Development of smart contact backup rolls in ultra-wide stainless strip rolling process
In order to solve the serious backup roll spalling of roughing mill during ultra-wide stainless steel rolling process, a 3D elastic deformation finite element model of 4-high roll stacks was established for simulating the mechanical behavior during the hot rolling process. The asymmetric contact pressure between backup and work rolls is the key factor for the frequent roll spalling accidents. Based on the principle of homogenizing contact pressure between rolls, minimizing harmful contact zone in different strip widths and considering roll wearing as a whole, SCR (Smart Contact Backup Rolls) was developed. The simulation reveals when using the SMS200 backup roll contour, the peak position of contact pressure keeps consistent with the practical spalling position. Instead, the peak value of the roll contact pressure with SCR technology decreases significantly with various strip widths. The unevenness coefficients of roll contact pressure with SCR technology decline sharply from 1.36 and more to less than 1.18 with different strip widths. The roll consumption decreases from 0.1254kg/t to 0.055kg/t. During the continuous strip production of 20 million tons and more, non-occurring backup roll spalling, uniform roll wear and remarkable decrease in roll consumption have been validated by long-term industrial applications of the 2250 hot strip mill.