The effect of charging conditions on hydrogen embrittlement (HE) of the hot-stamping boron steel was investigated with its hydrogen distributions and reversibility properties. With low hydrogen concentration, no noticeable hydrogen-induced cracking was detected, coupled with the uniform distributed diffusible hydrogen, realizing reversible HE. The quasi-cleavage fracture modes suggested the hydrogen-enhanced localized plasticity (HELP) mechanism. At high hydrogen concentration, the diffusible hydrogen distributed at the martensitic block and prior austenite grain boundaries which facilitated hydrogen-induced cracking initiation and propagated along the {110}_M plane, leading to irreversible HE. The intergranular fracture modes suggested the transition of HELP to hydrogen-enhanced decohesion mechanism (HEDE).

研究了充电条件对热冲压硼钢氢脆（HE）的影响及其氢分布和可逆性。在低氢浓度下，没有检测到明显的氢致开裂，再加上均匀分布的扩散氢，实现了可逆HE。准解理断裂模式表明氢增强局部塑性（HELP）机制。在高氢浓度下，扩散氢分布在马氏体块和原奥氏体晶界，促进氢致开裂萌生并沿{110} _M面扩展，导致不可逆的 HE。沿晶断裂模式表明 HELP 向氢增强脱粘机制 (HEDE) 的转变。