Jfe Steel Corporation

Kawasaki Steel Corporation

Hideo Sasaoka

Kazuo Mochizuki

Hiroki Nakamaru

Chiaki Kato

Hiroyuki Ogata

Chiyoko Tada

Shigeru Umino

Sachiko Suzuki

Kazumi Yamashita

Kazuhiko Higai

Fuminori Mukaihara

Yoshinori Gotou

Kazuo Wakasa

Disclosed is a phosphated galvanized steel sheet comprising a steel sheet, a zinc-plating layer of &#x3b7; single phase which is formed on at least one side of the steel sheet and contains Ni in an amount of not less than 10 ppm by mass and not more than the solubility limit thereof, and a phosphate layer which is formed on the zinc-plating layer and contains Mg in an amount of not less than 0.1 % by mass and less than 2.0 % by mass. Although this steel sheet is not subjected to sealing, it has corrosion resistance equivalent to or higher than those of conventional steel sheets which have been subjected to sealing, while having excellent blackening resistance.

Phosphate-treated zinc-coated steel sheet

The coating composition includes a methacrylic resin prepared by copolymerization of styrene or a substituted styrene (A), a methacrylic ester obtained from an alcohol having at least two carbon atoms and methacrylic acid (B), and an olefinic compound having at least one carboxylic group (C), in which the molar ratio thereof is 1:(0.05 to 44.5):(0.12 to 13). A metal sheet lubricated with the coating composition has superior characteristics of dissolution of the film in an alkaline solution, chemical processing, paint dryness, blocking resistance, corrosion resistance, stability of coating composition, and press formability (powdering resistance and galling resistance).

Coating composition and lubricated metal sheets

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Chiba, Japan

Hideo Sasaoka