PROCESS FOR PRODUCING STAINLESS-STEEL PIPE

摘要

A process for stainless-steel pipe production which comprises piercing and rolling a stainless steel containing 10-30 mass% chromium as a raw material to obtain a raw pipe to be finish-rolled, rolling the raw pipe by drawing rolling with a mandrel using a graphite-free lubricant, subsequently heating it in a reheating furnace, finish-rolling the heated pipe by sizing rolling to produce a hot-finished pipe, and then subjecting this pipe as a raw pipe to cold working to produce a stainless-steel pipe. In the reheating furnace, the raw pipe to be finish-rolled is heated to 1,000°C or higher and subjected to a heat treatment in which an oxidizing gas is blown against the inner surface thereof, whereby a stainless-steel pipe can be produced which is inhibited from generating a carburized layer in the inner surface of the pipe. When the finish rolling by sizing rolling is conducted by stretch reducer rolling at 860-1,050°C, a softening heat treatment of the raw pipe for cold working can be omitted. Thus, a stainless-steel pipe having excellent surface quality can be produced.