Method of lubricating steel strip for cold rolling, particularly temper rolling
AssigneeInland Steel Company
InventorsHarold L. Fischer, Ajay K. Singh, John M. Stadnik, Jr.
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Abstract
A method of processing steel strip such that the steel strip can be temper rolled at the increased speeds and better surface texture control of prior art dry lubricants, yet the steel strip can be temper rolled with less frequent replacement of temper mill working rolls. Further, the resulting steel strip has increased stretchability and can be temper rolled to achieve sufficient reduction of YPE at lower working roll pressures and/or lower strip tension, previously only effective when the steel strip was lubricated with a wet lubricant film. Enhanced corrosion resistance is another advantage of this process.
Claims32
A method of increasing the stretchability of a strip of steel comprising:
- annealing the steel strip:
- applying to a surface of said steel strip, before or after said strip has been annealed, a coating of a liquid lubricant;
- thereafter drying said liquid lubricant to form a dry lubricant film on said steel surface in an amount of at least 1 mg/ft.sup.2 ;
- and
- rolling said steel strip, having said dry lubricant film thereon, between at least one pair of steel mill in-line temper rollers, under pressure sufficient to elongate and reduce a thickness of said steel strip.
A method of manufacturing steel strip comprising:
- hot milling a slab of steel to form steel strip from said slab;
- conveying said steel strip through an acid bath for removal of iron oxides from said steel strip;
- rinsing said steel strip with a rinsing liquid comprising water for removal of acid from said steel strip;
- annealing said steel strip;
- applying to a surface of said steel strip, before or after said steel strip has been annealed, a coating of a liquid lubricant;
- thereafter drying said liquid lubricant no form a dry lubricant film on said steel surface in an amount of at least 1 mg/ft.sup.2 to improve the corrosion resistance of said steel strip;
- and
- rolling said steel strip, having said dry lubricant film thereon, between a pair of steel mill in-line temper rollers, under pressure sufficient to elongate and reduce a thickness of said steel strip.
A method of reducing a thickness of steel strip comprising:
- coating said steel strip with a film of a dry lubricant in an amount of at least 1 mg/ft.sup.2 ;
- and
- cold rolling said steel strip, having said dry lubricant film thereon, between a pair of steel mill in-line temper rollers, under pressure sufficient to achieve yield point elongation.
A method of making steel strip comprising:
- hot milling a steel slab to elongate said slab and reduce its thickness, thereby forming a steel strip;
- contacting said steel strip with an acid solution to separate iron oxides from the surfaces of said steel strip;
- rinsing said steel strip with an aqueous solution of a lubricant to rinse acid and iron oxides from said steel strip and to provide a film of dry lubricant on said steel strip in an amount of at least 1 mg/ft.sup.2 ;
- and
- cold rolling said steel strip, having said dry lubricant film thereon, between a pair of steel mill in-line temper rollers, under pressure sufficient to achieve yield point elongation.
Dependencies are inferred from the claim text.