Continuous casting: make better steel and more of it!

Abstract

An impressive number of papers are published each year that report on continuously-caststeel quality issues and new machine equipment; few of them (if any) discuss productivityand cost issues as they should be addressed by plant management, caster operators, andscientists. At Management & Quality Control meetings in steel plants, much time isspent discussing tenth of percent rejections at the end of the processing line. But,little time is devoted to discuss slab direct-application ratios where rejections areseveral percents and penalty on the overall scheduling and organization of the steelproduction line very serious. At IPC & SOP review meetings (Integrated ProcessControl & Standard Operating Practices review meetings), much time is spentdiscussing upper and lower statistical (6-sigma) control-limit diagrams. However, nomention is made that such diagrams only prove process capability (process repeatabilityand reproducibility) and not product quality. There should be no comfort if center line isat 10% slab abnormality code month after month! It is the goal of the author to draw froman approach that combines 30⁺ years of research and plant experience. Theresult is the opportunity to “connect the dots” and a wide breadth of in-situ processunderstanding. The paper looks at continuous casting machines as tools for maximizingcorporate earnings. It is about making good steel on the first attempt. Verysystematically and practically, the paper discusses disturbing steelmaking defects, theircauses, and how Electro-Magnetic Stirring technology can be used to eliminate them. Itdraws the attention to academics looking to validate or invalidate what they know or don’tknow, and provides in-depth, concise, practical explanations and guidelines to plantoperators who are less interested or do not have the time to assimilate highly-technicalpresentations and publications.