Tratamento termoquímico de cementação utilizando cinza da casca de arroz e carvão vegetal em aço SAE 1020 seguido de tratamento térmico de têmpera e revenido

Abstract

Aiming at improving the mechanical properties of metallic mechanical components, more precisely the resistance to surface wear and the hardness of the materials, studies on the thermal and thermochemical treatment processes of metals are constantly being developed. These, directly influence the mechanical properties of parts to meet the needs of their applications in their function. The general objective of this work is to compare the effects of the thermochemical treatment of cementation with two different carbon sources, being charcoal and rice husk ash; after carburizing, the quenching and tempering treatments were applied to obtain high hardness in SAE 1020 steel samples. The samples were analyzed by optical emission spectroscopy, optical microscopy, micro-durometer, and surface wear test. The results show that the thermal and thermochemical treatment procedures were performed correctly, obtaining higher values of surface hardness in the treated samples when compared to 1020 steel without thermal treatments; through the optical micrographs the carbon-enriched surface layer resulting from the cementation is evidenced; in the metallographic images the martensite malformation is observed in the microstructure of the samples with the tempering heat treatment; there was a significant increase in the surface wear resistance of the samples after the procedures performed. In general, the results of micro hardness and wear resistance were higher in 1020 steel samples that received carburizing with charcoal.