22MnB5高频焊管焊缝的横向裂纹原因分析  

Cause Analysis of Transverse Cracks in Welds of 22MnB5 HFW Pipe

作　　者：吴铖川 王洪利 涂露寒 林发驹[1,2] WU Chengchuan;WANG Hongli;TU Luhan;LIN Faju(Pangang Group Research Institute Co., Ltd., Panzhihua 617000, China;State Key Laboratory of Marine Equipment Made of Metal Material and Application,Anshan 114009, China)

机构地区：[1]攀钢集团研究院有限公司,四川攀枝花617000 [2]海洋装备用金属材料及其应用国家重点实验室,辽宁鞍山114009

出　　处：《热加工工艺》2018年第9期247-249,共3页Hot Working Technology

摘　　要：在高频直缝焊接φ31.8 mm×2.2 mm的22Mn B5焊管时偶尔会在外焊缝处出现垂直于焊缝的横向裂纹。通过分析焊管原料的化学成分和金相组织,在了解高频焊接生产工艺和为高频焊接提供原料的纵剪方式的基础上,分析了横向裂纹产生的原因。结果表明,热轧钢带存在中心偏析,纵剪后中心偏析带位于高频焊接原料条的边部,焊缝经挤压和穿水冷却后,焊缝形成较多的粗大淬硬马氏体组织。在焊接热应力的作用下焊缝成为横向裂纹源。Transverse cracks perpendicular to the welding seam occasionally appear at outside of the weld during high frequency straight welding of φ31.8 mm×2.2 mm 22 Mn B5 pipe. Through chemical composition and microstructure analysis of welding pipe raw material, and on the basis of understanding the high frequency welding process and the slitting method of providing raw material for the high frequency welding, the causes of transverse cracks were analyzed. The results show that the hot rolling steel strip has central segregation and the central segregation zone is located at the edge of the steel strip for high frequency welding after slitting. After the weld is extruded and cooled through water, there is a large amount of coarse quenched martensite in the weld. Under the action of welding thermal stress, the weld becomes the source of transverse cracks.

关 键 词：高频焊接 横向裂纹 22Mn B5 中心偏析带 

分 类 号：TG457.6[金属学及工艺—焊接] TG441.7