Research on the wear mechanisms during the high-speed tapping in 316L stainless steel

Abstract

Internal threads are present in all mechanical assemblies in modern industry. Independent of diameter, geometry or threaded length, internal threads are regions that provide extreme flexibility, safety and precision in the mounting of the industrial products. The modern industry has many engineering material options used to manufacture thousands of different products. Among these materials is the stainless steel, which shows several applications in products since medical components, devices used to produce food until aerospace components. In this work, metric threads were manufactured in square plate stainless steel aiming to know the tool wear with high-speed cutting. The experimental methodology was carried out, in dry and emulsion condition, allowing the analysis of the tool wear and thread profile every 28 threaded holes. The tool wear was analysed in an optical microscope and the thread profile in the scanning electron microscopy. The results demonstrated that for dry tapping tests, almost 250 threaded holes were manufactured, on the other hand, when coolant in emulsion condition was used, 600 threaded holes were manufactured. It can be concluded that although tool wear showed a significant difference, considering the cooling system, the tool wear had not proved to be a determining factor in defining tool life. This situation occurred because the tapping process carried out with high-speed cutting showed a random behaviour with the non-occurrence of wear in all cutting edges.