Application of data-based technologies to demonstrate online quality control of mini-mills

The aim of this project was to develop and implement concepts for the online quality control of mini-mills. The surface quality of the hot rolled strip was chosen as the major focus for product quality, as an automatic surface inspection system was installed in the line. A new data acquisition and storing system for collecting relevant data from the whole process chain was integrated for realising the new quality control system (QCS). The data are collected near-online from the process computers and transformed to features in a flexible way, so that they can be used for efficient through-process monitoring and control of production. By application of suitable visualisation, data analysis and reporting techniques, the user can easily extract important insights to the whole production chain, which can be used for optimising process parameters. Furthermore, data-based models can be identified and cyclically applied in online mode for the evaluation and prediction of final product quality. By exploiting this new information, a scheme has been established for controlling production quality in open-loop fashion and successfully put into operation. An increase of product quality and reduction of production costs was realised as a result of the developed application of the introduced methodology. The developed solution is easily transferable to other product quality features as well as to other processing lines of flat steel, and it offers a significant value gain in the exploitation of available process data.