Eventos Anais de eventos
COBEF 2023
12th Brazilian Congress on Manufacturing Engineering
Temperature variation in radial turning
Submission Author:
Theodor Rucker van Caspel , SC , Brazil
Co-Authors:
Theodor Rucker van Caspel, michel Tavares, Claudio Abilio da Silveira, Rolf Schroeter
Presenter: Theodor Rucker van Caspel
doi://10.26678/ABCM.COBEF2023.COF23-0314
Abstract
Hard turning has become an alternative to grinding as a finishing process for hardened steel since the early 80’s. Since then, there is a need to better understand the hard turning process. Recent hard turning studies reported a decrease in forces and an increase in white layer formation as the tool approached the workpiece center during radial turning, which indicates a temperature increase along the process. This increase occurred with constant process parameters, cutting speed 150 m/min, cutting depth 0.2 mm and feed 0.08 mm/rev, with the only variation during the process being the lathe spindle rotation. The objective of this study is to determine if there is an increase in temperature during radial turning and to investigate a possible cause for this increase. To do this a prototype of a temperature measuring device was used to measure the temperature in fixed points of the workpieces. The temperature was measured with an acquisition rate of 1 kHz. The experiments consisted of the radial turning of SAE 1040 steel with cutting speed of 150 m/min, feed of 0.08 mm/rev and depth of 0.2 mm using a worn tool. Each workpiece was a 100 mm diameter disc with a central hole of 24 mm of diameter. Two thermocouples were embedded positioned radially 15 mm and 30 mm. The thermocouples were 2.6 mm from the surface in the first pass of each experiment and would become closer to the surface in each successive pass. As the device used to measure temperature was a prototype, only qualitative analysis was made. The temperature measurements have shown that the centermost thermocouple had always a higher temperature that the outermost thermocouple. In the later passes pulsed signals with frequency close to the instant spindle rotation when the tool was above the specific thermocouple were detected. These pulsed signals were identified as the tool passage, creating a sudden increase in temperature followed by a cooling curve. These results confirm that there is an increase in temperature as the tool approaches the center of the workpiece and that this increase occurs because of a diminishing in the cooling time of the region due to the increase of tool passage frequency.
Keywords
machining, Radial turning, temperature measurement
