The present study was attempted to evaluate the hydrogen embrittlement (HE) of commercial 20SiMn2CrNiMo, PSB1080 and PH13-8Mo high strength steels using slow strain rate tensile tests with smooth cylindrical tensile specimens. The results reveal that three steels exhibit the superior strength and plasticity in the absence of hydrogen. However, the mechanical properties are deteriorated after hydrogen charging and the resistance to HE is 20SiMn2CrNiMo steel, PH13-8Mo steel and PSB1080 steel, which is ranked in a decreasing order. Fine lath boundaries in 20SiMn2CrNiMo steel disperse hydrogen atoms, reduce local hydrogen accumulation and then result in the lowest HE. Coherent NiAl precipitates in PH13-8Mo steel and O-Mg-Al-Si-Ca type inclusions in PSB1080 steel are responsible for the high HE susceptibility due to the concurrent effect of the stress concentration and hydrogen-enhanced decohesion mechanism. It is thus suggested that the inclusions in steels should be eliminated and the efforts concerning to obtain low HE susceptibility in steels strengthened by the coherent precipitates should be conducted to guarantee the safe service of engineering components fabricated from high strength steels.

本研究试图通过使用平滑圆柱拉伸试样的慢应变速率拉伸试验来评估商用20SiMn2CrNiMo，PSB1080和PH13-8Mo高强度钢的氢脆（HE）。结果表明，在不存在氢的情况下，三种钢表现出优异的强度和可塑性。但是，充氢后机械性能变差，对HE的耐性依次为20SiMn2CrNiMo钢，PH13-8Mo钢和PSB1080钢。20SiMn2CrNiMo钢中的细条状边界分散了氢原子，减少了局部氢的积累，从而导致最低的HE。由于应力集中和氢增强脱粘机理的共同作用，PH13-8Mo钢中相干的NiAl析出物和PSB1080钢中的O-Mg-Al-Si-Ca型夹杂物对HE的敏感性很高。因此，建议应消除钢中的夹杂物，并应采取相关措施，以降低由相干析出物强化的钢中HE的敏感性，以确保由高强度钢制成的工程部件的安全使用。