Hydrogen-assisted Crack Propagation in Pre-strained Twinning-induced Plasticity Steel: from Initiation at a Small Defect to Failure

Hydrogen-assisted crack growth of pre-strained twinning-induced plasticity (TWIP) steel was investigated using artificial defects (micro-drilled holes), which acted as initiation sites. Hydrogen introduced into the specimens by electrochemical hydrogen charging during slow strain rate tensile test. The quasi-cleavage propagation observed due to repeated near tip and subsequent coalescence. Crack occurred after plastic deformation tip, pre-straining facilitated plasticity-driven initiation. early stage sensitive length remote stress level. Accordingly, in increased with increase initial defect size. In following growth, exhibited a complicated trend respect length, is possibly plastic-wake-altered field around depends on