Patent ID: 7211159

Claim:
Ferritic heat-resistant steel comprising, on the basis of percent by weight, 1.0 to 13% of chromium, 0.1 to 8.0% of cobalt, 0.01 to 0.088% of nitrogen, 3.0% or less of nickel, 0.01 to 0.060% of niobium and 0.01 to 0.50% of one or more elements selected from a group consisting of vanadium, tantalum, titanium, hafnium, and zirconium that are MX precipitate forming elements, 0.0 1% or less of carbon and a balance being substantially iron and inevitable impurities, wherein MX precipitates precipitate on grain boundaries and in entire grains, and the grain boundary existing ratio of an M 23 C 6 precipitate precipitating on the grain boundaries is 50% or less.