Surface Descaling of Hot Rolled Steel

In processing of hot rolling of steel, the quality of the rolled metal surfaces depends to a large extent on effective descaling. In order to avoid surface damage, iron oxide scale layers are therefore removed from the hot steel surface by high-pressure water spraying prior to the actual hot rolling process.

Because the interface bond between the scale and the steel surface can be very different a proper descaling nozzle setup is of major importance to reach best descaling results. The setup of a descaling system includes nozzle parameters and the nozzle arrangement. Both have a major influence on the descaling factors, hence the descaling performances.

At the same time, this enables potential energy savings to be realized, which counteract rising energy costs or result from ecological considerations.

In hydraulic descaling processes, the jets are formed by special descaling nozzles which are arranged in a descaling box (or mill descalers), the products (slab, strip, billet, bloom, beam blanket, etc.) through from the box, its working pressure range from 70 to 400 bar.

The selection of the best descaling nozzles and their optimum arrangement in the process is therefore a key factor.

The demands placed on the surface quality of rolled steel material combined with a further reduction in the amount of energy used can only be met by using state-of-the-art descaling nozzles.