Anti-friction Mechanism Of The Tools In High-speed Self-organization Turning Of Ultrahigh-strength Steel 300M

High-speed cutting of high-strength,high-hardness materials is one of the major challenges in contemporary manufacturing.40 Cr Ni2Si2Mo VA(300M)possess many excellent performance,which has been widely used in the field of aviation at home and abroad.However,due to its own characteristics to make its poor machinability,seriously affecting the cutting efficiency and processing costs.This paper is based on the self-organization theory of thermodynamics,chemistry,physics,tribology,mechanics and other disciplines.The self-organization phenomenon of high-speed cutting tool in friction and wear system is studied.And the influence of the self-organization structure on tool life,wear mechanism and machined surface roughness is pointed out.Firstly,the matching between tool and the workpiece is studied by finite element three-dimensional simulation software,and the heat-force-chemical performance matching model is established.The results show that the wear abrasion resistance and heat resistance of Ti CN-Ti N is good and Ti CN-Al2O3 coating can effectively reduce the cutting temperature.For determining the reasonable tool material of high-speed self-organization turning 300 M,the model provides a reliable theoretical basis.Secondly,through the high-speed cutting test,the self-organization phenomenon is revealed,and the self-organization structure and characteristics are studied;Through the study of tool life,wear morphology and surface composition,the conditions of high-speed self-organization structure formation are determined.The results show that the adhesive passivation layer and the oxidized tribo-film are the main characteristics of self-organizing structure in high-speed turning.The cutting conditions generated by the self-organization structure are vc=300~500 m/min,f=0.15~0.2 mm/r,ap=0.15~0.2 mm using KCP10 B in high-speed turning of 300 M steel.The cutting conditions of CP200 are vc=300~400 m/min,f=0.1~0.15 mm/r,ap=0.1~0.15 mm in high-speed self-organization cutting.Through the high-speed self-organization turning test,the effect of cutting force,cutting temperatuer and cutting parameters on the formation of self-organization structure is studied.The wear process and evolution mechanism of high-speed cutting tool are studied,and the anti-friction characteristic of high-speed self-organization turning is revealed.The results show the anti-friction mechanism of self-organization structure is energy and matter continuously exchanged at the interface between tool and workpiece in initial stage.In stable stage,the formation of adhensive passivation layers and the oxidized tribo-film played a protective role.A large number of oxygen-rich aluminum and titanium oxide generation,played a lubricated role and reduced friction.Finally,according to the test of high-speed cutting and high-speed self-organization turning,the influence of coating and cuttin g parameters on the roughness is studied,and finally the influence of self-organization structure on the surface roughness is revealed.The results show that the formation of self-organization structures improves and maintains the optimum cutting environment,maintaining the stability of the machined surface roughness.The research significance of this topic is to imp rove the turning performance of 300 M high-strength steel.The self-lubricating and self-protection can effectively improve the tool life,reduce the frict ion and wear,and for designing coating tool provide a certain application value in high-speed turning of high-strength steel.