激光-电弧复合焊接热源布置方式对焊缝组织和性能的影响  

Effect of heat source arrangement on microstructure and property of welded joint for laser-MAG arc hybrid welded

作　　者：邵奇深 张宏[1] 刘凤德[1] 刘双宇[1] 

机构地区：[1]长春理工大学机电工程学院,吉林长春130022

出　　处：《材料热处理学报》2015年第8期66-72,共7页Transactions of Materials and Heat Treatment

基　　金：吉林省自然基金资助项目(201215140)

摘　　要：以低合金高强钢为试验材料,采用Nd:YAG激光-MAG电弧复合焊接的方法,研究了激光与电弧的前后布置方式对焊缝形貌、组织和性能的影响。结果表明:电弧引导时焊缝主要以柱状晶为主,焊缝中心有少量的树枝晶,电弧区的柱状晶生长出二次枝晶,二次枝晶非常细小和致密,激光区的二次晶枝较粗且稀疏。激光引导的电弧区为柱状晶和树枝晶,但柱状晶较短并具有明显的层状特征,激光区中心为等轴晶,两侧为树枝晶和柱状晶,晶枝及晶枝臂粗大,晶枝臂间的间隙较小,焊缝区冲击功平均值比电弧引导时提高了33%,冲击断口的形貌表明:电弧引导时,韧窝较浅,并且存在较多的穿晶断裂区,而激光引导时韧窝较深,韧窝边缘较锐利。电弧引导比激光引导的热影响区窄,板条马氏体的晶粒相对较小。Low alloy high-strength steel was taken as welding base material, and Nd：YAG laser-MAG arc hybrid welding method was used to study the effect of laser and arc arrangement on morphology, microstructure and mechanical properties of the weld. The results indicate that the weld is mainly composed of columnar crystals with a small amount of dendrite in the weld seam center when arc leading, the fine and dense secondary dendrites grow out from the columnar crystals of arc zone, and the laser zone is mainly composed of coarse and sparse secondary dendrites. The arc zone consists of smaller and layered columnar crystal and dendrites when laser leading. The equiaxed grains are observed in the laser zone center and on both sides of the center is columnar crystals and coarse dendrites with dense distribution. The average impact energy of the weld zone for the laser leading increases by 33% than that for the arc leading. The impact fracture morphology indicate that the dimples are shallower for the arc leading and some transgranular fracture zone exists,while the dimples are deeper for the laser leading and their edge is sharper. The heat-affected zone of the arc leading is narrower than that of the laser leading and the lath martensite grains are relatively smaller.

关 键 词：激光-电弧复合焊接 高强钢 接头 组织 韧性 

分 类 号：TG456[金属学及工艺—焊接]