Effects of α′ martensite and deformation twin on hydrogen-assisted fatigue crack growth in cold/warm-rolled type 304 stainless steel. (8th February 2018)

• Record Type: Journal Article
• Authors: Chen, Xingyang; Zhou, Chengshuang; Zheng, Jinyang; Zhang, Lin
• Is Part Of: International journal of hydrogen energy. Volume 43:Number 6(2018)
• Page Start: 3342
• Page End: 3352
• Publication Date: 2018-02-08
• Subjects: Cold/warm rolling -- Fatigue crack growth -- α′ martensite -- Deformation twin -- Hydrogen environment embrittlement; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2017.12.173
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: The effects of α′ martensite and deformation twin on hydrogen-assisted fatigue crack growth (FCG) were investigated in cold/warm-rolled type 304 stainless steel in 5 MPa hydrogen and argon gas atmosphere. The rate of FCG is reduced in argon gas, while greatly enhanced in hydrogen gas after cold-rolling. The FCG rates of warm-rolled specimens, no matter tested in hydrogen gas or argon gas, are reduced comparing with as-received specimens. After cold-rolling, α′ martensite formed around the grain boundary promotes hydrogen-assisted crack initiation and propagation. The deformation twin plays an important role during FCG besides α′ martensite after warm-rolling, and hydrogen-assisted cracking along the twin boundary and slip band can enhance the FCG rate during cycle loading. Graphical abstract: The figure shows the fatigue crack growth (FCG) rates (da/dN) vs the stress intensity factor range (ΔK) curves for as-received and cold/warm-rolled 304 stainless steel and the surface crack morphology for warm-rolled specimen. The FCG rate is reduced in argon gas, while greatly enhanced in hydrogen gas after cold-rolling. The FCG rates of warm-rolled specimens, no matter tested in hydrogen gas or argon gas, are reduced comparing with as-received specimens. Hydrogen-assisted cracking along the twin boundary and slip band can enhance the FCG rate of the warm-rolled 304 specimen during cycle loading. Highlights: The FCG rate of 304 SS tested in argon gas is reduced after cold/warm-rolling. The FCG rate of 304 SS tested in hydrogen gas is reduced after warm-rolling. α′ martensite formed by cold-rolling promotes hydrogen-assisted crack propagation. Hydrogen-induced cracking along twin boundary and slip band can raise the FCG rate.