The heat generated is partially absorbed by the work rolls through which the strip passes. This causes localised, irregular and variable thermal expansion of the work rolls. The changing profile of the work rolls is transferred to the strip and if uncorrected this results in out of shape, non-flat sheet being produced with wavy edges and buckles.
Establishing a uniform homogenous cooling across the rolling width with a uniform and acceptable thermal distribution, without gradients, is the ultimate goal in terms of cooling to assure that the universal problem of post-cooled shape after recoil is minimized.
The most important considerations in production are:
Maintaining uniform, stable roll temperatures, circumferentially around the roll and transversely across the roll with precise controlled and metered cooling.
Creating optimum thermal crowns and minimum differential temperature in the upper and lower work rolls with optimum heat extraction.