MANUFACTURING PROCESS AND EQUlPMENT FEATURES OF ROLL TYPE HOT-EXPANDING PIPE MILL

Described in the article are the main aspects of the 711. 2mm Roll Type Hot-expanding Pipe Mill located at the Dalmine Steel Works, Italy, including manufacturing process and equipment features, layout of the mill plant as well as the technical-economic benefits produced by the mill. A hydraulic fine setting mechanism is used in the plug system of the mill to compensate the gauge uneveness occurring during rolling. The said roll type pipe-expanding process provides such advantages as better tube geometric accuracy, particular concentricity, fewer sizes of blank tubes neededfor a wider expanding size range and cost-effective production,of tubes on a small lot basis.