Rolling is unique in that it cannot be conducted without friction. Friction draws the workpiece into the roll gap and facilitates its passage through the deformation zone. This chapter provides an overview of the mechanics and tribology of flat rolling processes and explains how various aspects of the theory apply to shape rolling as well. It derives numerous equations and models to help quantify the forces, torque, and power involved in rolling operations and the associated heating, slip, strain distribution, and deformation in both the workpiece and rolls. It describes the friction and wear that occur in hot and cold rolling under hydrodynamic and mixed-film lubrication; the influence of viscosity, film thickness, rolling speed, interface pressure, pass reduction, and lubricant breakdown; and the effect of surface finish and defects. The chapter also provides best practices for evaluating, applying, and treating lubricants for industrially important materials including iron-base, nickel-base, and aluminum alloys.

Roll forming is a process in which flat strip or sheet material is progressively bent as it passes through a series of contoured rollers. This chapter describes the basic configuration and operating principles of a roll forming line and the cross-sectional profiles that can be achieved. It explains how to determine strip width and bending sequences and identifies the cause of common roll-forming defects. It also discusses the selection of roll materials and explains how software helps simplify the design of roll forming lines.

This chapter provides an overview of the rolling and finishing processes required to create a sheet, plate, or foil product from a direct chill (DC) cast ingot. The flow paths, equipment, and operations are described with a view to the basic evolution of the microstructure, surface characteristics, and dimensions.