| 摘要 |
<p>Disclosed is a heat-resistant steel which is excellent in high-temperature long-term creep strength and creep-fatigue strength. Specifically disclosed is a heat-resistant steel having a composition consisting of, in mass%, 0.01-0.13% of C, 0.15-0.50% of Si, 0.2-0.5% of Mn, not more than 0.02% of P, not more than 0.005% of S, more than 8.0% but less than 12.0% of Cr, 0.1-1.5% of Mo, 1.0-3.0% of W, 0.1-0.5% of V, 0.02-0.10% of Nb, not more than 0.015% of sol. Al, 0.005-0.070% of N, 0. 005-0.050% of Nd, 0.002-0.015% of B, and the balance of Fe and impurities. As some of the impurities, less than 0.3% of Ni, less than 0.3% of Co and less than 0.1% of Cu are contained in the heat-resistant steel. This ferritic heat-resistant steel contains Nd inclusions at a density of not less than 10,000 inclusions/mm^3. This steel may further contain one or more elements selected from Ta, Hf, Ti, Ca and Mg in addition to the above-described components.</p> |
