Metal material surface treatment process

Abstract

This invention provides a surface treatment process for metal materials that can impart better corrosion resistance, coating adhesion, and appearance. One aspect of this surface treatment process is a process for treating metal materials, comprising: a pretreatment step, in which the metal material is treated with a pretreatment agent; a chemical forming step, in which the pretreatment metal material is chemically formed; and a coating step, in which the chemically formed metal material is coated; wherein the pretreatment agent contains an amine-containing compound and has a pH value of 6.0 or higher and less than 12.0.