摘要
Laser-MIG hybrid welding experiments of 7 mm thick Invar alloy are carried out.The macro appearance of joints is observed and the influence of arc energy on the cross-section morphology is analyzed.The distribution of temperature field is simulated to explain the relationship between heat effect and microstructure.Besides,the average grain size of weld under different arc energies is quantitatively studied.The results indicate that welded joints with uniformity and good formation are obtained.The weld width and the weld seam area increase and the depth to width ratio decreases with the increase of arc heat input.The transition of columnar crystals to equiaxed crystals is observed from the fusion line to the weld center.It is found that the higher the arc energy,the coarser the columnar crystal.
开展了7 mm厚Invar合金激光-MIG复合焊接实验,对接头的宏观形貌进行了观察,并分析了电弧能量对横截面形貌的影响。通过模拟温度场分布解释了焊接热效应与微观组织的关联关系。除此之外,定量研究了不同电弧热输入下焊缝的晶粒度大小。结果表明,形成焊缝具有良好的均匀性与成形,随着电弧热输入量的增加,焊缝熔宽及焊缝面积增加,深宽比有所减小。从熔合线到焊缝中心可以观察到柱状晶逐渐转变为等轴晶。同时发现电弧能量越大,柱状晶越粗。
