Abstract:
When a hot-rolled steel strip 1 is rolled at a large rolling reduction by a cold-rolling mill 4, cracking and interlayer peeling occur in those mill-scales which can not keep up with the elongation of base steel so as to weaken the adhesiveness of the mill-scales to the base steel. When such a steel strip is then brushed, the threads of the brush penetrate into the cracks formed in the scale layer, whereby the mill-scales are removed from the steel strip. The rolling reduction R (%) is set to satisfy the formula of t×R≧150 in relation with the thickness t (&mgr;m) of the mill-scales. The mill-scales weakened in adhesiveness by the heavy-duty rolling are removed from the surface of the steep strip 1 by brush rolls 5 provided in the pass of the steel strip 1 between the cold-rolling mill 4 and the bridle rolls 5. Water or a water-soluble rolling oil having a large friction coefficient is preferably supplied to the roll bites between work rolls of the cold-rolling mill 4 and the steel strip 1 during the heavy-duty rolling. Since the steel strip 1 is given required properties by the heavy-duty rolling in advance of pickling 8, it is used as a cold-rolled steel strip having the required properties simply by heat treatment or slight cold-rolling after pickling.
Abstract:
A roll eccentricity control system for rolling apparatus in which a period of each cycle corresponding to one revolution of the roll is divided into a plurality of sections, a deviation in thickness of the rolled material in each section is sampled during the rolling operation, the sampled deviations in the respective sections for at least one period are averaged to determine a period average deviation and the deviations sampled during plural periods are averaged separately for the respective sections to determine section average deviations of the respective sections which are stored as basic data, the period average deviation is subtracted from the section average deviations and the resultant differences for the respective sections are stored as basic patterns, the basic data and the basic pattern stored for each section are readout at a suitable timing to be used for producing a reduction position control signal for that section, which is adapted to compensate the thickness variation of the rolled material when rolled under that section.