scholarly journals Influence of Specimen Surface Roughness on Hydrogen Embrittlement Induced in Austenitic Steels during In-Situ Small Punch Testing in High-Pressure Hydrogen Environments

Metals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1579
Author(s):  
Hyung-Seop Shin ◽  
Juho Yeo ◽  
Un-Bong Baek
Keyword(s):  
Surface Roughness ◽  
High Pressure ◽  
Hydrogen Embrittlement ◽  
Test Method ◽  
Austenitic Steels ◽  
Specimen Surface ◽  
Dominant Factor ◽  
Small Punch ◽  
Pressure Hydrogen

An in-situ small punch (SP) test method has recently been developed as a simple screening technique for evaluating the properties of metallic materials used in high-pressure hydrogen environments. With this method, the test conditions including temperature and gas pressure can easily be adjusted to those used in practice. In this study, specimens of STS316L steel and 18 wt% Mn steel were prepared at two different surface roughness, fabricated using wire-cutting and mechanical polishing. Their effects on hydrogen embrittlement (HE) were evaluated using in-situ SP testing at both room temperature and a lower temperature where HE was shown to occur under 10 MPa hydrogen. Both steels were evaluated using two variables obtained from in-situ SP testing, the SP energy, and the relative reduction of thickness (RRT), to quantitatively determine the effect of specimen surface roughness on HE susceptibility. Their fracture characteristics due to HE under 10 MPa hydrogen showed little difference with surface finish. Surface roughness had a negligible influence on these quantitative factors describing HE, indicating that it is not a dominant factor to be considered in in-situ SP testing when it is used to screen for HE compatibility in steels used in high-pressure hydrogen environments.

Screening Technique of Hydrogen Embrittlement Sensitivity in Austenitic Stainless Steels Using In-Situ Small Punch Test Method

2019 ◽  
Author(s):  
Hyung-Seop Shin ◽  
Kyung-Oh Bae ◽  
Hyuckmin Kim ◽  
Un-Bong Baek ◽  
Seung-Hoon Nahm
Keyword(s):  
Hydrogen Embrittlement ◽  
Stainless Steels ◽  
Austenitic Stainless Steels ◽  
Hydrogen Gas ◽  
Test Method ◽  
Austenitic Steels ◽  
Hydrogen Energy ◽  
Small Punch ◽  
Screening Technique

Abstract In this study, a simple screening technique using an in-situ small-punch (SP) test and based on the hydrogen embrittlement (HE) sensitivity of austenitic stainless steels was developed for use in hydrogen energy facilities. To investigate the HE behaviors of metallic materials, the in-situ SP tests were carried out under high-pressure hydrogen gas environments. The reductions of thickness at the fractured parts of the specimen were measured. The relative reductions of thickness (RRT) were determined after conducting SP tests in both hydrogen and inert gas environments. Similar to the relative reduction of area (RRA) obtained using the slow strain-rate tensile test, RRT obtained using the in-situ SP test is a quantitative measure of the influence of the HE behaviors. The influence of punch velocity on HE sensitivity was examined. The HE behaviors of austenitic steels were evaluated qualitatively and quantitatively. The high-Mn steels were also evaluated because they are candidates for storage and transportation of hydrogen gas. A screening technique for determining the practical environmental conditions at the point of use could be established by confirming the effectiveness of the influencing factor, RRT, using this in-situ SP test method.

Effect of High Pressure Gaseous Hydrogen on the Tensile Properties of Four Types of Stainless Steels: Investigation of Materials Properties in High Pressure Gaseous Hydrogen—1

2007 ◽  
Author(s):  
Hideki Nakagawa
Keyword(s):  
High Pressure ◽  
Stainless Steel ◽  
Hydrogen Embrittlement ◽  
Storage System ◽  
Gaseous Hydrogen ◽  
Fuel Cell Vehicle ◽  
Ductility Loss ◽  
Hydrogen Storage System ◽  
Type 316L ◽  
Pressure Hydrogen

Practical application of fuel cell vehicle has started in the world, and high-pressure hydrogen tanks are currently considered to be the mainstream hydrogen storage system for commercially implemented fuel cell vehicle. Application of metallic materials to the components of high-pressure hydrogen storage system: hydrogen tanks, valves, measuring instructions and so on, have been discussed. In this work, tensile properties of four types of stainless steels were evaluated in 45MPa (6527psig) and 75MPa (10878psig) high-pressure gaseous hydrogen at a slow strain rate of 3×10−6 s−1 at ambient temperature. Type 316L (UNS S31603) stainless steel hardly showed ductility loss in gaseous hydrogen, since it had stable austenitic structure. On the other hand, Type 304 (UNS S30400) metastable austenitic stainless steel showed remarkable ductility loss in gaseous hydrogen, which was caused by the hydrogen embrittlement of strain induced martensitic phase. Likewise, Type 205 (UNS S20500) nitrogen-strengthened austenitic stainless steel showed remarkable ductility loss in gaseous hydrogen, though it had stable austenitic structure in the same manner as Type 316L. The ductility loss of Type 205 was due to the hydrogen embrittlement of austenitic phase resulting from the formation of planar dislocation array. Furthermore, Type 329J4L (UNS S31260) duplex stainless steel showed extreme ductility loss in gaseous hydrogen, which was caused by the hydrogen embrittlement of ferritic phase.

Evaluation of Hydrogen Embrittlement of Cr-Mo Low Alloy Steel by Slow Strain Rate Technique With Cathodically Charged Specimen

2017 ◽  
Author(s):  
Daichi Tsurumi ◽  
Hiroyuki Saito ◽  
Hirokazu Tsuji
Keyword(s):  
High Pressure ◽  
Hydrogen Embrittlement ◽  
Fracture Surface ◽  
Strain Rate ◽  
Current Density ◽  
Cleavage Fracture ◽  
Hydrogen Gas ◽  
Low Alloy Steel ◽  
Slow Strain Rate Technique ◽  
Pressure Hydrogen

As an alternative method to slow strain rate technique (SSRT) under high-pressure hydrogen gas evaluation, SSRT was performed with a cathodically charged specimen. Cr-Mo low alloy steel with a tensile strength of 1000 MPa grade was selected as a test material. Cathodic charging was performed in 3% NaCl solution and at a current density in the range of 50–600 A/m2. The effect of specimen size on the hydrogen embrittlement properties was evaluated. Relative reduction of area (RRA) values obtained by tests at a cathode current density of 400 A/m2 were equivalent to those performed in hydrogen gas at pressures of 10 to 35 MPa. Fracture surface observations were also performed using scanning electron microscopy (SEM). The quasi-cleavage fracture surface was observed only after rupture of small specimens that were subjected to hydrogen charged tests. It was also necessary for the diameter of the specimen to be small to form the quasi-cleavage fracture surface. The results indicated that to simulate the high-pressure hydrogen gas test, a specimen with a smaller parallel section diameter that is continuously charged until rupture is preferable.

scholarly journals In Situ High Pressure Hydrogen Tribological Testing of Common Polymer Materials Used in the Hydrogen Delivery Infrastructure

10.3791/56884 ◽  
2018 ◽  
Author(s):  
Edward R. Duranty ◽  
Timothy J. Roosendaal ◽  
Stan G. Pitman ◽  
Joseph C. Tucker ◽  
Stanley L. Owsley ◽  
...  
Keyword(s):  
High Pressure ◽  
Polymer Materials ◽  
Materials Used ◽  
Pressure Hydrogen

Effect of δ-ferrite on susceptibility to hydrogen embrittlement of 304 austenitic stainless steel in high-pressure hydrogen atmosphere

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Fan Bao ◽  
Kaiyu Zhang ◽  
Zhengrong Zhou ◽  
Wenli Zhang ◽  
Xiao Cai ◽  
...  
Keyword(s):  
High Pressure ◽  
Stainless Steel ◽  
Fatigue Crack ◽  
Hydrogen Embrittlement ◽  
Hydrogen Gas ◽  
304 Stainless Steel ◽  
Content Type ◽  
Gas Environment ◽  
Type 304 ◽  
Pressure Hydrogen

Purpose The purpose of this paper is to demonstrate the effect of δ-ferrite on the susceptibility to hydrogen embrittlement of type 304 stainless steel in hydrogen gas environment. Design/methodology/approach The mechanical properties of as-received and solution-treated specimens were investigated by the test of tensile and fatigue crack growth (FCG) in 5 MPa argon and hydrogen. Findings The presence of δ-ferrite reduced the relative elongation and the relative reduction area (H2/Ar) of 304 stainless steel, indicating that δ-ferrite increased the susceptibility of hydrogen embrittlement in 304 stainless steel. Moreover, δ-ferrite promoted the fatigue crack initiation and propagation at the interface between δ-ferrite and austenite. The FCG tests were used to investigate the effect of δ-ferrite on the FCG rate in hydrogen gas environment, and it was found that δ-ferrite accelerated the FCG rate, which was attributed to rapid diffusion and accumulation of hydrogen around the fatigue crack tip through δ-ferrite in high-pressure hydrogen gas environment. Originality/value The dependence of the susceptibility to hydrogen embrittlement on δ-ferrite was first investigated in type 304 steel in hydrogen environment with high pressures, which provided the basis for the design and development of a high strength, hydrogen embrittle-resistant austenitic stainless steel.

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