1. Effects of grain boundary character distribution on hydrogen-induced cracks initiation and propagation at different strain rates in a nickel-saving and high-nitrogen austenitic stainless steel.
- Author
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Mao, L.Y., Luo, Z.A., Huang, C., Wang, Y.Q., Duan, R.H., and Zhang, X.M.
- Subjects
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STRAIN rate , *CRYSTAL grain boundaries , *CRACK propagation (Fracture mechanics) , *AUSTENITIC stainless steel , *HYDROGEN atom , *FRACTURE strength , *STAINLESS steel - Abstract
The effect of grain boundary character distribution (GBCD) on hydrogen-induced cracks (HICs) initiation and propagation in nickel-saving austenitic stainless steel was investigated at different strain rates with electrochemical hydrogen charging. The fracture strength and elongation of specimens decreased as the strain rates decreased due to more hydrogen atoms being transported by mobile dislocations. HICs are more likely to initiate at random grain boundaries (RGBs) because of poor deformation coordination of adjacent grains at RGBs after hydrogen charging. Special boundaries (SBs) deflected HICs and hindered the propagation of HICs owing to a more stable boundary structure and less strain localization during slow strain rate tensile (SSRT) deformation with hydrogen charging. Furthermore, highly efficient distributions of SBs contribute to great resistance to hydrogen embrittlement. • Higher content of SBs reduced the elongation and strength degeneration of material after H-charging. • With the increase of SB, the fracture mode changes from intergranular to quasi-cleavage. • SBs are beneficial to delay hydrogen permeation. • HICs prefer to initiate on RGBs due to poor deformation coordination after H-charging. • HICs are deflected and terminated by special boundaries, a higher fraction of f J2 /(1-f J3) effectively inhibit HICs propagation. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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