异种钢LMHW与MIG焊接头力学性能对比分析

Comparative analysis on mechanical properties of dissimilar steel welded joints by LMHW and MIG welding

摘要: 激光-MIG复合焊（LMHW）由于结合了激光和电弧两个独立热源各自的优点，极大程度地避免了二者的缺点，因此成为在汽车、船舶、石油化工等领域具有极大应用前景的新型焊接方法. 以25CrMo4和33MnCrB5-2异种钢试样为研究对象，对比研究了LMHW和MIG焊的焊接接头金相组织差别与硬度分布差异. 结果表明，LMHW焊缝成形均匀饱满，焊接成形效果好于MIG焊接. LMHW接头焊缝中心的组织比MIG焊的组织更细，整体硬度比MIG焊接头整体硬度高，接头的质量较MIG焊的接头质量好. LMHW的接头整体硬度高出MIG焊接头的整体硬度30%.

Abstract: Laser-MIG hybrid welding (LMHW), which combines the advantages of both laser and arc independent heat sources as well as greatly avoids their disadvantages, is a new welding method with great application prospects in the fields of automobiles, ships, petrochemicals, etc. The differences in microstructure and hardness distribution of the dissimilar steel welded joints of 25CrMo4 and 33MnCrB5-2 by LMHW and MIG welding were investigated. The results show that the effect of LMHW was better than that of MIG welding, performing an uniform and full weld seam. LMHW joints exhibited higher overall hardness, finer microsfructure in welding joint centre and better joint quality than MIG welding joints. Specifically, the overall hardness of welded joints of LMHW was 30% higher than MIG welding.