Posco

Yung-Keun Kim

Yeon-Ho Kim

Yong-Woon Kim

Yon-Kyun Song

Young-Jun Park

Provided are a zinc-base plated steel material comprising a base steel and a zinc-based plated layer and a post-treatment film, which are sequentially formed on the base steel. The post-treatment film comprises an oxide or oxide salt of at least one group A element selected from B, Al, V, and Fe and an organic compound, wherein the content of oxygen atoms in the post-treatment film is 50 atom % or more, and wherein when the mole number of oxygen atoms forming a covalent bond with hydrogen in the post-treatment film is a and the mole number of oxygen atoms not forming the covalent bond with hydrogen is b, a/b is 0.3 or greater; and a composition for forming the post-treatment film.

Zinc-based plated steel material having excellent sealer adhesion

Provided is a zinc-based plated steel sheet having a post-treated coating filmed thereon including: a steel sheet; a zinc plated layer formed on the steel sheet; and a post-treated coating formed on the plated layer, wherein the atomic ratio (O/M) of oxygen (O) to metals (M) contained in the post-treated coating is greater than 2 and less than 20, and a method for post-treating a zinc-based plated steel sheet. According to this, the zinc-based plated steel sheet having the post-treated coating formed thereon has the effects excellent in lubricity, weldability, adhesiveness, film-removing property and paintability. As the method of post-treating a zinc-based plated steel sheet of the present invention employs a simple coating method irrespective of the kind of plating layer, the process is simple and economical and the process operation cost is low.

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Gwangyang-si, South Korea

Yung-Keun Kim