Method for heat-treating metal tubes or pipes for nuclear power plant, batch-type vacuum heat treatment furnace used therefor, and metal tubes or pipes for nuclear power plant heat-treated by the same

Abstract

In a method for heat treating a metal tube or pipe for a nuclear power plant, the tube or pipe being accommodated in a batch-type vacuum heat treatment furnace, when the tube or pipe is laid down on and is subjected to heat treatment on a plurality of metal cross beams arranged along a longitudinal direction of the tube or pipe, it is possible to suppress scratches to be formed on the outer surface of the tube or pipe and attributable to heat treatment, and to reduce the discoloration on the outer surface of the tube or pipe by holding the tube or pipe and the metal cross beams in indirect contact with each other by virtue of a heat resistant fabric having a thickness of 0.1 to 1.2 mm interposed in between.

Dependencies are inferred from the claim text.