Development of Multi-rifled Seamless Steel Tubes for High-pressure Boiler

The technical conditions and process procedure of the cold drawn multi-rifled seamless steel tubes for high-pressure boiler are described and the control points such as rib height, side scratches and collapse distortion of convex ribs and also the lubrication conditions are analyzed and discussed. The test and analysis show that, with the independently designed inner and outer drawing dies, using the mandrel mill rolled shell as the mother pipe, the Ф51 mm×5.7 mm 15CrMoG multi-rifled seamless steel tubes with 8 ribs produced through the process procedure of one pass cold drawing and wall thickness finishing plus one pass cold drawing to form the multi-rifled tubes, which is developed for high-pressure boiler, fully meet the technical conditions required by the standard GB/T 20409—2006.