冷轧带钢激光焊接接头断带分析及改善措施  

Analysis and Improvement Measures for Strip Breakage in Laser Welding Joint of Cold-Rolled Strip Steel

作　　者：陈广兴 吴荣华 万照堂 罗世明 郑浩 CHEN Guangxing;WU Ronghua;WAN Zhaotang;LUO Shiming;ZHENG Hao(Baosteel Zhanjiang Iron and Steel Co.,Ltd.,Zhanjiang 524094,China)

机构地区：[1]宝钢湛江钢铁有限公司,广东湛江524067

出　　处：《电焊机》2024年第12期101-106,共6页Electric Welding Machine

基　　金：2023年广东省科技创新战略专项资金(2023A01006)。

摘　　要：利用光学显微镜和扫描电镜分析了冷轧带钢焊缝断带的原因,并开展焊接试验以及结合硬度和折弯性能检测进行验证,结果表明:焊缝两侧焊接热影响区晶粒尺寸存在明显差异,其中晶粒粗大的一侧热影响区力学性能恶化是导致冷轧带钢焊缝断带的直接原因。焊接热影响区的晶粒尺寸受冷轧带钢变形纤维组织尺寸的影响,而纤维组织尺寸由热卷的组织决定。当焊缝两侧的母材纤维组织尺寸相同时,其焊接接头中焊缝两侧的焊接热影响区晶粒尺寸无明显差异,此时,焊接接头的硬度分布得到明显改善,且其折弯性能提升了一倍、经折弯26次后仍未开裂。可通过细化带钢热卷的组织尺寸和降低激光焊接的热输入等方式提升焊接接头的力学性能,以减轻薄弱环节的不利影响。The causes of welding joint breakage in cold-rolled strip steel were analyzed by means of optical microscopy and scanning electron microscopy,and then welding tests and hardness and bending performance testing of welding joints for verification were carried out.The results show that a significant difference in the grain size of the heat affected zone on both sides of the welded joint,and the deterioration of the mechanical properties of the heat affected zone on the side with coarse grains is the direct reason for the fracture of the cold rolled strip weld.The size of the heat affected zone of the welded joint is influenced by the size of the deformed fiber microstructure of the cold-rolled strip steel which is determined by the size of microstructure of the hot coil.When the fiber microstructure size of the base material on both sides of the weld seam is the same,there is no significant difference in the grain size of the welding heat affected zone on both sides of the weld seam in the welded joint,which hardness distribution has significantly improved,and the bending performance has been improved at least twice with which still does not crack after 26 bends.The mechanical properties of welded joints can be improved by re‐fining the hot coil microstructures and reducing laser welding heat input,thereby weakening the adverse effects of weak links.

关 键 词：冷轧带钢 激光焊接 断带 热影响区 晶粒尺寸 

分 类 号：TG406[金属学及工艺—焊接]