ADJUSTING METHOD FOR ROLLING OIL IN COLD ROLLING STEEL

PURPOSE:To adjust the addition of coolant in the optimum condition at the time of rolling a highly deformation-resistant material into a thin sheet using highly viscous rolling oil. CONSTITUTION:This adjusting method of rolling oil is that the concentration setting of the rolling oil for decreasing the max. coefficient of friction which is present in an intermediate velocity region is executed and, moreover, the lubricating condition which is adjusted in the state of more than the min.coefficient of friction when slip due to overlubrication is generated is set and the rolling oil is adjusted at the time of cold rolling a steel sheet having the deformation resistance of >=80kg/mm at the final rolling stand into =150cst at 40 deg.C. The rolling speed region is divided into a low speed region, intermediate speed region and high speed region by the degree of the variation of the coefficient of friction of the rolling oil with the variation of rolling speed for cold rolling the steel within the range of 0-2000mpm of rolling speed and, after adjusting the coefficient of friction of the rolling oil to the allowable max. value in the region of the max. coefficient of friction of the rolling oil in the intermediate speed region of the rolling speed and, when the material is passed through the intermediate speed region, the coefficient of friction of the rolling oil is decreased.