摘要

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 280 MPa, respectively, which can meet the requirement of warm rolling process of Fe-6.5%Si alloy.

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