Patent ID: 8047039
Filing Date: 2011-11-01
Classification: B21B,C21D,C22C

Abstract:
1. A process for producing stainless steel pipes by subjecting a stainless steel raw material containing, by mass, Cr: 10-30%, to piercing rolling to give a hollow shell, subjecting the hollow shell to elongating rolling to give a finishing rolling blank pipe using a mandrel bar, together with a graphite-free lubricant, and heating the blank pipe in a reheating furnace and subjecting the heated blank pipe to finishing rolling by sizing rolling, wherein the finishing rolling blank pipe is subjected to heating in which it is heated to a temperature not less than 1000° C. in the reheating furnace and an oxidizing gas is blown into the inside of the finishing rolling blank pipe from one end thereof using a blowing nozzle such that combustion of C is fully promoted in the carburized layer in the inside of the finishing rolling blank pipe.