Technical feasibility of hard coating by flux-cored arc welding on a sugarcane cutting knife

Abstract

The sugarcane agroindustry covers 10,184,340 ha of arable land in Brazil. Harvesting this crop requires increasingly sophisticated equipment and sugarcane uses a basal cutting system with knives. These knives deteriorate rapidly due to abrasion with silica in the soil, which makes hard coating feasible for these components. Hard coatings generally involve the addition of chromium to increase the service life of agricultural machinery parts. The need to reduce the levels of chemical elements harmful to humans and animals in agricultural soils requires a study of alternatives to substitute chromium in hard metal alloys. Based on that, this work is aimed to investigate an alternative this respect; the present study proposes a change in coating from tungsten carbide paste (WC), which contains chromium, to a titanium carbide–based coating without chromium. To this end, FCAW (flux-cored arc welding) welding process was used, with self-shielding flux-cored wire containing alloy elements that increase resistance to abrasion, thereby extending the service life of the component. Simultaneous optimization of multiple responses was used to determine proposed welding parameters. For validation purposes, abrasion wear tests with a rubber wheel and dry sand were conducted to compare resistance to abrasion between the proposed material and that used in commercial knives. Results from accelerated wear tests showed FCAW higher performance (around 48%) compared to the WC coating. This demonstrates technical feasibility of the proposed hard metal deposition process using FCAW welding aimed to increase the service life of basal cutting knives without chromium.