DESCALING METHOD FOR HOT ROLLING

PURPOSE:To descale efficiently by injecting high-pressure water to a rolling material at several positions on the rolling stage and by interrupting the injection with a priority lower ranking of to moderate the lowering of the injection pressure of high-pressure water, when the injections are conducted parallelly. CONSTITUTION:In the hot rolling stage of the rolling material traveling to the direction of arrow A, the injection nozzles 4-6 are disposed on a scale breaker 1, roughing mill 2 and finishing mill 3 respectively and the descaling of the rolling material is performed by the injections of high-pressure water from a piping system equipped with several pumps 8 and an accumulator 7. Then the preferential orders (1) front and rear surfaces of the finishing mill 3, (2) the scale breaker 1, (3) front and rear surfaces of the roughing mill 3, etc. are set in due consideration of the conditions such as effectiveness and influence. When the injections of high-pressure water are simultaneously carried out, the injections are interrupted by said priority of lower ranking. In this way, the lowering of injection pressure is moderated and the descaling is performed efficiently by minimum number of pumps.