COMPUTER-AIDED APPLICATION OF MATERIAL AN D PROCESS MODELS IN THE HOT-ROLLING OF LONG PRODUCTS

Objective. The requirement to manufacture high-grade rolled products w ith a narrow range of precisely defined quality characteristics and, a t the same time, high product quality and cost efficiency is necessita ting an intensive development and application of material and process models. New information processing methods that are becoming increasin gly important for complex functions were hence to be examined and suit ably put to use. The procedure and the development of the sub-models a re demonstrated with the aid of selected examples. Summary. An overvie w of the current state of process modelling for the rolling of long pr oducts is presented. Models which take account of process- and plant-s pecific parameters are a suitable and proven means both for simulation and fully automatic process control applications. The individual comp onents of an integrated process control system are described, taking t he example of a beam rolling mill. The basis for the technological con trol of such processes is the mathematical modelling of the material b ehaviour with respect to thermo-mechanical stresses, the location- and time-dependent temperatures, the enthalpy in the rolling stock, the p lasticity-mechanical and rolling parameters, and the change in microst ructure during deformation and controlled cooling, including the micro structural property relationships. Physico-mathematical and analytico- numerical methods of computation prove to be advantageous in this conn ection, with the empirically based knowledge being implemented as repr oducible rules. Reference is made to the latest developments regarding deformation behaviour characterization, computer-aided calibration, a nd FEM analysis of local material stresses.