Effect of friction time on heat distribution, material flow, and microstructure of friction welding of dissimilar steels

Abstract

In this paper, 1045 steel is joined to Q235 steel using continuous drive friction welding. The temperature distribution and material flow during the welding process were analyzed by numerical simulation and the flow behavior was further explained by grain distribution. The microstructure and mechanical properties of the joint were investigated experimentally. The results show that with the increase of friction time, the joint temperature first increases and remains in dynamic equilibrium. The joints were divided into a central region, a 0.5R region, and an edge region along the radial direction. The highest temperature of the joint first appears in the edge region, with a relatively low temperature in the central region. The material flow rate in the edge region is faster than that in the center and 0.5 R regions, and the maximum material flow rate increases and then decreases with increasing friction time. When the friction time is suitable, the heat distribution is uniform and sufficient, and the grains show a better refinement effect, which is beneficial to the improvement of the mechanical properties of the joint. Due to the grain refinement of the joint, the highest microhardness is obtained at the weld zone in all welding conditions. All joints fractured on the Q235 steel base material side, and the fracture form was ductile fracture.