激光参数对高强度不锈钢搭接焊接结构和断裂行为的影响  

Effects of laser parameters on the weld geometry and failure performance of overlap joints of high strength stainless steels

作　　者：刘伟[1] 王松[1] 宋慧娟[1] 林基安[1] 夏海涛[1] 刘亚娇[1] 

机构地区：[1]北京交通大学机械与电子控制工程学院,北京100044

出　　处：《北京交通大学学报》2014年第1期122-127,共6页JOURNAL OF BEIJING JIAOTONG UNIVERSITY

基　　金：铁道部科技研究开发计划项目资助(2011J015-B)

摘　　要：通过焊接和拉伸试验及微观组织分析,研究了焊接参数对高强度301L-HT板搭接非熔透激光焊接接头结构、断裂行为和力学性能的影响.结果表明:激光焊缝的硬度为HV215,δ铁素体比电阻点焊少,热影响区硬度更接近于母材;焊缝几何结构对激光参数敏感,熔深变化的规律性更明显,特定部位的熔宽与焊接参数耦合有关;板材厚度相同的焊接接头变形刚度接近,焊缝的几何结构决定最后的变形和断裂行为,焊接内板的弯曲变形角度比外板大,两板的弯曲角度差随熔深增加而减小;焊接板弯曲角度和焊接强度随焊缝尺寸同步升高;焊缝硬度低于母材和热影响区导致拉伸变形集中在很窄的区域,焊接接头的断裂位移都小于2 mm.Experimental studies of 301L-HT cold rolled plates welding processes,weld tensile properties,metallurgical observations were focused on the effects of laser power,welding velocity and defocus distance on weld geometry,failure behavior and mechanical properties of overlap welded joints.The results showed that the average hardness of the laser weld was 215HV,and its amount of δ-ferrite was less than that in resistance spot welds.The hardness of the HAZ was closer to that of the cold rolled plates.The weld geometry was sensitive to welding parameters.The regularity of penetration depths was more evident,and the weld width was related to the welding parameters coupling.The welded joints with same plate thickness displayed similar deformation stiffness,and the weld geometry size affected their last fracture behavior.The partial penetration plates bended smaller angles than the full penetration plates,and the difference between them decreased with penetration depth increased.The bended angles of the welded plates and weld failure strengths increased with geometry size.Weld hardness lower than the base material and the HAZ resulting in failure deformation concentrated in the very narrow area,and displacements of all welded joints were less than 2 mm.

关 键 词：激光焊接 301L-HT板 激光参数 焊缝结构 断裂行为 力学性能 

分 类 号：TG456.7[金属学及工艺—焊接]