Method with welding residual stress control and crack prevention functions

The invention discloses a method with welding residual stress control and crack prevention functions, which comprises the following steps of: before welding, determining preheating temperature and heat preservation time according to the strength of a workpiece material, a stress state, a welding method and welding parameters; the annular large-wall-thickness welding seam of the workpiece material is subjected to segmented welding; repeated multi-pass welding is adopted for midway welding, a final plugging section is reserved, and welding is conducted; in the welding process, real-time temperature monitoring is conducted on a welding area, welding parameters are adjusted according to real-time temperature data, and the welding temperature and the welding speed are controlled; and after welding, a welding joint is cooled. The method is used for solving the technical problems that an existing method for controlling the welding stress and preventing the welding cracks cannot well adapt to the welding requirements