Chromium carbide cermet thermal spray coating covering member and a method of manufacturing the same excellent high temperature hardness

摘要

PROBLEM TO BE SOLVED: To improve the properties of chromium carbide cermet sprayed coating relatively low in hardness and having problems as to wear resistance and erosion resistance in spite of its excellent heat resistance.;SOLUTION: The surface of a base material is thermally sprayed with a cermet thermal spraying material obtd. by blending chromium carbide with a binder metal composed of carbide forming metals (Cr, Ti, Ta, Nb, Mo and W) and intermetallic compd. forming metals (Ni, Co and Al), and the conditions of a thermal spraying heat source, a thermal spraying atmosphere, the flying speed of thermal spraying particles flying in the heat source or the like are controlled, by which chromium carbide sprayed coating in which the amt. of oxide contained in the coating reaches 0.8 wt.% expressed in terms of the oxygen content is formed. Moreover, by subjecting this chromium carbide cermet sprayed coating to heat treatment under the conditions of 500 to 1,250°C for 0.3 to 5 h or using it in a practical environment of ≥500°C, the carburizing (carbide forming) reaction in the binder metal in the coating and the forming and precipitating reaction of an intermetallic compd. are brought into to improve the high temp. hardness of the coating.;COPYRIGHT: (C)2000,JPO