AUSTENITIC STAINLESS STEEL TUBE HAVING EXCELLENT STEAM OXIDATION RESISTANCE, AND METHOD FOR PRODUCING SAME

摘要

There is provided an austenitic stainless steel pipe excellent in steam oxidation resistance. The austenitic stainless steel pipe excellent in steam oxidation resistance contains, by mass percent, 14 to 28% of Cr and 6 to 30% of Ni, and is configured so that a region satisfying the following Formula exists in a metal structure at a depth of 5 to 20 µm from the inner surface of the steel pipe: ± / ² × ´ / µ × 100 ‰¥ 0.3
where the meanings of symbols in the above Formula are as follows:
±: sum total of the number of pixels of digital image in region in which orientation difference of adjacent crystals detected by electron backscattering pattern is 5 to 50 degrees
²: the number of total pixels of digital image in region of measurement using electron backscattering pattern
µ: analysis pitch width of electron backscattering pattern (µm)
´: grain boundary width (µm).