Fe-6.5%Si合金热轧板焊接接头的组织和力学性能

摘要 针对Fe-6.5%Si合金热轧板焊接接头易萌生裂纹的问题，研究了不同氩弧焊工艺对焊接接头显微组织和力学性能的影响规律.研究表明:不使用填充焊丝的TIG焊不适合Fe-6.5%Si合金热轧板焊接，因在焊缝内出现大量显微裂纹；使用工业纯铁焊丝的MIG焊实现了Fe-6.5%Si合金热轧板的良好连接，焊缝表面连续、鱼鳞纹均匀，焊缝内无显微裂纹.稀释硅浓度是改善焊缝区组织和力性的有效方法.优化工艺下的焊接接头在500℃拉伸延伸率5.5%，抗拉强度280MPa，满足Fe-6.5%Si合金板带制造过程中的温轧工艺要求.
Abstract：To solve the problem that welding joint is easy to crack in hot bands of Fe-6.5%Si alloy， the effect of argon arc welding process on the microstructure and mechanical properties of joints was investigated. The results showed that TIG welding without filler wire is not suitable for the welding of Fe-6.5%Si alloy hot bands because it produces a large number of cracks in the weld. While MIG welding using the electrodes made of industrial pure iron successfully connects the hot bands. The weld is continuous in the surface， the fish-scale pattern is uniform and no micro-cracks are in the weld. The optimization of microstructure and plasticity can be attributed to the dilution of silicon concentration in the weld zone. After the optimization of welding process， the tensile elongation and the ultimate tensile strength of the joint are 5.5% and 280MPa， respectively， which can meet the requirement of warm rolling process of Fe-6.5%Si alloy.