Investigating variations in hydrogen-assisted crack propagation of X52 pipeline steel with different microstructural characteristics
Yifan Du, Liang Lv, Kai Chen, Guiming Dang, Haoyun Xu, Shuqi Zheng
Abstract
In this study, the fracture behavior of two X52 pipeline steels with different microstructures in gaseous hydrogen environments was investigated. Specimen with polygonal ferrite and spheroidal pearlite exhibited reduced crack propagation resistance and brittle morphology in hydrogen gas, with crack selectively propagating along specific low-index planes (such as {001} and {011}). Conversely, specimen with acicular ferrite and spheroidal pearlite maintained ductile fracture behavior in hydrogen gas, characterized by crack blunting. The possible mechanisms of hydrogen-induced fracture toughness degradation were discussed in relation to grain boundary configuration and hydrogen content.