TEMPERATURE EVALUATION WHEN MACHINING HARDENED HOT WORK DIE STEEL USING PCBN TOOLING

The aim of this work is to investigate the temperature distribution an d heat generation when turning fully hardened AISI H13 hot work die st eel (52 HRC) using De Beers DBC50 cutting tools over a range of operat ing parameters. Three different techniques were used: a) infrared radi ation (using an optical pyrometer), b) implanted thermocouple and c) t ool/chip thermocouple. Temperature was found to increase with cutting speed, feed rate, depth of cut and tool wear. Highest temperature valu es were observed when employing the tool/chip thermocouple, followed b y the infrared pyrometer and the implanted thermocouple. However, an a nalysis of variance of the results indicated that the level of signifi cance of the results indicated that the level of significance of each operating parameter to the recorded temperature varied according to th e measuring technique.