Analysis on deformation control of stainless steel subway car body bottom edge beams MAG welding

The edge beams of the stainless steel car body frame are usually formed by steel plate roll bending technology. In order to strengthen the structure of the edge beams themselves and consider the assembly structure with traction sleepers, the bottom frame edge beams are usually reinforced by a structure of reinforcing plates and sealing plates in the surrounding area of the sleepers. Stainless steel material has the physical characteristics of low thermal conductivity and high coefficient of linear expansion, which leads to significant deformation of the bottom frame edge beam when welding reinforcement and sealing plates using MAG welding method, affecting the subsequent process of bottom frame assembly. This article analyzes the structural welding simulation and welding sequence optimization of the bottom frame edge beam, providing a reference method for controlling the welding deformation of stainless steel subway bottom frame edge beams.