Hydrogen Damage in Superaustenitic 904L Stainless Steels

Abstract

In this work, results on the influence of hydrogen on corrosion resistance and of hydrogen embrittlement of 904L superaustenitic stainless steel were investigated. The cracking behavior was studied by performing a slow strain rate test in synthetic seawater under varying cathodic polarization conditions. The results showed that the steelÕs plasticity varied with the applied cathodic current density. Significant reductions in ductility were found, indicating its susceptibility to hydrogen-assisted fracture at current density of 20 mA/ cm 2. Fractographical examinations showed that an increase in hydrogenation current density causes a stepwise decrease in ductility on the fracture surface. The effect of hydrogen on passivity and on pitting corrosion resistance was qualified with the polarization curves registered in synthetic seawater. The conclusion is that hydrogen may affect the passive film stability and thus may decrease the corrosion resistance of the studied steel. The presence of hydrogen increases corrosion current density and decreases the potential of the film breakdown. It was also found that the degree of the susceptibility to hydrogen degradation was dependent on the hydrogen charging conditions.

Corrosion Mechanisms of High-Mn Twinning-Induced Plasticity (TWIP) Steels: A Critical Review

“…The phenomenon known as HE is a destructive process of hydrogen damage to the mechanical properties of a metal, which has been extensively studied in high-Mn TWIP steels [156][157][158][159][160][161][162][163][164][165][166][167][168]. The introduction of hydrogen into the steel depends on variables such as hydrogen concentration, temperature, applied or residual stress, microstructure, and surface finishing [152,[169][170][171][172], and may be introduced into the steel from finishing processes including electroplating, forging, welding, corrosion, and cathodic protection system [173,174].…”

“…Fe−Mn−C TWIP steels show superior elongation and strength due to deformation twinning [164], therefore they are highly suitable for automobile applications [159,160]. Various Fe−Mn−C austenitic steels, however, have reported HE in recent works [154,[156][157][158][159][160][161][162][163][164][165]. Koyama et al have reported an excellent overview of HE susceptibility of high-Mn steels, however the mechanistic effect of adding Al to TWIP steels has not been sufficiently investigated [167][168][169][170][171][172][173][174][175].…”

“…Hydrogen was effectively introduced to the specimens during the tensile tests by simple diffusion as well as dislocation motions [158,198], resulting in a clear embrittlement phenomenon. Mobility of slip dislocations [150], the behavior of martensitic transformation [195,196], the deformation twinning [160,161], and the cohesive energy of the grain boundary are affected by hydrogen in austenitic steels [199,200].…”

Comparison of resistance to damage of unalloyed carbon steels under the influence of hydrogen

“…Obtained as a result of the study, stress-strain curves (SSRT, static tensile test) in conjunction with the fractures analysis by the quantitative fractography method lead to a more complete characteristics of the phenomenon of degradation of the alloys in corrosive environments [3]. Different concentrations of hydrogen not only reflect on the surface of the fractures after a static tensile test (change in the nature the fractures) [16][17], but also in the deterioration of the corrosive properties [6,[18][19][20]. To assess the degree of hydrogen degradation in materials also non-destructive methods are used.…”

Effects of hydrogen-charging on the properties of S235JR steel

“…The presence of trapped hydrogen in defects in the microstructure affects the change of materials' fracture mechanisms [3]. Differences in hydrogen concentration are not only reflected on the surface of the breakthroughs after the tensile test [4,5] but also in deterioration of corrosion properties [6][7][8]. In addition, recent research has shown that the method of quantitative assessment of breakthroughs can be used in assessing the hydrogen degradation level of alloys [9].…”