高压气瓶用34CrMo4钢的抗氢脆性能及影响因素

摘要

To ensure the safe use of high pressure cylinders with the risk of hydrogen embrittlement,the chemical composition analysis,mechanical property testing and hydrogen embrittlement resistance test of 34CrMo4 steel for high pressure cylinder from two domestic steel mills were conducted.The hydrogen embrittlement resistance and influence factors of 34CrMo4 steel from different steel mills were studied and compared.The results show that the main chemical composition of 34CrMo4 steel from different steel mills was basically the same.Due to relatively big differences in the content of the gas elements O,N and H,the harmful elements P and S and the trace elements (V+Nb+Ti+B+Zr),in the grade of non-metallic inclusions,and in the impact properties of the steel, the tensile strength for passing the hydrogen embrittlement test was different,which was 901 MPa and 968 MPa, respectively.The corresponding maximum hydrogen embrittlement indexes were 1.93 and 1.92,respectively.For the high pressure cylinders with the risk of hydrogen embrittlement,the maximum tensile strength and the yield ratio of the materials should be limited.In addition,the content of harmful elements P and S and that of the trace elements (V+Nb+Ti+B+Zr)should be limited.%为保证具有氢脆风险的高压气瓶的安全使用,对国内两个钢厂生产的高压气瓶用34CrMo4钢进行了化学成分分析、力学性能测试和抗氢脆性能试验,对比研究了不同厂家34CrMo4钢的抗氢脆性能及影响因素.结果表明:不同钢厂生产的34CrMo4钢中的主要化学成分基本一致,但由于钢中气体元素氧、氮、氢,有害元素磷、硫和微量元素(钒+铌+钛+硼+锆)的含量,非金属夹杂物级别,以及钢的冲击性能相差较大,导致其通过氢脆试验的抗拉强度不同,分别为901,968MPa,对应的最大氢脆化指数分别为1.93,1.92;对具有氢脆风险的高压气瓶,除应限定材料最大抗拉强度与屈强比外,还应限定有害元素磷、硫和微量元素(钒+铌+钛+硼+锆)的含量.