Crystallographic study of hydrogen-induced twin boundary separation in type 304 stainless steel under cyclic loading. (December 2017)

• Record Type: Journal Article
• Authors: Ueki, Shohei; Mine, Yoji; Takashima, Kazuki
• Is Part Of: Corrosion science. Volume 129(2018)
• Page Start: 205
• Page End: 213
• Publication Date: 2017-12
• Subjects: A. Stainless steel -- B. SEM -- B. TEM -- C. Hydrogen embrittlement -- C. Interfaces -- C. Corrosion fatigue; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2017.10.013
• Languages: English
• ISSNs: 0010-938X

Abstract

Highlights: We used small compact-tension specimens with twinned crystals of stainless steel. This study focused on the martensitic transformation during fatigue crack growth. The crack extended in martensite formed at crack tip in the uncharged specimen. Hydrogen-induced twin boundary separation occurred at martensite/austenite interface. Hydrogen can facilitate a slip-off crack growth mechanism in high stress intensity. Abstract: This study focused on the martensitic transformation during fatigue crack growth in twinned crystals using small compact-tension specimens to elucidate the hydrogen-induced twin boundary separation in type 304 stainless steel. In the uncharged specimen, martensite variants were formed with their habit planes parallel to the most highly shear-stressed slip plane. The crack extended in martensite that was earlier formed ahead of the crack tip and deflected from the twin boundary. Hydrogen-induced twin boundary separation occurred predominantly at the interface between martensite and austenite in a medium stress intensity range. As the stress intensity range increased, martensite variants symmetrically arranged with respect to the twin plane dominated, suggesting that a slip-off crack growth mechanism was facilitated by hydrogen.