Determinação das temperaturas de transformação AR1 e AR3 em barras de aço CA-50 laminadas a quente / Determination of the transformation temperatures AR1 and AR3 for hot rolled CA-50 steel rebars

Felipe Farage David, Luan Marcel Costa Vasconcelos, Vinicius Aleixo Silvestre, Sayd Farage David


 This paper has as objective to determinate the critical temperatures of transformation Ar1 and Ar3 for steel rebars from ABNT/NBR CA-50 class [1], which are produced by hot rolling process. To determinate these temperatures, quenching heat treatments are going to be made at various temperatures, determining the start of the Austenite formation (Ar1 temperature) and complete Austenite formation (Ar3 temperature). To have these temperatures known is so important to reach the desired microstructure in the product after the hot rolling process and consequently, control its mechanical properties. Furthermore, rolling the steel at inter critic field (located between the Ar1 and Ar3 temperatures) requires greater rolling efforts, reducing the rolling chain service life. That way, the determination of the Ar1 and Ar3 temperatures are of great importance for the steel industry. The used methods, metallographic and hardness method showed efficient for the critical temperatures calculation.


Quenching heat treatment, Transformation temperature Ar1, Transformation temperature Ar3, Vickers Hardness, Metallography.


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