Caracterização e estudo termodinâmico de inclusões do aço SAE 8620 produzido via Aciaria Elétrica

Authors

  • Wagner Viana Bielefeldt
  • Carlos Alberto Mendes Moraes
  • Antonio Cezar Faria Vilela
  • Luis Augusto Colembergue Klujszo
  • Paulo Carvalho Fernandes

Abstract

The concept of quality is strongly linked to the steel micro-inclusionary cleanness. The aims of the correct refining practices are: 1) to adequate the non-metallic inclusions amount to acceptable values; and 2) to guarantee that the remaining inclusions will not be detrimental to the mechanical properties of steels. To reach such aims, the present work will evaluate the non-metallic inclusions analysis during steel making via EAF process. The characterization of inclusions consisted in the sampling of steel during the SAE 8620 refining. This steel is used in the production of automotive components industry. The characterization of steel inclusions consisted in analyzing 1) area occupied by inclusions and their size and; 2) chemical composition. The results were analyzed via ternary and pseudo-ternary phase diagrams. Some correlations between inclusion composition and steel making process were also done. The inclusions appear mainly as Si/Mn oxides in the beginning of the ladle furnace processing, and as Ca-Al oxides in the beginning of the continuous casting. The inclusions medium size was determined in the range of 4 to 10Pm. It was also observed a gradual decreasing of the occupied area by inclusions during the process, which is an important aim of the refining practices. A thermodynamic study was carried out were the results of inclusion analysis was compared with FactSage simulations and the results are compatible. The results of this work shown that the application of different techniques becomes possible the study and development of high quality steels.

Key words: SAE 8620 steel, characterization, inclusions, FactSage.

 

Published

2021-06-02

Issue

Section

Article