Profile and flatness control technology for schedule-free rolling in hot wide strip mills

In order to meet the requirement of schedule-free rolling for wide non-oriented electrical steel strip production with a large number of the same width strip rolling campaigns, an asymmetry self-compensating work roils (ASR-C) technology was developed. A three-dimensional finite element analysis model of roll stacks was built by ANSYS software package. The finite element analysis and industrial tests indicate that the developed ASR-C technology has both crown control ability and wear control ability for different widths of strips or different rolling periods within the entire roiling campaign. At the same time, the roll gap stiffness and the crown control range by bending force with asymmetry self-compensating work rolls are greater than those with conventional work rolls in hot finishing mills. The ASR-C technology has been applied to production of the same strip-width 2.55 mm× 1280 mm wide non-oriented electrical steel strips in the 1700 mm hot strip mill of WlSCO for test. The industrial test results show that the rate of the measured strip crown less than 45μm is increased from 41.8% to 98.2%, the rate of the measured strip crown more than 53μm is decreased from 33.9% to 1.8%, and the self-maintenances of roll contours for ASR-C reach to 88%. The schedule-free rolling (SFR) for a large number of the same width strip rolling campaigns is significantly achieved by the ASR-C technology with stable crown control ability and wear control ability.