Temperature drop of steel bye hydraulic descaling for a hot strip rolling mill

Abstract

When scale formed during reheating and continous rolling of steel strips is commonly by hydraulic descaling, a temperature drop of the strips inevitably occurs. On an experimental survey of parameters which had been expected to control the descaling behaviours, the temperature drop of steel strips on removing the secondary scale by hydraulic descaling was measured precisely on the basis of design of experiments. It was found that the temperature drop has correlations with the water consumption V at a pressure of 9.8 MPa, interaction between V and the distance H between the steel and the nozzle, water pressure P. The temperature drop ΔTD(°C) of steel strips by hydraulic descaling can be then expressed by the descaling parameters as follows; ΔTD = 451.7 PV/H2 + 9.54 It is concluded that H should be increased with V to keep the temperature drop small when a certain pressure impact pressure is required to remove the secondary scale.