Numerial Simulation Of The End-quanching Process In 40Cr And 60Si2Mn Steels

Computer simulation of quenching process can be achieved on the quenching quality control and prediction, much attention is being increasingly. Compared with the traditional test, simulation / simulation experiment is flexible, fast, low-cost., it can significantly reduce the test cost and shorten the test cycle.1,This article is based on theories of thermodynamics and phase transofmration, and thermal elastic-plastic constitutive equation, with 40Cr steel and steel 60Si2Mn quencheing experiments as the research objects. Calculations are carried out to simulate the top of quenching process of specimens at different temperature austenitizing by using large heat treatment software COSMAP. The paper focuses on simulation and prediction of specimens three-dimensional transient temperature field quenching, organizational field, stress field and hardness, while prediction of the changes in hardenability as the same material imcreasing austenitizing temperature.In temperature field simulation, Applicating partial differential equations of index frame of the transient temperature field items in the three-dimensional flow field of the same-sex body calculate the temperature field. while setting the initial conditions and boundary conditions of the actual process,and considering the impact of the nonlinear factors such as the boundary heat transfer coefficient, latent heat and thermal properties parameters, greatly reduces simulation error when dealing with nonlinear problems of the quenching process by using the finite element software only can be replaced by the constant. To improve simulation accuracy and save computation time, using the surface of the cell model and variable time-step breakdown of other methods in this paper. using the equivalent heat capacity method deals latent heat raise the temperature accuracy.2,Quenching process is a continuous cooling transformation, therefore this means of Scheil's additivity principle, dealing with the continuous cooling while assuming that changes in volume and phase shift was a function of temperature, that time discrete equivalent of continuous cooling transformation cooling for the ladder, for each discrete period of time can change by isothermal treatment. In this paper, the TTT curve of input computer, the method of linear regression involved the 40Cr steel and 60Si2Mn undercooled austenite isothermal transformation curve (TTT curve) for partition processing, fitted out by ORIGIN software isothermal transformation the linear regression equation parameters. In calculating the amount of organizational change, the use of diffusion Avrami model with variables such as temperature changes; using Inoue model (Magee model Modified) is calculated on the martensitic transformation. 3,In the stress field simulation, the full consideration of the material the nature of the changes with temperature and time, phase transformation hardening, and plastic and other factors.4,Finally, the top quenching experiments by the determination of hardness, microstructure observation, and with published literature data on the simulation results are verified, in good agreement.