| 摘要 |
<p>The present invention relates to a turbine wheel of an automotive turbocharger, including a Ni-based alloy having a composition which contains, in terms of mass%: C: 0.08 to 0.20%; Mn: 0.25% or less; Si: 0.01 to 0.50%; Cr: 12.0 to 14.0%; Mo: 3.80 to 5.20%; Nb+Ta: 1.80 to 2.80%; Ti: 0.50 to 1.00%; Al: 5.50 to 6.50%; B: 0.005 to 0.015%; Zr: 0.05 to 0.15%; and Fe: 0.01 to 2.5%, with the remainder being Ni and unavoidable impurities, in which the turbine wheel includes a wing part and a shaft part, and a size of ³' phase in each site of from a tip of the wing part to the shaft part is structure-controlled so as to fall within a range of from 0.4 to 0.8 µm.</p> |
