Ferritic heat-resistant steel and method for producing it

摘要

The invention provides a ferritic heat-resistant steel having excellent high-temperature oxidation resistance, especially excellent steam oxidation-resistant characteristics. In high-Cr ferritic heat-resistant steel, ultra-fine oxide particles having a size of not larger than 1 mu m are formed just below the oxide films and formed on the steel base, whereby the adhesiveness between the films and the base is enhanced. The ferretic heat-resistant steel consists of: C from 0.02 to 0.18% Si up to 1.0%, Mn up to 1.5%, P up to 0.030%, S up to 0.015% Cr from 8.0 to 13.0% Mo up to 2%, W up to 4%, with W + 2Mo ≤4% V from 0.10 to 0.50%, Nb from 0.02 to 0.14% either Ti and/or Y, with 0.01 ≤Ti + Y ≤0.30% either Rh and/or Ir, with 0.3% ≤Rh + (1/2)Ir ≤5% either Pd and/or Pt in a total amount between 0.3 and 5% balance Fe