| 摘要 |
PROBLEM TO BE SOLVED: To provide high strength ferritic heat resistant steel having excellent creep rupture strength as the material for high temperature used for boiler tubes for heat generation, turbine parts, chemical plant apparatus, nuclear powder plants or the like. SOLUTION: As to the high strength ferritic heat resistant steel, in an Fe based alloy in which >=90% of the matrix is always formed of a ferritic phase in all temperature ranges of the melting point or lower, an intermetallic compound is age-precipitated. Alternatively, in the steel, sufficient solid solution treatment is performed before aging, so that the uniform and fine age- precipitation of an intermetallic compound is promoted. Further, the steel has a composition containing one or more kinds selected from <=40% Cr, <=10% Si, <=10% Al, <=10% W and <=10% Mo, and the balance Fe with inevitable impurities. Alternatively, the steel further contains <=0.05% C and <=0.05% N, and further contains one or more kinds selected from V, Nb, Ti, Ta, Mn, B, Ni, Co, Cu and rare earth elements by <=5% in total.
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