Construction method for welding furnace tube and dissimilar steel

The invention relates to a construction method of a furnace tube and a dissimilar steel, comprising the following steps: adopting a special fixture to assemble welded bonds, cleaning weldments, filling argon in a pipeline for replacement, welding the pipeline layer by layer, checking appearance after welding, performing weld bond repair and rework on unqualified pipelines, carrying out PT and RT detection after qualification confirmation, and carrying out thermal treatment on the welded bonds; hoisting in place after hardness test, ball passing test and strength test are qualified; and detecting system gas tightness, issuing completion documents. The invention can realize furnace tube conversion from entire import to localization, lowers equipment acquisition value, facilitates transportation, and can ensure construction period and quality in the overhauling process in a chemical industry factory. By repeated simulation tests and construction of similar projects, the welding and thermal treatment technologies