Viabilidade técnica de revestimento duro por soldagem FCAW em facas de corte de cana-de-açúcar

Abstract

The sugarcane agroindustry occupies 10,184,340 hectares of arable land in Brazil. In order to harvest this crop, increasingly technological equipment is required and sugarcane uses a basal cutting system with knives. In this case, knives present fast deterioration due to abrasion process considering the silica contained in the soil. It requires the application of hard coating in knives. Hard coatings generally has the addition of chromium in its chemical composition. Chromium is used to increase the service life of agricultural machine components. From the need to reduce levels of chemical elements present in agricultural soils, harmful to humans and animals, studies involving alternatives for the chromium replacement in hard coatingalloys becomes necessary. This work is aimed to propose an alternative for the use of tungsten carbide paste (WC), which uses chromium in its composition, by a coating based on titanium carbide, without the addition of chromium. For this purpose, Flux-cored arc welding (FCAW) process was used, containing alloy elements that provided abrasion resistance and service life increasing. In order to determine welding parameters, simultaneous response optimization was used. For validation purposes, abrasion wear tests were performed by using a rubber wheel machine and dry sand in order to compare the abrasion resistance between the proposed material and that used in commercial knives. Results obtained by means of accelerated wear tests showed that the proposed coating, without the addition of chromium, had performance 48% higher than WC coating. This enable further investigations in the field for a new process of hard coating deposition via FCAW welding process without the addition of chromium.