Effects of Rolling Condition on the Surface Temperature of Work Roll in Hot Strip Mill

Abstract

The roll surface deterioration is affected by the temperature of roll surface, and it shortens the roll life and decreases the availability of continuous mill products. This paper deals with the roll surface deterioration by analyzing effects of rolling condition on the surface temperature of work rolls in the finishing train of hot strip mill. A FORTRAN program for calculation of roll temperature with passschedule has been developed. The following were analytically determined by theoritical calculation.
(1) Roll surface temperature becomes higher at the intermediate stands in a finishing train, but a heated surface layer is the deepest at roughing stands and it is shallower at finishing stands as rolling proceeds.
(2) Roll surface temperature is more affected by rolled materials, and under the thinner gauge rolling it becomes higher, especially at roughing stands.
(3) Surface temperature of work rolls which is continuously in contact with the strip is more affected by roll cooling at the outlet side.
(4) Patterns of heat cracks on roll surface become finer at finishing stands than at roughing stands and they have been determined to be closely connected with heated surface layer of roll surface.
(5) Damages on rolls such as big comet tail and scale banding in strip rolling are caused by severe heating, but it has been determined that such damage on rolls is possibly reduced by roll cooling.