热源前后位置对高强钢焊缝组织和性能的影响  

Effects of Heat Source Relative Location on Microstructure and Properties of Welding Seam of High-strength Steel

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：《热加工工艺》2015年第15期181-184,187,共5页Hot Working Technology

基　　金：吉林省自然基金资助项目(201215140)

摘　　要：采用Nd:YAG激光-MAG电弧复合焊接的方法,研究了激光引导和电弧引导时焊缝区组织和性能的区别。试验结果表明:电弧引导时,焊缝区的晶粒以柱状晶和树枝晶的方式生长并朝向熔池中心,晶枝间隙较大,整个焊缝区均为板条马氏体;激光引导时晶粒同样以柱状晶和树枝晶的方式生长,但趋向熔池表面,晶枝间隙致密,焊缝区的上部为板条马氏体,下部为奥氏体。电弧引导的抗拉强度要高于激光引导。断口分析表明:两种引导方式均为韧性断裂,但电弧引导的断口韧窝较深且密集,韧窝边缘较锐利;激光引导的下部即奥氏体相区只有很少区域存在韧窝,大部分区域是"台阶"状的沿晶断裂平面。激光引导的冲击韧度要高于电弧引导,平均值高出4.3 J。激光引导时晶枝间隙致密,对应力的削弱能力高于电弧引导。An Nd：YAG laser-MAG arc hybrid welding method was used to study the difference of laser leading and arc leading on the microstructure and mechanical properties of the weld seam. The test results show that： when there is arc leading, the growth mode of grains in the weld zone is columnar crystals and dendrite. The grains growth towards the center of the pool. The dendrites gap is comparatively large. The Entire weld area is lath martensite. When there is laser leading, the grains growth in the same way is columnar crystal and dendrite. But the growth tends to pool surface and the dendrites gap is dense. The upper part of the weld zone is lath martensite. The lower part is austenitic. The tensile strength of arc leading is stronger than laser leading. The fracture analysis shows that： two kinds of guide way are both ductile fracture. But the arc leading dimples is deeper and intensive, dimple edge sharper. The lower part of laser leading namely austenite phase region rarely has dimple area. Most of the area is ＂Steped＂ intergranular fracture plane. The average impact toughness of laser leading is 4.3J higher than that of the arc leading. The dendrites gap is dense when there is laser leading, so the weaken ability on the stress is higher than that of arc leading.

关 键 词：激光-电弧复合焊接 高强钢 焊缝 组织 力学性能 

分 类 号：TG456.7[金属学及工艺—焊接]