热轧超高强度复相钢的氢脆敏感性

通过电化学充氢和升温脱氢分析(TDS)试验,研究了热轧超高强度复相钢M950的氢逸出行为和氢陷阱类型。利用慢应变速率拉伸(SSRT)试验,研究了M950钢的氢脆敏感性,并采用场发射扫描电镜(FESEM)分析了拉伸断口的微观形貌。结果表明,试验钢的氢陷阱激活能为15.0 kJ/mol,该钢的主要氢陷阱为晶界。随着电化学充氢时间的延长,试验钢氢含量逐渐增加,塑性明显下降,但抗拉强度下降幅度较小;拉伸断口形貌由微孔聚集型韧性断裂向准解理、沿晶脆性断裂过渡。

Hydrogen embrittlement susceptibility of a hot-rolled ultra-high strength complex phase steel

Hydrogen escape behaviour and hydrogen trap of the hot-rolled ultra-high strength complex phase steel M950 were studied by means of electrochemical hydrogen charging experiment and thermal desorption spectroscopy (TDS). The hydrogen embrittlement susceptibility of the tested steel was analysed by means of slow strain rate tensile (SSRT) test. And the fracture morphology was observed using field emission scanning electron microscope (FESEM). The results show that hydrogen trap activation energy of the tested steel is 15.0 kJ/mol. The main hydrogen trap of the steel is grain boundary. With the prolongation of electrochemical hydrogenation time, the hydrogen content of the tested steel increases gradually, and the plasticity decreases significantly, but the decline of tensile strength is not obvious. The tensile fracture morphology changes from pore-concentrating ductile fracture to quasi-cleavage and intergranular brittle fracture.