Patent ID: 8287968

Claim:
A coating-film forming method comprising: a metal-powder producing step of producing a metal powder containing an element exhibiting a lubricating property when oxidized and comprising a mixture of chromium (Cr), nickel (Ni), tungsten (W), and cobalt (Co); an oxidizing step of oxidizing the metal powder to produce an oxidized metal powder, the amount of oxygen contained in the oxidized metal powder is within 6 weight % to 14 weight %; and a coating-film forming step of forming a coating film from the oxidized metal powder on a material subject to a treatment, the coating film having such a composition that an area where an oxygen content is 3 weight % or less and an area where an oxygen content is 8 weight % or more are distributed in a unit area of the coating film, and an oxygen content of the entire coating film is within 5 weight % to 9 weight %.