| 摘要 |
<p>A heat-resistant cast steel, which has a chemical composition that C: 0.1 to 0.5 %, Si: 2.5 % or less, Mn: 2.5 % or less, Cr: 15 to 26 %, Ni: 8 to 23 %, Nb: 0.1 to 1.2 %, Ti: 0.01 to 1.0 %, Ce: 0.001 to 0.15 %, N: 0.06 % or less, and the balance: substantially Fe, with the proviso that a P value calculated from the formula: P = 89.3 - 78.4C + 0.1Si - 5.7Mn - 1.7Cr + 0.01Ni + 2Nb + 5.3Ti -36.5N -50.8Ce is 20 to 45. Optionally, the cast steel may further comprise one or more of 0.001 to 0.05 % of B, 0.01 to 0.5 % of Zr and 0.001 to 0.15 % of La, and/or 0.01 to 0.3 % of Al. In some cases, the composition is preferably limited to C: 0.1 to 0.3 %, Cr: 15 to 20 % and Ni: 8 to 18 %. The above heat-resistant cast steel is excellent in strength at a high temperature, aging ductility, fatigue characteristics and the like, and thus can be suitably used as a material of a steam reforming reaction tube, for use in an apparatus for producing hydrogen for a fuel cell and the like.</p> |
