Title:
CHROMIUM-FREE TREATED GALVANIZED STEEL SHEET EXCELLENT IN BLACKENING RESISTANCE
Document Type and Number:
Japanese Patent JP3414348
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide an organic composite coated steel sheet in which blackening is suppressed while securing needed corrosion resistance by depositing a chromium-free corrosion inhibition film on a galvanized steel sheet subjected to mechanical treatment such as skinpass rolling and roll brush cleaning.
SOLUTION: The corrosion inhibition film is the one essentially consisting of a silicic compound and an organic resin, and the area ratio (S) of a new face formed by mechanical treatment and the corrosion resisting capacity (T) evaluated by the area ratio of while rust generated on the surface of the steel sheet after a salt spray test for 72 hr in accordance with JIS Z2371 after the deposition of the film satisfy the following inequality: (1) S≤5Ln(T)+75 (where T>0) or (2) S≤75 (where T=0).
Inventors:
Yoji Koji
Application Number:
JP2000001654A
Publication Date:
June 09, 2003
Filing Date:
January 07, 2000
Export Citation:
Assignee:
SUMITOMO METAL INDUSTRIES,LTD.
International Classes:
B05D7/14; B32B15/08; C23C22/00; C23C22/53; C23C22/77; C23C22/78; (IPC1-7): C23C22/53; B32B15/08; C23C22/00; C23C22/77; C23C22/78
Domestic Patent References:
| JP913158A | ||||
| JP108228A | ||||
| JP11106945A | ||||
| JP10130861A |
Attorney, Agent or Firm:
Shoichi Hirose