The Research On Optimizing The Microstructure And Performance Of Spinning Rings

The spinning ring is the key part of ring spinner to cooperate with spinning travelers to complete yarn twisting and winding process.It has a great influence on higher delivery speed and products' quality.It is also traveler's orbit and spindle,guide wire datum.Ring of ring spinning frame is called ring,that is why it is so important.Fifty years ago,it is so simple about ring's materials and types,only Gs and G.With the high speed development in textile industry,high speed ring is also developing so fast.Now there are so many kinds of rings and the materials,processing technology,surfacetreatment technology of rings have also made a new development.The performances of rings determine the yarn quality,including yarn twist,package density,yarn breakage,yarn hairinss and so on.With the process of ring spinning technology,ring is as the key part of ring frame and twister,it's manufacturing technology has developed rapidly,but there is also a certain gap in the advanced technology of domestic and foreign in the performance of ring.In this paper,it is mainly for comparative analyzing and researching on the difference of microstructure and surface properties of rings at domestic and foreign,and research on optimizing the microstrcture and performance of rings.Firstly,the differences between the foreign spinning rings and the domestic spinning rings,including the raw material,the microstructure,hardness,the size of austenite and volume of residual austenitic grain,surface plating chromium layer,were for explore its optimizing manufacturing process.The raw material of foreign bearing spinning ring(100Cr6)and the domestic bearing spinning ring(GCr15)has the similar chemical compositions.It is just the grade of domestic and foreign spinning rings is different.The content of each element component is 0.99%C,0.24%Si,0.31% Mn,1.44%Cr,0.01%P,0.003%S,and the rest is Fe.Nowadays domestic and foreign textile ringsare mostly using plating treatment to improve surface wear resistance and prolong ring's useful life.By detecting and comparative analyzing that the hardness of foreign bearing spinning ring is less than domestic bearing spinning ring is 61 HRC,the hardness of domestic bearing spinning ring is 64 HRC,so there is a difference on obdurability between domestic and foreign.For comparative analyzing the microstucture of domestic and foreign textile rings discovered that martensite and undissolved carbide of foreign bearing spinning ring is finer and distributing more uniform than domestic bearing spinning ring,the average size of undissolved carbide is 0.32?m,and the average size of undissolved carbide in domestic bearing spinning ring is 0.45?m.And there are lots of problems in domestic bearing spinning ring,such as strange shape undissolved carbide,net proeutectoid cementite,uneven undissolved carbide and so on,they all come from abnormal nodularizing.Researching on spheroidizing annealing of GCr15 bearing rings for the ineffective spheroidizing in a manufacturer.Six kinds of spheroidizing processes are investigated,which are normalizing + general spheroidizing annealing and general spheroidizing annealing,normalizing + isothermal spheroidizing and isothermal spheroidizing,solid solution + high temperature tempering and solid solution + isothermal spheroidizing.The influence of spheroidizing processes on structure and properties of bearing steel GCr15 are studied after quenching and tempering process.The test results show that normalizing + conventional spheroidizing annealing and solid-solution + high temperature tempering has gained double refining which can balling and refine carbides effectively,and the properties of material are improved.And the best technology parameter is 1050oC(solution treatment)×30min?950oC(oil quenched)?790oC×2h?720oC×2h?650oC(air cooling).Finally,it was discovered that the wear resistance of material is the most important influence in textile rings by using test and experiment in each sample,hardness is a decisive element of superior wear resistance.But for textile it is not that the better wear resistance with the higher hardness,martensite and undissolved carbide of textile bearing spinning ring also have influence on wear resistance.By comparison with wear resistance test,after preprocessing,that is the normalizing and high temperature solid solution treatment of samples with better strong toughness,wear less,better wear resistance.