Vida útil de ferramentas no torneamento longitudinal de aço ASTM 4140 temperado e cromado

Abstract

The production of hydraulic cylindres Applied in the automobile industry, has as its main components the manufacture of machined rods. As they are safety items, and in need of meeting specific mechanical properties, most of these items are produced with hardened steels, in addition to undergoing a chrome plating process in order to increase surface hardness and ensure corrosion resistance. Thus, the necessity of the evolution of the machining processes to remove hardened material, as low machinability directly affects the production costs of these componentes, making them expensive and often impraticable. The objective of this work is to contribute to themain study of machining of tempered and chromed ASTM 4140 steel, through longitudinal turning using cutting tools. Two cutting tools were tested, the first being Carbide and the second ceramic, in order to obtain the best performance in therms of tool life and production time, in addition to identifying the wear measurement criteria ranging from 0.2 mm for carbide tool to 0.3 mm for ceramic tool were observed in all tests. The best results were obtained when machining with the ceramic tool. The ceramic tool had a 36,3% longer tool life na 82% increase in the number of parts compared to the Carbide tool. Machining time using ceramic inserts reduced 49,56%. The total production costs calculated for the best result of the tests with the ceramic tool are lower than for the best result obtained with the carbide tool, as long as the tool cost does not exceed 2.11 times the tool cost. Keeping this cost ratio within this proportionality range, the ceramic insert was indicated for application in the production process. [resumo fornecido pelo autor]