HIGH CHROMIUM STEEL FOR WASTE INCINERATION WASTE HEAT BOILER TUBE

摘要

PURPOSE:To form a protective Al2O3 layer excellent in corrosion resistance on the surface of a tube product and to obtain a tube product capable of use for a long period even in a corrosive environment by producing various tube products for waste heat boiler to be provided to a waste incinerator by using a high Cr steel containing specific amounts of Al. CONSTITUTION:Since various tube products used for a waste heat boiler utilizing the heat generated at the time of incinerating municipal refuse, industrial wastes, etc., are exposed to a highly corrosive high temp. gas composed essentially of hydrogen chloride gas in a combustion gas, a tube product prepared by using a stock which has a composition containing, by weight, 0.005-0.05% C, 2% Si, 2% Mn, 9-16% Cr, 2-10% Ni, and 1-6% Al or further containing 0.1-1.0%, in total, of one or more elements among Ti, Nb, and Zr is used. By this method, a dense protective Al2O3 film excellent in corrosion resistance can be formed on the surface of the tube product, by which the tube product having superior corrosion resistance even to a severe and corrosive high temp. combustion gas can be obtained.