| 摘要 |
PURPOSE:To apply surface treatment excellent in surface pressure resistance, wear resistance, and corrosion resistance to a steel product or casting with an austenitic structure, by subjecting a matrix in the vicinity of a surface to be treated to subzero treatment to the prescribed depth and then to artificial aging treatment and by applying vacuum plating to the resulting hardened surface to be treated so as to form a hard film. CONSTITUTION:By applying subzero treatment to the surface, to be vacuum- plated, of the above-mentioned steel product or casting, the matrix in the vicinity of the above-mentioned surface to be treated is subjected to martensite transformation to the prescribed depth to which subzero temp. can be transmitted. Subsequently, artificial aging treatment consisting of heating to 300-600 deg.C for the prescribed time and air cooling is applied to the matrix formed into martensitic structure in the vicinity of the surface to be treated so as to form the structure into (tempered martensitic structure + carbide) and carry out age hardening. Then, vacuum plating is applied to the above-mentioned age- hardened surface to be treated so as to form a hard film. In this way, the above-described superior surface treatment can be applied to the steel product or casting mentioned above.
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