DP1180和S700MC异种高强钢激光焊接接头的组织和性能

Microstructure and Mechanical Properties of Laser Welded Joint of DP1180 and S700MC Dissimilar High Strength Steels

采用激光搭接焊对DP1180和S700MC异种高强钢进行焊接,研究了焊接接头的微观组织和力学性能,并与DP1180同种钢焊接接头进行了对比。结果表明:DP1180和S700MC异种钢焊缝的横截面呈Y形,而DP1180同种钢焊缝的横截面呈V形;异种钢搭接焊接头的DP1180钢侧热影响区分别出现了软化和硬化现象,而S700MC钢侧热影响区只出现了较为严重的硬化现象,并没有明显的软化现象;在相同的熔宽条件下,DP1180和S700MC异种钢接头的拉剪力明显小于DP1180同种钢接头,但仍高于S700MC钢母材;所有接头的拉伸性能稳定,力学性能良好,并且同种钢和异种钢焊接均可通过增加焊长来提升焊接接头的承载性能。

Laser overlap welding was performed on DP1180 and S700MC dissimilar high strength steels.The microstructure and mechanical properties of the welded joint were studied,and compared with those of the welded joints of DP1180 similar high strength steels.The results showed that(a)the cross-section of the weld of DP1180 and S700MC dissimilar steels was Y-shaped,while that of the weld of DP1180 similar steels was V-shaped;(b)the heat affected zone(HAZ)on DP1180 steel side in the overlap welded joint of dissimilar steels presented both softening and hardening respectively,however,the HAZ on S700MC steel side only presented relatively serious hardening and was without obvious softening;(c)under the condition of the same weld width,the tensile shear load of the joint of DP1180 and S700MC dissimilar steels was obviously lower than that of the DP1180 similar steels,but still higher than that of S700MC steel base metal;(d)all joints had stable tensile properties and excellent mechanical properties,and the load-bearing ability of the welded joints of similar and dissimilar steels could be improved by increasing the welding length.