EUROPEAN STEEL TECHNOLOGY AND APPLICATION DAYS 2017 - ESTAD 2017

Rolling of thin strips in a finishing mill of Endless Strip Production (ESP), Compact Strip Production (CSP) and Hot Strip Mill (HSM) with an outstanding thickness performance and stability has increased requirements to the tension and thickness control concept of finishing mills. To fulfill these requirements Primetals Technologies developed in the first step a new control concept for rolling of very thin hot strips in a finishing mill of an ESP which is called “Ultra-Thin Rolling Control”. This is an adapted control concept of Tandem Cold Mills, which has been used successfully many times during cold rolling. The concept uses primary the roll gap to control the entry strip tension at the mill stand. Thereby the looper measures the strip tension between the stand while not changing its position. The controller is implemented at each mill stand. Depending on the material dimension or the rolling condition the controller mode will be selected accordingly and with smooth transition functionality. This control improves at Rizhao ESP 3 the strip tension and - thickness performance during rolling in endless mode by using fast actuators and by compensating periodic disturbances. Moreover it is well adjusted to the Thickness Monitor, which controls the exit thickness of finishing mill. In the next step Primetals Technologies works on an extension of “Ultra-Thin Rolling Control” for rolling of thin hot strips in a finishing mill of a CSP and of a HSM with an improved thickness performance and stability.