Effects of Annealing on the Connection Strength of Assembled Camshafts
Torsional strength is an important indicator for evaluating assembled camshafts.In order to solve the problem of low torsional strength of assembled camshafts,a method is proposed to improve the torsional strength by improving the microstructure.A mathematical model of the relation between the annealing process parameters and grain size is established through core axis annealing and tensile experiments.The influence of different annealing processes on the mechanical performance parameters is analyzed.Based on the simulation results of hydraulic expansion,the influence of different annealing processes on the contact area and torsional strength of the assembled camshafts is studied,and the influence of grain size on the connection strength of the assembled camshafts is explored.The research has shown that the annealing temperature,holding time and core grain size meet the austenite grain growth model.As the annealing temperature and holding time increase,the yield strength,tensile strength and microhardness of the core gradually decrease,and the elongation after fracture gradually increases.The increase in plasticity leads to an increase in the contact area between the cam and the core after expansion.Compared to the unannealed core,the torsional strength of the assembled camshaft is improved.The results show that improving the microstructure of the core shaft can improve the torsional strength of the assembled camshaft,and this method has important guiding significance for the production and processing of the assembled camshafts.
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