Análise de porosidade interna “blowholes” em tarugos de aço baixo carbono

Abstract

The Continuous Casting of Steel is a modern casting process used in Brazil since the mid-60s in order to increase productivity, energy savings and labor. Because be a process that favors a large-scale production, the it is subject to various defects in the product such as the shape, surface and internal. The internal defect bubble surface "blowholes" is located mainly in the section of dowel, being a contributor to poor product quality, because it causes crashes in the lamination process and reduces the elongation and tensile strength of rebar for the construction. The objective of this study was to determine the main factors in the formation of internal defects solidification surface bubbles "blowholes" in medium carbon steel billets in Sinobras through metallographic characterization techniques and prepare a corrective action plan for the reduction of material scrapped continuous casting process in electric arc furnace. The work of analyzing the characteristics of the defect allowed the quantification of their form and distribution in the billet section correlating directly with the operating parameters that led to the emergence of the same time as high processing ladle furnace and excess moisture from distributors, providing the preparation a corrective action plan to reduce the rate of scrapping monthly.