Study of the scale behaviour in the finishing mill to improve the strip surface quality

Abstract

The cracking behaviour of the oxide layer formed during hot rolling was studied together with different combinations of process parameters in order to find their single influence on the surface quality and formation of oxide defects. Several trials were performed on the CRM pilot line to study in detail the impact of strip reduction, strip temperature, entry scale thickness, roll degradation, lubrication, skin cooling, chemical composition and humidity on the scale behaviour. In general, the degree of deformation, entry scale thickness and rolling temperatures are the most important parameters and the importance decreases in that order.