Study On Tool Wear For300M Ultra High Strength Steel In High-speed Turning Process

300M ultra-high strength steel is widely used as bearing components in thearea of aviation because of its good comprehensive mechanical performance.There is a prominent problem that rapid wear of the tool generates lose efficacywhen high-speed turning300M ultra-high strength steel. In order to improve thesituation of the use of300M ultra-high strength steel in high speed turning tool,this paper carried out the following research:First of all, aiming at the high speed turning of300M ultra-high strengthsteel，this paper conducted a contrast experiment which consider the tool wear asan indicator of optimization of PCBN cutting tool. Based on finite elementanalysis software Third wave Advantedge, chamfering parameters of PCBN toolare optimized with the cutting force and cutting temperature as an indicator. Thesimulation results showed that: the optimal parameters is20°and between0.15mm to0.2mm of the chamfer angle and chamfer width, respectively.Then the experiments on the cutting force and thermal characteristics of toolwere carried out in high-speed turning process with PCBN tool, which study theinfluence of cutting parameters on the strength and thermal, and analyses theinfluence of tool wear on the cutting force and cutting temperature. Based on thestudy, wear experiment was conducted in high-speed turning300M steel. Wearmorphology and damaged morphology were observed by using ultra-precisionmicroscope. The results show that the wear is mainly in the form of atypicalsense rake crater wear, flank groove-shaped micro-abrasive wear and boundarywear, chipping and slight damage at the cutting edge. Energy spectrum analysisperformed on PCBN cutting tool after high-speed turning with scanning electronmicroscope. We can see that tool wear is a complex mechanism of interactionwhich mainly composes by mechanical wear, accompanied by adhesive wear, diffusion wear, oxidative wear and so on. In the same cutting conditions, thefurther analysis of tool wear process shows that with the growth of time the rakeface wear is mainly on crater depth KT value changes, at the same time, alongwith the growth of the time, flank wear VB value performance for linear growth.It is obvious that wear rate is closely related to cutting speed when changing thecutting conditions. The impact of corner radius on cutting tool wear is mainlyreflected in the wear position and the former flank wear width.Finally, based on the orthogonal test, an empirical model of PCBN tool wearwas established using the principle of least square method to achieve the toolwear prediction when high-speed turning300M ultra-high strength steel. Rangeanalysis and comparison were made on PCBN tool wear influence factors,Studies have shown that the order of primary and secondary factors influence thePCBN tool wear cutting speed, feed rate, cutting depth.