AUSTENITE-BASE STAINLESS STEEL PIPE, FOR BOILER, HAVING EXCELLENT HIGH-TEMPERATURE STEAM OXIDATION RESISTANCE

摘要

The present invention relates to an austenitic stainless steel tube for boiler, used for superheater or reheater in thermal power plant, giving excellent resistance to high temperature steam oxidation, in particular to an austenitic stainless steel tube containing 16 to 20% Cr by weight, and being cold-worked at the inner surface of the tube. The Cr concentration in the vicinity of the inner surface of the steel tube is 14% by weight or larger, and the hardness at 100 µm depth from the inner surface of the steel tube is 1.5 times or larger the average hardness of the mother material or is HV 300 or larger.