| 摘要 |
A Ni-base heat resistant alloy, which comprises by mass percent, C: 0.1% or less, Si: 1% or less, Mn: 1% or less, Cr: not less than 15% to less than 28%, Fe: 15% or less, W: more than 5% to not more than 20%, Al: more than 0.5% to not more than 2%, Ti: more than 0.5% to not more than 2%, Nd: 0.001 to 0.1% and B: 0.0005 to 0.01%, with the balance being Ni and impurities, in which the contents of P, S, Sn, Pb, Sb, Zn and As among the impurities are P: 0.03% or less, S: 0.01% or less, Sn: 0.020% or less, Pb: 0.010% or less, Sb: 0.005% or less, Zn: 0.005% or less and As: 0.005% or less, and further satisfies the formulas of [0.015 ‰¤ Nd + 13.4 × B ‰¤ 0.13], [Sn + Pb‰¤ 0.025] and [Sb + Zn + As ‰¤ 0.010] is an alloy in which much higher strength than the conventional Ni-base heat resistant alloy can be achieved, the ductility and toughness after a long period of use at a high temperature are remarkably improved, and moreover the zero ductility temperature and the hot workability are also further improved. This alloy can be suitably used as a pipe material, a thick plate material for a heat resistant pressure member, a bar material, a forging, and the like for a boiler for power generation, a plant for chemical industry, and the like. This alloy may contain a specific amount of one or more elements selected from Mo, Co, Nb, V, Zr, Hf, Mg, Ca, La, Ce, Ta and Re. |
