Patent ID: 8431230

Claim:
A cast product for use in high temperature atmosphere, said cast product comprising: a cast body of a heat-resistant alloy consisting essentially of, in mass percent, 0.05 to 0.7% of C, more than 0% and no more than 2.5% of Si, more than 0% and no more than 3.0% of Mn, 15 to 50% of Cr, 20 to 70% of Ni, 2 to 4% of Al, 0.005 to 0.4% of rare-earth elements, and at least one member selected from the group consisting of 0.5 to 10% of W and 0.1 to 5% of Mo, the balance being Fe and inevitable impurities; and a barrier layer formed on a surface of the cast body to be brought into contact with said high temperature atmosphere; wherein said barrier layer comprises an Al 2 O 3 layer having a thickness of 0.5 μm or more; wherein at least 80 area % of an outermost surface of the cast body is Al 2 O 3 ; wherein said cast product has Cr-based particles dispersed at an interface between the Al 2 O 3 layer and the cast body at a higher Cr concentration than a Cr concentration of a matrix of the alloy; and wherein the surface of the cast body before forming Al 2 O 3 layer is of a roughness (Ra) of 0.05 to 2.5.