Development of New Intermediate Nickel Alloys for Application in Automotive Valves of High Performance Engines

UNS N07751 and UNS N07080 alloys are commonly applied for automotive valve production for high performance internal combustion engines. These alloys present high hot resistance to mechanical strength, oxidation, corrosion, creep and microstructural stability. However, these alloys present low wear resistance and high cost due to the high nickel contents. In this work it is presented the development of two new nickel intermediate alloys for application in automotive high performance valves that are alternatives to the alloys UNS N07751 and UNS N07080.

The new developed alloys are based on a high nickel chromium austenitic matrix with dispersion of γ' and γ'' phases and containing different NbC contents. Due to the nickel content reduction in the developed alloys in comparison with the current used alloys, the new alloys present an economical advantage for substitution of these traditional Ni-based alloys, once the new alloys present similar to better properties than UNS N07751 and UNS N07080 alloys.