In the hot and cold strip rolling process in steel manufacturing, there has been greater-than-ever demand for thin strip and high strength steel rolling (demand for high-load rolling) along with high productivity (demand for high-speed rolling), to meet the recent need for light-weight vehicle bodies for better fuel efficiency and tightened emissions control regulations in the automobile industry. Meanwhile, due to improved efficiency in motors for hybrid vehicles and electric vehicles, a small strip crown is desirable for the electrical steel sheets used in the iron cores of motors (demand for greater control over the cross-section shape of the strip). Furthermore, in order to address the imminent decrease in the size of the working population, demand for labor saving and automation in facility maintenance has also been increasing. Among the many technologies developed to realize these needs, the key for hot rolling equipment is a hot rolling mill with high ability to control the cross-section shape of the strip. Primetals Technologies has been developing a hot rolling mill called the Pair Cross Mill (PC Mill) that has the capability to address current needs. The PC Mill offers greater competitive advantages over high-load rolling or high-speed rolling, since it can utilize a flat roll for the work roll and back up roll. On the other hand, it also has a disadvantage in that the large number of parts makes maintenance difficult. The 4th generation PC Mill developed as the next flagship hot rolling mill has fewer parts requiring maintenance due to its full hydraulic cylinder control and is capable of automatic roll position adjustment in the rolling direction, which used to be handled manually. This has been achieved through the utilization of a sensor embedded in the cylinder. This report will introduce the features and other relevant information of the 4th generation PC Mill, as well as actual orders from Nippon Steel Corporation in Setouchi Works (Hirohata Area) and a U.S. company for installation in hot rolling mills.
