High hardness, high corrosion resistance and high wear resistance alloy
View Patent ↗There are provided a high hardness, high corrosion resistance and high wear resistance alloy, wherein the alloy is an aging heat treated Cr(chromium)-Al(aluminum)-Ni(nickel)-base alloy, 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)/[Iγ(200)+Iγ′(004)]×100, and a component comprising this alloy, a material for an alloy which can form this alloy, and a process for producing this alloy. The present invention can provide a Cr—Al—Ni-base alloy possessing excellent corrosion resistance, hardness, wear resistance, releasability, fatigue strength, and planishing property in a molding face, a component comprising this alloy, a material for an alloy which can form this alloy, and a process for producing this alloy.
1. 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.