不同钛含量汽车用热成型钢的抗氢脆敏感性研究  

Study on hydrogen embrittlement resistance of Ti-microalloying hot forming steel for automobile

作　　者：刘汉华[1,2] Liu Hanhua(School of Mechanical and Electrical Engineering,Liuzhou Vocational and Technical College,Liuzhou 545616,Guangxi,China;Technical Center of Liuzhou Iron and Steel Group Co.,Ltd.,Liuzhou 545616,Guangxi,China)

机构地区：[1]柳州职业技术学院机电工程学院,广西柳州545616 [2]柳州钢铁集团有限公司技术中心,广西柳州545616

出　　处：《钢铁钒钛》2022年第4期178-183,共6页Iron Steel Vanadium Titanium

基　　金：柳州钢铁公司科技计划项目(2018BPB-016-03)。

摘　　要：利用充氢拉伸及氢解吸试验手段对比研究了两种钛含量汽车用含Nb-Mo热成型钢的抗氢脆敏感性。试验结果表明:随着Nb-Mo热成型钢中的钛含量由0.015%增加至0.03%,其原奥氏体晶粒尺寸由5.40μm降低至4.35μm,晶界数量增多;新析出粗大的TiC颗粒,且(Nb,Ti)C、(Nb,Mo,Ti)C颗粒尺寸明显增大。虽然钛含量的增加会导致Nb-Mo热成型钢中析出粗大的Ti(C,N),可促进氢脆断裂行为的发生,但是粗大碳化物颗粒导致材料的氢解吸高温峰对应的氢脱附激活能由83.4 kJ/mol增加至105.9 kJ/mol,对氢原子的不可逆捕获能增加,有效减少了钢中的可扩散氢原子,且奥氏体晶界数量的增加使氢原子分布更为均匀,最终可提升Nb-Mo热成型钢的抗氢脆敏感性。The hydrogen embrittlement resistance of two kinds of Nb-Mo hot forming steels with different Ti contents for automobile was studied by slow strain rate tensile test along with hydrogen charging and hydrogen desorption test in this paper.The results show that with increasing titanium content from 0.015%to 0.03%,the original austenite grain size of Nb-Mo hot forming steel decreases from 5.40μm to 4.35μm.Besides,the number of grain boundaries increased,and newly precipitated TiC particles are coarse,the size of(Nb,Ti)C,(Nb,Mo,Ti)C particles increases remarkably.The increase of Ti content leads to the precipitation of coarse Ti(C,N)in Nb-Mo hot forming steel,which promotes the occurrence of hydrogen embrittlement fracture.However,the activation energy of hydrogen desorption corresponding to the high temperature peak of hydrogen desorption is increased from 83.4 kJ/mol to 105.9 kJ/mol due to the coarse carbide particles.The energy of capturing irreversible hydrogen atom is increased,which can effectively reduce the amount of diffusible hydrogen atom in the steel.The increasing number of austenite grain boundaries can enable the hydrogen atom distribution more uniform,and finally improves the hydrogen embrittlement resistance of Nb-Mo hot forming steel.

关 键 词：热成型钢 氢脆 钛含量 氢解吸 

分 类 号：TG142.1[一般工业技术—材料科学与工程]