The effect of water temperature on cooling during high pressure water descaling

Production of hot rolled steel plates is connected with high temperatures at which steel reacts with oxygen in the atmosphere and oxide layers (scales) are formed on the surface. Scales affect the surface quality of the product and must be eliminated before the product enters any further rolling operations. The scales are usually removed by high pressure flat jet water nozzles in a process called hydraulic descaling. One side effect of this form of descaling is intense cooling of the product, which runs counter to the purpose of descaling. One way to decrease this effect is to use water at higher temperatures. Laboratory experiments were performed in order to determine the degree of influence of water temperature on the intensity of cooling. Temperature measurements were used as an input for inverse algorithm calculations and heat transfer coefficient determinations. The variables were computed as a function of time and position. The results were compared and significant decrease in the cooling intensity was observed. The findings are discussed in detail.