Welding method for fan foundation jacket flange and main steel pipe

The invention relates to a welding method for a fan foundation jacket flange and a main steel pipe. The welding method comprises the following steps that S1, a groove is formed, specifically, an asymmetric X-shaped groove is manufactured in a joint of the fan foundation jacket flange and the main steel pipe; and S2, welding is conducted, specifically, a welding gun is preheated, the area is welded in a combined welding mode of a right welding method, a backward welding method and a skip welding method, the backward welding method is mainly adopted, and when welding deformation needs to be controlled, the backward welding method and the skip welding method are adopted; a welding nozzle for flux-cored wire gas shielded welding is a conical nozzle, so that the welding reliability of a priming coat is improved, and root forming is guaranteed; and hydrogen elimination treatment is conducted on the area after welding is completed. Flux-cored wire gas shielded welding and vertical assembling are adopted, compared wi