2002 Volume 42 Issue 3 Pages 283-289
The scale on the surface of hot rolled steel is removed by high pressure hydraulic descaling in a rolling mill. If the impact pressure of the water jet is higher, the scale is removed well. However, the temperature drop of the hot rolled steel is increased owing to the flow rate of the water jet. On this account, the temperature distribution of the hot rolled steel should be analyzed during the process of the hydraulic descaling. However, the analysis of the temperature distribution is difficult due to lack of the literatures on the convective heat transfer coefficient for the high pressure water jet. In the present study, the hydraulic descaling system is manufactured and the impact pressure is deduced from the relationship between spray pressure and spray height. And then the equation of the convective heat transfer coefficient is induced by the function of the impact pressure. The convective heat transfer coefficient is obtained from the experimental values by the hydraulic descaling system and the values calculated by numerical analysis. The equation of theconvective heat transfer coefficient will aid to establish the most suitable conditions for operations in the rolling mill.