▎ 摘　　要

NOVELTY - The method involves removing oil and impurity in a copper-steel composite plate. The copper steel composite plate after cleaning is rolled by a rolling pipe mold to obtain a copper steel composite circular arc pipe. A seam of the copper steel composite circular arc pipe is welded to obtain a circular tube semifinished product (1). Burrs at the welding seam is removed by a scraper. A steel base material is exposed. A fixing tool (2) made of graphene material is sleeved on the circular tube semifinished product. An inner diameter side of the fixing tool is formed with a solder filling groove (3) axially parallel to the fixing tool. A welding material is completely covered on an exposed portion of a steel base material, and fused with a copper layer of a copper-steel composite winding pipe at two sides of a welding line (5). USE - Method for manufacturing a copper-steel composite coil pipe used in a current domestic air conditioner or commercial air conditioner and a heat pump water heater. ADVANTAGE - The method enables welding a middle connection portion by brazing process, so that a tubing satisfies rust-proof and brazing requirements at low cost, and increasing stainless steel pipe strength, anti-rust effect and quality of a copper steel composite coil pipe by enhancing fire-resistant and heat-resistant property, and avoiding deformation of the pipe in transportation. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of a circular tube semi-finished product. Circular tube semifinished product (1) Fixing tool (2) Solder filling groove (3) Solder (4) Welding line (5)