Numerical Simulation And Experimental Study Of Quenching And Cooling Process Of Spiral Bevel Gear Based On Coupled Thermo-fluid-solid Model

Spiral bevel gears are widely used in mechanical equipment due to their high load-bearing capacity and smooth transmission.Quenching is an indispensable process in the manufacturing of Spiral bevel gears.The design of quenching process for Spiral bevel gears often employs a trial-and-error method,which is time-consuming and costly.Therefore,numerical simulation techniques that offer advantages such as shorter cycle time and lower cost have become important means for contemporary quenching process design.In the numerical simulation study of quenching processes,the heat transfer coefficient is an important input parameter.However,due to its complex influencing factors,the determined results lack universality and significantly increase the complexity and errors in the numerical simulation process.This paper proposes a new numerical simulation method for quenching processes by expanding the simulation domain,introducing the coupling heat transfer between the liquid quenching medium and the workpiece,and replacing the role of heat transfer coefficient in the numerical simulation of quenching processes.The method is applied to the numerical simulation of quenching in spiral bevel gears,effectively avoiding the process of experimentally obtaining heat transfer coefficients.This method provides a better solution to the problem of varying heat transfer coefficients in different parts of spiral bevel gears due to their shape and size.The paper’s approach provides guidance for determining the quenching process parameters of spiral bevel gears.The main research findings of this paper are as follows:(1)Research on numerical simulation method for thermo-fluid-solid coupling during quenching process.Due to the differences in physical field characteristics between the fluid domain of the quenching medium and the solid domain of the quenched workpiece,the discretization principles and numerical analysis methods used for the two are different.The finite volume method is used for the fluid domain,while the finite element method is used for the solid domain.To address the fluid-solid coupling interaction during the quenching process,wall function and Gaussian integral interpolation methods are used to replace the role of the heat transfer coefficient in the simulation.The finite element-finite volume coupling is used to solve the evolution laws of the flow field,temperature field,microstructure field,and stress field during the quenching process,providing a new approach for simulation of the quenching process.(2)Numerical simulation and experimental study of thermo-fluid-solid coupling during quenching process.To reduce sources of error and control the influence of fluid state and workpiece shape,water quenching experiments were conducted on a 45 steel rod.The results showed that the overall agreement between the predicted results of the simulation of thermo-fluid-solid coupling and the measured results is good,with consistent microstructure composition.The maximum relative error of hardness comparison was 3.6%,the maximum relative error of cooling curve was 9%,and the relative error of residual stress was 5.1%.This verifies the accuracy of the simulation of thermo-fluid-solid coupling during the quenching process.(3)Study of the effect of quenching medium flow parameters on the quenching process.A quenching tank structure was designed to change the flow state of the quenching medium,and the effect of changes in quenching medium flow parameters on quenching effectiveness was studied using numerical simulation of the thermo-fluid-solid coupling during the quenching process.The results showed that by changing the placement of the workpiece,the temperature distribution of the workpiece could be improved.At an inlet flow rate of 2m/s,the distance between the final cooling position and the geometric center was reduced from2.79 mm to 0.6mm.By selecting a suitable water temperature,the risk of cracking can be reduced while ensuring the hardness of the workpiece.In the studied conditions,the optimal quenching water temperature was found to be 50℃,which can provide a reference for the formulation of quenching process parameters.(4)Numerical simulation study of thermo-fluid-solid coupling during quenching of spiral bevel gears.Comparing the quenching cooling curves obtained by different simulation methods and experiments,the results showed that the maximum relative errors between the quenching cooling curves obtained by the thermo-fluid-solid coupling simulation and traditional simulation and the experimental measurement were 9.2% and 7.4%,respectively.The thermo-fluid-solid coupling simulation more accurately described the temperature distribution on the Spiral bevel gears,verifying the accuracy and convenience of the quenching thermo-fluid-solid coupling simulation.By selecting a reasonable inlet velocity,residual stress can be reduced while ensuring the hardness of the workpiece.Under the conditions studied in the paper,the optimal inlet velocity was found to be 2m/s,which can provide a reference for the formulation of quenching process parameters for helical bevel gears.