Thermal Behavior of Aluminum Rolling

Abstract

Proper roll cooling has been identified as a critical factor in the problems of excessive roll spalling and poor thermal crowning in modern, high-speed rolling mills. In this paper, an analytical model has been developed to determine the temperature profiles of the roll and the strip. This model uses basic heat transfer theory and provides the capability of studying the influence of operating parameters on both the work-roll and workpiece temperatures. Examples on cold and hot rolling of aluminum alloys are given to demonstrate the feasibility and capability of the model developed. Previous work on thermal modeling of rolling processes is also briefly reviewed.

Experimental Study of Interfacial Heat Flux and Surface Temperature by Inverse Analysis with Thermocouple (Fully Embedded) during Hot Steel Strip Rolling

“…The surface temperature and the interfacial heat flux present good agreement with classical predictive models like the old analytical model of Tseng et al (1990) [6]. This study emphasizes the heat due to friction and plastic deformation because several reductions have been tested.…”

A model for evaluating thermo-mechanical stresses within work-rolls in hot-strip rolling

“…Accordingly, it can be assumed that only the outer layer of the work-rolls with the thickness of R − r * experiences considerable temperature changes. The thickness of this layer can be estimated by using the Peclet number calculated as Pe = R 2 ωρ r c r /k r , where ω is the angular velocity of the work-roll and "R" is work-roll radius [1]. The above heat-conduction problem can be solved by a variational method and the finite-element method; details of the numerical procedures can be found in [21, Chap.…”

“…1 below [20, Chap. 1], ignoring heat conduction along the roll axis, i.e., the z-direction; also the thermal conduction at the top and bottom sides of the strip has been taken identical; 1 …”

Development of a Two-Phase Model for the Hot Deformation of Highly-Alloyed Aluminum

“…Industrial plant measurements suggest a heat transfer coefficient, h air , of 0.85 kW/m 2 K for coolant-covered surfaces of the plate exposed to air, corresponding to the region outside the roll bite [31]. Heat transfer coefficients between the plate and roll, h roll , have been reported to range from as low as 9.3 kW/m 2 K for cold-rolling of commercially pure aluminum [32] to as high as 450 kW/m 2 K for hot-rolling of AA5000 series alloys [33]. The computed texture was relatively insensitive to the value of h roll when it was in the range 10 kW/m 2 K to 60 kW/m 2 K. For the simulations described in detail below, we used h roll =21 kW/m 2 K, a figure suggested by plant measurements [31].…”