Design of Warm Extrusion Process for Forging Billet
Billet preparation In order to ensure accurate positioning of the billet during extrusion and to prevent problems such as breakage of the punch due to the eccentric force during the extrusion process, the billet for warm extrusion should adopt a precise blanking method. After turning, the surface Clean and free of defects, so that the shape and size of the billet can be strictly controlled, and the quality deviation is allowed to be 2. According to the principle of constant volume, the blank volume is calculated according to the size given in the forging drawing, and the cylindrical blank is selected. The blank size is 33mm×22mm, and the mass is (147.7±1.5)g. Warm extrusion temperature According to the thermal processing characteristics of 20CrMo alloy structural steel and various comprehensive factors, it is more appropriate to select the billet heating temperature as 850 °C. The heating equipment adopts a self-made intermediate frequency induction heating furnace, the surface of the billet is less burned, the thickness of the oxide skin is less than 0.15mm, and the temperature difference between the core and the surface is ±10°C. At the same time, the pushing time is controlled at 15-20S under the condition that the temperature of the billet is uniform. between. In order to prevent the die from being prematurely damaged due to the rapid drop in temperature of the billet at the beginning of extrusion, the die should be preheated to 200~300°C.