摘要 |
The surface of a pre-molded article made of SKH51 (Fe-based alloy) is coated with a powder of Al, Cr and the like. The coating may be performed by applying a coating agent which is prepared by dispersing the powder in an organic solvent. The coating agent may contain a reducing agent. After coating, the pre-molded article is subjected to heat treatment to form a carbonized product of the metal. The pre-molded article may be further treated with nitrogen, thereby forming a layered Fe-based alloy which has a diffusion layer which is formed by the diffusion of the carbonized product, a nitrided product and AIN in the base material. Subsequently, the article may be subjected to finishing process to give a punch having a predetermined shape for use in a hot-roll forging process.
|