More advanced methods are adopted to accurately predict the shrinkage cavity and porosity defects in the solidification process of steel and iron castings. The application of display list, alternating refresh and double buffer technology to complete high-quality dynamic display and observation, greatly enhance the performance of dynamic observation simulation results, and realize the animation display of solidification process. In addition, the development of material database and complete user interface are also completed, The program is basically formed into a complete numerical simulation system, which lays a solid foundation for the formation of further complete commercial numerical simulation software. The specific conclusions are as follows:
- The calculation program of temperature field in the solidification process of steel and iron castings is completed. Based on the Fourier heat conduction equation, the finite difference temperature field program is compiled, and the combination of equivalent specific heat method and temperature rise method is used to accurately deal with the problem of latent heat in the solidification process.
- Based on the temperature field calculation program, the calculation method of isolated region of steel and iron castings is completed, which can dynamically and quickly calculate all the hot spots of isolated region in the solidification process of steel and iron castings.
- Based on the calculation of temperature field and isolated region, the prediction of shrinkage porosity and shrinkage cavity defects in the solidification process of general steel castings and nodular iron castings is completed:1) The size, location and shape of shrinkage cavity defects in general steel and iron castings during solidification were predicted by shrinkage and compensation method and temperature grade selection method; The method is applied to predict the occurrence of shrinkage porosity in general steel and iron castings.2) Based on the dynamic superposition of shrinkage and expansion during solidification, the size, position and shape of shrinkage defects in nodular iron castings during solidification were predicted; The shrinkage and expansion method of hot joint is used to determine the occurrence of shrinkage porosity in steel and iron castings. 3) Through the calculation of standard steel and cast iron castings and actual production steel and cast iron castings, the accuracy of the software is verified.
- The pre-processing and post-processing graphics display program is developed to realize the basic transformation of graphics: translation, rotation, scaling and sectioning, as follows:1) Using the technology, the display program of pre-treatment mesh generation is successfully improved, and the dynamic observation of steel and iron castings after mesh generation is realized.2) Using technology and language programming technology, the animation display of the solidification process of steel and iron castings in the calculation process is realized, and the solidification process and temperature change process of steel and iron castings are displayed in real time.3) Using the technology, the calculation process and defect display program are successfully compiled, and the clear and accurate dynamic observation effect of the calculation results of steel and iron castings is realized.
- A simple and practical solidification numerical simulation software material database system is developed, and the management operations such as adding, deleting and modifying the material data in the database are completed. The database system is successfully embedded into the numerical simulation software, which has become an important part of the numerical software.
- Using object-oriented technology, this paper constructs the overall framework of numerical simulation software, integrates three parts: pre-processing mesh generation, intermediate temperature field calculation and defect post-processing display, and compiles a friendly human-computer interaction software interface. At the same time, it lays a good foundation for the improvement of software and the in-depth development of other functions, builds an extensible platform and completes the development task.