Cast Rolls with
Grooves

When rolls are deeply grooved as in Heavy Section mill rolls, it is necessary to produce a roll with a similar hardness at the top of the collar and at the bottom of the groove.

A significant hardness fall off along the groove will lead to an uneven wearing behaviour and a rapid deterioration of the dimensional stability and tolerances of the rolled section. This will require frequent roll changes, redressings and a significant increase of the operational cost.

In the case of steel rolls, since the hardness and the microstructure are adjusted by the heat treatment, it is relatively easy to premachine the grooves before the heat treatment in order to have the same hardness at the top of the collars than at the bottom of the grooves.

In the case of cast iron rolls, where the microstructure and the hardness are basically obtained in as-cast condition, it is a distinct advantage to shape the mould of the roll with a contour as close as possible to the shape of the finished roll.

At TSR we have developed a moulding technique using a solid chill for the outer contour of the roll barrel and shaped cast iron chills bolted to the outer chill to produce the grooves promoting rapid solidification in the working area of the roll. This minimizes the appearance of solidification defects and produces a fine grained wear resistant structure which results in enhanced mill performance.