摘要 |
<p>A layer of a nitride or carbonitride containig at least one of chromium, Group Va elements, titanium and zirconium is formed on the surface of an iron alloy material which has been nitrided. The layer is formed by heating the iron alloy material at a temperature not exceeding 700oC with a material containing at least one of chromium, Group Va elements, titanium and zirconium and a treating agent. It is a dense layer bonded tightly to the iron alloy material. As a low temperature not exceedind 700oC is employed, no large amount of heat energy is required, nor is any thermal strain produced in the iron alloy material.</p> |