Study In Forecasting The Shrinkage Defects In Steel And Iron Casting And The Development Of Numerical Simulation Software

Numerical simulation for foundry process is one of the hot research topics in material processing. Many kinds of commercial casting simulation software built by several developed countries have been put into industrial application now, and in contrast, there are also several software poor of strong capabilities created by a few Chinese units. In this paper, by adapting development to the numerical simulation, a numerical profile software including modulus of temperature field simulation, shrinkage defects prediction, material database, data visualization, and etc has been developed. We have independent intellectual property rights for it.In temperature field solving module, the direct difference scheme was used for numerical discretization, and the temperature compensation method and equivalent specific heat method were used together to deal with the latent heat, and the equivalent coefficient of heat transfer was used to deal with the interface coefficient, so a temperature field simulation module was set up, and also the isolate hot spots during the solidification of casting can be traced rapidly and accurately just in time. For steel castings, ELSDM (Equivalent Liquid Surface Descending Method) and Niyama Method were applied to search the shrinkage and porosity defects; however, for iron castings, DECAM (Dynamic Expansion Contraction Accumulation Method) was employed. Then a few calculation instances verified the validity of them.For the database module in our software, by investigating several kinds of software from domestic or abroad, a thermal-physical database management system was developed on the base of PARADOX, with functions of adding, deleting, editing and querying data records in lists of the software database.In data visualization module, OpenGL, an advanced graphics technology, was adopted to set up the data visualization program under the developing environment of C++Builder. At last the functions such as the graphic's real-time translation, rotation, and scaling were carried out, which makes it possible to perceive the whole casting from all aspects. In addition, the dynamic process of casting solidification in color display was achieved.In order to construct software interface, the abundant components of C++Builder was used, and then a friendly interface was built up, including the pre-process module, the temperature calculation module, the database system, and the post-process module. In the end, the easy operating casting simulation software was finished.