| Gear industry is the foundation of machinery industry.Gear material and processing technology play a decisive role in the precision manufacturing of gear.17Cr2Ni2MoVNb gear steel is a new carburized gear steel jointly developed by Beijing Iron and Steel Research Institute.Many scholars at home and abroad have carried out in-depth research on the carburizing process of 17Cr2Ni2MoVNb gear steel,and the research on the cutting performance of 17Cr2Ni2MoVNb gear steel is less,but the cutting is particularly important in the manufacture of precision gear,and 17Cr2Ni2MoVNb gear steel has high strength,high hardness,strong toughness,there are machining difficulties such as too much cutting force,too high cutting temperature and serious cutting tool wear.Therefore,it is of great significance to study the cutting process of 17Cr2Ni2MoVNb gear steel.In this paper,the cutting performance of 17Cr2Ni2MoVNb gear steel turned by carbide tool is studied by finite element simulation,cutting experiment and tool wear experiment.The main research contents and conclusions are as follows:(1)Finite element simulation of cutting performance of 17Cr2Ni2MoVNb gear steel.A three-dimensional cutting simulation model of 17Cr2Ni2MoVNb gear steel turning with carbide tool was established by using finite element analysis software ABAQUS,and the model was verified by single factor experiment.The effects of cutting parameters on cutting heat,main cutting force and unit cutting force were analyzed.The range analysis shows that the degree of influence of cutting parameters on cutting temperature is in the order of v>f>a_p.The order of influence of cutting parameters on unit cutting force is f>v>a_p.(2)Research on cutting force and chip morphology of 17Cr2Ni2MoVNb gear steel.The influence of cutting depth and feed rate on critical cutting speed was studied by cutting experiment,the empirical formula of cutting force was established,and the influence of cutting parameters on chip morphology was analyzed.The results show that the critical cutting speed of 17Cr2Ni2MoVNb gear steel is 160m/min～200m/min when the cutting depth of YT15 tool is 0.25mm～0.75mm and the feeding rate is 0.05mm/r～0.15mm/r.The critical cutting speed increases with the increase of cutting depth and feed.In the machining of17Cr2Ni2MoVNb gear steel,larger cutting depth,appropriate cutting speed and smaller feed should be selected.(3)Analysis of carbide tool wear life and mechanism.Three cemented carbide cutting tools were selected to cutting 17Cr2Ni2MoVNb gear steel bar.The tool wear life,wear morphology and cutting force at different cutting speeds of 80m/min～280m/min were studied.It is found that YT15 tool is more suitable for machining 17Cr2Ni2MoVNb gear steel.The cutting force of carbide tool increases with the increase of tool wear.Tool wear with the increase of cutting speed from C zone to N zone,the back tool surface wear mainly develops from hard point wear to groove wear,and the adhesion on the back tool surface increases gradually. |
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