METHOD FOR PREVENTING A SPALLING OF WORK ROLL IN HOT MILL PROCESS

Provided is a method for preventing spalling of work rolls in hot rolling process, the method for lowering spalling frequency of the rolls by calculating rolling force changed in real-time, abrasion of rolls and local tension concentration, thereby alleviating tension concentration of the rolls. A method for preventing spalling of work rolls in hot rolling process comprises: a step of judging rolling start by determining whether a rolling material is led in a rolling mill or not; a step of calculating a shaft core approach amount(delta) between work rolls and back up rolls of a rolling mill in which a corresponding rolling material is led when starting rolling; a step of calculating an actual contact length(b) in a circumferential direction from the calculated shaft core approach amount(delta); a step of obtaining an axial directional contact length(L) of the work rolls and the back up rolls during rolling by comparing actually measured abrasion profiles with the shaft core approach amount after measuring degree of roll abrasion of the rolling mill; a step of obtaining contact area from the calculated axial directional contact length(L) and circumferential directional contact length(b), and obtaining contact tension per unit contact area of corresponding rolls from the obtained contact area; and a step of judging whether rolls are spalled or not by comparing the calculated contact tension per unit contact area and the number of revolutions of current rolls with a tension-revolution number curve(S-N curve) of corresponding rolls.