A COMPARATIVE THERMAL ANALYSIS OF TWO WORKPIECE MATERIALS OF DIFFERENT MACHINABILITY WHEN TURNING BASED ON IR THERMOGRAPHY

Abstract

The comparative thermography analysis of temperature during machining by turning was presented. For the tests cast iron EN-GJL 250 and stainless steel 1.4301 were used. The machining by turning was performed with the TNMG 220408HS PC9030 and TNMA 220208 NC6210 cutting inserts design for machining that kind of materials. The temperature was measured on the machined material and on the surface of the cutting insert. The temperature distribution was performed during 3 subsequent turning passes; therefore, the coolant was not used during machining. The emissivity of TNMG 220408HS PC9030 and TNMA 220208 NC6210 cutting inserts was performed. In the case of EN-GJL-250 cast iron, the tests have shown that due to safety reasons (the lack of the safety cover in the working area of the lathe) it was impossible to perform the measurements at the highest assumed machining speed of 339.1 m/min. The higher average temperatures in the material were recorded for 1.4301 steel, even though the machining process was performed at a much lower machining speed than in the case of EN-GJL-250 cast iron. The average cutting insert temperature when turning EN-GJL-250 cast iron was approximately 100°C higher than for 1.4301 steel.