Melhoria Do Desempenho Operacional E Da Qualidade Das Placas De Baixo Carbono Ligados Ao Al E Si Para Aplicações Elétricas

Abstract

In this paper will be presented the improvement of operational and quality performance in slabs of low carbon Al and Si alloyed for electrical applications. Using the process variables controlling and statistical tools, it was possible to identify a specific steel into the low carbon steel grades which presented high breakout alarms index when compared to conventional low carbon grades. In addition, these alarms caused downgrades in some slabs and eventually heat sequence interruption. Analyzing the steel chemical composition and the flux chemical composition modification during the casting, by sampling the liquid mold flux, it was possible to identify the reason of operational and quality problems, that is related to Al2O3 mold flux pick up, that leads to viscosity increase and deficient lubrication. A specific mold flux was suggested and tested to maintain the lubrication capacity even with high Al2O3 mold flux pick up. It was possible to measure the improvement using the breakout alarms index and the friction in the mold. Both variables presented significative improvement, which lead to better quality and operational results.