| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a heat treatment method of a long steel pipe capable of simply and reliably preventing generation of scales on the inner surface of the steel pipe due to heat treatment to thereby be able to eliminate a step of removing scales on the inner surface by polishing, pickling, or the like. <P>SOLUTION: The method includes: tightly closing both ends of the long steel pipe 1, degassing the inside of the tightly closed long steel pipe 1, or filling the same with an inert gas or reducing gas after the degassing, and then, heating the entire circumference of the long steel pipe 1 while moving the same in the axial direction, followed by cooling. <P>COPYRIGHT: (C)2013,JPO&INPIT |
