Torneamento do aço-ferramenta AISI D6 temperado e revenido nas condições seco, jorro e LN2: uma análise técnico-econômica

Abstract

A lot of attention has been paid about the environmental impacts caused by the machining industry. The use of conventional cutting fluids based on mineral oils, for example, has been approached as a practice to be overcome or, at least, minimized. However, the solution for this question comes up against technical aspects, mainly in the case of machining of difficult-to-cut materials. In this sense, the effectiveness of technical practices that appear as environmentally sustainable, as the case of cryogenic machining with liquid nitrogen (LN2), have been investigated. Several investigations have shown that the machining assisted by LN2 present a lot of technical advantages and besides to be considered a sustainable cutting fluid. Nevertheless, the use of LN2 as cutting fluid in the industry is considered irrelevant. In this sense, the present work was intended to investigate the technical and economic feasibility of using liquid nitrogen as cutting fluid in machining of quenched and tempered AISI D6 tool steel with PCBN inserts. In this case, three flows of LN2 were investigated. For comparison purposes, turning trials under dry and wet conditions were also performed. As output variables cutting tool wear and chip morphology were monitored. The technical and economic analyses were performed based on the cost/hour related with the consumption of cutting tool, cutting fluid, electric energy and cutting fluid disposal. It was concluded that the dry machining was more feasible as compared to the other conditions. However, it should be noticed that cryogenic machining with LN2 can be justified because of its technical benefits to the machined component.