Análise mecânico-metalúrgica dos rolos despigadores de plataforma para colheita de milho e avaliação do seu desgaste pós-

Abstract

Wear is one of the primary failure modes in agricultural machinery and implements, impairing their performance and productivity in the field. Investigations in this domain become relevant to assist in the development of technological innovation in the sector. These studies can result in the adoption of advanced analytical techniques, selection of advanced materials and processes, and implementation of preventive and predictive maintenance strategies, benefiting farmers and strengthening the industry. In this context, this work sought to assess the impact of corn harvesting operations on the integrity of husking rollers, which are part of the mechanized system for cutting corn stalks. To this end, characterization of wear and mechanical-metallurgical properties of their cutting edge was performed, considering both new and used parts. Wear assessment included visual analysis, 2D and 3D roughness measurements, topographic analysis, and analysis of cutting edge profiles using stereomicroscopy and image analysis software. Metallurgical analyses were conducted through optical microscopy, optical emission spectrometry for chemical composition determination, and X-ray diffraction for phase determination. Mechanical analysis involved Vickers hardness profile measurements along the cutting edge and instrumented indentation to determine the elastoplastic characteristics of the material used in roller production. Comparative analysis between new and worn husking rollers revealed significant differences in various characteristics. There was material loss and deformation in the worn blades of the worn roller compared to the blades of the new roller. Both materials exhibited the same microstructure but with variations in the fraction of perlite and ferrite. Chemical composition and metallurgical phase analyses confirmed compliance with material specifications. The hardness of the new roller was higher than that of the worn roller, and the blades in position 1 showed greater hardness than those in position 2. Characterization of 2D and 3D roughness evidenced a substantial reduction in the worn surface, attributed to abrasion during harvesting. The surface topography of the worn roller blades showed marked differences between worn and transposed surfaces, reflecting abrasion wear. 3D roughness parameters highlighted lower peaks and less profound valleys on the worn surface, indicating more significant wear in this region. Ultimately, the results indicate that premature failure of the material used in husking roller fabrication occurs due to its low mechanical resistance.