OXIDE DISPERSION STRENGTHENED-TYPE FERRITIC STEEL FOR CHROMIZING TREATMENT

摘要

PURPOSE:To obtain a steel usable in a chromized state and excellent in strength at high temp. and high-temp. corrosion resistance by limiting C content in an oxide dispersion stiengthened-type ferritic steel of specific Cr content to a specific value. CONSTITUTION:In an oxide dispersion strengthened-type ferritic steel containing =25%, by weight, Cr, C content is regulated to 0.04% and, if necessary, 0.5-3% Ti is incorporated. Further, when =0.04% C is mixed in the course of producing the above steel, the composition of the above steel is regulated so that it contains 0.04-0.25% C and 2.3% Ti and further contains 0.5-3%, in total, of one or more elements among Nb, V, and Zr to form carbide and fix the amount of solid-solution C. Moreover, it is preferable that the grain size of the grains of the above oxides, such as Y2O3, ZrO2, and TiO2, is regulated to = about 0.5mum, particularly about 0.01-0.05mum. By this method, the oxide dispersion strengthened-type ferritic steel for chromizing treatment excellent in strength at high temp. and high-temp. corrosion resistance in a chromized state can be obtained.