Grain boundary engineering for improving stress corrosion cracking of 304 stainless steel

ABSTRACT

Grain boundary engineering (GBE) via low strain tension and annealing was used to enhance the resistance to stress corrosion cracking of a 304 stainless steel. Electron backscattered diffraction (EBSD) analysis exhibited that the GBE steel had a higher fraction of low-∑ coincidence site lattice (CSL) boundaries, larger grain-clusters, longer twin boundary chains, and fewer paths of connected non-twin boundaries with a more zigzag shape. Slow strain rate tests in high-temperature water showed that the GBE steel performed better plasticity, higher tensile strength, and similar yield strength compared to conventional steel. The low fraction of random boundaries in GBE steel resulted in a lower frequency of intergranular crack initiation, and the zigzag paths of non-twin boundaries made the intergranular crack propagation more difficult.

KEYWORDS:

• Stainless steel
• grain boundary engineering
• slow strain rate testing
• twin boundary
• stress corrosion cracking

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Tingguang Liu http://orcid.org/0000-0002-3253-6817

Additional information

Funding

This work was supported by the National Natural Science Foundation of China (51701017, 51671122 and 51871144) and Beijing Natural Science Foundation (2182044).