Crystallographic effects on transgranular chloride-induced stress corrosion crack propagation of arc welded austenitic stainless steel

TL;DR

This study investigates how crystallographic orientation influences transgranular chloride-induced stress corrosion cracking in arc welded 304L austenitic stainless steel, revealing the roles of mechanical stress, grain boundary types, and corrosion factors.

Contribution

It provides new insights into the crystallographic and mechanical factors affecting crack propagation and arrest in welded stainless steel under chloride stress corrosion conditions.

Findings

Cracks propagate from hard to soft grains or vice versa.

Crack arrest at grain boundaries depends on stress and orientation.

Grain boundary type has minimal impact on cracking behavior.

Abstract

The effect of crystallography on transgranular chloride-induced stress corrosion cracking (TGCISCC) of arc welded 304L austenitic stainless steel is studied on >300 grains along crack paths. Schmid and Taylor factor mismatches across grain boundaries (GBs) reveal that cracks propagate either from a hard to soft grain, which can be explained merely by mechanical arguments, or soft to hard grain. In the latter case, finite element analysis reveals that TGCISCC will arrest at GBs without sufficient mechanical stress, favorable crystallographic orientations, or crack tip corrosion. GB type does not play a significant role in determining TGCISCC cracking behavior nor susceptibility. TGCISCC crack behaviors at GBs are discussed in the context of the competition between mechanical, crystallographic, and corrosion factors.