Effects of external hydrogen on hydrogen-assisted crack initiation in type 304 stainless steel

Abstract

Purpose The purpose of this paper is to present a crack initiation mechanism of the external hydrogen effect on type 304 stainless steel, as well as on fatigue crack propagation in the presence of hydrogen gas. Design/methodology/approach The effects of external hydrogen on hydrogen-assisted crack initiation in type 304 stainless steel were discussed by performing fatigue crack growth rate and fatigue life tests in 5 MPa argon and hydrogen. Findings Hydrogen can reduce the incubation period of fatigue crack initiation of smooth fatigue specimens and greatly promote the fatigue crack growth rate during the subsequent fatigue cycle. During the fatigue cycle, hydrogen invades into matrix through the intrusion and extrusion and segregates at the boundaries of α′ martensite and austenite. As the fatigue cycle increased, hydrogen-induced cracks would initiate along the slip bands. The crack initiation progress would greatly accelerate in the presence of hydrogen. Originality/value To the best of the authors’ knowledge, this paper is an original work carried out by the authors on the hydrogen environment embrittlement of type 304 stainless steel. The effects of external hydrogen and argon were compared to provide understanding on the hydrogen-assisted crack initiation behaviors during cycle loading.

Avoiding glass spot defect arising from roller hydrogen embrittlement via regulating protective atmosphere distribution

“…The position where H exists has obvious hydrogen‐enhanced localized plasticity and hydrogen‐enhanced decohesion effect when the H content increases 39,40 . Besides, the growth and linkage of microvoids increase with the increase in H content, allowing the matrix material to falloff and adhere to the glass ribbon 41–44 …”

“…39,40 Besides, the growth and linkage of microvoids increase with the increase in H content, allowing the matrix material to falloff and adhere to the glass ribbon. [41][42][43][44] The previous analysis indicates that the H 2 content in the high-temperature zones of the annealing lehr must be strictly controlled. After measurement and simulation, the H 2 concentration is ∼.5 wt% in zone A and ∼.4 wt% in zone B, and in this scenario, the previous defect can be produced easily (Figure 3C; the position of the FEM simulated results section is at the vent as shown in Figure S2).…”

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

“…Figure 1(c) shows that the compact tensile (CT) specimens used for the FCG test with their shapes and sizes. The size and shape of the specimens were the same as those in the literature (Chen et al, 2019;Chen et al, 2020). The FCG tests were directed inside a steady burden range in argon and hydrogen gas.…”

“…In addition, the results show that the a 0 martensitic change in the region of the break tip added to the speeding up of exhaustion break development. Previous studies focused on the acceleration of the fatigue crack rate because of hydrogen (Kanezaki et al, 2008;Aoki et al, 2005;Chen et al, 2020), yet they have not considered the impacts of d -ferrite on exhaustion crack initiation and growth rate in high-pressure hydrogen atmosphere.…”

Evaluation of hydrogen embrittlement by the scratch method

“…In the process of metal processing, manufacturing and service, hydrogen can enter the material and accumulate at defects. When the hydrogen concentration reaches a certain level, the properties of the material will change, and unpredictable cracks may be induced, leading to increasing risk of failure and accidents (Chen et al , 2020). Therefore, the problem of hydrogen embrittlement has received widespread attention.…”