Development of a 4-mill stand design for rolling wire rod and bar with high dimensional accuracy

Kawasaki Steel has developed a new free-size rolling technology using a 4-r oll design to supply products of optimum size for various working processes and high-dimensional accuracy. The world's first installations are at Kawa saki Steel's Mizushima Works. In April 1994, it was installed in the bar mi ll and in August 1998 in the wire rod mill line. This technology makes maxi mum use of the advantages of the 4-roll design, which is useful in securing higher dimensional accuracy and a wider free-size range than possible with the 2-roll and 3-roll designs in practical use today. At the same time, a number of new technologies for the mill housing and mill drive system were applied to realize a rolling mill with excellent operating and maintenance performance which is indispensable for equipment to be used in a successful commercial mill.