大厚板高强钢补焊横向裂纹试验及产生机理  

Formation mechanism and experiment of transverse crack for large thick plate of high-strength steel

作　　者：张华军[1,2] 陆汉忠 沈大明 蔡春波[1] 

机构地区：[1]哈尔滨理工大学材料科学与工程学院,哈尔滨150040 [2]上海振华重工(集团)股份有限公司,上海200125

出　　处：《焊接学报》2011年第4期75-78,117,共4页Transactions of The China Welding Institution

基　　金：国家博士后科学基金资助项目(20090460616);黑龙江省教育厅科技项目(20100503066);哈尔滨市科技创新人才基金资助项目(2010RFQXG005)

摘　　要：大厚板高强钢构件补焊易产生横向冷裂纹,为了探究其补焊横向裂纹的产生原因,设计了一种小窗口两端加强约束裂纹试验方法来模拟现场施工情况,预制出补焊的横向裂纹.通过金相观察和微观硬度测.试结果表明,在补焊区域出现较大横向裂纹,裂纹面与焊接方向呈45°,这主要是由于氢含量过高和拘束应力过大而引起的氢致裂纹,并在补焊底部熔合区出现很多的微裂纹,其裂纹面与焊接方向垂直,这主要是由于淬硬组织导致的冷裂纹.Because cold transverse cracks occur usually in repair welding for large-scale thick plate of high-strength steel,in order to investigate the induced cause of transverse crack in repair welding,a new experimental method to produce delay transverse crack,both-end restraint crack experiment by small window,is developed for high strength steel.The results of microstructure investigation and hardness measurement show that the large-scale transverse cracks are found in repair welding zone,the angle between plane of crack and welding direction is 45°,and this macro crack is a hydrogen-induced crack because of high hydrogen contents and high restraint stresses.Lots of micro transverse cracks are found in root fusion zone of repair welding,the angle between plane of crack and welding direction is 90°,and this micro crack is a cold crack due to hardened structure.

关 键 词：补焊 横向裂纹 S355高强钢 拘束裂纹试验 锯齿形裂纹 

分 类 号：TG407[金属学及工艺—焊接]