Análise da influência do uso de fluido de corte no desgaste de brocas helicoidais de aço rápido após a furação de chapas de aço ASTM - A36

Abstract

Drilling is one of the most widely used machining processes in the industry, involving the removal of material from a workpiece using a drill to create a hole. The wear and tear on the drill represent a critical aspect of this process. A common strategy to mitigate wear is the use of cutting fluid, which serves to cool and lubricate the interaction between the tool and the workpiece. This study aimed to analyze whether the use of integral and synthetic cutting fluids contributes to the reduction of wear in helical drills of type N, manufactured from high-Speed Steel (HSS). Two different rotations per minute, 900 RPM and 1390 RPM, were considered, and a comparison was made with drilling without the use of these fluids. To conduct these analyses, drilling was performed on ASTM-A36 steel sheets with a thickness of 6 mm. Integral and synthetic cutting fluids were employed in conjunction with helical drills made of HSS type N, following DIN 338 standards. Six identical drills were used, each subjected to different conditions during the drilling process, including no pilot hole, continuous drilling, and through drilling. The drills were grouped into three pairs, with each pair operating at 900 RPM and 1390 RPM. The first pair performed dry drilling, the second used synthetic cutting fluid, and the third employed integral cutting fluid. Each drill executed a total of ten holes, and after every five holes, chips were collected and subsequently analyzed. Photographic records of the flank of each drill were captured using a USB microscope with a zoom of up to 1600x. Subsequently, these records were subjected to analysis using the ImageJ software to measure flank wear based on the ABNT NBR ISO 3685 (2017) standard. The data collection allowed for the identification of the main wear mechanisms in each drill and facilitated comparisons between the results obtained. It was observed that drills conducting dry drilling exhibited higher wear compared to those using cutting fluid. The slight differences between the results were primarily attributed to measurement errors and the absence of automatic feed.