Control of residual stress and shape in hot rolled coil

• Main Author: Cox, S. D.
• Published: Swansea University 2001
• Subjects: 669
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.636311

Unwanted distortion in the final strip product manufactured at Port Talbot is referred to as strip shape. The occurrence of shape defects in hot rolled coil is a recurring problem that is far from understood. The primary objective of this research programme was to develop a mathematical model to simulate the run-out table process in order to understand the formation of residual stress and shape in hot rolled coil resulting from the operation. The software tool developed to predict the final characteristics of the strip steel condition is comprised of several mathematical and finite element model components. Data from the plant measurement systems has been incorporated within the run-out table model to more accurately represent both the initial condition of the strip and the set-up of the manufacturing process. Experimental testing has been used to acquire data to describe the material behaviour for predictive calculations within the software tool. Furthermore, test data was obtained from the hot mill for validation of model components. Finally, plant trials were designed and performed in order to benchmark the performance of the model. The design eliminated any imposition of distortion in the samples from downstream processes and measurements of residual stress and shape defect levels in the samples were carried out using laboratory equipment. The results have proven a good level of accuracy in several components of the software tool. Consequently, a greater understanding of the run-out table operation has been achieved and is demonstrated by the recommendations for both future improvements to the process and related areas of research.