(19) |
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(11) |
EP 0 310 376 A3 |
(12) |
EUROPEAN PATENT APPLICATION |
(88) |
Date of publication A3: |
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17.01.1990 Bulletin 1990/03 |
(43) |
Date of publication A2: |
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05.04.1989 Bulletin 1989/14 |
(22) |
Date of filing: 29.09.1988 |
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(51) |
International Patent Classification (IPC)4: B21B 1/38 |
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(84) |
Designated Contracting States: |
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DE FR GB |
(30) |
Priority: |
30.09.1987 JP 244190/87 30.09.1987 JP 244191/87
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(71) |
Applicant: KAWASAKI STEEL CORPORATION |
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Chuo-ku
Kobe City (JP) |
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(72) |
Inventors: |
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- Hiruta, Toshiki
c/o Technical Research Division
Chiba City
Chiba Pref. (JP)
- Yarita, Ikuo
c/o Technical Research Division
Chiba City
Chiba Pref. (JP)
- Abe, Hideo
c/o Technical Research Division
Chiba City
Chiba Pref. (JP)
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(74) |
Representative: Overbury, Richard Douglas et al |
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HASELTINE LAKE & CO
Hazlitt House
28 Southampton Buildings
Chancery Lane London WC2A 1AT London WC2A 1AT (GB) |
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(54) |
Rolling process for clad steel |
(57) A process for rolling a clad steel satisfactorily reduces the adverse influence of
the difference of the deformation resistance of the metal layers composing the clad
steel and thereby improves the yield of the rolling process. The rolling process for
clad steel includes a step pre-form rolling for a length of 20% to 80% of the overall
length of the clad steel. After pre-forming rolling, reduction rolling is performed
at a draft substantially equal to or greater than the draft of the pre-form rolling.
According to the invention, pre-form rolling process and reduction rolling process
are performed for at least two passes.