteristics of the corrosion resistant matrix. SF-SMSS 0.7%B presents an abrasive wear resistance considerably higher than spray-formed supermartensitic stainless steel without boron addition (SF-SMSS.

  13. Weld bonding of stainless steel

    DEFF Research Database (Denmark)

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

    2004-01-01

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

  14. Nickel release from stainless steels.

    Science.gov (United States)

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

    1997-09-01

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

  15. Effect of cold working and aging on high temperature deformation of high Mn stainless steel

    International Nuclear Information System (INIS)

    Yoshikawa, M.; Habara, Y.; Matsuki, R.; Aoyama, H.

    1999-01-01

    By the addition of N, the strength of high Mn stainless steel can be increased. Cold rolling and aging are effective to increase its strength further, and with those treatments this grade is often used for high temperature applications. In this study, creep deformation behavior and high temperature strength of the high Mn stainless steel in cold rolled and aged conditions are discussed as compared to Type 304 stainless steel. It has been revealed that as-rolled specimens show instant elongation at the beginning of creep tests and its amount is larger in the high Mn grade than in Type 304. Also, the creep rate of the high Mn stainless steel is smaller than that of Type 304. These facts may be related to the change in microstructure. (orig.)

  16. Influence of hydrogen on the corrosion behavior of stainless steels in lithium

    Science.gov (United States)

    Shulga, A. V.

    2008-02-01

    Corrosion behavior of several stainless steels in lithium and lithium with 0.05%H has been examined. Corrosion tests were performed under static conditions at 600 and 700 °C in the austenitic stainless steel of the type AISI 304 containers. Intensive formation of σ-phase of the composition Fe 50Cr 43Mo 3Ni 4 on the surface of austenitic stainless steels of the type AISI 316 at 700 °C for 1000 h was established as a result of isothermal mass transfer. Addition of 0.05%H in the form of LiH to lithium resulted in an increase in the quantity of the σ-phase. After corrosion tests of ferritic/martensitic steel in lithium at 700 °C for 1000 h the formation of the γ-phase was observed. In Li + 0.05%H besides the γ-phase was also formed the σ-phase. The features of decarburization of investigated stainless steels were examined using the direct method of activation autoradiography on carbon. Addition of 0.05%H in lithium significantly decreased the carbon content in the decarburization zone of austenitic stainless steel Fe-18Cr-15Ni-0.15C-0.23B without a noticeable change in the thickness of the decarburization zone. Decarburization of ferritic/martensitic stainless steel was less than of austenitic stainless steel using the same corrosion tests.

  17. Surface analysis of localized corrosion of austenitic 316L and duplex 2205 stainless steels in simulated body solutions

    NARCIS (Netherlands)

    Conradi, Marjetka; Schön, Peter Manfred; Kocijan, Aleksandra; Jenko, M.; Vancso, Gyula J.

    2011-01-01

    We report on cyclic voltammetry and in situ electrochemical atomic force microscopy (EC-AFM) studies of localized corrosion of duplex 2205 stainless steel (DSS 2205) and austenitic stainless steel of the type AISI 316L in two model solutions, including artificial saliva (AS) and a simulated

  18. The influence of cold work on the oxidation behaviour of stainless steel

    International Nuclear Information System (INIS)

    Langevoort, J.C.

    1985-01-01

    In this thesis the study of the interaction of oxygen gas with stainless steel surfaces is described. Thermogravimetry, microscopy and ellipsometry have been used to follow the oxidation in situ, while EDX, AES and XPS have been used to determine the oxide compositions. The aim of this thesis is to reveal the influence on the oxidation behaviour of stainless steel of i) cold work (rolling, drawing, milling, polishing and Ar ion bombardment) ii) the initially formed oxide and iii) the experimental conditions. Two types of stainless steels have been used (AISI 304 (a 18/8 Cr/Ni steel) and Incoloy 800 H (a 20/30 Cr/Ni steel)). (Auth.)

  19. Nano-composite stainless steel

    Science.gov (United States)

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

    2015-07-14

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

  20. Multicycle mechanical performance of titanium and stainless steel transpedicular spine implants.

    Science.gov (United States)

    Pienkowski, D; Stephens, G C; Doers, T M; Hamilton, D M

    1998-04-01

    This was a prospective in vitro study comparing titanium alloy and stainless steel alloy in transpedicular spine implants from two different manufactures. To compare the multicycle mechanical performance of these two alloys, used in each of two different implant designs. Transpedicular spine implants primarily have been manufactured from stainless steel, but titanium alloy offers imaging advantages. However, the notch sensitivity of titanium alloy has caused concern regarding how implants made from this material will compare in stiffness and fatigue life with implants made from stainless steel. Twenty-four implants (two alloys, two designs, six implants per group) were mounted in machined polyethylene wafers and repetitively loaded (up to 1 million cycles) from 80 N to 800 N using a 5-Hertz sinusoidal waveform. Load and displacement data were automatically and periodically sampled throughout the entire test. Implant stiffness increased with cycle load number, reached a steady state, then declined just before fatigue failure. Stiffness varied less in titanium transpedicular spine implants than in their stainless counterparts. All stainless steel implant types were stiffer (steady-state value, P titanium alloy counterparts. One titanium implant design failed with fewer (P stainless steel counterpart, whereas a stainless steel implant of another design failed with fewer (P titanium counterpart. Overall, fatigue life, i.e., the total number of load cycles until failure, was related to implant type (P implant material. A transpedicular spine implant's fatigue lifetime depends on both the design and the material and cannot be judged on material alone. Stainless steel implants are stiffer than titanium alloy implants of equal design and size; however, for those designs in which the fatigue life of the titanium alloy version is superior, enlargement of the implant's components can compensate for titanium's lower modulus of elasticity and result in an implant equally stiff

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

    International Nuclear Information System (INIS)

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

    1979-01-01

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

  2. Pitting corrosion of low-Cr austenitic stainless steels

    International Nuclear Information System (INIS)

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

    1996-01-01

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

  3. Bending Behavior of Porous Sintered Stainless Steel Fiber Honeycombs

    Science.gov (United States)

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

    2017-02-01

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

  4. Stainless steels for cryogenic bolts and nuts

    International Nuclear Information System (INIS)

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

    1975-01-01

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

  5. Segregation effects in welded stainless steels

    International Nuclear Information System (INIS)

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

    1987-01-01

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

  6. Hydrogenation of stainless steels implanted with nitrogen

    International Nuclear Information System (INIS)

    Silva Ramos, L.E. da.

    1989-01-01

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

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

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1999-01-01

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

  8. Hybrid Stainless Steel Girder for Bridge Construction

    OpenAIRE

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

    2017-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Viera Zatkalíková

    2011-09-01

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

  10. Microstructural and Mechanical Characterization of Solidified Austenitic Stainless Steels

    Directory of Open Access Journals (Sweden)

    Aktaş Çelik G.

    2017-09-01

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

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

    International Nuclear Information System (INIS)

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

    1991-01-01

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

  12. Creep embrittlement of austenitic stainless steels with titanium addition

    International Nuclear Information System (INIS)

    Felsen, M.F.

    1983-04-01

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

  13. The repair of preveneered posterior stainless steel crowns.

    Science.gov (United States)

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

    2008-01-01

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

  14. Fireside carburization of stainless steel furnace tubes

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-11-01

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

  15. Stainless steel-zirconium alloy waste forms

    International Nuclear Information System (INIS)

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

    1996-01-01

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

  16. Friction behavior of 304 stainless steel of varying hardness lubricated with benzene and some benzyl structures

    Science.gov (United States)

    Buckley, D. H.

    1974-01-01

    The lubricating properties of some benzyl and benzene structures were determined by using 304 stainless steel surfaces strained to various hardness. Friction coefficients and wear track widths were measured with a Bowden-Leben type friction apparatus by using a pin-on-disk specimen configuration. Results obtained indicate that benzyl monosulfide, dibenzyl disulfide, and benzyl alcohol resulted in the lowest friction coefficients for 304 stainless steel, while benzyl ether provided the least surface protection and gave the highest friction. Strainhardening of the 304 stainless steel prior to sliding resulted in reduced friction in dry sliding. With benzyl monosulfide, dibenzyl disulfide, and benzyl alcohol changes in 304 stainless steel hardness had no effect upon friction behavior.

  17. Solidification cracking in austenitic stainless steel welds

    Indian Academy of Sciences (India)

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

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

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

    Science.gov (United States)

    Rajasekhara, Shreyas

    2007-12-01

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

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

    Directory of Open Access Journals (Sweden)

    Syed Altaf Khalid

    2012-01-01

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

  20. Effect of Temperature and Chloride Ion Concentration on Corrosion of Passive Films on Nano/Ultrafine Grained Stainless Steels

    Science.gov (United States)

    Jinlong, Lv; Hongyun, Luo

    2014-12-01

    The effects of solution temperature, concentration of chloride ions, and grain refinement on the corrosion resistance of the passive film formed on 304 stainless steels in borate buffer solution were investigated by electrochemical impedance spectroscopy and Mott-Schottky measurements. The results showed that the passive films formed on the surface of 304 stainless steels possessed n- and p-type semiconductor characteristics. With the increase of solution temperature, the corrosion resistance of the passive film of coarse and nano/ultrafine grained stainless steels decreased. However, the corrosion resistance of the passive film in nano/ultrafine grained stainless steel was higher than that in the coarse grained one. Moreover, in cyclic potentiodynamic polarization tests, chloride ions changed semiconductor characteristics of the passive film formed on the surface of stainless steel.

  1. Infrared electro-thermal NDE of stainless steel

    International Nuclear Information System (INIS)

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

    1975-01-01

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

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

    International Nuclear Information System (INIS)

    Chopra, O.K.; Ayrault, G.

    1983-10-01

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

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

    International Nuclear Information System (INIS)

    Henrikson, Sture

    1989-12-01

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

  4. Liquid Phase Sintering of Highly Alloyed Stainless Steel

    DEFF Research Database (Denmark)

    Mathiesen, Troels

    1996-01-01

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

  5. Finite Element Modelling of Cold Formed Stainless Steel Columns

    Directory of Open Access Journals (Sweden)

    M. Macdonald

    2005-01-01

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

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

  7. 77 FR 22561 - Drawn Stainless Steel Sinks From the People's Republic of China: Correction to Notice of...

    Science.gov (United States)

    2012-04-16

    ... multiple drawn bowls, with or without drain boards, whether finished or unfinished, regardless of type of... vertical corners to form the bowls. Stainless steel sinks with fabricated bowls may sometimes be referred...

  8. 78 FR 21592 - Drawn Stainless Steel Sinks from the People's Republic of China: Amended Final Determination of...

    Science.gov (United States)

    2013-04-11

    ... unfinished, regardless of type of finish, gauge, or grade of stainless steel. Mounting clips, fasteners... Co., Ltd. Grand Hill Work Company....... Zhongshan Xintian 33.51 Hardware Co., Ltd. Guangdong G-Top...

  9. Irradiation embrittlement of ferritic stainless steels

    International Nuclear Information System (INIS)

    Suganuma, K.; Kayano, H.

    1984-01-01

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

  10. Development of new high-performance stainless steels

    International Nuclear Information System (INIS)

    Park, Yong Soo

    2002-01-01

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

  11. Characterization of corrosion scale formed on stainless steel delivery pipe for reclaimed water treatment.

    Science.gov (United States)

    Cui, Yong; Liu, Shuming; Smith, Kate; Yu, Kanghua; Hu, Hongying; Jiang, Wei; Li, Yuhong

    2016-01-01

    To reveal corrosion behavior of stainless steel delivery pipe used in reclaimed water treatment, this research focused on the morphological, mineralogical and chemical characteristics of stainless steel corrosion scale and corroded passive film. Corrosion scale and coupon samples were taken from a type 304 pipe delivering reclaimed water to a clear well in service for more than 12 years. Stainless steel corrosion scales and four representative pipe coupons were investigated using mineralogy and material science research methods. The results showed corrosion scale was predominantly composed of goethite, lepidocrocite, hematite, magnetite, ferrous oxide, siderite, chrome green and chromite, the same as that of corroded pipe coupons. Hence, corrosion scale can be identified as podiform chromite deposit. The loss of chromium in passive film is a critical phenomenon when stainless steel passive film is damaged by localized corrosion. This may provide key insights toward improving a better comprehension of the formation of stainless steel corrosion scale and the process of localized corrosion. The localized corrosion behavior of stainless steel is directly connected with reclaimed water quality parameters such as residual chlorine, DO, Cl(-) and SO4(2-). In particular, when a certain amount of residual chlorine in reclaimed water is present as an oxidant, ferric iron is the main chemical state of iron minerals. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Effects of chitosan inhibitor on the electrochemical corrosion behavior of 2205 duplex stainless steel

    Science.gov (United States)

    Yang, Se-fei; Wen, Ying; Yi, Pan; Xiao, Kui; Dong, Chao-fang

    2017-11-01

    The effects of chitosan inhibitor on the corrosion behavior of 2205 duplex stainless steel were studied by electrochemical measurements, immersion tests, and stereology microscopy. The influences of immersion time, temperature, and chitosan concentration on the corrosion inhibition performance of chitosan were investigated. The optimum parameters of water-soluble chitosan on the corrosion inhibition performance of 2205 duplex stainless steel were also determined. The water-soluble chitosan showed excellent corrosion inhibition performance on the 2205 duplex stainless steel. Polarization curves demonstrated that chitosan acted as a mixed-type inhibitor. When the stainless steel specimen was immersed in the 0.2 g/L chitosan solution for 4 h, a dense and uniform adsorption film covered the sample surface and the inhibition efficiency (IE) reached its maximum value. Moreover, temperature was found to strongly influence the corrosion inhibition of chitosan; the inhibition efficiency gradually decreased with increasing temperature. The 2205 duplex stainless steel specimen immersed in 0.4 g/L water-soluble chitosan at 30°C displayed the best corrosion inhibition among the investigated specimens. Moreover, chitosan decreased the corrosion rate of the 2205 duplex stainless steel in an FeCl3 solution.

  13. The Otto Aufranc Award: Enhanced Biocompatibility of Stainless Steel Implants by Titanium Coating and Microarc Oxidation

    Science.gov (United States)

    Lim, Young Wook; Kwon, Soon Yong; Sun, Doo Hoon

    2010-01-01

    Background Stainless steel is one of the most widely used biomaterials for internal fixation devices, but is not used in cementless arthroplasty implants because a stable oxide layer essential for biocompatibility cannot be formed on the surface. We applied a Ti electron beam coating, to form oxide layer on the stainless steel surface. To form a thicker oxide layer, we used a microarc oxidation process on the surface of Ti coated stainless steel. Modification of the surface using Ti electron beam coating and microarc oxidation could improve the ability of stainless steel implants to osseointegrate. Questions/purposes The ability of cells to adhere to grit-blasted, titanium-coated, microarc-oxidated stainless steel in vitro was compared with that of two different types of surface modifications, machined and titanium-coated, and microarc-oxidated. Methods We performed energy-dispersive x-ray spectroscopy and scanning electron microscopy investigations to assess the chemical composition and structure of the stainless steel surfaces and cell morphology. The biologic responses of an osteoblastlike cell line (SaOS-2) were examined by measuring proliferation (cell proliferation assay), differentiation (alkaline phosphatase activity), and attraction ability (cell migration assay). Results Cell proliferation, alkaline phosphatase activity, migration, and adhesion were increased in the grit-blasted, titanium-coated, microarc-oxidated group compared to the two other groups. Osteoblastlike cells on the grit-blasted, titanium-coated, microarc-oxidated surface were strongly adhered, and proliferated well compared to those on the other surfaces. Conclusions The surface modifications we used (grit blasting, titanium coating, microarc oxidation) enhanced the biocompatibility (proliferation and migration of osteoblastlike cells) of stainless steel. Clinical Relevance This process is not unique to stainless steel; it can be applied to many metals to improve their biocompatibility

  14. Hydrogen damage in stainless steel

    International Nuclear Information System (INIS)

    Caskey, G.R. Jr.

    1981-01-01

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

  15. Recycle of radiologically contaminated austenitic stainless steels

    International Nuclear Information System (INIS)

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

    1995-01-01

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

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

    Science.gov (United States)

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

    1980-01-01

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

  17. High cycle fatigue of austenitic stainless steels

    International Nuclear Information System (INIS)

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

    1990-01-01

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

  18. Evaluation of SCC morphology on L-grade stainless steels in BWRs

    International Nuclear Information System (INIS)

    Suzuki, Shunichi; Takamori, Kenrou; Kumagai, Katsuhiko; Ooki, Suguru; Fukuda, Toshihiko; Yamashita, Hironobu; Futami, Tsuneo

    2004-01-01

    Recently, a large number of stress corrosion cracking (SCC) have been observed in core shrouds and re-circulation (PLR) pipings made of L-grade stainless steel in Japanese BWRs (Boiling Water Reactors). L-grade stainless steels, which contain less carbon to avoid the sensitization due to welding, have been developed as SCC-resistant materials after many SCC experiences on sensitized type304. As L-grade materials, especially type 316L and 316NG stainless steels have shown little susceptibility to SCC initiation in laboratory tests, it has to be considered that there exist some unknown factors excluding sensitization that cause SCC in these materials. From the detailed investigations of plant components so far, SCC of L-grade stainless steels show different characteristics from those observed on conventional sensitized type 304 especially in their crack morphology. In this paper, classification of observed cracks according to their morphology is discussed, followed by evaluation on root causes of SCC. The present conclusions are (1) crack orientations mainly depend on the maximum principal stress direction of welding residual stresses, (2) SCC susceptibility of L-grade stainless steels is enhanced by material hardening by machining or grinding, and (3) in L-grade materials SCC can propagate into the weld metal but in many case, cracks seem to be arrested near the fusion line. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-07-01

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

  20. Initiation and growth of thermal fatigue crack networks in an AISI 304 L type austenitic stainless steel (X2 CrNi18-09); Amorcage et propagation de reseaux de fissures de fatigue thermique dans un acier inoxydable austenitique de type X2 CrNi18-09 (AISI 304 L)

    Energy Technology Data Exchange (ETDEWEB)

    Maillot, V

    2004-07-01

    We studied the behaviour of a 304 L type austenitic stainless steel submitted to thermal fatigue. Using the SPLASH equipment of CEA/SRMA we tested parallelepipedal specimens on two sides: the specimens are continuously heated by Joule effect, while two opposites faces are cyclically. cooled by a mixed spray of distilled water and compressed air. This device allows the reproduction and the study of crack networks similar to those observed in nuclear power plants, on the inner side of circuits fatigued by mixed pressurized water flows at different temperatures. The crack initiation and the network constitution at the surface were observed under different thermal conditions (Tmax = 320 deg C, {delta}T between 125 and 200 deg C). The experiment produced a stress gradient in the specimen, and due to this gradient, the in-depth growth of the cracks finally stopped. The obtained crack networks were studied quantitatively by image analysis, and different parameters were studied: at the surface during the cycling, and post mortem by step-by-step layer removal by grinding. The maximal depth obtained experimentally, 2.5 mm, is relatively coherent with the finite element modelling of the SPLASH test, in which compressive stresses appear at a depth of 2 mm. Some of the crack networks obtained by thermal fatigue were also tested in isothermal fatigue crack growth under 4-point bending, at imposed load. The mechanisms of the crack selection, and the appearance of the dominating crack are described. Compared to the propagation of a single crack, the crack networks delay the propagation, depending on the severity of the crack competition for domination. The dominating crack can be at the network periphery, in that case it is not as shielded by its neighbours as a crack located in the center of the network. It can also be a straight crack surrounded by more sinuous neighbours. Indeed, on sinuous cracks, the loading is not the same all along the crack path, leading to some

  1. Horizontal electron beam welding for stainless steels

    International Nuclear Information System (INIS)

    Martin, P.; Olivera, J.J.

    1977-01-01

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

  2. Consitutive modeling of metastable austenitic stainless steel

    NARCIS (Netherlands)

    Perdahcioglu, Emin Semih; Perdahcioglu, Emin Semih

    2008-01-01

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

  3. Stainless Steel to Titanium Bimetallic Transitions

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-01-01

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

  4. Mechanical and structural characteristics in high temperature of stainless steel welded joint

    International Nuclear Information System (INIS)

    Monteiro, S.N.; Carvalho Mota, A.F. de

    1980-01-01

    The mechanical behavior at 600 0 C of weldments made of type 304 stainless as base metal and niobium containing type 347 stainless as weld metal has been investigated. This was done through tensile and creep tests. Heat treatments at 600 0 C and up to 6000 hours permited a simultaneous follow up of the mechanical and microstructural changes. It was observed that the exposure at 600 0 C under load contributes, from the begining, to the strengthening of the weld. This is due to the acceleration of the second phase precipitation hardening. (Author) [pt

  5. Duplex stainless steel—Microstructure and properties

    Science.gov (United States)

    Debold, Terry A.

    1989-03-01

    Literature describing the microstructure of austenitic-ferritic stainless steels is reviewed, including phases which can be deleterious, such as σ and ά. The mechanical properties and corrosion resistance of Carpenter Technology's 7-Mo PLUSsr stainless (UNS S32950) demonstrate the resistance of this material to the formation of these phases and their deleterious effects. This material was evaluated in the annealed and welded conditions and after extended thermal treatments to simulate boiler and pressure vessel service.

  6. Plasma spot welding of ferritic stainless steels

    Directory of Open Access Journals (Sweden)

    Lešnjak, A.

    2002-06-01

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

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

  7. Phase Transformations in Cast Duplex Stainless Steels

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-01-01

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

  8. Phase transformations in cast duplex stainless steels

    Science.gov (United States)

    Kim, Yoon-Jun

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

  9. Nonmetallic inclusions in JBK-75 stainless steel

    International Nuclear Information System (INIS)

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

    1977-01-01

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

  10. Fracture toughness of stainless steel welds

    International Nuclear Information System (INIS)

    Mills, W.J.

    1985-11-01

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

  11. The effects of stainless steel radial reflector on core reactivity for small modular reactor

    Science.gov (United States)

    Kang, Jung Kil; Hah, Chang Joo; Cho, Sung Ju; Seong, Ki Bong

    2016-01-01

    Commercial PWR core is surrounded by a radial reflector, which consists of a baffle and water. Radial reflector is designed to reflect neutron back into the core region to improve the neutron efficiency of the reactor and to protect the reactor vessels from the embrittling effects caused by irradiation during power operation. Reflector also helps to flatten the neutron flux and power distributions in the reactor core. The conceptual nuclear design for boron-free small modular reactor (SMR) under development in Korea requires to have the cycle length of 4˜5 years, rated power of 180 MWth and enrichment less than 5 w/o. The aim of this paper is to analyze the effects of stainless steel radial reflector on the performance of the SMR using UO2 fuels. Three types of reflectors such as water, water/stainless steel 304 mixture and stainless steel 304 are selected to investigate the effect on core reactivity. Additionally, the thickness of stainless steel and double layer reflector type are also investigated. CASMO-4/SIMULATE-3 code system is used for this analysis. The results of analysis show that single layer stainless steel reflector is the most efficient reflector.

  12. A contribution to the question of stress-corrosion cracking of austenitic stainless steel cladding in nuclear power plants

    International Nuclear Information System (INIS)

    Kupka, I.; Mrkous, P.

    1977-01-01

    A brief review is presented of the basic types of corrosion damage (uniform corrosion, intergranular corrosion, stress corrosion) and their influence on operational safety are estimated. Corrosion cracking is analyzed of austenitic stainless steel cladding taking into account the adverse impact of coolant and stress (both operational and residual) in a light water reactor primary circuit. Experimental data are given of residual stresses in the stainless steel clad material, as well as their magnitude and distribution after cladding and heat treatment. (author)

  13. Cutting of Stainless Steel With Fiber and Disk Laser

    DEFF Research Database (Denmark)

    Wandera, Catherine; Salminen, Antti; Olsen, Flemming Ove

    2006-01-01

    role also in cutting applications. This has not happened mainly due to the fact that beam quality has not been sufficient. The introduction of new generation of solid state lasers has raised the interest of use of them in cutting application. This study was concentrated on use of fiber and disk lasers......, the new laser types with a high beam quality, in cutting of austenitic stainless steel. The performance of these new lasers at power level of 4 kW was compared with CO2-laser in respect of cutting speed, kerf width, kerf edge roughness and perpendicularity (squarness) in order to validate the potential...

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

    International Nuclear Information System (INIS)

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

    1982-01-01

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

  15. Corrosion Resistance of Some Stainless Steels in Chloride Solutions

    Directory of Open Access Journals (Sweden)

    Kasprzyk D.

    2017-06-01

    Full Text Available The present work compares corrosion behaviour of four types of S30403, S31603, S32615 austenitic and S32404 austenitic-ferritic stainless steels in chloride solutions (1%, 3% NaCl and in Ringer solution, at 37°C temperature. Corrosion resistance was determined by potentiodynamic polarization measurements and a thirty day immersion test conducted in Ringer solution. The immersion test was performed in term of biomedical application. These alloy were spontaneously passivated in all electrolytes, wherein S30403, S31603 and S32404 undergo pitting corrosion. Only S32615 containing 5.5% Si shows resistance to pitting corrosion.

  16. Elastic interaction between defects during dynamic aging of stainless steels

    International Nuclear Information System (INIS)

    Journaux, J.; Monteiro, S.N.

    1977-01-01

    The study of the mechanical properties through traction tests, at temperatures above room temperature in 316 type stainless steel emphasizes the existence of the dynamic aging phenomenon (Portevin-Lechantelier effect). The present paper explains in a general way the fundamental causes of this effect by examining the elastic interactions that occur between the solute atoms in solid solution and the crystal dislocations. These interactions, which are present only at a certain temperature range, are responsible for the improvement of the mechanical properties always noticed in the alloys showing this phenomenon. (F.R.) [pt

  17. 2014 Accomplishments-Tritium aging studies on stainless steel: Fracture toughness properties of forged stainless steels-Effect of hydrogen, forging strain rate, and forging temperature

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-02-01

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

  18. Precipitation reactions in austenitic stainless steels

    International Nuclear Information System (INIS)

    Hoch, M.; Yung-Shih Chen

    1979-01-01

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

  19. Tunneling corrosion mechanism of the hot forged austenitic stainless steel in highly oxidizing nitric acid

    International Nuclear Information System (INIS)

    Nagano, Hiroo; Kajimura, Haruhiko

    1993-01-01

    Austenitic Stainless Steels have been used for reprocessing plants where spent nuclear fuels are dealt with in hot nitric acid. Conventional stainless steels are resistant enough to nitric acid. However, they are prone to localized corrosion when nitric acid becomes highly oxidizing with birth of oxidants such as Ce 4+ or Cr 6+ ion during the reprocessing. Pitting type corrosion, so-called tunneling or end-grain corrosion occurred on the forgings of 25%-20%-Nb stainless steel (310Nb stainless steel) in such nitric acid solutions because of transpassive corrosion. It has been well known that metal surfaces of steel products casted, forged or rolled are susceptible to the tunneling corrosion in aggressive corrosion media. Nevertheless, neither clear explanations of the mechanism nor definite countermeasures have been proposed yet. This paper describes the mechanism and countermeasures on the tunneling corrosion of stainless steels in nitric acid relevant to spent nuclear fuel reprocessing. The results obtained are as follows: both general and intergranular corrosion occur on austenitic stainless steels in boiling 8N HNO 3 with Cr 6+ ions. Tunneling corrosion is initiated and propagates at the metal surfaces of 310Nb stainless steel forgings along chromium depleted areas vertical to metal flows. The grooves due to the tunneling corrosion are of diameters of 0.5 to 2 mm with a maximum depth of 6mm depending on exposure time and Cr 6+ concentration in nitric acid. Tunneling corrosion proceeds by build up of galvanic corrosion cells with Cr depleted parts as anodes and their neighborhoods as cathodes. The Cr depleted parts are formed during solidification of ingots and still retained parallel to the metal flow even after forging. The ESR (Electro Slag Remelting) is one of the useful preventive methods to tunneling corrosion from the view point of steel homogenization

  20. Heat transfer enhancement of flow insulator by combined stainless steel fibrous and wire net porous materials

    Science.gov (United States)

    Khantikomol, P.; Polsongkram, M.; Apisitpinyo, W.; Poowadin, T.

    2018-01-01

    The present research article aims to propose the heat transfer enhancement of the flow insulator using combined fibrous and wire net stainless steel porous material. The stainless fibrous plate with porosity of 0.9292 was combined to the stainless steel wire net having pore per inch (PPI) of 16 and total thickness of 30 mm. Two models of the arranging porous plates were prepared, which were model BA and model AB. Each porous plate segment had the same thickness. The examined porous plate model have porosities of 0.8452. The porous plate was placed normal to the flow direction. The air was used as working fluid heated by 5 kW electric heater, which was controlled by the automatic temperature control. Type-K thermocouples were employed to measure the air temperatures. The temperature at front of the porous plate was varied to be 350, 450, and 550°C. The air flow rate was varied in the range of 4-12 m3/hr. The experimental result showed that the temperature drop across the porous plate and the thermal efficiency increase with the inlet temperature. The air velocity slightly affects the temperature profile inside the test section at the upstream side of the porous plate but greatly affects temperature inside the porous plate. In consideration of the arranging porous plate, placing of the stainless steel wire net at the upstream side and placing the stainless steel fibrous at downstream side (model BA) results in the highest temperature drop and the highest thermal efficiency. At Re 733 and inlet temperature 550°C for model BA at 30 mm thickness, the thermal efficiency was 50%. It was shown that the combined stainless steel fibrous and stainless steel wire net porous material could be a good flow insulator.

  1. The "shadow sign": a radiographic differentiation of stainless steel versus titanium spinal instrumentation in spine surgery.

    Science.gov (United States)

    Jones-Quaidoo, Sean M; Novicoff, Wendy; Park, Andrew; Arlet, Vincent

    2011-12-01

    Stainless steel spinal instrumentation has been supplanted in recent years by titanium instrumentation. Knowing whether stainless steel or titanium was used in a previous surgery can guide clinical decision making processes, but frequently the clinician has no way to know what type of metal was used. We describe the radiographic "shadow sign," in which superimposed titanium rods and screws remain radiolucent enough that the contour of the underlying components can be seen on a lateral radiograph, whereas superimposed stainless steel rods and screws are completely radiopaque. This technique was evaluated using a retrospective, randomized, and blinded radiographic comparison of titanium and stainless steel spinal instrumentation. The objective was to determine whether the "shadow sign" can reliably differentiate titanium from stainless steel spinal instrumentation. Lateral radiographs from 16 cases of posterior spinal instrumentation (6 titanium, 6 stainless steel, and 2 replicates of each to assess intraobserver reliability) were randomly selected from a database of cases performed for pediatric scoliosis in a university setting from 2005 to 2009. The cases were randomized then shown to 19 orthopaedic surgery residents, 1 spine fellow, and 2 spine attendings. After the "shadow sign" was described, the surgeons were asked to determine what type of metal each implant was made of. The κ value for both stainless steel and titanium versus the gold standard was 0.83 [standard error (SE) = 0.053], indicating excellent agreement. The κ value for agreement between raters was 0.71 (SE = 0.016) and the κ value for agreement within raters was 0.70 (SE = 0.016), both of which indicated substantial agreement. The "shadow sign" can help a clinician differentiate titanium from stainless steel spinal instrumentation based on radiographic appearance alone. Furthermore, our study reveals that the level of experience in diagnosing spinal lateral radiographs also enhances the use of

  2. Effectiveness of transfixation and length of instrumentation on titanium and stainless steel transpedicular spine implants.

    Science.gov (United States)

    Korovessis, P; Baikousis, A; Deligianni, D; Mysirlis, Y; Soucacos, P

    2001-04-01

    This study compares the effectiveness of transfixation on the stiffness of two pedicle screw-rod constructs of different manufacture, implant design, and alloy, applied in one-and two-level instability. Four screws composed of either stainless steel or Titanium were assembled in pairs to two polymethylmethacrylate blocks to resemble one-and two-level corpectomy models and the construct underwent nondestructive torsional, extension, and flexion loading. In every loading test, each construct was tested using stainless steel or titanium rods of 4.9-mm diameter in two different lengths (short, 10 cm; long, 15 cm), not augmented or augmented with different transfixation devices or a pair of devices. The authors compared the stiffness of stainless steel and titanium constructs without cross-link with the stiffness of that reinforced with single or double Texas Scottish Rite Hospital (TSRH) cross-link, closed new-type cross-link (closed NTC), or open new-type cross-link (open NTC). The results showed that augmentation or no augmentation of short rods conferred significantly more stiffness than that of long rods of the same material in all three loading modes. The closed NTC provided the greatest increase of torsional, extension, and flexion stiffness, and single TSRH provided the least amount of stiffness. Torsional stiffness of short stainless steel rods augmented or not augmented was significantly greater than that of their titanium counterparts. Torsional stiffness of long titanium rods was always greater than that of their stainless steel counterparts. Extension stiffness of short nonaugmented titanium rods was superior to that of long titanium rods, whereas extension stiffness of nonaugmented short and long stainless steel rods was similar. Nonaugmented short titanium rods showed greater flexion stiffness than that of long titanium rods. Long stainless steel rods displayed significantly greater flexion stiffness than did their titanium counterparts. This

  3. Ion-nitriding of austenitic stainless steels

    International Nuclear Information System (INIS)

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

    1995-01-01

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

  4. Controlling radiation induced segregation in austenitic stainless steels

    International Nuclear Information System (INIS)

    Ahmedabadi, Parag M.; Kain, Vivekanand

    2011-01-01

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

  5. Pelepasan ion nikel dan kromium kawat Australia dan stainless steel dalam saliva buatan (The release of nickel and chromium ions from Australian wire and stainless steel in artificial saliva

    Directory of Open Access Journals (Sweden)

    Nolista Indah Rasyid

    2014-09-01

    Full Text Available Background: Fixed orthodontic treatment needs several types of wire to produce biomechanical force to move teeth. The use orthodontic wire within the mouth interacts with saliva, causing the release of nickel and chromium ions. Purpose: The study was aimed to examine the effect of immersion time in artificial saliva between special type of Australian wire and stainless steel on the release of nickel and chromium ions. Methods: Thirty special type Australian wires and 30 stainless steel wires were used in this study, each of which weighed 0.12 grams. The wires were immersed for 1, 7, 28, 35, 42, and 49 days in artificial saliva with a normal pH. The release of ions in saliva was examined using Atomic Absorption spectrophotometry. Results: The result indicated that the release of nickel ions on special type of Australian wire was larger than that on stainless steel wire (p<0.005, there were differences in the release of the amount of nickel ions on special type of Australia in different immersion time, and there was a correlation between the types of wire and immersion time. Nickel ions released from the special type of Australian wire detected on the 7th day of immersion and reached its peak on the 35th day, while from stainless steel wire were detected on the 49th day of immersion. The released of chromium ions from the special type of Australian wire and stainless steel wire were not detected until the 49th day of immersion. Conclusion: The release of nickel ions were highest on the 35th day of immersion in special type of Australian wire and they were detected on the 49th day in stainless steel wire. The release of chromium ions were not detected until 49th day of immersion in special type of Australian and stainless steel wire.Latar belakang: Perawatan ortodonti cekat memerlukan beberapa macam kawat untuk menghasilkan kekuatan biomekanika yang sesuai dalam menggerakkan gigi. Pemakaian kawat ortodonti di dalam mulut dapat bereaksi dengan

  6. Study of cyclic oxidation for stainless steels AISI 309 T 253 M A, with low additions of cerium; Estudio de la oxidacion ciclica de los aceros inoxidables AISI 309 T 253 MA, con pequenas adiciones de Cerio

    Energy Technology Data Exchange (ETDEWEB)

    Velazquez F, G.L.; Martinez, M.; Ruiz, A. [Universidad Nacional Experimental Politecnica (UNEXPO) - Vicerrectorado de Puerto Ordaz, Centro de Estudios de Corrosion. Puerto Ordaz. venezuela (Venezuela)

    1998-12-31

    It has been detected that the addition of small amounts (<1%) of the so called `reactive elements` such as Cerium to Fe-Cr alloys that was utilized in oxidating environment at high temperatures improving its resistance to oxidation under isothermal and cyclic conditions. In this work, it was evaluated the behavior under cyclic oxidation conditions for an austenitic stainless steel at chromium-nickel (253MA) with cerium addition, and comparing it with the AISI 310S austenitic stainless steel. The cyclic oxidation essays consist of five cycles by 24 hours each one, following of a cooling in air until ambient temperature from the temperatures of 850, 900 and 950 Centigrade, registering the gain mass of the specimen at end of each cycle. In order to this were prepared samples with dimensions of 20 mm. x 10 mm. x 1 mm. Later to the oxidation essays was evaluated the morphology of the corrosion products layer by scanning electron microscopy. The present phases were identified by X-ray diffraction and by chemical microanalysis by Dispersive energy (EDAX). The results obtained show that the steel with cerium addition, presents a higher adherence and resistance to the spalling noting that the cerium promotes the casting anchor of the oxides layer to matrix and by reducing the grain size of the layer improving its plasticity. Additionally the cerium promotes the preferential oxidation of the forming elements of protective layers like the chromium. (Author)

  7. Peptide-based biocoatings for corrosion protection of stainless steel biomaterial in a chloride solution.

    Science.gov (United States)

    Muruve, Noah G G; Cheng, Y Frank; Feng, Yuanchao; Liu, Tao; Muruve, Daniel A; Hassett, Daniel J; Irvin, Randall T

    2016-11-01

    In this work, PEGylated D-amino acid K122-4 peptide (D-K122-4-PEG), derived from the type IV pilin of Pseudomonas aeruginosa, coated on 304 stainless steel was investigated for its corrosion resistant properties in a sodium chloride solution by various electrochemical measurements, surface characterization and molecular dynamics simulation. As a comparison, stainless steel electrodes coated with non-PEGylated D-amino acid retroinverso peptide (RI-K122-4) and D-amino acid K122-4 peptide (D-K122-4) were used as control variables during electrochemical tests. It was found that the D-K122-4-PEG coating is able to protect the stainless steel from corrosion in the solution. The RI-K122-4 coating shows corrosion resistant property and should be investigated further, while the D-K122-4 peptide coating, in contrast, shows little to no effect on corrosion. The morphological characterizations support the corrosion resistance of D-K122-4-PEG on stainless steel. The adsorption of D-K122-4 molecules occurs preferentially on Fe2O3, rather than Cr2O3, present on the stainless steel surface. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Effects of nitrogen on corrosion of stainless steels in a liquid sodium environment

    International Nuclear Information System (INIS)

    Suzuki, Tadashi; Mutoh, Isao

    1990-01-01

    The corrosion of ferritic stainless steels using sodium at 650degC in a maximum isothermal region contained in a non-isothermal sodium loop constructed of a Type 316 stainless steel has been examined. Also, previous results on corrosion of austenitic stainless steels in sodium at 700degC in the same loop have been reproduced. The selective dissolution and absorption of nickel, the selective dissolution of chromium, and the resultant increase in iron in the surface of stainless steels in the loop mainly determine the corrosion loss of the stainless steel specimens. The austenitic steels hardly decarburize, but denitride. The ferritic steels decarburize and denitride and the denitriding is more remarkable than the decarburizing. The vanadium and niobium, carbide and nitride formers, in the ferritic steels inhibit the decarburizing to some extent, but barely inhibit the denitriding. The nitrogen in the steels rapidly diffuses to the grain boundaries, and rapidly dissolves into sodium, which will lower surface energy of the steels to enhance the dissolution of other elements. The dissolved N in sodium would then be transported to the free surface of the sodium adjacent to the argon cover gas of sodium and easily be released into the cover gas. This mechanism would cause the rapid dissolution of nitrogen into sodium and the enhancement of the corrosion rate of the steels containing nitrogen. (orig.)

  9. Assessment of stainless steel 348 fuel rod performance against literature available data using TRANSURANUS code

    Directory of Open Access Journals (Sweden)

    Giovedi Claudia

    2016-01-01

    Full Text Available Early pressurized water reactors were originally designed to operate using stainless steel as cladding material, but during their lifetime this material was replaced by zirconium-based alloys. However, after the Fukushima Daiichi accident, the problems related to the zirconium-based alloys due to the hydrogen production and explosion under severe accident brought the importance to assess different materials. In this sense, initiatives as ATF (Accident Tolerant Fuel program are considering different material as fuel cladding and, one candidate is iron-based alloy. In order to assess the fuel performance of fuel rods manufactured using iron-based alloy as cladding material, it was necessary to select a specific stainless steel (type 348 and modify properly conventional fuel performance codes developed in the last decades. Then, 348 stainless steel mechanical and physics properties were introduced in the TRANSURANUS code. The aim of this paper is to present the obtained results concerning the verification of the modified TRANSURANUS code version against data collected from the open literature, related to reactors which operated using stainless steel as cladding. Considering that some data were not available, some assumptions had to be made. Important differences related to the conventional fuel rods were taken into account. Obtained results regarding the cladding behavior are in agreement with available information. This constitutes an evidence of the modified TRANSURANUS code capabilities to perform fuel rod investigation of fuel rods manufactured using 348 stainless steel as cladding material.

  10. Pengaruh Variasi Arus Pengelasan dan Variasi Diameter Elektroda Terhadap Kekuatan Tarik Pada Stainless Steel AISI 304

    OpenAIRE

    Manurung, Erwin Makmur

    2016-01-01

    The usage of electric current will affect the outcome of welding result for powering weldingarc. Determination of the welding current for connecting the metal in the welding arc will affect the efficiency of work and welding materials. In this study using austenitic stainless steel AISI 304 Stainless Steel with Welding Shield Metal Arc Welding (SMAW), large of welding current 85 A, 95 A and 105 A, and the type of electrode E 308 L diameter of 2.6 mm, 3.2 mm , and 4.0 mm. The purpose of this s...

  11. Measurement techniques of magnetic properties for evaluation of neutron irradiation damage on austenitic stainless steels

    International Nuclear Information System (INIS)

    Yamagata, Ichiro; Konno, Shotaro; Hayashi, Takehiro; Takaya, Shigeru

    2012-01-01

    The remote-controlled equipment for measurement of magnetic flux density has been developed in order to evaluate the irradiation damage of austenitic stainless steels. Magnetic flux densities by neutron irradiation in austenitic stainless steels, SUS304 and Fast Breeder Reactor grade type 316 (316FR), have been measured by the equipment. The results show that irradiation damage affected to magnetic flux density, and indicate the measuring method of magnetic flux density using a small magnetizer with a permanent magnet of 2 mm in diameter is less affected by specimen shape. (author)

  12. A computational model for the carbon transfer in stainless steel sodium systems

    International Nuclear Information System (INIS)

    Casadio, S.; Scibona, G.

    1980-01-01

    A method is proposed of computing the carbon transfer in the type 316, 304 and 321 stainless steels in sodium environment as a function of temperature, exposure time and carbon concentration in the sodium. The method is based on the criteria developed at ANL by introducing some simplifications and takes also into account the correlations obtained at WARD. Calculated carbon profiles are compared both with experimental data and with the results available by the other computer methods. The limits for quantitative predictions of the stainless steel carburization or decarburization exposed in a specific environment are discussed. (author)

  13. Electrochemical methods for characterisation of thermal spray corrosion resistant stainless steel coatings

    NARCIS (Netherlands)

    Hofman, R.; Vreijling, M.P.W.; Ferrari, G.M.; Wit, J.H.W. de

    1998-01-01

    The use of thermal spray stainless steel coatings for protection of low alloyed steels against different types of corrosion is limited due to high porosity levels and oxide inclusions. In this paper electrochemical methods like corrosion potential monitoring and cyclic voltammetry are reported to

  14. Influence of surface texture on the galling characteristics of lean duplex and austenitic stainless steels

    DEFF Research Database (Denmark)

    Wadman, Boel; Eriksen, J.; Olsson, M.

    2010-01-01

    Two simulative test methods were used to study galling in sheet forming of two types of stainless steel sheet: austenitic (EN 1.4301) and lean duplex LDX 2101 (EN 1.4162) in different surface conditions. The pin-on-disc test was used to analyse the galling resistance of different combinations...

  15. Metallurgical analysis of a 304L stainless steel canister from the Spent Fuel Test - Climax

    International Nuclear Information System (INIS)

    Weiss, H.; Van Konynenburg, R.A.; McCright, R.D.

    1985-01-01

    Results of a metallurgical examination of a type 304L stainless steel canister that had been used to store spent nuclear fuel in an underground granite formation for about three years are reported. No observable corrosion or cracking were found. The results are applied to waste packages in a potential high level nuclear waste repository in tuff. 10 refs., 9 figs., 2 tabs

  16. Adhesive Properties of Bonded Orthodontic Retainers to Enamel : Stainless Steel Wire vs Fiber-reinforced Composites

    NARCIS (Netherlands)

    Foek, Dave Lie Sam; Krebs, Eliza; Sandham, John; Ozcan, Mutlu

    2009-01-01

    Purpose: The objectives of this study were to compare the bond strength of a stainless steel orthodontic wire vs various fiber-reinforced composites (FRC) used as orthodontic retainers on enamel, analyze the failure types after debonding, and investigate the influence of different application

  17. Corrosion Behavior of the Stressed Sensitized Austenitic Stainless Steels of High Nitrogen Content in Seawater

    Directory of Open Access Journals (Sweden)

    A. Almubarak

    2013-01-01

    Full Text Available The purpose of this paper is to study the effect of high nitrogen content on corrosion behavior of austenitic stainless steels in seawater under severe conditions such as tensile stresses and existence of sensitization in the structure. A constant tensile stress has been applied to sensitized specimens types 304, 316L, 304LN, 304NH, and 316NH stainless steels. Microstructure investigation revealed various degrees of stress corrosion cracking. SCC was severe in type 304, moderate in types 316L and 304LN, and very slight in types 304NH and 316NH. The electrochemical polarization curves showed an obvious second current peak for the sensitized alloys which indicated the existence of second phase in the structure and the presence of intergranular stress corrosion cracking. EPR test provided a rapid and efficient nondestructive testing method for showing passivity, degree of sensitization and determining IGSCC for stainless steels in seawater. A significant conclusion was obtained that austenitic stainless steels of high nitrogen content corrode at a much slower rate increase pitting resistance and offer an excellent resistance to stress corrosion cracking in seawater.

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

    DEFF Research Database (Denmark)

    Arnold, Dario; Dalstra, Michel; Verna, Carlalberta

    2016-01-01

    retainers in orthodontics. Materials and Methods: Torquing moments acting on a retainer wire were measured in a mechanical force testing system by applying buccal crown torque to an upper lateral incisor in both a 3-teeth and in a 2-teeth setup. Seven stainless steel wires with different shape, type (plain...

  19. Passivation behavior of a ferritic stainless steel in concentrated alkaline solutions

    Directory of Open Access Journals (Sweden)

    Arash Fattah-alhosseini

    2015-10-01

    Full Text Available The passivation behavior of AISI 430 ferritic stainless steel was investigated in concentrated alkaline solutions in relation to several test parameters, using electrochemical techniques. Increasing solution pH (varying from 11.5 to 14.0 leads to an increase in the corrosion rate of the alloy. Mott–Schottky analysis revealed that passive films formed on AISI 430 ferritic stainless steel behave as n-type semiconductor and the donor densities increased with pH. Electrochemical impedance spectroscopy (EIS results showed that the reciprocal capacitance of the passive film is directly proportional to its thickness, which decreases with pH increase. The results revealed that for this ferritic stainless steel in concentrated alkaline solutions, decreasing the solution pH offers better conditions for forming passive films with higher protection behavior, due to the growth of a much thicker and less defective film.

  20. Mechanical evaluation of quad-helix appliance made of low-nickel stainless steel wire.

    Science.gov (United States)

    dos Santos, Rogério Lacerda; Pithon, Matheus Melo

    2013-01-01

    The objective of this study was to test the hypothesis that there is no difference between stainless steel and low-nickel stainless steel wires as regards mechanical behavior. Force, resilience, and elastic modulus produced by Quad-helix appliances made of 0.032-inch and 0.036-inch wires were evaluated. Sixty Quad-helix appliances were made, thirty for each type of alloy, being fifteen for each wire thickness, 0.032-in and 0.036-in. All the archwires were submitted to mechanical compression test using an EMIC DL-10000 machine simulating activations of 4, 6, 9, and 12 mm. Analysis of variance (ANOVA) with multiple comparisons and Tukey's test were used (p steel alloy had force, resilience, and elastic modulus similar to those made of stainless steel alloy.

  1. Simulation of Mechanical Stress on Stainless Steel for Pb-Bi Corrosion Test by Using ABAQUS

    Science.gov (United States)

    Irwanto, D.; Mustari, A. P. A.; Budiman, B. A.

    2017-03-01

    Pb-Bi eutectic with its advantageous is proposed to be utilized as a coolant in the GEN IV type of rSeactor. However, high temperature corrosion when contact with stainless steels is one of the issues of Pb-Bi eutectic utilization. It is known that in the environment of high temperature Pb-Bi, mechanical strength of stainless steel may decrease. Thus, simulation of mechanical stress working on stainless steel during in-situ bending test by using ABAQUS was conducted. Several bending degrees were simulated at high temperature to obtain the mechanical stress information. Temperature condition was strongly affect the stress vs. displacement profile. The reported mechanical strength reduction percentage was used to draw predicted mechanical stress under high temperature Pb-Bi environment.

  2. On the mechanism of phosphorus influence on intercrystalline corrosion of stainless steels

    International Nuclear Information System (INIS)

    Kolotyrkin, Ya.M.; Kasparova, O.V.; Vasyukov, A.B.; Smakhtin, L.A.; Mekhryusheva, L.I.; Bogolyubskij, S.D.

    1979-01-01

    Products of the dissolving of hardened austenite stainless steels with phosphorus impurities were studied by the quantitative analysis in the state inclined to intercrystalline corrosion (ICC). The Cr20Ni20-type steels served as the object of the study. Electronic-microscopic analysis of foils and carbon cues has shown that the studied steels has a single-phase structure in a hardened state. They undergo ICC after anode etching. ICC is absent in a highly pure steel without phosphorus impurities. The hypothesis which relates ICC of hardened stainless steels to the segregation of phosphorus along grain boundaries is experimentally confirmed. So, one of the ways to increase resistance of hardened stainless steels to ICC is the development of methods impeding phosphorus segregation along grain boundaries or its selective oxidation

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

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  4. 77 FR 64545 - Drawn Stainless Steel Sinks From China

    Science.gov (United States)

    2012-10-22

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

  5. Phosphate coating on stainless steel 304 sensitized

    International Nuclear Information System (INIS)

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

    2009-01-01

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

  6. Ultrasonic testing of austenitic stainless steel welds

    International Nuclear Information System (INIS)

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

    1982-05-01

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

  7. Stainless Steel Microstructure and Mechanical Properties Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Switzner, Nathan T

    2010-06-01

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

  8. Posterior preveneered stainless steel crowns: clinical performance after three years.

    Science.gov (United States)

    O'Connell, Anne C; Kratunova, Evelina; Leith, Rona

    2014-01-01

    The purpose of this study was to evaluate the clinical performance of posterior preveneered stainless steel crowns after three years. NuSmile crowns and Kinder Krowns were randomly allocated on paired molars using a split-mouth design. Variables such as fracture, wear, gingival health, and esthetics were recorded. (Pcrowns in 14 children. After three years, 53 percent of crowns were fracture free compared to 81 percent at one year. There was minimal esthetic impact for most fractures due to the location of the veneer fracture, but five crowns had extensive fracture. No difference was reported in the clinical performance between the two crown types. Fracture was more likely to occur where the adjacent tooth was missing. Parents reported a satisfaction rating of 8.3 out of 10. Clinical performance of both crown types was similar and successful for three years. Facing fracture occurred in 47 percent of crowns but had minimal impact on the esthetic value or parental satisfaction in the majority of cases. These crowns offer an esthetic alternative to the traditional stainless steel crown, but parents should be alerted to the possibility of veneer loss over time.

  9. Evaluation of stainless steel pipe cracking: causes and fixes

    International Nuclear Information System (INIS)

    Shack, W.J.; Kassner, T.F.; Maiya, P.S.; Nichols, F.A.; Park, J.Y.; Ruther, W.; Rybicki, E.F.

    1985-01-01

    This paper discusses (1) studies of impurity effects on susceptibility to intergranular stress corrosion cracking (IGSCC), (2) intergranular crack growth rate measurements, (3) finite-element studies of the residual stresses produced by induction heating stress improvement (IHSI) and the addition of weld overlays to flawed piping, (4) leak-before-break analyses of piping with 360 deg part-through cracks, and (5) parametric studies on the effect of through-wall residual stresses on intergranular crack growth behavior in large diameter piping weldments. The studies on the effect of impurities on IGSCC of Type 304 stainless steel show a strong synergistic interaction between dissolved oxygen and impurity concentration of the water. Low carbon stainless steels (Type 316NG) appear resistant to IGSCC even in impurity environments. However, they can become susceptible to transgranular SCC with low levels of sulfate or chloride present in the environment. The finite-element calculations show that IHSI and the weld overlay produce compressive residual stresses on the inner surface, and that the stresses at the crack tip remain compressive under design loads at least for shallow cracks. (author)

  10. 77 FR 1504 - Stainless Steel Wire Rod From India

    Science.gov (United States)

    2012-01-10

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

  11. Low temperature gaseous surface hardening of stainless steel

    DEFF Research Database (Denmark)

    Christiansen, Thomas; Somers, Marcel A. J.

    2010-01-01

    The present contribution gives an overview of some of the technological aspects of low temperature thermochemical treatment of stainless steel. Examples of low temperature gaseous nitriding, carburising and nitrocarburising of stainless steel are presented and discussed. In particular......, the morphology, microstructure and characteristics of so-called expanite “layers” on stainless steel are addressed....

  12. Low temperature gaseous surface hardening of stainless steel

    DEFF Research Database (Denmark)

    Christiansen, Thomas; Somers, Marcel A. J.

    2011-01-01

    The present contribtion gives an overview of some of the technological aspects of low temperature thermochemical treatment of stainless steel. Examples of low temperature gaseous nitriding, carburising and nitrocarburising of stainless steel are presented and discussed. In particular......, the morphology, microstructure and characteristics of so-called expanded austenite "layers" on stainless steel are addressed....

  13. 21 CFR 872.3350 - Gold or stainless steel cusp.

    Science.gov (United States)

    2010-04-01

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

  14. 78 FR 21417 - Drawn Stainless Steel Sinks From China

    Science.gov (United States)

    2013-04-10

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

  15. Effect of metal surface composition on deposition behavior of stainless steel component dissolved in liquid sodium

    International Nuclear Information System (INIS)

    Yokota, Norikatsu; Shimoyashiki, Shigehiro

    1988-01-01

    Deposition behavior of corrosion products has been investigated to clarify the effect of metal surface composition on the deposition process in liquid sodium. For the study a sodium loop made of Type 304 stainless steel was employed. Deposition test pieces, which were Type 304 stainless steel, iron, nickel or Inconel 718, were immersed in the sodium pool of the test pot. Corrosion test pieces, which were Type 304 stainless steel, 50 at% Fe-50 at%Mn and Inconel 718, were set in a heater pin assembly along the axial direction of the heater pin surface. Sodium temperatures at the outlet and inlet of the heater pin assembly were controlled at 943 and 833 K, respectively. Sodium was purified at a cold trap temperature of 393 K and the deposition test was carried out for 4.3 x 10 2 - 2.9 x 10 4 ks. Several crystallized particles were observed on the surface of the deposition test pieces. The particles had compositions and crystal structures which depended on both the composition of deposition test pieces and the concentration of iron and manganese in sodium. Only iron-rich particles having a polyhedral shape deposited on the iron surface. Two types of particles, iron-rich α-phase and γ-phase with nearly the same composition as stainless steel, were deposited on Type 304 stainless steel. A Ni-Mn alloy was deposited on the nickel surface in the case of a higher concentration of manganese in sodium. On the other hand, for a lower manganese concentration, a Fe-Ni alloy was precipitated on the nickel surface. Particles deposited on nickel had a γ-phase crystal structure similar to the deposition test piece of nickel. Hence, the deposition process can be explained as follows: Corrosion products in liquid sodium were deposited on the metal surface by forming a metal alloy selectively with elements of the metal surface. (author)

  16. An in vitro Evaluation of Friction Characteristics of Conventional Stainless Steel and Self-ligating Stainless Steel Brackets with different Dimensions of Archwires in Various Bracket-archwire Combination.

    Science.gov (United States)

    Sridharan, K; Sandbhor, Shailesh; Rajasekaran, U B; Sam, George; Ramees, M Mohamed; Abraham, Esther A

    2017-08-01

    The purpose of this research is to compare the frictional attributes of stainless steel conventional brackets and self-ligating stainless steel brackets with different dimensions of archwires. The test was carried with two sets of maxillary brackets: (1) Conventional stainless steel (Victory Series), (2) stainless steel self-ligating (SmartClip) without first premolar brackets. Stainless steel, nickel-titanium (NiTi), and beta-Ti which are the types of orthodontic wire alloys were tested in this study. To monitor the frictional force, a universal testing machine (Instron 33R 4467) that comprises 10 kg tension load cell was assigned on a range of 1 kg and determined from 0 to 2 kg, which allows moving of an archwire along the brackets. One-way analysis of variance was used to test the difference between groups. To analyze the statistical difference between the two groups, Student's t-test was used. For Victory Series in static friction, p-value was 0.946 and for kinetic friction it was 0.944; at the same time for SmartClip, the p value for static and kinetic frictional resistance was 0.497 and 0.518 respectively. Hence, there was no statistically significant difference between the NiTi and stainless steel archwires. It is concluded that when compared with conventional brackets with stainless steel ligatures, self-ligating brackets can produce significantly less friction during sliding. Beta-Ti archwires expressed high amount of frictional resistance and the stainless steel archwires comprise low frictional resistance among all the archwire materials. In orthodontics, frictional resistance has always had a major role. Its ability to impair tooth movement leads to the need for higher forces to move the teeth and it extends the treatment time which results in loss of posterior anchorage. Friction in orthodontics is related with sliding mechanics when a wire is moving through one or a series of bracket slots.

  17. Modelling the material behaviour of metastable stainless

    NARCIS (Netherlands)

    Datta, K.; Geijselaers, Hubertus J.M.; Post, J.; Beyer, J.; Huetink, Han; Cesar de Sa, Jose M.A.; Santos, Abel D.

    2007-01-01

    Metastable austenitic stainless steels are designed to be thermodynamically unstable such that deformation even at room temperatures can bring about a change in the phase of face centred cubic austenite to either hexagonal close packed martensite and/or to body centred cubic martensite. This solid

  18. DETERMINATION OF METAL IONS RELEASED BY STAINLESS ...

    African Journals Online (AJOL)

    The amounts of cobalt, iron, manganese, nickel and chromium ions released from new and reused stainless steel arch bar used for maxillomandibular fixation was determined in Hank's solutions of different hydrogen and chloride ions concentrations, whole blood serum and phosphate buffered saline (PBS) in vitro, over a ...

  19. Granulate of stainless steel as compensator material

    NARCIS (Netherlands)

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

    1995-01-01

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

  20. Stainless steel forgings for nuclear chemical plants

    International Nuclear Information System (INIS)

    1982-02-01

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

  1. Austenitic stainless steels for cryogenic service

    International Nuclear Information System (INIS)

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

    1985-01-01

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

  2. CASE-HARDENING OF STAINLESS STEEL

    DEFF Research Database (Denmark)

    2004-01-01

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

  3. Silver deposition on stainless steel container surfaces in contact with disinfectant silver aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Petala, M., E-mail: petala@civil.auth.gr [Department of Civil Engineering, Aristotle University of Thessaloniki, Thessaloniki, 54124 (Greece); Tsiridis, V. [Department of Civil Engineering, Aristotle University of Thessaloniki, Thessaloniki, 54124 (Greece); Mintsouli, I. [Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki, 54124 (Greece); Pliatsikas, N. [Department of Physics, Aristotle University of Thessaloniki, Thessaloniki, 54124 (Greece); Spanos, Th. [Department of Petroleum and Mechanical Engineering Sciences, Eastern Macedonia and Thrace Institute of Technology, Kavala, 65404 (Greece); Rebeyre, P. [ESA/ESTEC, P.O.Box 299, 2200 AG, Noordwijk (Netherlands); Darakas, E. [Department of Civil Engineering, Aristotle University of Thessaloniki, Thessaloniki, 54124 (Greece); Patsalas, P.; Vourlias, G. [Department of Physics, Aristotle University of Thessaloniki, Thessaloniki, 54124 (Greece); Kostoglou, M.; Sotiropoulos, S.; Karapantsios, Th. [Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki, 54124 (Greece)

    2017-02-28

    Highlights: • Silver is one of the biocides of water consumed in the International Space Station. • Ionic silver is depleted from potable water when in contact with stainless steel (SS). • SEM and XPS analysis reveal a uniform silver deposition over the SS surface. • Silver deposits in its metallic form, in line with a galvanic deposition mechanism. • Evidence is provided that Cr and/ or Ni oxide builds-up on SS surfaces. - Abstract: Silver is the preservative used on the Russian segment of the International Space Station (ISS) to prevent microbial proliferation within potable water supplies. Yet, in the frame of the European Automated Transfer Vehicle (ATV) missions to ISS, silver depletion from water has been detected during ground transportation of this water to launch site, thereby indicating a degradation of water quality. This study investigates the silver loss from water when in contact with stainless steel surfaces. Experiments are conducted with several types of stainless steel surfaces being exposed to water containing 10 or 0.5 mg/L silver ions. Results show that silver deposits on stainless steel surfaces even when a passivation layer protects the metallic surface. The highest protection to silver deposition is offered by acid passivated and electropolished SS 316L. SEM and XPS experiments were carried out at several locations of the sample area that was in contact with the Ag solution and found similar morphological (SEM) and compositional (sputter-etch XPS) results. The results reveal that silver deposits uniformly across the wetted surface to a thickness larger than 3 nm. Moreover, evidence is provided that silver deposits in its metallic form on all stainless steel surfaces, in line with a galvanic deposition mechanism. Combination of ICP-MS and XPS results suggests a mechanism for Ag deposition/reduction with simultaneous substrate oxidation resulting in oxide growth at the exposed stainless steel surface.

  4. Silver deposition on stainless steel container surfaces in contact with disinfectant silver aqueous solutions

    International Nuclear Information System (INIS)

    Petala, M.; Tsiridis, V.; Mintsouli, I.; Pliatsikas, N.; Spanos, Th.; Rebeyre, P.; Darakas, E.; Patsalas, P.; Vourlias, G.; Kostoglou, M.; Sotiropoulos, S.; Karapantsios, Th.

    2017-01-01

    Highlights: • Silver is one of the biocides of water consumed in the International Space Station. • Ionic silver is depleted from potable water when in contact with stainless steel (SS). • SEM and XPS analysis reveal a uniform silver deposition over the SS surface. • Silver deposits in its metallic form, in line with a galvanic deposition mechanism. • Evidence is provided that Cr and/ or Ni oxide builds-up on SS surfaces. - Abstract: Silver is the preservative used on the Russian segment of the International Space Station (ISS) to prevent microbial proliferation within potable water supplies. Yet, in the frame of the European Automated Transfer Vehicle (ATV) missions to ISS, silver depletion from water has been detected during ground transportation of this water to launch site, thereby indicating a degradation of water quality. This study investigates the silver loss from water when in contact with stainless steel surfaces. Experiments are conducted with several types of stainless steel surfaces being exposed to water containing 10 or 0.5 mg/L silver ions. Results show that silver deposits on stainless steel surfaces even when a passivation layer protects the metallic surface. The highest protection to silver deposition is offered by acid passivated and electropolished SS 316L. SEM and XPS experiments were carried out at several locations of the sample area that was in contact with the Ag solution and found similar morphological (SEM) and compositional (sputter-etch XPS) results. The results reveal that silver deposits uniformly across the wetted surface to a thickness larger than 3 nm. Moreover, evidence is provided that silver deposits in its metallic form on all stainless steel surfaces, in line with a galvanic deposition mechanism. Combination of ICP-MS and XPS results suggests a mechanism for Ag deposition/reduction with simultaneous substrate oxidation resulting in oxide growth at the exposed stainless steel surface.

  5. Effect of small additions of niobium on the welding behavior of an austenitic stainless steel

    International Nuclear Information System (INIS)

    Moorhead, A.J.; Sikka, V.K.; Reed, R.W.

    1977-01-01

    To systematically study the effect of niobium on the behavior of Type 304 stainless steel, a low-niobium commercial heat was remelted with varying niobium additions - up to 1000 ppM. A standardized weldability test, the Spot Varestraint, was used to compare the propensity of various heats for hot cracking. The fusion and heat-affected zone cracking behavior of the experimental heats was similar to that of a heat of commercial Type 304, and much superior to that of a commercial heat of Type 347 stainless steel. The superior resistance to fusion zone cracking was attributed to the presence of a small amount of delta ferrite in the microstructure of the weld nugget in the experimental materials. The outstanding heat-affected zone cracking behavior was at least partly attributable to backfilling of grain boundary separations in the experimental heats, as well as in the commercial Type 304

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

    Science.gov (United States)

    Yang, Ke; Ren, Yibin

    2010-02-01

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

  7. Elevated temperature tensile properties of borated 304 stainless steel

    International Nuclear Information System (INIS)

    Stephens, J.J.; Sorenson, K.B.; McConnell, P.

    1993-01-01

    This paper presents a comparison of the tensile properties of Powder Metallurgy (PM) 'Grade A' material with that of the conventional IM 'Grade B' material for two selected Types (i.e., boron contents) as defined by the ASTM A887 specification: Types 304B5 and 304B7. Tensile properties have been generated for these materials at temperatures ranging from room temperature to 400degC (752degF). The data at higher temperatures are required for ASME Code Case purposes, since the use temperature of a basket under 'worst case' cask conditions may be as high as 343degC (650degF), due to self-heating by the activated fuel elements. We will also discuss the current status of efforts aimed at obtaining an ASME Boiler and Pressure Vessel Code Case for selected grades of borated stainless steel covered by the ASTM A887 specification. (J.P.N.)

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

    Energy Technology Data Exchange (ETDEWEB)

    Chopra, O.K.; Ayrault, G.

    1983-10-01

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

  9. Chromium depletion from stainless steels during vacuum annealing

    International Nuclear Information System (INIS)

    Smith, A.F.; Hales, R.

    1977-01-01

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

  10. Corrosion resistance of kolsterised austenitic 304 stainless steel

    International Nuclear Information System (INIS)

    Abudaia, F. B.; Khalil, E. O.; Esehiri, A. F.; Daw, K. E.

    2015-01-01

    Austenitic stainless suffers from low wear resistance in applications where rubbing against other surfaces is encountered. This drawback can be overcome by surface treatment such as coating by hard materials. Other treatments such as carburization at relatively low temperature become applicable recently to improve hardness and wear resistance. Carburization heat treatment would only be justified if the corrosion resistance is unaffected. In this work samples of 304 stainless steels treated by colossal supersaturation case carburizing (known as Kolsterising) carried out by Bodycote Company was examined for pitting corrosion resistance at room temperature and at 50 °C. Comparison with results obtained for untreated samples in similar testing conditions show that there is no deterioration in the pitting resistance due to the Kolsterising heat treatment. X ray diffraction patterns obtained for Kolsterising sample showed that peaks correspond to the austenite phase has shifted to lower 2θ values compared with those of the untreated sample. The shift is an indication for expansion of austenite unit cells caused by saturation with diffusing carbon atoms. The XRD of Kolsterising samples also revealed additional peaks appeared in the patterns due to formation of carbides in the kolsterised layer. Examination of these additional peaks showed that these peaks are attributed to a type of carbide known as Hagg carbide Fe 2 C 5 . The absence of carbides that contain chromium means that no Cr depletion occurred in the layer and the corrosion properties are maintained. Surface hardness measurements showed large increase after Kolsterising heat treatment

  11. Studies of stainless steel exposed to sandblasting

    Directory of Open Access Journals (Sweden)

    Horodek Paweł

    2015-12-01

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

  12. State on AISI 304 Stainless Steel

    Directory of Open Access Journals (Sweden)

    A. Fattah-alhosseini

    2011-01-01

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

  13. Microstructure of laser cladded martensitic stainless steel

    CSIR Research Space (South Africa)

    Van Rooyen, C

    2006-08-01

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

  14. Diffraction study on aging duplex stainless steel

    International Nuclear Information System (INIS)

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

    2001-01-01

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

  15. 76 FR 34964 - Stainless Steel Bar From India: Partial Rescission of Antidumping Duty Administrative Review

    Science.gov (United States)

    2011-06-15

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

  16. Corrosion Properties of Laser Welded Stainless Steel

    DEFF Research Database (Denmark)

    Weldingh, Jakob; Olsen, Flemmming Ove

    1997-01-01

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

  17. Molecular carbon nitride ion beams for enhanced corrosion resistance of stainless steel

    Science.gov (United States)

    Markwitz, A.; Kennedy, J.

    2017-10-01

    A novel approach is presented for molecular carbon nitride beams to coat stainless surfaces steel using conventional safe feeder gases and electrically conductive sputter targets for surface engineering with ion implantation technology. GNS Science's Penning type ion sources take advantage of the breaking up of ion species in the plasma to assemble novel combinations of ion species. To test this phenomenon for carbon nitride, mixtures of gases and sputter targets were used to probe for CN+ ions for simultaneous implantation into stainless steel. Results from mass analysed ion beams show that CN+ and a variety of other ion species such as CNH+ can be produced successfully. Preliminary measurements show that the corrosion resistance of stainless steel surfaces increased sharply when implanting CN+ at 30 keV compared to reference samples, which is interesting from an application point of view in which improved corrosion resistance, surface engineering and short processing time of stainless steel is required. The results are also interesting for novel research in carbon-based mesoporous materials for energy storage applications and as electrode materials for electrochemical capacitors, because of their high surface area, electrical conductivity, chemical stability and low cost.

  18. A comparative study of zircaloy and stainless steel as cladding material for pressurised water reactor

    International Nuclear Information System (INIS)

    Ganguly, C.; Roy, P.R.

    1977-01-01

    A comparative study of cladding material, stainless steel (Type 304, 347/348) and zircaloy (2 and 4) for oxide fuels of uranium, plutonium and mixed uranium-plutonium in pressurised light water cooled and moderated thermal reactor is made based on factors like: (i) neutrone economics, (ii) corrosion resistance, (iii) chemical interaction with fuel, impurities and fission products, (iv) pellet clad mechanical interaction- tensile, creep and fatigue properties, and (v) overall performance. Though the physical and mechanical properties and also the in-reactor performance record of stainless steel is better than zircaloy, the better neutron economics with zircaloy, because of its twelve times less neutron absorption cross section, overrides all the advantages of stainless steel. As a result all P.W.R.s are switching over to Zircaloy claddings. To achieve the failure rate as low as those for stainless steel the zircaloy fuel elements need modifications like use of smaller diameter pins with greater wall thickness, graphite of siloxane coating of clad internal surface, fuel pin pre-pressurisation, vacuum hot drying of pellets prior to loading and final end capping, use of short (length/diameter = 1 maximum), dished, chamferred, high density fuel pellets with uniformly distributed pores and enough diametral gap between pellet and clad. (author)

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

    Directory of Open Access Journals (Sweden)

    Noriaki Hirota, Fuxing Yin, Tsukasa Azuma and Tadanobu Inoue

    2010-01-01

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

  20. Long term ground support with stainless steel and nickel alloy rock bolts

    International Nuclear Information System (INIS)

    Shaffer, T.F.; Revie, R.W.; Mandal, A.

    1994-01-01

    Stainless steel and nickel alloy Swellex rock bolts have been developed to provide long-term ground support in corrosive environments or in underground openings that are inaccessible for periodic reconditioning. Laboratory and underground testing has shown that the mechanical properties of stainless steel Swellex rock bolts am adequate for long term service. The corrosivity of underground sites may vary considerably and no one grade of stainless steel will provide adequate corrosion resistance economically for permanent service at all sites. Six stainless steels and two nickel alloys have been evaluated and used to manufacture Swellex. These alloys can be used to manufacture all types of rock bolts including mechanically anchored bolts. The selection of the lowest-cost corrosion-resistant alloy suitable for the lifetime objective at a given site may be problematic. Therefore, a mine corrosivity assessment procedure, in which the performance of several candidate materials for permanent service at a specific site can be determined quickly and economically, is being developed and will be available in 1995

  1. Mechanical evaluation of quad-helix appliance made of low-nickel stainless steel wire

    Directory of Open Access Journals (Sweden)

    Rogério Lacerda dos Santos

    2013-06-01

    Full Text Available OBJECTIVE: The objective of this study was to test the hypothesis that there is no difference between stainless steel and low-nickel stainless steel wires as regards mechanical behavior. Force, resilience, and elastic modulus produced by Quad-helix appliances made of 0.032-inch and 0.036-inch wires were evaluated. METHODS: Sixty Quad-helix appliances were made, thirty for each type of alloy, being fifteen for each wire thickness, 0.032-in and 0.036-in. All the archwires were submitted to mechanical compression test using an EMIC DL-10000 machine simulating activations of 4, 6, 9, and 12 mm. Analysis of variance (ANOVA with multiple comparisons and Tukey's test were used (p < 0.05 to assess force, resilience, and elastic modulus. RESULTS: Statistically significant difference in the forces generated, resilience and elastic modulus were found between the 0.032-in 0.036-in thicknesses (p < 0.05. CONCLUSIONS: Appliances made of low-nickel stainless steel alloy had force, resilience, and elastic modulus similar to those made of stainless steel alloy.

  2. Impact Testing of Stainless Steel Materials

    International Nuclear Information System (INIS)

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

    2005-01-01

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

  3. Colorimetric values of esthetic stainless steel crowns.

    Science.gov (United States)

    Hosoya, Yumiko; Omachi, Koichi; Staninec, Michal

    2002-01-01

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

  4. Computer simulation of sensitization in stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    Logan, R W

    1983-12-20

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

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

    International Nuclear Information System (INIS)

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

    1994-01-01

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

  6. Characteristic of Low Temperature Carburized Austenitic Stainless Steel

    Science.gov (United States)

    Istiroyah; Pamungkas, M. A.; Saroja, G.; Ghufron, M.; Juwono, A. M.

    2018-01-01

    Low temperature carburizing process has been carried out on austenitic stainless steel (ASS) type AISI 316L, that contain chromium in above 12 at%. Therefore, conventional heat treatment processes that are usually carried out at high temperatures are not applicable. The sensitization process due to chromium migration from the grain boundary will lead to stress corrosion crack and decrease the corrosion resistance of the steel. In this study, the carburizing process was carried out at low temperatures below 500 °C. Surface morphology and mechanical properties of carburized specimens were investigated using optical microscopy, non destructive profilometer, and Vicker microhardness. The surface roughness analysis show the carburising process improves the roughness of ASS surface. This improvement is due to the adsorption of carbon atoms on the surface of the specimen. Likewise, the hardness test results indicate the carburising process increases the hardness of ASS.

  7. Microstructural observation of ion-irradiated austenitic stainless steel

    International Nuclear Information System (INIS)

    Sawai, T.; Hamada, S.; Hishinuma, A.

    1992-01-01

    Type 316 stainless steel, base metal and weld metal obtained from an electron beam weld joint, was irradiated with 90 MeV Br +6 in the JAERI tandem accelerator. Cross-sectional TEM specimens were obtained by nickel plating. Microstructural observation revealed a band of tiny dislocation loops was observed around the mean projected range and the measured distance from the surface was 6.75±0.15μm. This is slightly larger than the calculated value using Ziegler's stopping power. Defect clusters were also observed around defect sinks within the mean projected range, suggesting cascade-sink interaction. These sinks are the grain boundary in the base metal specimen and preexisting dislocation lines in the weld metal specimen. Surface roughness of polished specimen was detected at the shallower side of the peak damage band, although no visible crystalline defect cluster was observed. This suggests radiation-induced microchemical evolution prior to sever microstructural evolution. (author)

  8. Improvement of the stainless steel electropolishing process by organic additives

    Directory of Open Access Journals (Sweden)

    Lochynski Pawel

    2016-12-01

    Full Text Available The influence of organic additives on the process of surface electropolishing of AISI 304 type steel was determined. Additives were selected in initial potentiodynamic tests pursuant to the plateau analysis on the current/potential curves. The assessment of the operational effectiveness of additives consisted in determining the relationship between surface gloss after electropolishing and the mass loss of the sample and in determining surface roughness. The applied electropolishing bath consisted of a mixture of concentrated acids: H3PO4 and H2SO4, and the following organic additives were used: triethylamine, ethanolamine, diethanolamine, triethanolamine, diethylene glycol monobutyl ether and glycerol. The best electropolishing result, i.e. low roughness and high gloss of stainless steel surface with a relatively low mass loss of the sample at the same time were obtained for baths containing triethanolamine.

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

    International Nuclear Information System (INIS)

    Petrman, I.; Safek, V.

    1994-01-01

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

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

    International Nuclear Information System (INIS)

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

    1995-01-01

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

  11. Forces in the presence of ceramic versus stainless steel brackets with unconventional vs conventional ligatures.

    Science.gov (United States)

    Baccetti, Tiziano; Franchi, Lorenzo; Camporesi, Matteo

    2008-01-01

    To compare the forces resulting from four types of bracket/ligature combinations: ceramic brackets and stainless steel brackets combined with unconventional elastomeric ligatures (UEL) and conventional elastomeric ligatures (CEL) during the leveling and aligning phases of orthodontic therapy. The testing model consisted of five 0.022-inch preadjusted brackets (second premolar, first premolar, canine, lateral incisor, and central incisor) for each of the two bracket types. The canine bracket was welded to a sliding bar that allowed for different amounts of offset in the gingival direction. The forces generated by a 0.014-inch superelastic nickel titanium wire in the presence of either the UEL or CEL bracket/ligature systems at different amounts of upward canine misalignment (1.5 mm, 3 mm, 4.5 mm, and 6 mm) were recorded. Significant differences were found between UEL and CEL systems for all tested variables (P < .01) with the exception of the canine misalignment of 1.5 mm. The average amount of recorded force in the presence of CEL was negligible with 3.0 mm or greater of canine misalignment. On the contrary, during alignment, a force available for tooth movement was recorded in the presence of both ceramic and stainless steel brackets when associated with UEL. The type of ligature used influenced the actual amount of force released by the orthodontic system significantly more than the type of bracket used (stainless steel vs ceramic).

  12. Low cycle fatigue strength of some austenitic stainless steels at room temperature and elevated temperatures

    International Nuclear Information System (INIS)

    Type 304, 316, and 316L stainless steels were tested from room temperature to 650 0 C using two kinds of bending test specimens. Particularly, Type 304 was tested at several cyclic rates and 550 0 and 650 0 C, and the effect of cyclic rate on its fatigue strength was investigated. Test results are summarized as follows: (1) The bending fatigue strength at room temperature test shows good agreement with the axial fatigue one, (2) Manson--Coffin's fatigue equation can be applied to the results, (3) the ratio of crack initiation to failure life becomes larger at higher stress level, and (4) the relation between crack propagation life and total strain range or elastic strain range are linear in log-log scale. This relation also agrees with the equations which were derived from some crack propagation laws. It was also observed at the elevated temperature test: (1) The reduction of fatigue strength is not noticeable below 500 0 C, but it is noted at higher temperature. (2) The cycle rate does not affect on fatigue strength in faster cyclic rate than 20 cpm and below 100,000 cycles life range. (3) Type 316 stainless steel shows better fatigue property than type 304 and 316L stainless steels. 30 figures

  13. Tritium distributing in stainless steel determined by chemical etchin

    International Nuclear Information System (INIS)

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

    2009-01-01

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

  14. Failure probability estimate of type 304 stainless steel piping

    International Nuclear Information System (INIS)

    Daugherty, W.L.; Awadalla, N.G.; Sindelar, R.L.; Mehta, H.S.; Ranganath, S.

    1989-01-01

    The primary source of in-service degradation of the SRS production reactor process water piping is intergranular stress corrosion cracking (IGSCC). IGSCC has occurred in a limited number of weld heat affected zones, areas known to be susceptible to IGSCC. A model has been developed to combine crack growth rates, crack size distributions, in-service examination reliability estimates and other considerations to estimate the pipe large-break frequency. This frequency estimates the probability that an IGSCC crack will initiate, escape detection by ultrasonic (UT) examination, and grow to instability prior to extending through-wall and being detected by the sensitive leak detection system. These events are combined as the product of four factors: (1) the probability that a given weld heat affected zone contains IGSCC; (2) the conditional probability, given the presence of IGSCC, that the cracking will escape detection during UT examination; (3) the conditional probability, given a crack escapes detection by UT, that it will not grow through-wall and be detected by leakage; (4) the conditional probability, given a crack is not detected by leakage, that it grows to instability prior to the next UT exam. These four factors estimate the occurrence of several conditions that must coexist in order for a crack to lead to a large break of the process water piping. When evaluated for the SRS production reactors, they produce an extremely low break frequency. The objective of this paper is to present the assumptions, methodology, results and conclusions of a probabilistic evaluation for the direct failure of the primary coolant piping resulting from normal operation and seismic loads. This evaluation was performed to support the ongoing PRA effort and to complement deterministic analyses addressing the credibility of a double-ended guillotine break

  15. HYDROGEN EFFECTS ON THE FRACTURE TOUGHNESS PROPERTIES OF FORGED STAINLESS STEELS

    Energy Technology Data Exchange (ETDEWEB)

    Morgan, M

    2008-03-28

    The effect of hydrogen on the fracture toughness properties of Types 304L, 316L and 21-6-9 forged stainless steels was investigated. Fracture toughness samples were fabricated from forward-extruded forgings. Samples were uniformly saturated with hydrogen after exposure to hydrogen gas at 34 MPa or 69 and 623 K prior to testing. The fracture toughness properties were characterized by measuring the J-R behavior at ambient temperature in air. The results show that the hydrogen-charged steels have fracture toughness values that were about 50-60% of the values measured for the unexposed steels. The reduction in fracture toughness was accompanied by a change in fracture appearance. Both uncharged and hydrogen-charged samples failed by microvoid nucleation and coalescence, but the fracture surfaces of the hydrogen-charged steels had smaller microvoids. Type 316L stainless steel had the highest fracture toughness properties and the greatest resistance to hydrogen degradation.

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

    Science.gov (United States)

    2013-08-01

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

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    Thermochemical surface engineering by nitriding of austenitic stainless steel transforms the surface zone into expanded austenite, which improves the wear resistance of the stainless steel while preserving the stainless behavior. As a consequence of the thermochemical surface engineering, huge re...

  18. 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

  19. Ultrasonic detection and sizing of cracks in cast stainless steel samples

    International Nuclear Information System (INIS)

    Allidi, F.; Edelmann, X.; Phister, O.; Hoegberg, K.; Pers-Anderson, E.B.

    1986-01-01

    The test consisted of 15 samples of cast stainless steel, each with a weld. Some of the specimens were provided with artificially made thermal fatique cracks. The inspection was performed with the P-scan method. The investigations showed an improvement of recognizability relative to earlier investigations. One probe, the dual type, longitudinal wave 45 degrees, low frequence 0.5-1 MHz gives the best results. (G.B.)

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

    OpenAIRE

    Bernice Victoria; Dr. Gene George; Kevin Ark Kumar

    2015-01-01

    Abstract Due to increasing concern on potential impact of materials on human health and environment the materials used in hygienic applications should be durable corrosion resistant clean surface etc. Type 2205 duplex stainless steel is a preferred material for use in biomedical pharmaceutical nuclear pressure vessels chemical tankers etc. it exhibits good mechanical strength and high resistance to corrosion. The strength toughness hardness of such materials are usually determined by destruct...

  1. Eddy Current Transducer Dedicated for Sigma Phase Evaluation in Duplex Stainless Steel

    Directory of Open Access Journals (Sweden)

    Grzegorz Psuj

    2012-01-01

    Full Text Available The paper describes a new transducer dedicated for evaluation of a duplex stainless steel (DSS. Different phases which exist in DSS have influence on mechanical as well as on electrical properties. Therefore, an eddy current transducer was utilized. In order to achieve high sensitivity, a differential type of the transducer was selected. The performance of the transducer was verified by utilizing the samples which had a different amount of sigma phase.

  2. The effects of fast-neutron irradiation on the mechanical properties of austenitic stainless steel

    International Nuclear Information System (INIS)

    Dalton, J.H.

    1978-01-01

    The paper reviews the effects of fast-neutron irradiation on the tensile properties of austenitic stainless steels at irradiation temperatures of less than 400 degrees Celcius, using as an example, work carried out at Pelindaba on an AISI 316 type steel produced in South Africa. Damage produced in these steels at higher irradiation temperatures and fluences is also briefly discussed. The paper concludes with a discussion of some methods of overcoming or decreasing the effects of irradiation damage [af

  3. Welding stainless steels for structures operating at liquid helium temperature

    Energy Technology Data Exchange (ETDEWEB)

    Witherell, C.E.

    1980-04-18

    Superconducting magnets for fusion energy reactors require massive monolithic stainless steel weldments which must operate at extremely low temperatures under stresses approaching 100 ksi (700 MPa). A three-year study was conducted to determine the feasibility of producing heavy-section welds having usable levels of strength and toughness at 4.2/sup 0/K for fabrication of these structures in Type 304LN plate. Seven welding processes were evaluated. Test weldments in full-thickness plate were made under severe restraint to simulate that of actual structures. Type 316L filler metal was used for most welds. Welds deposited under some conditions and which solidify as primary austenite have exhibited intergranular embrittlement at 4.2/sup 0/K. This is believed to be associated with grain boundary metal carbides or carbonitrides precipitated during reheating of already deposited beads by subsequent passes. Weld deposits which solidify as primary delta ferrite appear immune. Through use of fully austenitic filler metals of low nitrogen content under controlled shielded metal arc welding conditions, and through use of filler metals solidifying as primary delta ferrite where only minimum residuals remain to room temperature, welds of Type 316L composition have been made with 4.2K yield strength matching that of Type 304LN plate and acceptable levels of soundness, ductility and toughness.

  4. Effect of vibratory stress relief during welding of thick stainless steel plate

    Science.gov (United States)

    Spooner, S.; David, S. A.; Wang, X. L.; Hubbard, C. R.; Holden, T. M.; Root, J. H.

    1993-12-01

    Residual strains were measured in two welded 25-mm thick plates of type 304 stainless steel by the neutron diffraction technique. The filler metal employed to weld these plates was type 308 stainless steel. One of the two welds was prepared without any vibratory stress relief treatment and the other was vibrated at a frequency below the resonant condition which gives a fraction the resonant amplitude during welding. In both plates the largest residual stress component found in the heat affected zone and in the base metal is along the fusion joint (longitudinal) and is found at the boundary between the weld zone and the heat affected zone. This longitudinal component is 300 +/- 50 MPa in tension. The associated normal stress was close to zero and the transverse stress was 80 +/- 50 MPa. Variations in residual stresses with thickness through the base metal plate were small. The treated plate and untreated plate showed nearly identical patterns of stress distribution. Differences in the measured stresses between the vibratory-stress-relief treated and the untreated plates fall within the error bars of the stress determination in these particular 25 mm thick 300-type stainless steel plates.

  5. Eddy current testing technology research of aluminum coating thickness on stainless steel tube inwall

    International Nuclear Information System (INIS)

    Li Xiaona; Hao Xingui

    2014-01-01

    Dynamic testing method of coating layer thickness of stainless steel tube is built up using eddy current testing technology. It is determined that others-contrast point-type probe is adopted, by comparing the detection performance of self-contrast and others-contrast type probes. To effectively solve the lift-off effect between dynamic detection, 3 nylon (4 m long per piece) is distributed by 120° in the circumferential direction of tube to be tested, which ensure the rotational alignment and avoid point-type probe lifting off the tube inner surface. And the special tighten clamping fixture is used for fixing stainless steel tube; so, the dynamic transmission device is designed and realized. Accuracy study under the condition of different frequency and gain is carried out using multi-frequency detection technology. At the same time, the detection precision under quadratic curve and exponential curve calibration modal is compared. And then, test parameters and curve generated model is determined to achieve the best accuracy. Finally, spiral scanning eddy current method is achieved for testing the aluminium cladding thickness on stainless steel tube inwall. The accuracy of detecting the thickness of coating layer by this method is ±3μm, the instability of rotating tooling is lower than 10%. This method achieved the domestic leading level. (authors)

  6. Comparing the Formability of AISI 304 and AISI 202 Stainless Steels

    Science.gov (United States)

    du Toit, M.; Steyn, H. G.

    2012-07-01

    The formability of AISI 202 austenitic stainless steel was compared with that of type AISI 304 stainless steel. Type 202 is a low-nickel austenitic stainless steel alloyed with manganese and nitrogen. In this study, the formability of the two grades was examined using Erichsen cupping tests and room temperature uniaxial tensile tests performed at various angles to the rolling direction. AISI 202 appears to work-harden at a slightly higher rate than AISI 304, even though the austenite in type 202 is more stable than that in 304 with respect to the formation of deformation-induced α' martensite. Although both grades are predicted to be susceptible to earing during deep drawing, AISI 202 displays a higher work-hardening exponent, higher average normal anisotropy, and a higher limiting drawing ratio than AISI 304. Similar cup heights were measured during Erichsen cupping tests, confirming that the two grades have very similar deep drawing properties. The results of this investigation therefore suggest that AISI 202 is a suitable alternative for AISI 304 in applications requiring good deep drawing properties.

  7. Corrosion and inhibition of stainless steel pitting corrosion in alkaline medium and the effect of Cl- and Br- anions

    International Nuclear Information System (INIS)

    Refaey, S.A.M.; Taha, F.; El-Malak, A.M. Abd

    2005-01-01

    The effect of carbonate anion on the pitting corrosion and inhibition behavior of stainless steel samples (304L SS and 316L SS) has been studied using potentiodynamic and scanning electron microscope (SEM) techniques. The effect of concentration of CO 3 2- ions, pH, potential scanning rate and the composition of stainless steel are discussed. Additions of Cl - and Br - ions into the carbonate solution increase the anodic dissolution of stainless steel and decrease its pitting corrosion resistance. The effect of CO 3 2- anion on the inhibition of chloride and bromide pitting corrosion of the two stainless steel types has been studied also. Pitting corrosion decrease with the increasing of sodium carbonate concentration, i.e. increases the resistance of stainless steels towards the chloride and bromide pitting corrosion. This inhibition effect argued to formation of [Fe,Cr]CO 3 film caused by preferential adsorption of the CO 3 2- ion, leading to instantaneous repair of weak sites for pit nucleation

  8. Effects of molybdenum additions on the corrosion resistance of stainless steels in inorganic aqueous solutions and organic media (A review)

    International Nuclear Information System (INIS)

    Charbonnier, J.-C.

    1975-01-01

    The effects of molybdenum additions on the corrosion resistance of austenitic and ferritic stainless steels are reviewed. The following types of corrosion are considered: uniform attack in inorganic and organic acids, pitting and crevice corrosion in chloride media. The survey has been conducted with particular emphasis on the recent works. The different hypotheses which have been suggested in order to clarify the role of the molybdenum additions on the improvement of the corrosion resistance of stainless steels are analyzed and discussed. A synthesis is given [fr

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

    National Research Council Canada - National Science Library

    Kain, Robert

    2000-01-01

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

  10. The catalytic oxidation of H2S in a stainless steel membrane reactor with separate feed of reactants.

    NARCIS (Netherlands)

    Neomagus, H.W.J.P.; van Swaaij, Willibrordus Petrus Maria; Versteeg, Geert

    1998-01-01

    The oxidation of H2S is studied in a membrane reactor with separate feed of reactants. As a novelty in the concept of separate introduction of the reactants, a sintered stainless steel membrane is used, because this type of material is easy to integrate into the reactor, and the catalytic properties

  11. The catalytic oxidation of H2S in a stainless steel membrane reactor with separate feed of reactants

    NARCIS (Netherlands)

    Neomagus, H.W.J.P.; Swaaij, W.P.M. van; Versteeg, G.F.

    1998-01-01

    The oxidation of H2S is studied in a membrane reactor with separate feed of reactants. As a novelty in the concept of separate introduction of the reactants, a sintered stainless steel membrane is used, because this type of material is easy to integrate into the reactor, and the catalytic properties

  12. Extended X-Ray Absorption Fine Structure Investigation of Carbon Stabilized Expanded Austenite and Carbides in Stainless Steel AISI 316

    DEFF Research Database (Denmark)

    Oddershede, Jette; Christiansen, Thomas; Ståhl, Kenny

    2011-01-01

    Low temperature carburized AISI 316 stainless steel - carbon expanded austenite - was investigated with EXAFS and synchrotron diffraction together with synthesized carbides of the type M3C2, M7C3 and M23C6. It was found that the chemical environment of carbon expanded austenite is not associated ...

  13. Numerical modeling and optimization of machining duplex stainless steels

    Directory of Open Access Journals (Sweden)

    Rastee D. Koyee

    2015-01-01

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

  14. Antimicrobial Cu-bearing stainless steel scaffolds

    International Nuclear Information System (INIS)

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

    2016-01-01

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

  15. Aging degradation of cast stainless steel

    International Nuclear Information System (INIS)

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

    1986-10-01

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

  16. STRUCTURAL STRESS RELAXATION IN STAINLESS INSTABILITY STEEL

    Directory of Open Access Journals (Sweden)

    S. Lyabuk

    2017-06-01

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

  17. Static strain aging in austenitic stainless steels

    International Nuclear Information System (INIS)

    Monteiro, S.N.

    1978-07-01

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

  18. 2017 Accomplishments – Tritium Aging Studies on Stainless Steel Weldments and Heat-Affected Zones

    Energy Technology Data Exchange (ETDEWEB)

    Morgan, Michael J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hitchcock, Dale [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Krentz, Tim [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); McNamara, Joy [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Duncan, Andrew [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2018-01-31

    In this study, the combined effects tritium and decay helium in forged and welded Types 304L and 21-6-9 stainless steels were studied. To measure these effects, fracture mechanic specimens were thermally precharged with tritium and aged for approximately 17 years to build in decay helium from tritium decay prior to testing. The results are compared to earlier measurements on the same alloys and weldments (4-5, 8-9). In support of Enhanced Surveillance, “Tritium Effects on Materials”, the fracture toughness properties of long-aged tritium-charged stainless-steel base metals and weldments were measured and compared to earlier measurements. The fracture-toughness data were measured by thermally precharging as-forged and as-welded specimens with tritium gas at 34.5 MPa and 350°C and aging for approximately 17 years to build-in decay helium prior to testing. These data result from the longest aged specimens ever tested in the history of the tritium effects programs at Savannah River and the fracture toughness values measured were the lowest ever recorded for tritium-exposed stainless steel. For Type 21-6-9 stainless steel, fracture toughness values were reduced to less than 2-4% of the as-forged values to 41 lbs / in specimens that contained more than 1300 appm helium from tritium decay. The fracture toughness properties of long-aged weldments were also measured. The fracture toughness reductions were not as severe because the specimens did not retain as much tritium from the charging and aging as did the base metals. For Type 304L weldments, the specimens in this study contained approximately 600 appm helium and their fracture toughness values averaged 750 lbs / in. The results for other steels and weldments are reported and additional tests will be conducted during FY18.

  19. 77 FR 23752 - Drawn Stainless Steel Sinks From China

    Science.gov (United States)

    2012-04-20

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

  20. Solidification cracking in austenitic stainless steel welds

    Indian Academy of Sciences (India)

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

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

    Indian Academy of Sciences (India)

    Unknown

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

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

    Indian Academy of Sciences (India)

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

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

    Indian Academy of Sciences (India)

    Unknown

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

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

    Science.gov (United States)

    Douglas R. Rammer; Samuel L. Zelinka

    2015-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-07-01

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

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

    African Journals Online (AJOL)

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

  7. Hydrogen Absorption Induced Slow Crack Growth in Austenitic Stainless Steels for Petrochemical Pressure Vessel Industries

    Directory of Open Access Journals (Sweden)

    Ronnie Rusli

    2011-05-01

    Full Text Available Type 304Land type 309 austenitic stainless steels were tested either by exposed to gaseous hydrogen or undergoing polarized cathodic charging. Slow crack growth by straining was observed in type 304L, and the formation of α‘ martensite was indicated to be precursor for such cracking. Gross plastic deformation was observed at the tip of the notch, and a single crack grew slowly from this region in a direction approximately perpendicular to the tensile axis. Martensite formation is not a necessary condition for hydrogen embrittlement in the austenitic phase.

  8. Citric Acid Passivation of Stainless Steel

    Science.gov (United States)

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

    2009-01-01

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

  9. Carburization of stainless steel furnace tubes

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-12-31

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

  10. Carburization of stainless steel furnace tubes

    International Nuclear Information System (INIS)

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

    1998-01-01

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

  11. Single pit propagation on austenitic stainless steel

    International Nuclear Information System (INIS)

    Heurtault, Stephane

    2016-01-01

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

  12. 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)

  13. Low Temperature Surface Carburization of Stainless Steels

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-12-07

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

  14. Recent studies on the welding of austenitic stainless steel piping for BWR service

    International Nuclear Information System (INIS)

    Childs, W.J.

    1986-01-01

    The incidence of intergranular stress corrosion cracking (IGSCC) in stainless steel piping in BWR power plants has led to the development of various countermeasures. Replacement of the susceptible Type 304 stainless steel with Type 316 nuclear grade stainless steel has been done by a number of plants. In order to minimize radiation exposure to welding personnel, automatic GTA welding has been used wherever possible when we make the field welds. Studies have shown that the residual stresses in the welded butt joints are affected by the welding process, weld joint design and welding procedures. A new weld joint design has been developed which minimizes the volume of deposited metal while providing adequate access for welding. It also minimizes axial and radial shrinkage and the resulting residual stresses. Other countermeasures, which have been used, include stress modifications such as induction heating stress improvement (IHSI) and last pass heat sink welding (LPHSW). It has been shown that these remedies must be process adjusted to account for the welding process employed. In some cases where UT cracking indication have been detected or where through wall cracking has occurred, weld surfacing has been used to extend life. A further approach to preventing IGSCC in the weld HAZ has been through improvement of the water chemistry by injecting hydrogen to reduce the oxygen level and by keeping the impurity level low

  15. Effects of Ce on Inclusions, Microstructure, Mechanical Properties, and Corrosion Behavior of AISI 202 Stainless Steel

    Science.gov (United States)

    Cai, Guojun; Li, Changsheng

    2015-10-01

    The sizes and morphologies of nonmetallic inclusions, microhardness, tensile strength, and Charpy impact toughness in AISI 202 stainless steel with different Ce contents were synthetically analyzed by means of SEM, TEM, microhardness tester, and tensile and Charpy impact tests. Effects of Ce addition on the corrosion behavior were investigated in 5 wt.% H2SO4 solution for different periods of time through measuring AC impedance. The EIS measurements indicate that the steels with Ce addition exhibit higher R p values than those without Ce, which illustrates the relative resistance to uniform corrosion is accompanied by an increasing Ce addition. Ce addition to AISI 202 stainless steel improves its uniform corrosion resistance owing to metamorphic inclusions and the improvement of electrode potential in matrix. Upon increasing Ce addition, the indentation morphology of samples transfers from sink-in types to pile-up types, explaining good machinability of steels containing Ce. It is witnessed from the fracture mode that Ce refines the grain size of steels, significantly increasing the strength; in the meantime, its plasticity is improved, thereby solving the contradiction between the strength and the plasticity of steels. It is concluded that AISI 202 stainless steel with 0.016 wt.% Ce addition in the mass fraction has the best mechanical properties and the uniform corrosion resistance.

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

    Directory of Open Access Journals (Sweden)

    Bernice Victoria

    2015-08-01

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

  17. 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

  18. Effects of high-pressure hydrogen charging on the structure of austenitic stainless steels

    International Nuclear Information System (INIS)

    Hoelzel, M.; Danilkin, S.A.; Ehrenberg, H.; Toebbens, D.M.; Udovic, T.J.; Fuess, H.; Wipf, H.

    2004-01-01

    The effects of high-pressure hydrogen and deuterium charging on the structure of AISI type 304 and AISI type 310 austenitic stainless steels have been investigated by neutron and X-ray diffraction. Rietveld analyses of the neutron diffraction data revealed that hydrogen atoms occupy exclusively the octahedral interstitial sites in both steels. No phase transformations have been observed in 310 stainless steel within the whole range of hydrogen-to-metal atomic ratios H/Me up to ∼ 1. In 304 stainless steel, the formation of ε-martensite was observed not only after hydrogenation at 3.0 GPa (H/Me = 0.56), but also after applying a pressure of 4.0 GPa without hydrogen. The results differ significantly from published studies on cathodically hydrogenated samples, where high amounts of ε-martensite were observed in both steels. High-pressure hydrogenation and cathodic hydrogen charging result in different phase transformation behaviour. The discrepancies can be explained by different hydrogen distributions resulting in quite different stress states

  19. Irradiation assisted stress corrosion cracking of low carbon stainless steel in BWR

    International Nuclear Information System (INIS)

    Mayuzumi, Masami

    2008-01-01

    Some examples and characteristics of old intergranular stress corrosion cracking (IGSCC) and the improvement methods are described. Stress corrosion cracking (SCC) of low carbon stainless steel in the core shroud and major piping of BWR has been reported since 1990. Most parts of them start at the transgranular stress corrosion cracking (TGSCC) and progress to IGSCC. The shape of crack is originated by the residual tensile stress that depends on welding and mechanical processing. The chromium-deficient layer was not observed. The crack progressed from the parent materials to the deposited metal with low content of ferrite. SCC crack growth rates of type SUS316 were 1/10 of type SUS304 stainless steel. The countermeasures of SCC of low carbon stainless steel to control its generation and progressing are stated. Method for SCC of major piping can include the introduction heating stress improvement (IHSI) and narrow gap edge welding. Methods for SCC of shroud include the laser peening, water jet peening, and polish processing. (S.Y.)

  20. A Basic Study on the Defect Detectability of Austenitic Stainless Steel Weldments using Ultrasonic Testing

    International Nuclear Information System (INIS)

    Park, M. H.; Park, K. H.; Seo, D. M.; Yoon, K. S.

    1989-01-01

    This paper presents the ultrasonic characteristics of weldment and detectability of defects of weldment in Austenitic Stainless Steel Type 304 that is composed of mostly coolant piping system in nuclear power plants. The results of this experiment show as follows: 1. When the ultrasonic beam detects the defects on the side of base metal and on the opposite side of weldment, the indications which was detected on the screen show different amplitude and different metal path each. 2. The ultrasonically estimated notch depth is generally oversized than actual notch depth. 3. It is easy for the false indication to show up on the screen because of columnar structure of weldment in austenitic stainless steel. 4. The higher frequencies of transducer have more difficulties to detect the defects of the opposite side of weldment because of ultrasonic attenuation in weldment and the longitudinal transmitter-receiver transducer is the most effective in detecting the opposite side defects of weldment

  1. The effects of Ti implantation on corrosion and adhesion of TiN coated stainless steel

    Science.gov (United States)

    Baba, K.; Nagata, S.; Hatada, R.; Daikoku, T.; Hasaka, M.

    1993-06-01

    Thin titanium nitride (TiN) films of 40 and 70 nm in thickness were deposited on austenitic-type 304 stainless steel substrates by a rf ion plating process, and these specimens were irradiated with 70 kV titanium ions at a fluence of 1 × 10 17/cm 2 by use of MEVVA IV metallic ion source at room temperature. After that TiN films of 2 μm were deposited by the same method. The results of X-ray photoelectron spectroscopy and Auger electron spectroscopy revealed that implanted titanium penetrated into the substrate and interfacial mixing was verified. The adhesion strength was estimated by a scratch test. It was found that ion implantation can enhance the adhesion strength between the film and the substrate. The corrosion resistance of the specimens was evaluated in aqueous solutions of sulfuric acid by an electrochemical method. Titanium implantation was extremely effective in suppressing the anodic dissolution of stainless steel.

  2. Effect of titanium on microstructural changes in SUS 316 stainless steels

    International Nuclear Information System (INIS)

    Kawanishi, H.; Yamada, M.; Fukuya, K.; Ishino, S.

    1982-01-01

    The microstructural changes have been examined in order to study the effect of titanium addition to type 316 stainless steels on void swelling. Titanium ions of 400 keV from an accelerator have been implanted at room temperature to solution treated SUS 316 stainless steels which have the original titanium content of 0.02 wt.% to the concentration increase of titanium by 0.01, 0.02 and 0.1 wt.%. Following the preinjection of 20 at.ppm helium at ambient temperature, 400 keV-aluminium ions have been irradiated to the specimen to 40 dpa at 550, 625 and 675 0 C. The TEM observations have revealed that the void number density is drastically increased in the specimen with the content of implanted titanium of more than 0.01 wt.%, whereas the void diameter is remarkably decreased with the titanium content. (orig.)

  3. Bioaccumulation and food chain transfer of corrosion products from radioactive stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Young, J.S.

    1986-07-01

    Two sets of experiments were conducted to determine if corrosion products from radioactive Type 347 stainless steel could be biologically transferred from sediment through a marine food chain, and whether corrosion products dissolved in seawater could be bioaccumulated and then eliminated. Corrosion products containing /sup 60/Co and /sup 63/Ni from the radioactive stainless steel were introduced into marine sediments. Infaunal polychaete worms exposed to these sediments bioaccumulated the radionuclides. The feeding of these worms to shrimp and fish resulted in a trophic transfer of the radioactive products across a one-step food chain. The magnitude of the transfers are described in terms of transfer factors. Dissolved corrosion products as measured by the radionuclides were also bioaccumulated by shrimp and fish concentrating more than fish. Concentration factors were calculated.

  4. Perspective on present and future alloy development efforts on austenitic stainless steels for fusion application

    Energy Technology Data Exchange (ETDEWEB)

    Maziasz, P.J.

    1984-01-01

    The purpose of this paper is to address important questions concerning how to effect further alloy development of austenitic stainless steels for resistance, and to what extent the behavior of other properties under irradiation, such as strength/embrittlement, fatigue/irradiation creep, corrosion (under irradiation), and radiation-induced activation must be influenced. To summarize current understanding, helium has been found to have major effects on swelling and embrittlement, but several metallurgical avenues are available for significant improvement relative to type 316 stainless steel. Studies on fatigue and irradiation creep, particularly including helium effects, are preliminary but have yet to reveal engineering problems requiring additional alloy development remedies. The effects of irradiation on corrosion behavior are unknown, but higher alloy nickel contents make thermal corrosion in lithium worse. 67 refs. (JDB)

  5. Characterisation of creep cavitation damage in a stainless steel pressure vessel using small angle neutron scattering

    CERN Document Server

    Bouchard, P J; Treimer, W

    2002-01-01

    Grain-boundary cavitation is the dominant failure mode associated with initiation of reheat cracking, which has been widely observed in austenitic stainless steel pressure vessels operating at temperatures within the creep range (>450 C). Small angle neutron scattering (SANS) experiments at the LLB PAXE instrument (Saclay) and the V12 double-crystal diffractometer of the HMI-BENSC facility (Berlin) are used to characterise cavitation damage (in the size range R=10-2000 nm) in a variety of creep specimens extracted from ex-service plant. Factors that affect the evolution of cavities and the cavity-size distribution are discussed. The results demonstrate that SANS techniques have the potential to quantify the development of creep damage in type-316H stainless steel, and thereby link microstructural damage with ductility-exhaustion models of reheat cracking. (orig.)

  6. Isotope effects on desorption kinetics of hydrogen isotopes implanted into stainless steel by glow discharge

    International Nuclear Information System (INIS)

    Matsuyama, M.; Kondo, M.; Noda, N.; Tanaka, M.; Nishimura, K.

    2015-01-01

    In a fusion device the control of fuel particles implies to know the desorption rate of hydrogen isotopes by the plasma-facing materials. In this paper desorption kinetics of hydrogen isotopes implanted into type 316L stainless steel by glow discharge have been studied by experiment and numerical calculation. The temperature of a maximum desorption rate depends on glow discharge time and heating rate. Desorption spectra observed under various experimental conditions have been successfully reproduced by numerical simulations that are based on a diffusion-limited process. It is suggested, therefore, that desorption rate of a hydrogen isotope implanted into the stainless steel is limited by a diffusion process of hydrogen isotope atoms in bulk. Furthermore, small isotope effects were observed for the diffusion process of hydrogen isotope atoms. (authors)

  7. Inter- and intragranular stresses in cyclically-deformed 316 stainless steel

    International Nuclear Information System (INIS)

    Wang, X.-L.; Wang, Y.D.; Stoica, A.D.; Horton, D.J.; Tian, H.; Liaw, P.K.; Choo, H.; Richardson, J.W.; Maxey, E.

    2005-01-01

    Neutron diffraction was used to study residual stresses in cyclically-deformed 316 LN stainless steel. The tension-compression high-cycle fatigue tests were conducted in air with a frequency of 0.2 Hz. Large intergranular stresses were found to develop in the stainless steel as a result of elastic and plastic anisotropy. These intergranular stresses started to decrease when micro-cracks were initiated at the surface and vanished when the sample reached failure. Cyclic loading also led to the development of intragranular stresses, as evidenced by the broadening of the diffraction peaks. Analysis of the orientation dependence of the measured peak widths indicates that the immobile dislocations generated by fatigue deformation are mostly edge rather than screw type

  8. Perspective on present and future alloy development efforts on austenitic stainless steels for fusion application

    International Nuclear Information System (INIS)

    Maziasz, P.J.

    1984-01-01

    The purpose of this paper is to address important questions concerning how to effect further alloy development of austenitic stainless steels for resistance, and to what extent the behavior of other properties under irradiation, such as strength/embrittlement, fatigue/irradiation creep, corrosion (under irradiation), and radiation-induced activation must be influenced. To summarize current understanding, helium has been found to have major effects on swelling and embrittlement, but several metallurgical avenues are available for significant improvement relative to type 316 stainless steel. Studies on fatigue and irradiation creep, particularly including helium effects, are preliminary but have yet to reveal engineering problems requiring additional alloy development remedies. The effects of irradiation on corrosion behavior are unknown, but higher alloy nickel contents make thermal corrosion in lithium worse. 67 refs

  9. A review of compatibility of IFR fuel and austenitic stainless steel

    International Nuclear Information System (INIS)

    Keiser, D.D. Jr.

    1996-01-01

    Interdiffusion experiments have been conducted to investigate the compatibility of various austenitic stainless steels with U-Pu-Zr alloys, which are alloys to be employed as fuel for the Integral Fast Reactor being developed by Argonne National Laboratory. These tests have also studied the compatibility of austenitic stainless steels with fission products, like the minor actinides (Np and Am) and lanthanides (Ce and Nd), that are generated during the fission process in an IFR. This paper compares the results of these investigations in the context of fuel-cladding compatibility in IFR fuel elements, specifically focusing on the relative Interdiffusion behavior of the components and the types of phases that develop based on binary phase diagrams. Results of Interdiffusion tests are assessed in the light of observations derived from post-test examinations of actual irradiated fuel elements

  10. In situ TEM study of stress corrosion cracking of austenitic stainless steel

    International Nuclear Information System (INIS)

    Li, J.X.; Chu, W.Y.; Wang, Y.B.; Qiao, L.J.

    2003-01-01

    A constant deflection device designed for use within a transmission electron microscope (TEM) was used to investigate the change in dislocation configuration ahead of a crack tip during stress corrosion cracking (SCC) of type 310 austenitic stainless steel in a boiling MgCl 2 solution, and the initiation of stress corrosion microcracking. Results showed that crack tip corrosion processes during SCC-enhanced dislocation emission, multiplication and motion. SCC microcracks initiated when the corrosion-enhanced dislocation emission and motion had fully develop. A passive film formed during corrosion of austenitic stainless steel in the boiling MgCl 2 solution generated a tensile stress. During SCC, the additive tensile stress generated at the metal/passive film interface assists the applied stress to enhance dislocation emission and motion

  11. Clean forming of stainless steel and titanium products by lubricious oxides

    DEFF Research Database (Denmark)

    Heikkilä, Irma; Wadman, Boel; Thoors, Håkan

    2012-01-01

    Big social benefits can be attained through increased use of stainless steel or titanium in new sheet metal applications. Unfortunately, forming of these materials is often a challenging and costly operation, that can lead to environmental and health problems when solving the technical limitations...... is called lubricious oxides with a rutile crystal structure. Oxides of Ti, Mo, V, and Zn can build rutiles under certain contact temperatures during rolling and forming. The aim of this investigation is to evaluate if oxides designed on metal sheets display a lubricious effect under conditions similar...... to industrial forming processes. Preliminary evaluations show a beneficial influence of two oxides types, on stainless steel and on titanium. More work is needed to test the lubricating effect in other forming operations and to analyse the sustainability aspects for products manufactured with this alternative...

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

    Science.gov (United States)

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

    2017-09-01

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

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

    Directory of Open Access Journals (Sweden)

    Sivaram Subbiah

    2010-01-01

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

  14. Effect of irrigation and stainless steel drills on dental implant bed heat generation.

    Science.gov (United States)

    Bullon, B; Bueno, E F; Herrero, M; Fernandez-Palacin, A; Rios, J V; Bullon, P; Gil, F J

    2015-02-01

    The objective of this study is assessing the influence of the use of different drill types and external irrigation on heat generation in the bone. In-vitro study to compare two different sequences for implant-bed preparation by means of two stainless steels: precipitation-hardening stainless steel (AISI 420B) (K drills), and martensitic stainless steel (AISI 440) (S drills). Besides, the drilled sequences were realized without irrigation, and with external irrigation by means of normal saline solution at room temperature. The study was realized on bovine ribs using: K without irrigation (KSI) and with irrigation (KCI) and S without irrigation (SSI) and with irrigation (SCI) with five drills for each system. Each drill was used 100 times. Bone temperature was measured with a thermocouple immediately after drilled. Average bone temperature with irrigation was for K drills 17.58±3.32 °C and for S drills 16.66±1.30 °C. Average bone temperature without irrigation was for K drills 23.58±2.94 °C and for S drills 19.41±2.27 °C. Statistically significant differences were found between K without irrigation versus S with irrigation and K with irrigation (pirrigated groups (K=5.6%, S=5.1% vs. without irrigation groups K=9.4%, S=9.3%). The first K drill generated more heat than the remaining drills. No significant differences were detected among temperature values in any of the analyzed drill groups. Unlike irrigation, drill use and type were observed to have no significant impact on heat generation. The stainless steel AISI 420B presents better mechanical properties and corrosion resistance than AISI440.

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

    Directory of Open Access Journals (Sweden)

    Bibo Yao

    2016-03-01

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

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

    Science.gov (United States)

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

    2016-03-04

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

  17. Comparison of adhesion of the food spoilage bacterium Shewanella putrefaciens to stainless steel and silver surfaces

    DEFF Research Database (Denmark)

    Hjelm, Mette; Hilbert, Lisbeth Rischel; Møller, Per

    2002-01-01

    The aim of this study is to compare the number of attached bacteria, Shewanella putrefaciens, on stainless steel with different silver surfaces. Thus evaluating if silver surfaces could contribute to a higher hygienic status in the food industry. Bacterial adhesion to three types of silver surfaces...... than one log unit in bacterial numbers on the two types of materials was observed, but for most samples the difference was within one log unit. Treating new silver with sulphide to try to reproduce a tarnished silver surface did not result in a similar lowering of adhering cells when compared to steel...

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

    International Nuclear Information System (INIS)

    Pacheco, D.J.

    1977-01-01

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

  19. Improved swelling resistance for PCA austenitic stainless steel under HFIR irradiation through microstructural control

    International Nuclear Information System (INIS)

    Maziasz, P.J.; Braski, D.N.

    1984-01-01

    Swelling evaluation of PCA variants and 20%-cold-worked (N-Lot) type 316 stainless steel (CW 316) at 300 to 600 0 C was extended to 44 dpa. Swelling was negligible in all the steels at 300 0 C after approx. 44 dpa. At 500 to 600 0 C 25%-cold-worked PCA showed better void swelling resistance than type 316 at approx. 44 dpa. There was less swelling variation among alloys at 400 0 C, but again 25%-cold-worked PCA was the best

  20. Cast alumina forming austenitic stainless steels

    Science.gov (United States)

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

    2013-04-30

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

  1. Electrochemical decontamination of Pu contaminated stainless steel

    International Nuclear Information System (INIS)

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

    1983-08-01

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

  2. Phase identification in neutron irradiated stainless steels

    International Nuclear Information System (INIS)

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

    1980-01-01

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

  3. Complex Protection of Vertical Stainless Steel Tanks

    Directory of Open Access Journals (Sweden)

    Fakhrislamov Radik Zakievich

    2014-03-01

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

  4. [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.

  5. Systemic hypersensitivity reaction to endovascular stainless steel stent.

    Science.gov (United States)

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

    2018-02-01

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

  6. Structural Analysis of Cavitation for Different Stainless Steels

    Directory of Open Access Journals (Sweden)

    Mădălina-Elena Mânzână

    2011-09-01

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

  7. Compatibility of different stainless steels in molten Pb-Bi eutectic at high temperatures

    International Nuclear Information System (INIS)

    Chandra, K.; Kain, Vivekanand; Laik, A.; Sharma, B.P.; Bhattacharya, S.; Debnath, A.K.

    2005-10-01

    Advanced nuclear reactors and the accelerator driven subcritical (ADS) system require the structural materials to be in contact with the molten metals/lead-bismuth eutectic at 400 degC and higher temperatures. One of the primary concerns in using the molten lead-bismuth eutectic (LBE) as a coolant in the primary circuit of these systems is the degradation of structural materials in contact with LBE. An experimental setup has been fabricated to expose the materials in the molten LBE at high temperatures in stagnant condition under inert atmosphere. Samples from five different stainless steels (types 304L, 316L, 403, duplex SS SAF 2205 and super austenitic SS 2RK65) were exposed in this setup at 450 degC for 200h and at 500 degC for 600 and 2100 h under argon atmosphere. A different setup was prepared in which type 316L SS tube in the as-welded condition was exposed in molten LBE at 500 degC for 1200 h in rotating condition. All the samples showed formation of oxide on their surfaces. The thickness and compositional profiles of these oxides analyzed by EPMA confirmed formation of a double layer oxide on type 316L SS. The oxide thickness was highest on SS 403, while it was lowest on 304L and 316L SS. SEM results showed dissolution of materials at the surface in Sandvik 2RK65 and preferential dissolution of austenite phase in duplex SS. None of the stainless steels, except the duplex and the super austenitic stainless steels, showed any localized or selective corrosion. The composition of LBE before and after the exposure tests was analyzed by XRF technique. The result showed presence of Fe, Cr and Ni in the used LBE but these elements were not present in the virgin Pb-Ei alloy. This showed that the corrosion of stainless steels in LBE at temperatures upto 500 degC is due to oxidation and dissolution of alloying elements through the oxide on stainless steels. (author)

  8. The compatibility of stainless steels with particles and powders of uranium carbide and low-sulphur UCS fuels

    International Nuclear Information System (INIS)

    Venter, S.

    1978-05-01

    Slightly hyperstoichiometric (U,Pu)C is a potential nuclear fuel for fast breeder reactors. The excess carbon above the stoichiometric amount results in a higher carbon activity in the fuel, and carbon is transferred to the stainless steel cladding, resulting in embrittlement of the cladding. It is with this problem of carbon transfer from the fuel to the cladding that this thesis is concerned. For practical reasons, UC and not (U,Pu)C was used as the fuel. The theory of decarburisation of carbide fuel and the carburisation of stainless steel, the facilities constructed for the project at the Atomic Energy Board, and the experimental techniques used, including preparation of the fuels, are discussed. The effect of a number of variables of uranium carbide fuel on its compatibility behaviour with stainless steels was investigated, as well as the effect om microstructure and type of stainless steel (304, 304 L and 316) on the rate of carburisation. These studies can be briefly summarised under the following headings: powder-particle size; surface oxidation of uranium carbide; preparation temperature of uranium carbide; low sulfur UCS fuels; uranium sulfide and the microstructure and type of steel. The author concludes that: the effect of surface oxidation and particle size must be taken into account when evaluating out-of-pile tests; the possible effects of surface oxidation must be taken into account when considering vibro-compacted carbide fuels; there is no advantage in replacing a fraction of the carbon atoms by sulphur atoms in slightly hyperstoichiometric carbide fuels, and the type and thermo-mechanical treatment of the stainless steel used as cladding material in a fuel pin is not important as far as the rate of carburisation by the fuel is concerned

  9. Product consistency testing of three reference glasses in stainless steel and perfluoroalkoxy resin vessels

    International Nuclear Information System (INIS)

    Olson, K.M.; Smith, G.L.; Marschman, S.C.

    1995-03-01

    Because of their chemical durability, silicate glasses have been proposed and researched since the mid-1950s as a medium for incorporating high-level radioactive waste (HLW) generated from processing of nuclear materials. A number of different waste forms were evaluated and ranked in the early 1980s; durability (leach resistance) was the highest weighted factor. Borosilicate glass was rated the best waste form available for incorporation of HLW. Four different types of vessels and three different glasses were used to study the possible effect of vessel composition on durability test results from the Production Consistency Test (PCT). The vessels were 45-m 304 stainless steel vessels, 150-m 304 L stainless steel vessels, and 60-m perfluoroalkoxy (PFA) fluoropolymer resin vessels. The three glasses were the Environmental Assessment glass manufactured by Corning Incorporated and supplied by Westinghouse Savannah River company, and West Valley Nuclear Services reference glasses 5 and 6, manufactured and supplied by Catholic University of America. Within experimental error, no differences were found in durability test results using the 3 different glasses in the 304L stainless steel or PFA fluoropolymer resin vessels over the seven-day test period

  10. Anodized titanium and stainless steel in contact with CFRP: an electrochemical approach considering galvanic corrosion.

    Science.gov (United States)

    Mueller, Yves; Tognini, Roger; Mayer, Joerg; Virtanen, Sannakaisa

    2007-09-15

    The combination of different materials in an implant gives the opportunity to better fulfill the requirements that are needed to improve the healing process. However, using different materials increases the risk of galvanic coupling corrosion. In this study, coupling effects of gold-anodized titanium, stainless steel for biomedical applications, carbon fiber reinforced polyetheretherketone (CFRP), and CFRP containing tantalum fibers are investigated electrochemically and by long-term immersion experiments in simulated body fluid (SBF). Potentiodynamic polarization experiments (i/E curves) and electrochemical impedance spectroscopy (EIS) of the separated materials showed a passive behavior of the metallic samples. Anodized titanium showed no corrosion attacks, whereas stainless steel is highly susceptibility for localized corrosion. On the other side, an active dissolution behavior of both of the CFRPs in the given environment could be determined, leading to delaminating of the carbon fibers from the matrix. Long-term immersion experiments were carried out using a set-up especially developed to simulate coupling conditions of a point contact fixator system (PC-Fix) in a biological environment. Electrochemical data were acquired in situ during the whole immersion time. The results of the immersion experiments correlate with the findings of the electrochemical investigation. Localized corrosion attacks were found on stainless steel, whereas anodized titanium showed no corrosion attacks. No significant differences between the two CFRP types could be found. Galvanic coupling corrosion in combination with crevice conditions and possible corrosion mechanisms are discussed. Copyright 2007 Wiley Periodicals, Inc.

  11. The Influence of Porosity on Corrosion Attack of Austenitic Stainless Steel

    Science.gov (United States)

    Abdullah, Z.; Ismail, A.; Ahmad, S.

    2017-10-01

    Porous metals also known as metal foams is a metallic body having spaces orpores through which liquid or air may pass. Porous metals get an attention from researchers nowadays due to their unique combination of properties includes excellent mechanical and electrical, high energy absorption, good thermal and sound insulation and water and gas permeability. Porous metals have been applied in numerous applications such as in automotive, aerospace and also in biomedical applications. This research reveals the influence of corrosion attack in porous austenitic stainless steel 316L. The cyclic polarization potential analysis was performed on the porous austenitic stainless steel 316L in 3.5% NaCl solution. The morphology and the element presence on the samples before and after corrosion attack was examined using scanning electron microscopy (SEM) and energy dispersive x-ray (EDX) respectively to determine the corrosion mechanism structure. The cyclic polarization potential analysis showed the result of (E corr ) for porous austenitic stainless steel type 316L in the range of -0.40v to -0.60v and breakdown potential (E b ) is -0.3v to -0.4v in NaCl solution.

  12. Promising in vitro performances of a new nickel-free stainless steel.

    Science.gov (United States)

    Montanaro, Lucio; Cervellati, Marina; Campoccia, Davide; Arciola, Carla Renata

    2006-03-01

    Stainless steel is a metallic alloy largely employed in orthopaedics. However, the presence in its composition of a high quantity of nickel, an agent known to trigger toxic and allergic responses, is cause for concern. In this study, we have investigated the in vitro biocompatibility of a new nickel-reduced stainless steel, namely Böhler P558, in comparison to the conventional stainless steel AISI 316L. The neutral red (NR) uptake and the amido black (AB) tests were performed on L929 fibroblasts and MG63 osteoblasts to assess the cytotoxicity, while cytogenetic effects were evaluated on CHOK1 cells by studying the frequency of Sister Chromatid Exchanges (SCE) and chromosomal aberrations. Ames test was used to detect the mutagenic activity. The expression of selected markers typical of differentiated osteoblasts, such as alkaline phosphatase activity (ALP), type I collagen (CICP) and osteocalcin (OC) production, were also monitored in MG63 cells cultured on the tested materials. Our results indicate the absence of significant cytotoxicity and genotoxicity for both test alloys. ALP, CICP and OC analyses confirmed that both materials support the expression of these phenotypic markers. Overall, these data show that this Ni-free alloy possesses good in vitro biocompatibility and could have a potential for orthopaedic applications.

  13. Study of the Contact Resistance of Interlaced Stainless Steel Yarns Embedded in Hybrid Woven Fabrics

    Directory of Open Access Journals (Sweden)

    Vasile Simona

    2017-06-01

    Full Text Available The contact resistance of two interlacing electro-conductive yarns embedded in a hybrid woven fabric will constitute a problem for electro-conductive textiles under certain circumstances. A high contact resistance can induce hotspots, while a variable contact resistance may cause malfunctioning of the components that are interconnected by the electro-conductive yarns. Moreover, the contact robustness should be preserved over time and various treatments such as washing or abrading should not alter the functioning of the electro-conductive textiles. The electrical resistance developed in the contact point of two interlacing electro-conductive yarns is the result of various factors. The influence of diameter of the electro-conductive stainless steel yarns, the weave pattern, the weft density, and the abrasion on the contact resistance was investigated. Hybrid polyester fabrics were produced according to the design of experiments (DoE and statistical models were found that describe the variation of the contact resistance with the selected input parameters. It was concluded that the diameter of the stainless steel warp and weft yarns has a statistically significant influence on the contact resistance regardless of the weave. Weft density had a significant influence on the contact resistance but only in case of the twill fabrics. Abrasion led to an increase in contact resistance regardless of the weave pattern and the type of stainless steel yarn that was used. Finally, a combination of parameters that leads to plain and twill fabrics with low contact resistance and robust contacts is recommended.

  14. A morphological evaluation of a duplex stainless steel processed by high energy Ball Mill

    International Nuclear Information System (INIS)

    Yonekubo, Ariane Emi; Cintho, Osvaldo Mitsuyuki; Aguiar, Denilson Jose Marcolino de; Capocchi, Jose Deodoro Trani

    2009-01-01

    The duplex stainless steels are formed by a ferrite and austenite mixture, giving them a combination of properties. Commercially, these steels are hot rolled, developing an anisotropic, alternated ferrite and austenite elongated lamellae microstructure. In this work, a duplex stainless steel was produced by the mixture of elementary powders with the composition Fe-19.5Cr-5Ni processed in an ATTRITOR ball mill during periods up to 15 hours. The powders obtained were compressed in specimens and were heat treated in the temperatures of 900, 1050 and 1200 °C during 1 hour and analysed by x ray diffraction, optic microscopy, scanning electron microscopy and energy dispersion spectroscopy. An optimized microstructure with ultrafine, equiaxial and regular duplex microstructure was obtained in the 15 hour milling and 1200 °C heat treatment. Afterwards, a commercially super duplex stainless steel UNS S32520 was aged at 800 °C aiming the precipitation of σ phase in order to reduce its toughness and then, milled in SPEX mill. The resulting microstructure was a very fine duplex type with irregular grain boundary morphology duo to the grain growth barrier promoted by the renascent σ phase particles during sintering process. (author)

  15. Heat treatment temperature influence on ASTM A890 GR 6A super duplex stainless steel microstructure

    International Nuclear Information System (INIS)

    Martins, Marcelo; Casteletti, Luiz Carlos

    2005-01-01

    Duplex and super duplex stainless steels are ferrous alloys with up to 26% chromium, 8% nickel, 5% molybdenum and 0.3% nitrogen, which are largely used in applications in media containing ions from the halogen family, mainly the chloride ion (Cl - ). The emergence of this material aimed at substituting Copper-Nickel alloys (Cupro-Nickel) that despite presenting good corrosion resistance, has mechanical properties quite inferior to steel properties. The metallurgy of duplex and super duplex stainless steel is complex due to high sensitiveness to sigma phase precipitation that becomes apparent, due to the temperatures they are exposed on cooling from solidification as well as from heat treatment processes. The objective of this study was to verify the influence of heat treating temperatures on the microstructure and hardness of ASTM A890/A890M Gr 6A super duplex stainless steel type. Microstructure control is of extreme importance for castings, as the chemical composition and cooling during solidification inevitably provide conditions for precipitation of sigma phase. Higher hardness in these materials is directly associated to high sigma phase concentration in the microstructure, precipitated in the ferrite/austenite interface. While heat treatment temperature during solution treatment increases, the sigma phase content in the microstructure decreases and consequently, the material hardness diminishes. When the sigma phase was completely dissolved by the heat treatment, the material hardness was influenced only due to ferrite and austenite contents in the microstructure

  16. Corrosion behavior of a superduplex stainless steel in chloride aqueous solution

    Science.gov (United States)

    Dabalà, Manuele; Calliari, Irene; Variola, Alessandra

    2004-04-01

    Super duplex stainless steels (SDSS) have been widely used as structural materials for chemical plants (especially in those engaged in phosphoric acid production), in the hydrometallurgy industries, and as materials for offshore applications due to their excellent corrosion resistance in chloride environments, compared with other commercial types of ferritic stainless steels. These alloys also possess superior weldability and better mechanical properties than austenitic stainless steels. However, due to their two-phase structure, the nature of which is very dependent on their composition and thermal history, the behavior of SDSS regarding localized corrosion appears difficult to predict, especially in chloride environments. To improve their final properties, the effect of the partition of the alloying elements between the two phases, and the composition and microstructure of each phase are the key to understanding the localized corrosion phenomena of SDSS. This paper concerns the effects of the SDSS microstructure and heat treatment on the SDSS corrosion resistance in aqueous solutions, containing different amounts of NaCl at room temperature.

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

    Science.gov (United States)

    Soloveichik, Grigorii Lev

    2014-01-21

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

  18. Performance of high molybdenum superaustenitic stainless steel welds in harsh chloride environments

    International Nuclear Information System (INIS)

    Stenvall, P.; Liljas, M.; Wallen, B.

    1996-01-01

    Superaustenitic steels are normally welded with nickel-based alloys as filler materials. To clarify the understanding of weld behavior in superaustenitic stainless steels this paper presents the development history of 6Mo and 7Mo steels, and results of laboratory tests and field tests on welds of UNS S31254 (6Mo) and UNS S32654 (7 Mo) in different types of chloride containing environments. The laboratory tests consisted of the well known ferric chloride test (ASTM G 48 Method A). Shielded metal arc welds, gas tungsten arc welds and submerged arc welds in both grades were tested. The critical pitting temperatures were determined and the locations of the attack were noted. Some specimens were sectioned at the position of the attack followed by studies using light optical microscopy. The critical pitting temperatures of the welds in S31254 and S32654 were at normal levels for both grades, i.e., 40--50 C for S31254 and 60--75 C for S32654. The locations of the attack differed depending on the welding process. In shielded metal arc welds the attack was mostly located in the weld metal. In gas tungsten arc welds the attack was predominantly located next to the fusion line. The field tests showed that the behavior of welds and parent metal of superaustenitic stainless steels, as well as of nickel-based alloys, is much dependent on the corrosive environment. In oxidizing chloride solutions, similar results to those of the ferric chloride test, are observed. However, crevice corrosion in the parent material is at a greater risk than pitting corrosion in the welds. In very oxidizing solutions of low chloride concentrations, welds made of nickel-based fillers may corrode faster than the stainless steel base metal due to transpassive uniform corrosion. The opposite situation exists when active uniform corrosion prevails, i.e., welds made of nickel-based fillers corrode less than the stainless steel parent material

  19. UNS S31603 Stainless Steel Tungsten Inert Gas Welds Made with Microparticle and Nanoparticle Oxides

    Directory of Open Access Journals (Sweden)

    Kuang-Hung Tseng

    2014-06-01

    Full Text Available The purpose of this study was to investigate the difference between tungsten inert gas (TIG welding of austenitic stainless steel assisted by microparticle oxides and that assisted by nanoparticle oxides. SiO2 and Al2O3 were used to investigate the effects of the thermal stability and the particle size of the activated compounds on the surface appearance, geometric shape, angular distortion, delta ferrite content and Vickers hardness of the UNS S31603 stainless steel TIG weld. The results show that the use of SiO2 leads to a satisfactory surface appearance compared to that of the TIG weld made with Al2O3. The surface appearance of the TIG weld made with nanoparticle oxide has less flux slag compared with the one made with microparticle oxide of the same type. Compared with microparticle SiO2, the TIG welding with nanoparticle SiO2 has the potential benefits of high joint penetration and less angular distortion in the resulting weldment. The TIG welding with nanoparticle Al2O3 does not result in a significant increase in the penetration or reduction of distortion. The TIG welding with microparticle or nanoparticle SiO2 uses a heat source with higher power density, resulting in a higher ferrite content and hardness of the stainless steel weld metal. In contrast, microparticle or nanoparticle Al2O3 results in no significant difference in metallurgical properties compared to that of the C-TIG weld metal. Compared with oxide particle size, the thermal stability of the oxide plays a significant role in enhancing the joint penetration capability of the weld, for the UNS S31603 stainless steel TIG welds made with activated oxides.

  20. UNS S31603 Stainless Steel Tungsten Inert Gas Welds Made with Microparticle and Nanoparticle Oxides.

    Science.gov (United States)

    Tseng, Kuang-Hung; Lin, Po-Yu

    2014-06-20

    The purpose of this study was to investigate the difference between tungsten inert gas (TIG) welding of austenitic stainless steel assisted by microparticle oxides and that assisted by nanoparticle oxides. SiO₂ and Al₂O₃ were used to investigate the effects of the thermal stability and the particle size of the activated compounds on the surface appearance, geometric shape, angular distortion, delta ferrite content and Vickers hardness of the UNS S31603 stainless steel TIG weld. The results show that the use of SiO₂ leads to a satisfactory surface appearance compared to that of the TIG weld made with Al₂O₃. The surface appearance of the TIG weld made with nanoparticle oxide has less flux slag compared with the one made with microparticle oxide of the same type. Compared with microparticle SiO₂, the TIG welding with nanoparticle SiO₂ has the potential benefits of high joint penetration and less angular distortion in the resulting weldment. The TIG welding with nanoparticle Al₂O₃ does not result in a significant increase in the penetration or reduction of distortion. The TIG welding with microparticle or nanoparticle SiO₂ uses a heat source with higher power density, resulting in a higher ferrite content and hardness of the stainless steel weld metal. In contrast, microparticle or nanoparticle Al₂O₃ results in no significant difference in metallurgical properties compared to that of the C-TIG weld metal. Compared with oxide particle size, the thermal stability of the oxide plays a significant role in enhancing the joint penetration capability of the weld, for the UNS S31603 stainless steel TIG welds made with activated oxides.

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

    Science.gov (United States)

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

    2009-08-01

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

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

    DEFF Research Database (Denmark)

    Christiansen, Thomas; Somers, Marcel A. J.

    2006-01-01

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

  3. Strengthening of stainless steel weldment by high temperature precipitation

    Directory of Open Access Journals (Sweden)

    Sergio Neves Monteiro

    2017-10-01

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

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

    International Nuclear Information System (INIS)

    1994-01-01

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

  5. Stress-Corrosion Cracking in Martensitic PH Stainless Steels

    Science.gov (United States)

    Humphries, T.; Nelson, E.

    1984-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Oladayo OLANIRAN

    2015-05-01

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

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

    International Nuclear Information System (INIS)

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

    2000-01-01

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

  8. Reactor Materials Program - Baseline Material Property Handbook - Mechanical Properties of 1950's Vintage Stainless Steel Weldment Components, Task Number 89-23-A-1

    Energy Technology Data Exchange (ETDEWEB)

    Stoner, K.J.

    1999-11-05

    The Process Water System (primary coolant) piping of the nuclear production reactors constructed in the 1950''s at Savannah River Site is comprised primarily of Type 304 stainless steel with Type 308 stainless steel weld filler. A program to measure the mechanical properties of archival PWS piping and weld materials (having approximately six years of service at temperatures between 25 and 100 degrees C) has been completed. The results from the mechanical testing has been synthesized to provide a mechanical properties database for structural analyses of the SRS piping.

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

    OpenAIRE

    Enerhaug, Jakob

    2002-01-01

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

  10. Optimization of electrical conduction and passivity properties of stainless steels used for PEM fuel cell bipolar plates; Opmisation des proprietes de conduction electrique et de passivite d'aciers inoxydables pour la realisation de plaques bipolaires de pile a combustible de type PEMFC

    Energy Technology Data Exchange (ETDEWEB)

    Andre, J

    2007-10-15

    Among the new technologies for energy for sustainable development, PEMFC (proton exchange membrane fuel cells) offer seducing aspects. However, in order to make this technology fit large scale application requirements, it has to comply with stringent cost, performance, and durability criteria. In such a frame, the goal of this work was to optimize electrical conduction properties and passivity of stainless steels for the conception of PEMFC bipolar plates, used instead of graphite, the reference material. This work presents the possible ways of performance loss when using stainless steels and some methods to solve this problem. Passive film properties were studied, as well as their modifications by low cost industrial surface treatments, without deposition. Ex situ characterizations of corrosion resistance and electrical conduction were performed. Electrochemical impedance spectroscopy, water analysis, surface analysis by microscopy and photoelectron spectroscopy allowed to study the impact of ageing on two alloys in different states, and several conditions representative of an exposure to PEMFC media. Correlations between semi-conductivity properties, composition, and structure of passive layers were considered, but not leading to clear identification of all parameters responsible for electrical conduction and passivity. The plate industrial state is not convenient for direct use in fuel cell to comply with durability and performance requirements. A surface modification studied improves widely electrical conduction at initial state. The performance is degraded with ageing, but maintaining a level higher than the initial industrial state. This treatment increases also corrosion resistance, particularly on the anode side. (author)

  11. Fatigue damage in coarse-grained lean duplex stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    Strubbia, R., E-mail: strubbia@ifir-conicet.gov.ar; Hereñú, S.; Marinelli, M.C.; Alvarez-Armas, I.

    2016-04-06

    The present investigation is focused on assessing the effect of a thermal treatment for grain coarsening on the low cycle fatigue damage evolution in two types of Lean Duplex Stainless Steels (LDSSs). The dislocation structure developed during cycling is observed by transmission electron microscopy (TEM). Additionally, a detailed analysis of short crack initiated and grown during low cycle fatigue (LCF) is performed by means of optical and scanning electron (SEM) microscopy in combination with automated electron back-scattered diffraction (EBSD) technique. Though in both coarse-grained LDSSs the short cracks nucleate in the ferrite phase, in each steels its origin is different. The embrittlement caused by the Cr{sub 2}N precipitation and the plastic activity sustained by each phase can explain this difference. The propagation behavior of the short cracks present two alternative growing mechanisms: the crack grows along a favorable slip plane with high Schmid Factor (SF) or the crack alternates between two slip systems. In both cases, the crack follows the path with the smallest tilt angle (β) at a grain boundary.

  12. Embrittlement in CN3MN Grade Superaustenitic Stainless Steels

    Science.gov (United States)

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

    2014-05-01

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

  13. Blister formation in multiple energy He+ implanted stainless steel

    International Nuclear Information System (INIS)

    Wilson, K.L.; Haggmark, L.G.; Langley, R.A.

    1976-12-01

    A series of multiple energy He + implantations has been conducted on type 316 stainless steel at 575 and 775 K. Pre-implantations with 3, 10 and 15 keV He + were used to create a series of uniform helium concentrations to a depth of approximately 700 A. The effects of these pre-implantation helium concentrations on subsequent 20 keV bombardment were studied by gas re-emission and scanning electron microscopy. If was found that serious blistering and exfoliation would occur unless the pre-implantation helium concentration was approximately greater than 0.3 atom fraction from the surface to nearly the depth of the 20 keV implant. At this pre-implant level, an interconnected pathway to the surface developed, allowing helium release without surface blistering. Evidence for rapid helium mobility along the interconnection was found at temperatures as low as 80K. These results indicate that multiple energy implantation will still produce extensive surface deformation if the helium accumulates to a local critical concentration before an interconnected pathway develops. Until detailed first wall particle fluxes are available, He + induced surface exfoliation cannot be ruled out as a potentially serious source of wall erosion and plasma contamination in a MFE reactor

  14. Neutron irradiation effect of thermally-sensitized stainless steels

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-03-01

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

  15. Effects of alloying elements on toughness of Fe-Cr-Al stainless steels. Fe-Cr-Al kei stainless ko no jinsei ni oyobosu gokin genso no eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Yamasaki, K.; Osaki, K.; Kawa, Y. (Nisshin Steel Co. Ltd., Tokyo (Japan))

    1990-06-29

    Fe-Cr-Al stainless steels are widely used as heat resistant materials or electric heating materials, but their toughness is low. The cause of decreasing the toughness is impure elements in them. This paper shows the results of the investigation on the effects of alloying elements on the toughness of Fe-Cr-Al stainless steels. The toughness was improved by decreasing the C content to less than 100 ppm. Deterioration of toughness was mainly by thin-film type precipitates of M {sub 23} C {sub 6} at the grain boundaries, as well as by block type precipitates of AIN inside the grains. The toughness of steels containing about 100ppm C was deteriorated by the addition of Ti and Nb. The authors consider that this may be due to the fact of Ti and Nb precipitation inside the grains. An improvement in toughness while decreasing the C content was achieved by lowering the amounts of precipitates at the grain boundaries. 28 refs., 13 figs., 1 tab.

  16. Effect of current and travel speed variation of TIG welding on microstructure and hardness of stainless steel SS 316L

    Science.gov (United States)

    Jatimurti, Wikan; Abdillah, Fakhri Aulia; Kurniawan, Budi Agung; Rochiem, Rochman

    2018-04-01

    One of the stainless steel types that widely used in industry is SS 316L, which is austenitic stainless steel. One of the welding methods to join stainless steel is Tungsten Inert Gas (TIG), which can affect its morphology, microstructure, strength, hardness, and even lead to cracks in the weld area due to the given heat input. This research has a purpose of analyzing the relationship between microstructure and hardness value of SS 316L stainless steel after TIG welding with the variation of current and travel speed. The macro observation shows a distinct difference in the weld metal and base metal area, and the weld form is not symmetrical. The metallographic test shows the phases that formed in the specimen are austenite and ferrite, which scattered in three welding areas. The hardness test showed that the highest hardness value found in the variation of travel speed 12 cm/min with current 100 A. Welding process and variation were given do not cause any defects in the microstructure, such as carbide precipitation and sigma phase, means that it does not affect the hardness and corrosion resistance of all welded specimen.

  17. [Studies on the recovery of pharmaceutical drug substances from surfaces made of defined stainless-steel alloys].

    Science.gov (United States)

    Kloss, S; Müller, U; Oelschläger, H

    2005-09-01

    Facilities for the manufacturing of pharmaceutical drug substances on the pilot-plant and the industrial scale as well as chemical reactors and vessels used for chemical work-up mainly consist of alloyed stainless steel. The influence of the alloy composition and the surface condition, i.e. of the roughness of the stainless-steel materials, on the adsorption of structurally diverse steroidal substances and, hence, on the quality of the products was studied. In general, stainless-steel alloys with smooth, not so rough surfaces are to be favored as reactor material. However, it was demonstrated in this study that, on account of the weak interaction between active substances and steel materials, mechanically polished materials of a medium roughness up to approx. 0.4 microm can be employed instead of the considerably more cost-intensive electrochemically polished stainless-steel surfaces. The type of surface finishing up to a defined roughness, then, has no influence on the quality of these pharmaceutical products. Substances that, because of their molecular structure, can function as "anions" in the presence of polar solvents, are adsorbed on very smooth surfaces prepared by electrochemical methods, forming an amorphous surface film. For substances with this structural characteristics, the lower-cost mechanically polished reactor materials of a medium roughness up to approx. 0.5 microm should be used exclusively.

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

    OpenAIRE

    Prabhu Paulraj; Rajnish Garg

    2015-01-01

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

  19. Effect of triple ion beam irradiation on mechanical properties of high chromium austenitic stainless steel

    International Nuclear Information System (INIS)

    Ioka, Ikuo; Futakawa, Masatoshi; Nanjyo, Yoshiyasu; Kiuchi, Kiyoshi; Anegawa, Takefumi

    2003-01-01

    A high-chromium austenitic stainless steel has been developed for an advanced fuel cladding tube considering waterside corrosion and irradiation embrittlement. The candidate material was irradiated in triple ion (Ni, He, H) beam modes at 573 K up to 50 dpa to simulate irradiation damage by neutron and transmutation product. The change in hardness of the very shallow surface layer of the irradiated specimen was estimated from the slope of load/depth-depth curve which is in direct proportion to the apparent hardness of the specimen. Besides, the Swift's power low constitutive equation (σ=A(ε 0 + ε) n , A: strength coefficient, ε 0 : equivalent strain by cold rolling, n: strain hardening exponent) of the damaged parts was derived from the indentation test combined with an inverse analysis using a finite element method (FEM). For comparison, Type304 stainless steel was investigated as well. Though both Type304SS and candidate material were also hardened by ion irradiation, the increase in apparent hardness of the candidate material was smaller than that of Type304SS. The yield stress and uniform elongation were estimated from the calculated constitutive equation by FEM inverse analysis. The irradiation hardening of the candidate material by irradiation can be expected to be lower than that of Type304SS. (author)

  20. Martensite transformation in antimony implanted stainless steel

    International Nuclear Information System (INIS)

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

    1981-01-01

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

  1. Austenitic stainless steel for high temperature applications

    International Nuclear Information System (INIS)

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

    1985-01-01

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

  2. Plasticity of low carbon stainless steels

    International Nuclear Information System (INIS)

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

    1975-01-01

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

  3. New Economical 19Cr Duplex Stainless Steels

    Science.gov (United States)

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

    2012-02-01

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

  4. Corrosion behaviour of sintered duplex stainless steels

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-07-01

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

  5. On the Stress Corrosion Cracking and Hydrogen Embrittlement Behavior of Austenitic Stainless Steels in Boiling Saturated Magnesium Chloride Solutions

    Directory of Open Access Journals (Sweden)

    Osama M. Alyousif

    2012-01-01

    Full Text Available The stress corrosion cracking (SCC and hydrogen embrittlement (HE behaviors for types 304, 310, and 316 austenitic stainless steels were investigated in boiling saturated magnesium chloride solutions using a constant load method under different conditions including test temperature, applied stress, and sensitization. Both of type 304 and type 316 stainless steels showed quite similar behavior characteristics, whereas type 310 stainless steel showed a different behavior. The time to failure (tf parameter was used among other parameters to characterize the materials behavior in the test solution and to develop a mathematical model for predicting the time to failure in the chloride solution. The combination of corrosion curve parameters and fracture surface micrographs gave some explanation for the cracking modes as well as an indication for the cracking mechanisms. On the basis of the results obtained, it was estimated that intergranular cracking was resulted from hydrogen embrittlement due to strain-induced formation of martensite along the grain boundaries, while transgranular cracking took place by propagating cracks nucleated at slip steps by dissolution.

  6. Fatigue life prediction for a cold worked T316 stainless steel

    International Nuclear Information System (INIS)

    Manjoine, M.J.

    1983-01-01

    Permanent damage curves of initiation-life and propagation-life which predict the fatigue life of specimens of a cold-worked type 316 stainless steel under complex strain-range histories were generated by a limited test program. Analysis of the test data showed that fatigue damage is not linear throughout life and that propagation life is longer than initiation-life at high strain ranges but is shorter at low strain ranges. If permanent damage has been initiated by prior history and/or fabrication, propagation to a given life can occur at a lower strain range than that estimated from the fatigue curves for constant CSR. (author) [pt

  7. Influence of neutron irradiation at 550C on the properties of austenitic stainless steels

    International Nuclear Information System (INIS)

    Wiffen, F.W.; Maziasz, P.J.

    1981-01-01

    Types 316 and 316 + 0.23 wt % Ti stainless steels and 16-8-2 weldment were irradiated in HFIR at 55 0 C to fluences up to 1.35 x 10 26 neutrons/m 2 ( 0 C strength properties, with the weldments the weakest of the materials. The ductility of all materials was reduced by the irradiation, the uniform elongation to only 0.4% in the cold-worked material. Tests at temperatures above the irradiation temperature showed an approach to unirradiated properties as the temperature was increased from 200 to 600 0 C. Helium embrittlement at 700 0 C severely reduced elongation

  8. Electrochemical and crystallographic aspects of the corrosion of austenitic stainless steels in concentrated hot soda solutions

    International Nuclear Information System (INIS)

    Santarini, G.; Boos, J.Y.

    1976-01-01

    Some electrochemical and crystallographic aspects of stainless steel corrosion in concentrated hot soda are presented. Caustic cracking appears when the metallic surface presents an active behavior as immerged; the initial activity induces a selective dissolution of iron and chromium, and appearance of a pure nickel layer, which, by galvanic coupling, displaces the underlying surface potential towards a pseudo-passivity area; pseudo-passivity is due to the formation of a mixed oxide of the NaMO 2 type, which requires a revision of the thermodynamics bases of the alkaline corrosion interpretations. The crystallographic aspects of the mixed oxide growth enables a better understanding of the stress corrosion mechanisms [fr

  9. A Plasma Control and Gas Protection System for Laser Welding of Stainless Steel

    DEFF Research Database (Denmark)

    Juhl, Thomas Winther; Olsen, Flemming Ove

    1997-01-01

    stability and protection against oxidation. Also oxidation related to special conditions at the starting edge has been investigated. The interaction between coaxial and plasma gas flow show that the coaxial flow widens the band in which the plasma gas flow suppresses the metal plasma. In this band the welds......A prototype shield gas box with different plasma control nozzles have been investigated for laser welding of stainless steel (AISI 316). Different gases for plasma control and gas protection of the weld seam have been used. The gas types, welding speed and gas flows show the impact on process...

  10. Plasma Control and Gas Protection System for Laser Welding of Stainless Steel

    DEFF Research Database (Denmark)

    Juhl, Thomas Winther; Olsen, Flemming Ove; Petersen, Kaj

    1997-01-01

    stability and protection against oxidation. Also oxidation related to special conditions at the starting edge has been investigated. The interaction between coaxial and plasma gas flow show that the coaxial flow widens the band in which the plasma gas flow suppresses the metal plasma. In this band the welds......An integrated plasma nozzle and a shield gas box have been investigated for laser welding of 2 mm stainless steel sheets. Different gases for plasma control and gas protection of the weld seam have been used. The gas types, welding speed and coaxial and plasma flow show the impact on process...

  11. Carbon coated stainless steel as counter electrode for dye sensitized solar cells

    Science.gov (United States)

    Prakash, Shejale Kiran; Sharma, Rakesh K.; Roy, Mahesh S.; Kumar, Mahesh

    2014-10-01

    A new type of counter electrode for dye sensitized solar cells has been fabricated using a stainless steel sheet as substrate and graphite, graphene and multiwall carbon nanotubes as the catalytic material which applied by screen printing technique. The sheet resistances of the substrates and there influence on the dye sensitized solar cells has been studied. The fabricated counter electrodes i.e. SS-graphite, SS-graphene SS-MWCNT and SS-platinum were tested for their photovoltaic response in the form of dye sensitized solar cells.

  12. Internal oxidation and probabilistic fracture model of irradiation assisted stress corrosion cracking in stainless steels

    Science.gov (United States)

    Konstantinović, M. J.

    2017-11-01

    A probabilistic fracture model is applied to irradiation assisted stress corrosion cracking effect, assuming that the oxidized part of stainless steel sample plays an essential role in the crack initiation, propagation and the sample failure. The Weibull statistical distribution of time-to-failures, estimated through the correlation with the statistical distribution of oxide strengths, including both the surface oxide layer and oxidized grain boundaries, fully describe the experimental scatter obtained in the constant load time-to-failure tests. Large failure uncertainties in these type of tests originate from an intrinsic stochastic behavior of the oxide cracking due to subcritical crack propagation process.

  13. The effects of a common stainless steel orthodontic bracket on the diagnostic quality of cranial and cervical 3T- MR images: a prospective, case-control study.

    Science.gov (United States)

    Cassetta, Michele; Pranno, Nicola; Stasolla, Alessandro; Orsogna, Nicola; Fierro, Davide; Cavallini, Costanza; Cantisani, Vito

    2017-08-01

    To evaluate the effect of orthodontic stainless steel brackets and two different types of archwires on the diagnostic quality of 3-T MR images. This prospective, case-control study was conducted following Strengthening the Reporting of Observational Studies in Epidemiology guidelines. The recruitment was conducted among orthodontic patients. 80 subjects, requiring MRI for the presence of temporomandibular disorders, were enrolled and divided into four groups: 20 patients using aligners (control group); 20 patients with stainless steel brackets without archwires; 20 patients with stainless steel brackets and nickel-titanium archwires; and 20 patients with stainless steel brackets and stainless steel archwires. Two experts in neuroradiology evaluated the images to determine the amount of distortion in 6 regions and 48 districts. A score was subjectively assigned according to a modified receiver operating characteristic method of distortion classification. Any disagreement was resolved through consensus seeking; when this was not possible, a third neuroradiologist was consulted. The following statistical methods were used: descriptive statistics, Cohen's kappa coefficient (k), Kruskal-Wallis test, pairwise comparisons using the Dunn-Bonferroni approach. The significance was set at p ≤ 0.05. The presence of stainless steel brackets with or without archwires negatively influenced MRI of the cervical region, paranasal sinuses, head and neck region, and cervical vertebrae but did not influence MRI of brain and temporomandibular joint regions. Patients with a stainless steel multibracket orthodontic appliance should remove it before cervical vertebrae, cervical region, paranasal sinuses, and head and neck MRI scans. The brain and temporomandibular joint region MRI should not require the removal of such appliances.

  14. Refining technology for the recycling of stainless steel radioactive scrap metals, FY 94 bi-annual report

    International Nuclear Information System (INIS)

    Mizia, R.E.; Atteridge, D.G.; Buckentin, J.; Carter, J.; Davis, H.L.; Devletian, J.H.; Scholl, M.R.; Turpin, R.B.; Webster, S.L.

    1994-08-01

    The research addressed under this project is the recycling of metallic nuclear-related by-product materials under the direction of Westinghouse Idaho Nuclear Company (WINCO). The program addresses the recycling of radioactive scrap metals (RSM) for beneficial re-use within the DOE complex; in particular, this program addresses the recycling of stainless steel RSM. It is anticipated that various stainless steel components under WINCO control at the Idaho Falls Engineering Laboratory (INEL), such as fuel pool criticality barriers and fuel storage racks will begin to be recycled in FY94-95. The end product of this recycling effort is expected to be waste and overpack canisters for densified high level waste for the Idaho Waste Immobilization Facility and/or the Universal Canister System for dry (interim) storage of spent fuel. The specific components of this problem area that are presently being, or have been, addressed by CAAMSEC are: (1) the melting/remelting of stainless steel RSM into billet form; (2) the melting/remelting initial research focus will be on the use of radioactive surrogates to study; (3) the cost effectiveness of RSM processing oriented towards privatization of RSM reuse and/or resale. Other components of this problem that may be addressed under program extension are: (4) the melting/remelting of carbon steel; (5) the processing of billet material into product form which shall meet all applicable ASTM requirements; and, (6) the fabrication of an actual prototypical product; the present concept of an end product is a low carbon Type 304/316 stainless steel cylindrical container for densified and/or vitrified high level radioactive waste and/or the Universal Canister System for dry (interim) storage of spent fuel. The specific work reported herein covers the melting/remelting of stainless steel open-quotes scrapclose quotes metal into billet form and the study of surrogate material removal effectiveness by various remelting techniques

  15. Simulasi Proses Deep Drawing Pelat Jenis Stainless Steel 304 Dengan Menggunakan Software Abaqus 6.9-3

    OpenAIRE

    Winarso, Sudi

    2015-01-01

    In the manufacturing process can not be separated from a loss defects such as wrinkles (wringkling), depletion (ironing), and break (fracture). Among the factors that influence the occurrence of the defect is material factor is the mechanical properties (plasticity). This simulation aims to determine the nature of the material plasticity. The simulation is performed using the software Abaqus 6.9-3. Type of material used is Stainless Steel 304 with a thickness of 1mm, and then determining the ...

  16. Performance improvement in direct methanol fuel cells using a highly porous corrosion-resisting stainless steel flow field

    OpenAIRE

    Shudo, Toshio; Suzuki, Kensuke

    2008-01-01

    Power generation with direct methanol fuel cell (DMFC) systems require only simple equipment, and has the important advantages of using a liquid fuel with higher energy density and easier handling characteristics than hydrogen. However, the power output of DMFC is lower than hydrogen fuel cells. To improve the power output of DMFC it is very important to reduce diffusion polarization at higher current density conditions. This research used a corrosion-resisting type porous stainless steel dev...

  17. Effect of acetic acid on corrosion behavior of AISI 201, 304 and 430 stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    Vashishtha, Himanshu; Taiwade, Ravindra V.; Sharma, Sumitra [Visvesvaraya National Institute of Technology (VNIT), Nagpur (India). Dept. of Metallurgical and Materials Engineering

    2017-05-15

    Austenitic stainless steels are often used to handle organic acids such as acetic acid (CH{sub 3}COOH), which are extensively used in food contact applications and chemical industries for manufacturing medicines, nutrition and various chemical amalgams. In the present investigation an attempt has been made to compare the corrosion behavior of Cr-Ni (AISI type 304), Cr-Mn-Ni (type 201) and Cr (type 430) stainless steel for economical replacement of higher cost Cr-Ni grade. Immersion testing was performed at room temperature and boiling temperature in acetic acid. Atomic absorption spectroscopy was carried out to evaluate metal ion concentration in the immersion solution. The surface morphology of pit formation was characterized using scanning electron microscopy coupled with energy dispersive X-ray spectroscopy. The effect of elemental leaching on electrical conductivity of the immersion solution was evaluated and correlated with pH measurements. A new mechanism has been proposed for the pit formation due to manganese sulfide inclusions. The replacement compatibility was further confirmed with anodic polarization testing and a successful replacement was established for room temperature applications.

  18. Stress corrosion cracking behavior of weldments of ferritic stainless steels in high temperature pure water

    International Nuclear Information System (INIS)

    Fujiwara, Kazuo; Tomari, Haruo; Shimogori, Kazutoshi

    1985-01-01

    Considering the application of a ferritic stainless steel as heat exchanger tubing for a moisture separator reheater of light water reactors, stress corrosion cracking behavior at the weldment of commercial ferritic stainless steels in high temperature pure water was studied. Double U-bend method was used for the study and the relationship with microstructure was discussed. Welded joint of Type 439SS containing 0.021% C, 0.025% N and 0.27% Ti with In-82 type filler metal was susceptible to intergranular stress corrosion cracking if a tight crevice was provided by inserting a teflon sheet between the inner and outer specimens of double U-bend. This was attributable to the formation of chromium depleted zone due to the precipitation of chromium carbides/nitrides along ferrite grain boundaries. On the other hand welded joint of Type 444SS with 0.007% C, 0.010% N and 0.26% Nb was immune to stress corrosion cracking, and this might be attributed to the higher ratio of Nb/(C+N) content. (author)

  19. Investigations of Localized Corrosion of Stainless Steel after Exposure to Supercritical CO2

    Energy Technology Data Exchange (ETDEWEB)

    M. Ziomek-Moroz; W. O’Connor; S. Bullard

    2012-03-11

    Severe localized corrosion of a 316 stainless steel autoclave occurred during investigating Type H Portland cement stability in 0.16 M CaCl{sub 2} + 0.02 M MgCl{sub 2} + 0.82 M NaCl brine in contact with supercritical CO{sub 2} containing 4% O{sub 2}. The system operated at 85 C and pressure of 29 MPa. However, no corrosion was observed in the same type of autoclave being exposed to the same environment, containing Type H Portland cement cylindrical samples, also operating at pressure of 29 MPa but at 50 C. The operation time for the 85 C autoclave was 53 days (1272 hours) while that for the 50 C autoclave was 66 days (1584 hours). Debris were collected from the base of both autoclaves and analyzed by X-ray diffraction (XRD). Corrosion products were only found in the debris from the 85 C autoclave. The cement samples were analyzed before and after the exposure by X-ray florescence (XRF) methods. Optical microscopy was used to estimate an extent of the 316 stainless steel corrosion degradation.

  20. In vitro corrosion behavior of bioceramic, metallic, and bioceramic-metallic coated stainless steel dental implants.

    Science.gov (United States)

    Fathi, M H; Salehi, M; Saatchi, A; Mortazavi, V; Moosavi, S B

    2003-05-01

    The most common metals and alloys used in dentistry may be exposed to a process of corrosion in vivo that make them cytotoxic. The biocompatibility of dental alloys is primarily related to their corrosion behavior. The aim of this work was to evaluate the corrosion behavior and thus the biocompatibility of the uncoated and coated stainless steels and compare the effect of type of coatings on corrosion behavior. Three types of coatings, hydroxyapatite (HA), titanium (Ti), and a double-layer HA/Ti on AISI 316L stainless steel were made. HA coating was produced using plasma-spraying technique and Ti coating was made using physical vapor deposition process. In order to perform a novel double-layer composite coating, a top layer of HA was plasma-sprayed over a physical vapor deposited Ti layer on AISI 316L stainless steel. Structural characterization techniques including XRD, SEM and EDX were used to investigate the microstructure, morphology and crystallinity of the coatings. Electrochemical potentiodynamic tests were performed in physiological solutions in order to determine and compare the corrosion behavior of the coated and uncoated specimens as an indication of biocompatibility. Double-layer HA/Ti coating on AISI 316L SS had a positive effect on improvement of corrosion behavior. The decrease in corrosion current densities was significant for these coated specimens and was much lower than the values obtained for uncoated and single HA coated specimens. Ti coating on AISI 316L SS also has a beneficial effect on corrosion behavior. The results were compared with the results of corrosion behavior of HA coated commercially pure titanium (cpTi) and uncoated cpTi. These results demonstrated that the double-layer HA/Ti coated 316L SS can be used as an endodontic implant and two goals including improvement of corrosion resistance and bone osteointegration can be obtained simultaneously.