Acquisition of HSLA steel weld joints with excellent mechanical performance through flash butt welding physical simulation

Flash butt welding (FBW) of high-strength low-alloy steel was physically simulated by the thermomechanical simulator and the influence of upset allowance (δu) on the microstructural and mechanical evolution of the welds was revealed. A moderate increase in δu from 3.5 to 6.5 mm will increase the amount of acicular ferrite and bainite ferrite with finer size in the weld zone, and also provide sufficient plastic deformation and proper dynamic recrystallization, paving the way to obtain excellent strength and plasticity being compatible with that of base metal. The findings will provide valuable references for the practical FBW process.