| 摘要 |
PURPOSE:To prevent deterioration in the characteristic of a steel owing to the carburization occurring in the decomposition of the binder in a method for subjecting the surface of a steel product to a chromizing treatment after coating a mixture composed of Ni powder and the binder thereon by specifying the shape of the Ni powder and the properties of the binder. CONSTITUTION:A mixture composed of an org. binder which evaporates effectively without causing thermal decomposition, for example, org. amide, and flake Ni powder is coated on the surface of a steel product and dried, then the surface is subjected to a chromizing treatment. Even if the binder used is quickly heated up, the binder evaporates and dispers without decomposing thermally and leaves no residues on the surface of the steel and therefore the need for a calcination stage after the above-mentioned coating is eliminated and the drying by heating at a low temp. is simply required. The chromized surface is made dense by the above-mentioned method and the carburization of the steel is not produced. hence the deterioration of the mechanical properties, particularly the high temp. strength of the steel are obviated. No carbide is produced in the chromized layer and the initial toughness of said layer is maintained without deterioration.
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