Research On Tool Wear And Parameter Optimization Of Hard Die Steel SKD61 Turning Tool

Compared with the traditional grinding method,hard turning technology could greatly reduce grinding time,shorten the mould manufacturing process,decrease heat treatment deformation and machining cost while turning die steel at their hardened state.There is no unified theoretical system for the study on hard cutting theory and still lack of understanding of tool wear mechanism in hard cutting process.Only based on full understanding of the tool wear mechanism and tool wear form could the hard cutting tools play an effective role and the cost of cutting tools be reduced.In this paper the wear behavior of hard SKD61 turning tools is studied by orthogonal experiment based on the hard SKD61(4Cr5MoSi V1)turning experiments.The main research contents are as follows:The influence of three cutting parameters on the wear mechanism and wear form of hard SKD61 turning tool is investigated.Single factor experimental data by changing the spindle speed,cutting depth and feed rate respectively is designed.Three-dimensional laser scanning microscope is used to observe and measure the wear pattern and radial wear of turning tools.The influence of spindle speed,cutting depth and feed rate on the tool wear mechanism and tool wear amount of uncoated and GP1115 coated turning tools is studied.The influence of three cutting parameters on the wear amount of uncoated and GP1115 coated hard SKD61 turning tool is studied by orthogonal experiment.Also the turning parameters of the uncoated and coated turning tools are optimized respectively.It is concluded that the wear amount of GP1115 coated Carbide turning tools is smaller than that of uncoated turning tools while turning hard SKD61 material.It is analyzed that the main wear mechanism of uncoated turning tool is adhesive wear.Due to coated TiN material,the GP1115 coated tools is characterized by high hardness,good abrasion resistance and low friction coefficient.Especially due to the low affinity of TiN with metals,the cold welding bonding rarely occurs and the main wear mechanism is abrasive wear.It is studied that the cutting speed influences the cutting heat most.As the cutting temperature rises and the cutting performance decreases,the tool wear speeds up.In this paper the influence of cutting parameters on the tool wear mechanism and wear amount in the turning process of hard die steel SKD61 is studied.The processing technology of improving the cutting quality and the tool durability of hard die steel SKD61 is explored which provides the technical support of promoting the popularization and application of hard turning technology.