Study On The Effect Of Chamfer Structure On The Milling Performance Of Hardened Steel

Chamfer edge is an important method of edge reinforcement,which can effectively avoid tool wear and breakage of cutting edge in cutting hardened steels and some other difficult-to-process materials,thus prolonging tool's life.However,the chamfer edge often leads to greater cutting force and higher temperature,as well as a greater uncertainty in the cutting process.Therefore,it is critical to design the chamfer structure reasonably.In this paper,based on the CNC milling experiment,the cutting performance in the hardened mold steel S136 milling process of the coating cemented carbide inserts with different chamfer-edge structures,which has been reinforced the edge,is comprehensively studied.At first,the current research status of hardened steel processing and chamfered tools'cutting both domestically and abroad is reviewed.Secondly,a metal cutting model which is suitable for chamfered tools is introduced,and the cutting force prediction formula of chamfered tools is accessible by deriving,and two mainstream serrated chip forming theories are summarized.Moreover,the cutting force orthogonal experiment on six milling inserts with different chamfer-edge structures is carried out,utilizing some statistical methods such as range analysis,variance analysis and multiple linear regression,the effect of chamfer-edge structural parameters and cutting parameters on milling force is compared.At the same time,the empirical formula of milling force with chamfered tools is established and the significance test is also carried out.Then,macro-observation on the wear process of each inserts as well as micro-analysis of their wear failure mechanism are implemented,meanwhile,the genesis of serrated chip's formation is analysed in this dissertation.At last,the cutting performance simulation with different cutting chamfer edges and the optimization of chamfer-edge structure are carried out,and some conclusions obtained from the CNC milling experiments were verified by these simulations.The research results of this dissertation demonstrates the importance of designing the chamfer-edge structure reasonably and choosing the cutting parameters correctly,which is of great significance to improve the processing efficiency of hardened mold steel materials and extend the service life of related tools,and also provides a practical reference for cutting tool manufacturers.