610MPa级水电用钢的再热脆化  

Reheat embitterment of CGHAZ of 610 MPa-grade hydroelectricity steel

作　　者：张熹[1] 许良红[1] 陈延清[1] 章军[1] 

机构地区：[1]首钢技术研究院用户技术研究所,北京100043

出　　处：《材料热处理学报》2011年第11期78-83,共6页Transactions of Materials and Heat Treatment

摘　　要：讨论了焊后热处理制度对不同热输入下610 MPa级水电钢粗晶区冲击韧性的影响,发现热输入在30 kJ/cm时在620℃附近有脆化倾向;热输入在40 kJ/cm时在580℃出现显著再热脆化。SEM、TEM及能谱试验结果表明,碳化物在原奥氏体晶界析出是发生再热脆化的原因。焊接热输入不同导致碳化物在焊后热处理时溶解规律不同,从而造成了40 kJ/cm焊接热输入下发生再热脆化的温度较30 kJ/cm焊接热输入下再热脆化温度向低温方向移动。最终根据试验结果优化了610 MPa水电钢焊后热处理工艺。Influence of post-weld heat treatment regime on impact toughness of coarse-grained heat affected zone（CGHAZ） of 610 MPa-grade hydroelectricity steel was investigated.The results indicate that 620 ℃ is ductile-brittle transition temperature for heat input of 30 kJ/cm,and when heat input is 40 kJ/cm,the ductile-brittle transition occurs at 580 ℃.The microstructure observation shows that precipitation of carbides at prior austenite grain boundary results in the ductile-brittle transition.The different heat input results in the different dissolution behavior of carbides during post-weld heat treatment.The reheat embitterment temperature moves to lower temperature for the higher input.The post-weld heat treatment regime of 610 MPa-grade hydroelectricity steel is optimized based on the experiment.

关 键 词：610MPa 粗晶区 再热脆化 焊后热处理 

分 类 号：TG457.11[金属学及工艺—焊接]