Method and machine for rolling a metal workpiece at a reduced rolling load

摘要

A rolling method and machine provides for decreasing the rolling load of work rolls of a rolling mill for a given reduction ratio achieved thereby. A pair of pinch rolls upstream of the work rolls have projections that form a large number of recesses in one or both surfaces of a metal workpiece. A lubricating agent is forced into the recesses in the region of contact between the workpiece and the work rolls. As a result, when the workpiece is rolled by the work rolls the lubricating agent is retained in the recesses such that the recesses progressively are flattened, thereby causing the lubricating agent to form a boundary film between the portion of the workpiece being rolled and the work rolls. The recesses are controlled to regulate the dimension of the length of each recess in the direction of rolling of the workpiece, to regulate the inclination of front and rear walls of each recess, and to regulate the total area of the recesses relative to the total surface area of the workpiece.