Research On The Computer Simulation Of Quenching Process Of Low-alloy Hypoeutectoid Steels

Quenching is one of the important methods used to improve the mechanical properties of steels in manufacturing industry. In order to obtain expected mechanical properties, the quenching parameters such as quenchant, cooling or heating rate have to be tuned to the proper values. With the development of computer, numerical simulation of heat treatment has been rapidly developed, becoming a fast and efficient guideline for the design of heat treatment technology.In this paper, thermodynamical calculation and empirical formulae were used to calculate Acm and A3 critical temperatures. Based on the results, the lever rule was applied to calculate the maximum volume fraction of ferrite during isothermal transformation of undercooled austenite. Compared with the experimental results, it is confirmed that the Acm and A3 critical temperatures calculated by the empirical equations are more appropriate to predict it in CL50 D steel.The isothermal salt-bath experiment was carried out to build the numerical relationships between structure parameters and isothermal temperature in CL50 D steel, empirical formulae were employed to calculate the mechanical properties. And the experiment results confirmed the method using isothermal temperature to predict the mechanical properties of ferrite/pearlite mixed structure.Based on the coupling relations between temperature-structure field, the numerical simulation model for the distribution of microstructure and mechanical property during end-quench process was established. Finite element software was utilized to predict the distribution of ferrite/pearlite mix microstructure and mechanical properties during end-quench process. Then the corresponding experiment verified calculated results.