• Journal of the Korean Society for Heat Treatment
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• v.18 no.4
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• pp.247-255
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• 2005

Although heat treatment is a process of great technological importance in order to obtain desired mechanical properties such as hardness, the process was required a tedious and expensive experimentation to specify the process parameters. Consequently, the availability of reliable and efficient numerical simulation program would enable easy specification of process parameters to achieve desired microstructure and mechanical properties without defects like crack and distortion. In present work, the developed numerical simulation program could predict distributions of microstructure and thermal stress in steels under different cooling conditions. The computer program is based on the finite difference method for temperature analysis and microstructural changes and the finite element method for thermal stress analysis. Multi-phase decomposition model was used for description of diffusional austenite decompositions in low alloy steels during cooling after austenitization. The model predicts the progress of ferrite, pearlite, and bainite transformations simultaneously during quenching and estimates the amount of martensite also by using Koistinen and Marburger equation. To verify the developed program, the calculated results are compared with experimental ones of casting product. Based on these results, newly designed heat treatment process is proposed and it was proved to be effective for industry.

• Magazine of the Korea Concrete Institute
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• v.7 no.6
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• pp.167-175
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• 1995

A temperature-analysis program, named ${\ulcorner}TAMCON{\lrcorner}$, was developed to predict the temperature rise due to the heat of hydration in hardening concrete. Finite element method was employed to facilitate the temperature analysis for the structures with complex geometry and various boundary conditions. In order to test the validity of the program, the results obtained from TAMCON for the wall-t.ype structure and the mat foundation were compared with the numerical analysis anti experimental data reported previously. As a result, it was found that they were in good agreement. TAMCON may be useful for the temperature control to restrain thermal cracking and the construction management to design the reasonable curing method in mass concrete.