贝氏体车轮钢的氢脆敏感性

摘要

用电解充氢试验方法研究了可扩散氢浓度对贝氏体车轮钢慢拉伸性能及氢致滞后开裂性能的影响，并与普通珠光体一铁素体车轮钢进行了对比。结果表明，在相同慢拉伸条件下，贝氏体车轮钢材料的塑性损失高于珠光体一铁素体车轮钢；在相同的充氢条件下，贝氏体车轮钢氢致开裂门槛应力强度因子相对于断裂韧性值的降低程度明显高于珠光体一铁素体车轮钢，具有较高的氢致开裂敏感性。%The influence of diffusible hydrogen concentration （Co） on the plasticity and hydrogen induced delayed cracking of a bainite railway wheel steel was investigated by means of the slow strain rate test （SSRT） specimens and wedge open loading （WOL） specimens charged in a solution respectively. The results showed that the plasticity loss of the bainite wheel steel was larger than that of the pearlite-ferrite CL60 wheel steel. The threshold stress intensity factor of hydrogen induced delayed cracking K1, of the bainitie wheel steel decreased with the increase of diffusible hydrogen concentration. The Km of the bainite wheel steel was much lower than that of the CL60 wheel steel when C0≥1.6 × 10-6, though the fracture toughness KIC of the bainite wheel steel was much higher than that of the CL60 wheel steel.