Efeito do cálcio no desgaste das placas refratárias de válvula gaveta de distribuidor no processo de lingotamento contínuo

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

Following the latest trends in steel production, steelmakers are looking forward to new developments aiming to increase steelmaking productivity and cost reduction without losing sight the quality requirements. As a major component of quality restriction, the steel cleanness is being a focus for new developments. In order overcome this issue the Ca-treated grades are becoming more common, and along, new challenges in the refractory research field is attracting more attention due the heavy corrosion on sliding gate plates caused by the Ca content in the steel. It was diagnosed that a considerable corrosion at the slide gate plate was caused by a chemical reaction witch continuously erodes the refractory matrix, forming a low melt point composites such as: anorthite( CaO.Al2O3.2SiO2), gehlenite( 2CaO. Al2O3.2SiO2) and calcium aluminates (12 CaO.7Al2O3). The purpose of this report is to study and analyze the plates wear, measuring the calcium effect and to demonstrate the influence of the refractory conception aiming to improve the refractory performance: This study is based on the materials recently adopted at the Arcelor Mittal Plant Vitória, previously known as CST. This work contributed for a better understanding of the wear mechanisms by chemical reaction of the calcium and the refractory materials used for these steel grades in comparison with MgO-C based materials. These materials are not prone to form liquid solutions. In this work was also evaluated the operational variables such as: temperature, sliding gate throttling, casting time, steel calcium content and the influence of refractory the design. Improvements on the material selection, adjustments of operational variable and refractory design, had allowed the increase of 60% in the performance of the refractory plates to continuous casting with calcium.

ASSUNTO(S)

placas refratárias cálcio lingotamento contínuo engenharia de materiais e metalurgica resistência à corrosão pelo cálcio distribuidor

ACESSO AO ARTIGO

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