A comparative study of hydrogen embrittlement of 20SiMn2CrNiMo, PSB1080 and PH13-8Mo high strength steels

Xinfeng Li, Jin Zhang, Qinqin Fu, Xiaolong Song, Sicong Shen, Qizhen Li

Index: 10.1016/j.msea.2018.03.076

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Abstract

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 by high strength steels.