Análise da eficiência de um tratamento isotérmico a 565ºC para aumento da dureza de um aço SAE 1020.

Abstract

The present work aims to evaluate the viability of an isothermal treatment at 565 ° C to increase the hardness of a SAE 1020 carbon steel, by kinetic characterization of the isothermal transformation at 565 ° C and observing the gradual alteration of its microstructure and, lastly how microhardness changes during transformation. Initially, six cut-out colors of the piece undergo the heat treatment consisting of three phases: austenitization at 900 ° C for 15 minutes; isothermal treatment at 565 ° C for a varying time per sample from 90 to 300 seconds; immersion in water at room temperature. Perform a metallographic analysis and phase quantification of the samples to determine the microstructure related to the progress of isothermal transformation. Vickers microhardness tests allow to verify the influence of the evaluated transformation on the mechanical properties of the material. 20% of the perlite, while in 300 seconds it is 68.7% of the perlite. Microhardness values may show an increase in material durability throughout the transformation, from an average of 176 HV to 227 HV, characteristic of the transition from a ferritic to perlitic microstructure.