The performance and quality of rolls generally depend on their chemical composition and manufacturing method; they can be evaluated based on microstructure, physical and mechanical properties, and the nature of internal residual stresses (see Roll Inspection). The performance of rolls in a rolling mill depends not only on the roll material and its metallurgical quality but also on operating conditions, roll design, and maintenance practices.
Operating conditions for rolls vary significantly across different types of rolling mills. Factors contributing to these differences include: (1) mill conditions, such as mill type, mill and roll design, pass design, water cooling conditions, and bearing types; (2) rolling conditions, such as the type and specifications of the rolled material, its resistance to deformation, reduction and temperature schedules, production requirements, and operational practices; and (3) requirements regarding product quality and surface finish.
