| 摘要 |
PROBLEM TO BE SOLVED: To increase the hardness of the member and to improve its wear resistance by forming sprayed coating of a chromium carbide cermet having a specified compsn. of chromium carbide and Ni and/or carbide forming metal(s), and in which the porosity and average hardness are controlled to specified values on the surface of a heat resistant metallic base material. SOLUTION: Sprayed coating to be formed on the surface of a base material has chemical components composed of, by weight, 95 to 50% chromium carbide and 5 to 50% Ni and/or one or more kinds of carbide forming metals among Cr, Ta, Ti, W, Mo and Nb. Then, it has film characteristics in which porosity shows the value of <1.20%, and the average hardness >=1000 Hv. The sprayed coating film can be obtd. by first executing thermal spraying in which the velocity of spray particles flying in a heat source is >=200 m/sec at 1800 to 2800 deg.C heat source temp. and next subjecting the formed sprayed coating film to heat treatment at 500 to 900 deg.C for 0.3 to 3 hr in the air.
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