Manual Self-Propagating High-Temperature Synthesis Welding of 45 Steel

A new style of emergency welding, named manual SHS welding ,was introduced. By this technique, metal materials could be welded on the condition of no electricity, no gas and no equipments. In this paper, the mechanism of manual SHS welding has been illustrated, the effect of thermit on welding and the microstructure of the welded joint have been studied, and the mechanical properties have been tested. Results showed that the combustion velocity of the combustion welding rod became higher when the content of (CuO+Al) thermit increased. The suitable (CuO+Al) content is 60%wt ~80%wt. The tested 45 steel plates were one-side welded with back formation. Microstructure analysis indicated that there are three zones in the welded joint, which are heat affected zone, fusion zone and weld metal. The weld metal and the 45 steel plates were combined metallurgically. The weld metal was copper based alloy. EDS patterns showed that there was diffusion of Cu, Fe and Ni in the three zones. The fracture of the weld joint is a typical ductile fracture. The tensile strength of the joints reached 400MPa and the impact absorbed energy was about 35J, which meet the requirement of mechanical properties for emergency welding. Manual SHS welding is an effective welding method for emergency maintenance in battlefield and outside field.