METHOD FOR HEAT-TREATING METAL PIPES, METAL PIPE, AND HEAT TREATMENT FURNACE

摘要

A method for heat treating a metal tube or pipe is provided to perform heat treatment in such a manner that metal tubes or pipes (1) to be accommodated in a heat treatment furnace are laid down on a plurality of cross beams (22) arranged along a longitudinal direction of the metal tubes or pipes with the distance between adjacent cross beams being in a range of 200 to 2500 mm. This makes it possible to inhibit bending and scratches of the metal tubes or pipes without causing discoloration and deterioration of the manufacturing efficiency for the metal tubes or pipes. When the metal tubes or pipes (1) are laid down on the cross beams (22), spacers may be interposed between the metal tubes or pipes (1) and the cross beams (22) on which they are laid down. In the method for heat treating a metal tube or pipe of the present invention, it is preferred to use cross beams having a convex top surface or spacers having a convex top surface, and this makes it possible to further inhibit scratches.