| 摘要 |
An object of the present invention is to provide an aluminum-alloy-made forged scroll part in which harmful primary Si crystals are not formed and variation in wrap height between the scrolls is low. The present invention also provides a process for producing the forged scroll part. An alloy material including Si: 8.0-12.5%; Cu: 1.0-5.0%; Mg: 0.2-1.3%; and if necessary, Ni: 2.0% or less and/or one or more species selected from among Sr, Ca, Na, and Sb: total 0.5% or less, is cast through continuous casting into a round bar material having a diameter of 130 mmphi or less, and subsequently, the material is subjected to upsetting and hot forging with back pressure to produce a forged scroll part containing substantially no Si particles having a size of 15 mum or more, the mean size of Si particles in the forged part being 3 mum or less. |
