METHOD FOR PRODUCING CR-CONTAINING NICKEL-BASE ALLOY TUBE AND CR-CONTAINING NICKEL-BASE ALLOY TUBE

摘要

To form a chromium oxide film on the inner surface of a Cr containing nickel-base alloy tube inexpensively and uniformly, the Cr containing nickel-base alloy tube is heated in atmospheric gas of carbon dioxide gas and non-oxidation gas to form an oxide film consisting of chromium oxide having a thickness of 0.2 to 1.5 µm on the inner surface of the Cr containing nickel-base alloy tube. The atmospheric gas may contain oxygen gas of 5 vol% or less and/or water vapor of 7.5 vol% or less.