| Friction Stir Welding which is an advanced Connection technology was developed byBritish Welding Institute (TWI) in 1991 for the aluminum alloy. compared with traditionalwelding methods,it has characteristic of high-quality, high efficiency, low consumption, smalldeformation, no pollution, low cost.and so on.As steel, titanium and other high melting point materials have high strength and hardness,so it has high demand of the pin's performance, requiring material has excellent wearresistance and strength under the conditions of high temperature. In this paper, welding headsof a variety of materials are tested, in order to improve the plasticity of steel and reduce theabrasion of the pin, using the method of electromagnetic induction and heating stick topreheat the Q235 plate before welding. In order to achieve stability and dynamic heat welding,welding platform and high-frequency induction heat's holding device were designed. Theresults showed that electromagnetic induction has higher efficiency than heating stick, andand which can put the heat together on the welding. the method of preheating can improvethe plasticity of steel and reduce the abrasion effectively, improving the life of the pin.Microstructure,mechanical properties and hardness of weld which has preheating and nopreheating were juxtaposed. The results showed that the weld tissue which has no preheatinghas dynamic recrystallization, smaller grain, higher mechanical properties. the weld which haspreheat has larger grains, poor mechanical performance. it can be seen that preheating reduceabrasion of the pin, but reduced the mechanical properties of the weld. Finally, summarizedthe deficiencies and areas for improvement of the experiment, which provides a theoreticalbasis for the hybrid friction stir welding.
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