Caliber-rolled TWIP steel for high-strength wire rods with enhanced hydrogen-delayed fracture resistance

Twinning-induced plasticity (TWIP) steels were fabricated in wire rods via cold caliber rolling (CCR), and their microstructure, mechanical properties and hydrogen-delayed fracture (HDF) resistance were evaluated. CCR TWIP steels showed a better combination of strength and ductility than conventional bolt steels as a result of CCR inducing all possible {111}〈112〉 twins. The HDF resistance of CCR TWIP steels was excellent, owing to the inherently low hydrogen diffusivity of the face-centered cubic structure and the high density of non-diffusible hydrogen trapping sites.