Patent ID: 9347135
Filing Date: 2016-05-24
CPC Classification: B22C,B22D,C23C

Claim Text:
1. A method for rust-proofing a mold having a molding surface and at least one cooling channel through which cooling water flows, the cooling channel being bored from a surface other than the molding surface of the mold toward an inside of the mold, comprising: an iron hydroxide-forming step for forming iron hydroxide on a whole surface of the at least one cooling channel; and a surface-treating step for forming a film covering the molding surface of the mold and for changing the iron hydroxide formed on the whole surface of the at least one cooling channel into black rust, by heating the mold on which the iron hydroxide is formed in the iron hydroxide-forming step under an oxygen-deficiency atmosphere containing an inert gas and a reactive gas for forming the film.