Effects Of Deep Cryogenic Treatment On Property And Microstructures Of The Key Parts Of Tire Shaping Drum

As the key equipment of the tire forming,the precision and stability of the tire building drum directly affect the safety,reliability and comfort of the tire.However,the tire building drum usually get invalided due to major parts wear in process of industrial production.The deep cryogenic treatment can significantly improve the mechanical properties of the material,such as hardness,wear resistance,fatigue strength,dimensional stability,and the service life of parts.In this paper,the orthogonal experiment was used to study the cryogenic treatment process of the key parts of the tire building drum.Due to the fact that the dynamic change of the sample cannot be directly observed in wear process,such as temperature,stress and plastic strain,the mechanism of cryogenic treatment and wear mechanism cannot be analyzed thoroughly,which has a negative effect on the application of cryogenic treatment.But the numerical simulation technology can be used to describe the changes,so the numerical simulation technology is an important supplement to the experiment.In order to optimize the cryogenic treatment process,a series of studies on the effects of deep cryogenic treatment on the properties and microstructure of the parts are carried out in this paper:(1)The cryogenic treatment test platform was built.Four processing parameters,including the cooling rate,the cryogenic temperature,the holding time and the cryogenic treatment were discussed.The deep cryogenic treatment of AISI 1045 steel,AISI 5140 steel,6061 aluminum alloy and 7075 was carried out based on orthogonal design.Then,the optimal scheme is given in the existing level range to maximize the wear resistance.(2)The inverse heat transfer method is used to calculate the heat transfer coefficient of the material in the process of cryogenic treatment through the temperature data measured in prophase.Afterwards,the multi physical field coupling model was built and the numerical simulation of quenching and cryogenic treatment process of AISI 1045 steel is carried out.The cooling curve and phase change in the simulation are basically consistent with the experimental values.This shows that the numerical simulation of the cryogenic treatment process is reasonable.(3)The finite element model of microstructure of AISI 5140 steel is established.And the simulation of the friction and wear process was carried out based on the Archard formula.Then the influence of microstructure on the stress and plastic deformation behavior during wear process.The results show that the fine grain can hinder the plastic deformation,avoid the stress concentration,exhibit a better wear resistance.