Mandrel bar for high alloy rolling, operation method of the finishing method and production method, and seamless steel tubes production device

摘要

Although the high alloy seamless steel tubes the heat are rolled, being finishing method of the mandrel bar which is used, after doing scale attaching heat treatment in the mandrel bar, Cr content 8% or less 50 passes or more rolls the common steel. Because of this it is possible to offer the resistance printing characteristic which is superior and the mandrel bar for high alloy rolling which possesses useful life.