Patent ID: 8062441

Claim:
A process for producing a high hardness, high corrosion resistance and high wear resistance alloy, said process comprising the steps of: forming a Cr(chromium)-Al(aluminum)-Ni(nickel)-base alloy material by a melting process; subjecting the material to hot working and cold working; subjecting the material to solid solution treatment in such a manner that the material is subjected to solid solution heat treatment and then immersed in an oil for quenching; and subjecting the material to aging heat treatment to form an alloy so that the proportion of a mixed phase of (α phase+γ′ phase+γ phase) precipitated at grain boundaries of γ phase grains in a metal structure in the cross section of the alloy is not less than 95% in terms of area ratio, and the intensity ratio as measured by X-ray diffractometry of the alloy is not less than 50% and not more than 200% in terms of Iα(110)/[Iy(200)+Iγ′(004)]×100, wherein the aging heat treatment is carried out at 500 to 850° C., and wherein, prior to the aging heat treatment, said material is subjected to (i) pretreatment heating in which the material is heated to 400 to 700° C. at a temperature rise rate of not less than 100° C./hr and not more than 500° C./hr and (ii) pretreatment heating in which the material is held in a temperature range of 400 to 500° C. for at least 0.5 hr.