Effect of nickel equivalent on hydrogen gas embrittlement of austenitic stainless steels based on type 316 at low temperatures

2008 ◽  
Vol 56 (14) ◽  
pp. 3414-3421 ◽  
Author(s):  
Lin Zhang ◽  
Mao Wen ◽  
Masaaki Imade ◽  
Seiji Fukuyama ◽  
Kiyoshi Yokogawa
Keyword(s):  
Stainless Steels ◽  
Low Temperatures ◽  
Austenitic Stainless Steels ◽  
Hydrogen Gas ◽  
Nickel Equivalent

Effects of External and Internal Hydrogen on Tensile Properties of Austenitic Stainless Steels Containing Additive Elements

2015 ◽  
Author(s):  
Hisatake Itoga ◽  
Hisao Matsunaga ◽  
Junichiro Yamabe ◽  
Saburo Matsuoka
Keyword(s):  
Stainless Steels ◽  
Room Temperature ◽  
Austenitic Stainless Steels ◽  
Hydrogen Gas ◽  
Nitrogen Gas ◽  
Material Compatibility ◽  
Internal Hydrogen ◽  
The Stability ◽  
Reduction Of Area ◽  
Nickel Equivalent

Effect of hydrogen on the slow strain rate tensile (SSRT) properties of five types of austenitic stainless steels, which contain small amounts of additive elements (e.g., nitrogen, niobium, vanadium and titanium), was studied. Some specimens were charged by exposing them to 100 MPa hydrogen gas at 543 K for 200 hours. The SSRT tests were carried out under various combinations of specimens and test atmospheres as follows: (i) non-charged specimens tested in air at room temperature (RT), (ii) non-charged specimens tested in 0.1 MPa nitrogen gas at 193 K, (iii) hydrogen-charged specimens tested in air at RT, (iv) hydrogen-charged specimens tested in 0.1 MPa nitrogen gas at 193 K, and (v) non-charged specimens tested in 115 MPa hydrogen gas at RT. In the tests without hydrogen (i.e., cases (i) and (ii)), the reduction of area (RA) was nearly constant in all the materials, regardless of test temperature. In contrast, in the tests of internal hydrogen (cases (iii) and (iv)), RA was much smaller at 193 K than at RT in all the materials. It was revealed that the susceptibility of the materials to hydrogen embrittlement (HE) can successfully be estimated in terms of the nickel equivalent, which represents the stability of austenite phase. The result suggested that the nickel equivalent can be used for evaluating the material compatibility of austenitic stainless steels for hydrogen service.

Abnormal effect of nitrogen on hydrogen gas embrittlement of austenitic stainless steels at low temperatures

2016 ◽  
Vol 41 (31) ◽  
pp. 13777-13785 ◽  
Author(s):  
Chengshuang Zhou ◽  
Yuanjian Hong ◽  
Lin Zhang ◽  
Bai An ◽  
Jinyang Zheng ◽  
...  
Keyword(s):  
Stainless Steels ◽  
Low Temperatures ◽  
Austenitic Stainless Steels ◽  
Hydrogen Gas ◽  
Abnormal Effect

Development of New Material Testing Apparatus in High-Pressure Hydrogen and Evaluation of Hydrogen Gas Embrittlement of Metals

2007 ◽  
Author(s):  
Seiji Fukuyama ◽  
Masaaki Imade ◽  
Kiyoshi Yokogawa
Keyword(s):  
High Pressure ◽  
Stainless Steels ◽  
Pressure Vessel ◽  
Austenitic Stainless Steels ◽  
Material Testing ◽  
Hydrogen Gas ◽  
Stage Ii ◽  
Fuel Cell Vehicle ◽  
Stage Iii ◽  
Pressure Hydrogen

A new type of apparatus for material testing in high-pressure gas of up to 100 MPa was developed. The apparatus consists of a pressure vessel and a high-pressure control system that applies the controlled pressure to the pressure vessel. A piston is installed inside a cylinder in the pressure vessel, and a specimen is connected to the lower part of the piston. The load is caused by the pressure difference between the upper room and the lower room separated by the piston, which can be controlled to a loading mode by the pressure valves of the high-pressure system supplying gas to the vessel. Hydrogen gas embrittlement (HGE) and internal reversible hydrogen embrittlement (IRHE) of austenitic stainless steels and iron- and nickel-based superalloys used for high-pressure hydrogen storage of fuel cell vehicle were evaluated by conducting tensile tests in 70 MPa hydrogen. Although the HGE of these metals depended on modified Ni equivalent, the IRHE did not. The HGE of austenitic stainless steels was larger than their IRHE; however, the HGE of superalloys was not always larger than their IRHE. The effects of the chemical composition and metallic structure of these materials on the HGE and IRHE were discussed. The HGE of austenitic stainless steels was examined in 105 MPa hydrogen. The following were identified; SUS304: HGE in stage II, solution-annealed SUS316: HGE in stage III, sensitized SUS316: HGE in stage II, SUS316L: HGE in FS, SUS316LN: HGE in stage III and SUS310S: no HGE.

Influence of low temperature prestrain on hydrogen gas embrittlement of metastable austenitic stainless steels

2013 ◽  
Vol 38 (25) ◽  
pp. 11181-11187 ◽  
Author(s):  
Lin Zhang ◽  
Zhiyuan Li ◽  
Jinyang Zheng ◽  
Yongzhi Zhao ◽  
Ping Xu ◽  
...  
Keyword(s):  
Low Temperature ◽  
Stainless Steels ◽  
Austenitic Stainless Steels ◽  
Hydrogen Gas

scholarly journals Fracture Threshold Measurements of Hydrogen Precharged Stainless Steel Weld Fusion Zones and Heat Affected Zones

2015 ◽  
Author(s):  
Joseph A. Ronevich ◽  
Brian P. Somerday ◽  
Chris W. San Marchi ◽  
Dorian K. Balch
Keyword(s):  
Stainless Steel ◽  
Fusion Zone ◽  
Stainless Steels ◽  
Heat Affected Zone ◽  
Austenitic Stainless Steels ◽  
Hydrogen Gas ◽  
Gas Tungsten Arc ◽  
Hydrogen Assisted Cracking ◽  
Point Bend ◽  
Subcritical Cracking

Austenitic stainless steels are used in hydrogen environments because of their generally accepted resistance to hydrogen embrittlement; however, hydrogen-assisted cracking can occur depending on the microstructures or composition of the stainless steel. One area that has not been well researched is welds and in particular heat affected zones. The goal of this work was to measure the subcritical cracking susceptibility of hydrogen precharged gas tungsten arc (GTA) welds in forged stainless steels (21Cr-6Ni-9Mn and 304L). Welds were fabricated using 308L filler metal to form 21-6-9/308L and 304L/308L weld rings, and subsequently three-point bend specimens were extracted from the fusion zone and heat affected zone and precharged in high-pressure hydrogen gas. Crack growth resistance curves were measured in air for the hydrogen precharged fusion zones and heat affected zones under rising-displacement loading, revealing significant susceptibility to subcritical cracking. Fracture thresholds of 304L/308L welds were lower than 21-6-9/308L welds which was attributed to higher ferrite fractions in 304L/308L since this phase governed the crack path. Fracture thresholds for the heat affected zone were greater than the fusion zone in 21-6-9/308L which is likely due to negligible ferrite in the heat affected zone. Modifications to the weld joint geometry through use of a single-J design were implemented to allow consistent testing of the heat affected zones by propagating the crack parallel to the fusion zone boundary. Despite low hydrogen diffusivity in the austenitic stainless steels, effects of displacement rates were observed and a critical rate was defined to yield lower-bound fracture thresholds.

SSRT and Fatigue Crack Growth Properties of High-Strength Austenitic Stainless Steels in High-Pressure Hydrogen Gas

2014 ◽  
Author(s):  
Hisatake Itoga ◽  
Takashi Matsuo ◽  
Akihiro Orita ◽  
Hisao Matsunaga ◽  
Saburo Matsuoka ◽  
...  
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Stainless Steels ◽  
Austenitic Stainless Steels ◽  
High Strength ◽  
Hydrogen Gas ◽  
Internal Hydrogen ◽  
Acceleration Rate ◽  
Type 304

Slow strain rate tests (SSRTs) were performed with two types of high-strength austenitic stainless steels, Types AH and BX, as well as with two types of conventional austenitic stainless steels, Types 304 and 316L. The tests used the following combinations of specimen types and test atmospheres: (i) non-charged specimens tested in air, (ii) hydrogen-charged specimens tested in air (tests for internal hydrogen), and (iii) non-charged specimens tested in hydrogen gas at pressures of 78 ∼ 115 MPa (tests for external hydrogen). Type 304 exhibited a marked reduction of ductility in the tests for both internal hydrogen and external hydrogen, whereas Types AH, BX and 316L exhibited little or no degradation. In addition, fatigue crack growth (FCG) tests for the four types of steels were also carried out in air and hydrogen gas at pressures of 100 ∼ 115 MPa. In Type 304, FCG in hydrogen gas was more than 10 times as fast as that in air, whereas the acceleration rate remained within 1.5 ∼ 3 times in Types AH, BX and 316L. It was presumed that, in Types AH and BX, a small amount of additive elements, e.g. nitrogen and niobium, increased the strength as well as the stability of the austenitic phase, which thereby led to the excellent resistance against hydrogen.

scholarly journals Study on the effect of ferrite number on impact toughness of austenitic stainless steels at low temperatures

2020 ◽  
Vol 7 (10) ◽  
pp. 102-111
Author(s):  
André de Albuquerque Vicente ◽  
Peter Aloysius D'silva ◽  
Bobby Jos ◽  
Tiago Felipe de Abreu Santos ◽  
Jorge Alberto Soares Tenório
Keyword(s):  
Impact Toughness ◽  
Stainless Steels ◽  
Low Temperatures ◽  
Austenitic Stainless Steels ◽  
Ferrite Number
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