摘要
采用真空电子束焊对18CrNiMo7-6合金结构钢进行了带锁底的对焊试验。通过对接头的组织形貌进行观察,并开展微观硬度、拉伸性能、冲击性能和疲劳性能等检测与试验,分析了18CrNiMo7-6合金结构钢真空电子束焊接头的组织和力学性能。结果表明:电子束热源能量密度高,焊接过程熔融金属快速冷却,接头焊缝区主要为板条马氏体组织,热影响区为马氏体+铁素体的混合组织;焊缝区和热影响区硬度比母材高,接头抗拉强度达到950MPa,焊接系数达到0.91,焊缝和热影响区的冲击性能高于母材;疲劳极限为354MPa,断口形貌呈现明显的疲劳分区特征。
Welding procedure test of 18CrNiMo7-6 with end-lock structure was carried out by vacuum electron beam welding.The microstructure and mechanical properties of vacuum electron beam welding joint of 18CrNiMo7-6 were analyzed by microscopic examination,microhardness,tensile test,Charpy impact test and fatigue test.The results show that,the molten metal is cooled rapidly during welding,weld region is mainly composed of lat martensite,and HAZ is composed of martensite and ferrite.Hardness value of weld zone and HAZ is higher than that of base material,the tensile strength of joint reaches 950MPa,and the welding coefficient reaches 0.91.The impact performance of weld and HAZ is higher than that of base material.The fatigue limit is 354MPa,the fracture morphology shows obvious fatigue partition characteristics.
作者
葛佳棋
齐开庆
范如意
程肇君
姚洋洋
GE Jiaqi;QI Kaiqing;FAN Ruyi;CHENG Zhaojun;YAO Yangyang(CRRC Qishuyan Institute Co.,Ltd.,Changzhou 213011,Jiangsu,China;Lean Beam Intelligent Manufacturing(Nantong)Co.,Ltd.,Nantong 226199,Jiangsu,China)
关键词
真空电子束焊
合金结构钢
微观组织
力学性能
疲劳性能
vacuum electron beam welding
structural alloy steel
microstructure
mechanical property
fatigue performance
