DESCRIPTION
Title of Invention: High Reduction Lubricated Rolling
Method
5
Technical Field
The present invention relates to a rolling method
which rolls stainless steel sheet by a high rolling
reduction without the occurrence of heat scratches and
10 slip.
Background Art
In the past, when using a tandem rolling mill which
is provided with a plurality of rolling stands to produce
15 high strength steel sheet, to improve productivity, high
reduction rolling is preferred. To use a tandem rolling
mill for high reduction rolling, it is necessary to raise
the rolling reduction at each rolling stand.
However, if raising the rolling reduction, the
20 amount of lubrication oil which flows between the rolling
rolls and the steel sheet is reduced, the film of this
oil between the rolling rolls and the steel sheet becomes
thinner, the contact pressure between the rolling rolls
and steel sheet rises, and heat scratches easily occur.
25 In particular, in high reduction rolling of stainless
steel sheet, heat scratches occur.
Note that, heat scratches are seizing defects which
occur with the rise in the boundary temperature between
the rolling rolls and steel sheet, the film of
lubrication oil being broken, and as a result the rolling
rolls and steel sheet directly contacting.
Steel sheets with defects of heat scratches on their
surfaces cannot be shipped out, so the yield naturally
falls. Further, rolling rolls where marks of heat
scratches remain have to be immediately replaced, so the
productivity remarkably falls.
For this reason, various methods of prevention of

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^ CLAIMS
Claim 1
A high reduction lubricated rolling method which
cold rolls pickled stainless steel sheet, characterized
5 by using a high viscosity lubrication oil of 140 cSt or
more at 40°C and rolling by a rolling reduction of 30% or
more by at least one rolling of rolling passes,
where the viscosity is a viscosity which is measured
based on JIS K 2283 by a Cannon-Fenske viscometer.
10 Claim 2
A high reduction lubricated rolling method as set
forth in claim 1 characterized by performing said cold
rolling by a tandem rolling mill provided with four or
more rolling stands.
15 Claim 3
A high reduction lubricated rolling method as set
forth in claim 2 characterized by performing rolling by a
rolling reduction of 30% by at least two rolling stands
other than a final rolling stand in tandem rolling by
20 said tandem rolling mill.
Claim 4
A high reduction lubricated rolling method as set
forth in claim 2 characterized by performing rolling in
said tandem rolling by a rolling reduction of 30% or more
25 by an initial rolling stand.
Claim 5
A high reduction lubricated rolling method as set
forth in claim 3 characterized by performing rolling in
said tandem rolling by a rolling reduction of 30% or more
30 by an initial rolling stand.
Claim 6
A high reduction lubricated rolling method as set
forth in claim 3 characterized by performing rolling in
said tandem rolling by a rolling reduction of 33% or less
35 at a rolling stand right before a final rolling stand.
Claim 7
A high reduction lubricated rolling method as set