Patent ID: 6546777
Filing Date: 2003-04-15
Classification: B21B

Abstract:
A method of continuously rolling a ferrous workpiece into a finished round, comprising:rolling said workpiece in an oval first roll pass and a round second roll pass at an elevated temperature of between about 650 to 1000Â° C., said first and second roll passes each being defined by two work rolls and being dimensioned to effect a combined reduction in the cross sectional area of said workpiece of at least about 20-55%, with an accompanying effective strain pattern dominated by a concentration of maximum effective strain at a central region of said cross sectional area; and while said effective strain pattern remains dominated by a concentration of maximum effective strain at a central region of said cross section, continuing to roll said workpiece in at least third and fourth consecutive round roll passes, each of said third and fourth roll passes being defined by at least three rolls and being sized to effect a combined reduction in the cross sectional area of said workpiece of not more than about 4-25%.