| 摘要 |
In this method, the inner surface of a metal pipe containing, by mass percent, 20 to 55% of Cr and 20 to 70% of Ni is subjected to mechanical treatment, the metal pipe is subjected to heat treatment such as to be held in a temperature range of 1050 to 1270°C for 0.5 to 60 minutes, and thereby an oxide scale layer consisting mainly of Cr is formed on at least the inner surface of the metal pipe. A metal pipe excellent in carburization resistance and coking resistance in a carburizing gas environment can be obtained by the method. |
