多层多道CrMoV钢埋弧焊焊缝金属冲击韧性波动  

Impact toughness variations of multi-pass,multi-layer CrMoV submerged arc welding weld metal

作　　者：田宏伟 鲁立[2] 赵重阳 石祥文 李克俭[3] TIAN Hongwei;LU Li;ZHAO Chongyang;SHI Xiangwen;LI Kejian(Jianbi Power Plant,National Energy Group,Zhenjiang 212006,China;Suzhou Nuclear Power Research Institute,Suzhou 215004,China;Department of Mechanical Engineering,Tsinghua University,Beijing 100084,China)

机构地区：[1]国家能源集团谏壁发电厂,镇江212006 [2]苏州热工研究院有限公司,苏州215004 [3]清华大学机械工程系,北京100084

出　　处：《清华大学学报（自然科学版）》2021年第11期1273-1280,共8页Journal of Tsinghua University(Science and Technology)

基　　金：国家能源集团科技项目(GJNY-19-82)。

摘　　要：采用多层多道埋弧焊工艺制备的CrMoV低合金钢焊缝金属在经焊后热处理后,室温冲击韧性波动较大。该文利用光学显微镜和扫描电镜对焊缝金属及裂纹扩展路径进行观察和分析,并利用扫描电镜对冲击断口形貌进行表征,采用Auger纳米探针对微观组织中的碳化物进行成分分析。结果表明:焊缝金属层间再热粗晶区是冲击韧性的薄弱环节,项链状分布的Fe_(3)C碳化物和非金属夹杂物会导致裂纹起裂;冲击试样V形缺口在焊缝金属的位置是决定冲击吸收功高低的关键因素;在沿着裂纹扩展路径的方向上,V形缺口距层间再热粗晶区的距离越远,其冲击韧性越高。After post-welding heat treatment,the impact toughness of CrMoV weld metal from multi-pass,multi-layer submerged arc welding fluctuated greatly at room temperature.The microstructures and crack propagation paths of various samples were characterized using optical and scanning electron microscopes with the fracture surface morphology observed using a scanning electron microscope.In addition,the carbides in the matrix were analyzed using an Auger electron spectroscope.The results show that the reheated coarse-grained zone of the weld metal is the weakest microstructure component for the impact toughness and that the necklace-like distributed Fe_(3)C carbides and nonmetallic inclusions can lead to crack initiation.The location of the V-shaped notch in the weld metal is the key factor determining the impact absorbed energy.A larger distance between the V-shaped notch and the reheated coarse-grained zone in the direction along the crack propagation path increases the weld metal impact toughness.

关 键 词：多层多道焊 冲击韧性 裂纹起裂 碳化物 缺口位置 

分 类 号：TG407[金属学及工艺—焊接]