(19) |
 |
|
(11) |
EP 0 480 355 A3 |
(12) |
EUROPEAN PATENT APPLICATION |
(88) |
Date of publication A3: |
|
02.09.1992 Bulletin 1992/36 |
(43) |
Date of publication A2: |
|
15.04.1992 Bulletin 1992/16 |
(22) |
Date of filing: 07.10.1991 |
|
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(84) |
Designated Contracting States: |
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DE |
(30) |
Priority: |
08.10.1990 JP 270171/90
|
(71) |
Applicant: NKK CORPORATION |
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Tokyo (JP) |
|
(72) |
Inventors: |
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- Sagiyama, Masaru,
c/o NKK Corporation
Tokyo (JP)
- Abe, Masaki,
c/o NKK Corporation
Tokyo (JP)
- Hiraya, Akira,
c/o NKK Corporation
Tokyo (JP)
- Inagaki, Junichi,
c/o NKK Corporation
Tokyo (JP)
- Morita, Masaya,
c/o NKK Corporation
Tokyo (JP)
|
(74) |
Representative: Henkel, Feiler, Hänzel & Partner |
|
Möhlstrasse 37 81675 München 81675 München (DE) |
|
|
|
(54) |
Iron-zinc alloy plated steel sheet having two plating layers and excellent in electropaintability
and press-formability |
(57) An iron-zinc alloy plated steel sheet having two plating layers and excellent in
electropaintability and press-formability, which comprises; a steel sheet; an alloying-treated
iron-zinc alloy dip-plating layer as a lower layer formed on at least one surface
of the steel sheet; and an iron-zinc alloy electroplating layer as an upper layer,
formed on the iron-zinc alloy dip-plating layer. The iron content in the iron-zinc
alloy dip-plating layer is from 7 to 15 wt.%, and the plating weight of the iron-zinc
alloy dip-plating layer is from 30 to 120 g/m² per surface of the steel sheet. The
iron content in the iron-zinc alloy electroplating layer is at least 60 wt.%. The
iron-zinc alloy electroplating layer has a plurality of dots of another iron-zinc
alloy; the iron content in each of the plurality of dots of another iron-zinc alloy
is under 60 wt.%; the total exposed area per unit area of the plurality of dots of
another iron-zinc alloy is from 5 to 50% of the unit area of the iron-zinc alloy electroplating
layer; the diameter of each of the plurality of dots of another iron-zinc alloy is
from 1 to 100 µm; and the total plating weight of the iron-zinc alloy electroplating
layer and the plurality of dots of another iron-zinc alloy is from 1 to 10 g/m² per
surface of the steel sheet.
