9th ECCC European Continuous Casting Conference – ECCC 2017

By the visual inspection of the hot slabs during casting it is possible to observe only major defects and only on the upper surface. So the inspection of cold slabs later is needed, especially if trials were made. And in practice inspection of all slabs is nearly impossible. So there was need for a tool to have images from the hot slabs during casting – for several purposes. A tool called Reveal CAST was developed. With this tool it is possible to take images from the hot slabs after cutting. With the special technique used to avoid thermal radiation surfaces of the slabs looks like taken from cold slabs. Images are taken from the all slabs and if needed from the all surfaces. Automatic defect detection is included. In this paper is presented several examples of the images and how they can be used to define the surface quality of the slabs. Also including cases how the images can give the respond on the surfaces of the slabs concerning when it is found abnormal events with online measurements like thermocouples. It is shown cases how slab surface can change gradually during casting from start to end and how this change can be connected to the heat transfer in the mould. For this kind of study it is needed to have 100 % coverage of the images of the all slabs. Images are equipped with the coordinates, so casting events can be located exactly on the slab surface features. It is presented cases where the defects are related to the behaviour of the casting flux. The role of the casting flux is essential. With images of Reveal CAST new studies and findings are possible concerning the function of the flux. Statistics of the different defects is shown with the tools included in the Reveal CAST. Also other useful features are presented as a video concerning online operation.