Pulsed switch-on preheating flash butt welding process for steel rims of heavy trucks

The invention discloses a pulsed switch-on preheating flash butt welding process for steel rims of heavy trucks, which belongs to the technical field of welding, and comprises the steps of blanking, reeling, flattening, welding condition setting, fitting, pulsed flash preheating, continuous flash, charged upsetting, pressure maintaining, clamp loosening, deburring, and the like. The process is characterized by comprising the controlled process parameters as follows: the overhanging length is 20-50mm; the flash allowance is 5-12mm; the upset allowance is 5-10mm; the upset force is (2-3)*105 N; the clamp force is (3-6)*105 N; the pulsed switch-on preheating process is (4-10) times*(0.5-1.2) s, (0.1- 0.2) s per pulse; the preheating and welding voltage is 10.8-14.6 V; the flash time is14-30s; and the upset charged time: 0.3-2s. The process disclosed by the invention has the advantages that the degree of automation is high; the process is suitable for welding steel rims (thickness: 3-8mm, width: 300-400mm) of heavy trucks, and after the welded steel rims are sequentially subjected to trimming, flaring, roll shaping and expanding, the welded joints have no crack defect.