Patent ID: 8900510

Claim:
A heat-resistant, ferritic cast steel having excellent room-temperature toughness, which has a composition comprising by mass 0.32-0.48% of C, 0.85% or less of Si, 2% or less of Mn, 1.5% or less of Ni, 16-19.8% of Cr, 3.2-5% of Nb, Nb/C being 9-11.5, 0.15% or less of N, 0.002-0.2% of S, and 0.8% or less in total of W and/or Mo, the balance being Fe and inevitable impurities, and a structure in which a eutectic (δ+NbC) phase formed from a δ phase and Nb carbide (NbC) has an area ratio of 60-90%.