ArcelorMittal S.A.
Hot rolling method

Abstract:

A method for the regulation of at least one of the parameters (.alpha.) of a hot rolling process of a semi-finished metal product in at least one rolling mill stand having at least two work rolls is provided. The regulation method includes calculating a forward slip ratio (FWS) with the following equation: ##EQU00001## where v.sub.exit is the speed of the semi-finished product at the exit of the respective stand and v.sub.stand is the linear velocity of the work rolls; calculating an estimated coefficient of friction (.mu..sub.real) as a function of a measured value of the screwdown force (F) of the work rolls in the stand and of the forward slip ratio (FWS); and regulating at least one of the parameters (.alpha.) based on the calculated estimated coefficient of friction (.mu..sub.real).