Title:
HOT DIP ZN-AL COATED STEEL SHEET HAVING EXCELLENT APPEARANCE, AGE BLACKENING RESISTANCE AND CORROSION RESISTANCE
Document Type and Number:
Japanese Patent JP2754126
Kind Code:
B2
Abstract:
PURPOSE: To produce the hot dip Zn-Al coated steel sheet having excellent appearance, age blackening resistance and corrosion resistance by forming hot dip Zn-Al plating films contg. specific ratios of Al, Ti and Mg and having the spangle size of the surfaces of a specific value on the steel sheet.
CONSTITUTION: The plating films of about 100 to 120g/m2 per surface of coating weight of plating are formed on the steel sheet by immersing the steel sheet into a hot dip coating bath (about 440°C bath temp.) consisting of 3 to 10wt.% Al, 0.01 to 1wt.% Ti, 0.01 to 1wt.% Mg and the balance Zn and inevitable impurities. The cooling rate of the steel sheet is adjusted to about 15 to 100°C/sec during the transition from about 400°C to 380°C to reduce the spangle size on the plating surfaces to ≤0.5mm at the time of cooling the steel sheet. As a result, the hot dip Zn-Al coated steel sheet having the excellent appearance, age blackening resistance and corrosion resistance is obtd.
Inventors:
FUJII SHIRO
TAIRA TAKETOSHI
TAIRA TAKETOSHI
Application Number:
JP31671892A
Publication Date:
May 20, 1998
Filing Date:
November 26, 1992
Export Citation:
Assignee:
SHINNIPPON SEITETSU KK
International Classes:
C22C18/04; C23C2/06; C23C2/40; C23C30/00; (IPC1-7): C23C2/06; C23C30/00
Domestic Patent References:
| JP49119834A |
Attorney, Agent or Firm:
Yu Shiina (1 person outside)
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