METHOD FOR MANUFACTURING RESIN-COATED STEEL PIPE EXCELLENT IN ANTI-CORROSIVE PROPERTY

摘要

PPROBLEM TO BE SOLVED: To provide a method for manufacturing a resin-coated steel pipe excellent in anti-corrosive properties, which provides an excellent anti-corrosive performance to a welded part and its vicinity, equivalent to the anti-corrosive performance provided to other parts of the steel pipe. PSOLUTION: The generation of pinholes and bubbles in a resin coating is effectively controlled by heating the part to be welded of the steel pipe before the resin coating is applied in a specific condition, and the anti-corrosive performance at the welded part or its vicinity is found drastically improved. In the method for manufacturing the resin-coated steel pipe wherein the welded pipe is coated with the resin, the part to be welded of the welded pipe is heated before the resin coating in the heating condition satisfying T≥270tSP-0.31/SPpreferably T≥438tSP-0.38/SP(provided, however, T: heating temperature (°C), t: heating retaining time (min)). PCOPYRIGHT: (C)2005,JPO&NCIPI