Finite-element analyses of die wear during hot extrusion of Hastelloy G3 tubes

Based on a modified Archard wear model,the effects of process variables,such as ram speed,initial billet temperature,friction factor and die angle,on the die wear during hot extrusion of corrosion-resistant nickel alloy (Hastelloy G3) tubes were investigated by using DEFORM-2D software.The results show that the wear concentrates on the die exit.The maximum wear depth of dies decreases with increasing ram velocity and billet temperature,but it increases with increasing friction factor.The wear depth on the die surface increases with increasing die angle.Under the optimal extrusion process variables of the ram velocity of 200 mm·s^-1,the initial billet temperature of 1 180 ℃,the friction factor of 0.05 and the heat transfer coefficient of 5 N·mm^-1·s^-1·℃^-1,the maximum wear depth of dies was 0.051 5 mm and the die can be reused 20 times.