High-speed steel is an important tool material, it has higher quenching and tempering hardness and red hardness than carbon tool steel, but its price is relatively high. In order to save high-speed steel materials and reduce tool costs, when manufacturing rod tools (such as twist drills, taps, etc.), carbon structural steel (handle material) and high-speed steel (blade material) are generally used for welding. Welding methods mainly include flash welding and friction welding. The welding quality of flash welding is unstable, and it is easy to produce oxidative decarburization and form ferrite strips, which causes metallurgical defects such as overheating and overburning of the structure. Friction welding can get a better welding effect. In this paper, the optimized friction welding process parameters and post-weld heat treatment process were used to obtain 45 steel / W8Co3N high-speed steel welded joints with good microstructure and mechanical properties.
Welding test materials used 45 steel and W8Co3N high-speed steel bar (14mm), the original state of the material is normalized (45 steel) and annealed (W8Co3N high-speed steel).
The C20 continuous drive friction welding machine is used for welding. The spindle speed of the welding machine is 1475r / min. The friction welding process parameters are shown in Table 1. Table 1. Friction welding process parameters friction pressure upset pressure pressure friction time upset time top brake system synchronous joint welding Immediately after the annealing treatment to eliminate the welding residual stress, then the overall quenching and three high temperature tempering. The annealing process is: 860 * C for 5 hours, air cooling after furnace cooling to 560 * C. The quenching process is: quenching heating temperature 1220 * C, tempering heating temperature 550
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