Hydrogen-assisted failure in a bimodal twinning-induced plasticity steel

Delamination events and damage evolution

authored by: Abbas Mohammadi, Motomichi Koyama, Gregory Gerstein, Hans Jürgen Maier, Hiroshi Noguchi
Abstract: The effect of the bimodal grain size distribution on the hydrogen susceptibility of a high-Mn fully austenitic twinning-induced plasticity (TWIP) steel was investigated by tensile testing under ongoing electrochemical hydrogen charging. Observation of the surface microstructure of the hydrogen-charged specimen yielded a correlation between the microstructure, crack initiation sites, and crack propagation path. The observed embrittlement arose from crack initiation/propagation along the grain and twin boundaries and delamination governed crack growth. In the present bimodal TWIP steel, the fine grained regions mostly showed intergranular cracking along the grain boundaries between the fine and coarse grains. By contrast, the coarse grained region exhibited transgranular cracking along the twin boundaries. The delamination cracking phenomena is rationalized by the evident nucleation, growth, and coalescence of microvoids in the tensile direction. The results reveal that the bimodal grain size distribution of TWIP steel plays a major role in hydrogen-assisted cracking and the evolution of delamination-related damage.
Organisation(s): Institute of Materials Science
External Organisation(s): Kyushu University
Type: Article
Journal: International Journal of Hydrogen Energy
Volume: 43
Pages: 2492-2502
No. of pages: 11
ISSN: 0360-3199
Publication date: 28.12.2017
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Renewable Energy, Sustainability and the Environment, Fuel Technology, Condensed Matter Physics, Energy Engineering and Power Technology
Sustainable Development Goals: SDG 7 - Affordable and Clean Energy
Electronic version(s): https://doi.org/10.1016/j.ijhydene.2017.11.177 (Access: Closed)