Method for manufacturing high-durability coated steel pipe using heterogeneous epoxy coating agents and coated steel pipe with improved durability manufactured thereby

摘要

The present invention relates to a method of manufacturing a highly durable coated steel pipe having excellent adhesion while preventing the deposition of scale or contaminants by using different types of epoxy coating agents having different compositions, and not causing corrosion for a long time. The method of manufacturing a coated steel pipe according to the present invention comprises the steps of: (a) coating the inner surface of the steel pipe with a first epoxy coating agent to a thickness of 50 to 500 µm to form a base coating layer; And (b) coating a second epoxy coating agent to a thickness of 150 to 1,000 μm on the inner surface of the steel pipe on which the undercoat layer is formed to form a double-layered inner coating layer including a undercoat layer and a top coat layer.