BENEFITS OF USING PROCAST SIMULATION SOFTWARE TO SOLVE CASTING DEFECTS IN ODLEWNIE POLSKIE S.A.

摘要

Numerical simulation and its use in the casting process is an increasingly common tool for analyzing the causes of casting defects Conventional methods are often not sufficient to pinpoint the causes, and moreover they always follow real tests. Only numerical simulation allows analysis of defects already at the design stage of the technology or casting design. These two stages of casting development, i.e. the design of the construction and the production technology, are closely related and at the same time they are going in many cases against each other. A casting design that is designed to meet the needs of the final part functions often does not consider the technological requirements for its production in the foundry. The numerical simulation allows the evaluation of the impact of each design change of the casting with respect to its final quality. From the point of view of technology, the numerical simulation offers many possibilities to ascertain in advance its shortcomings and to optimize the technological solution of the cast before the production in the development phase. For many foundries, numerical simulation has been incorporated into the casting process chain a long time ago, when the possibilities of numerical simulation were, compared to nowadays, very limited. This is also the case of the company ODLEWNIE POLSKIE S.A. where they started using ProCAST casting simulation suite in 1998. Software has since become an integral part of the technology design process and well used tool to detect problems and its causes. Nowadays, numerical simulation is not only used in the casting process on Loramendi and HWS production lines, but thanks to a special module also to predict defects associated with the process of cold-box production of sand cores. This fact, in combination with deep expertise and years of experiences of technologists in ODLEWNIE POLSKIE makes the company one of the most successful cast iron foundries on Polish market The article aims to show several examples of real castings from the ODLEWNIE POLSKIE portfolio, a method of implementing simulation in the standard cycle of each casting from the prototype stage to its serial production It will also demonstrate the cost reduction done by implementation of such virtual tool which allows to avoid the traditional problems associated with the trial-error approach. Numerical simulation allows user to see different kind of results based on which one can analyze many different metal behaviors. In case of gravity sand casting process starts with casting filling. Following given technological parameters like pouring temperature, pouring velocity or permeability of the mold, user is able to see what is really happening inside the casting mold. Using many different simulation results user of simulation software ProCAST is able to analyze process of filling, address all pain points from the temperature, velocity perspective, or evaluate those exact criteria which shows problematic behavior from the oxides or other kind of undesirable inclusions point of view. User is even able to see mold erosion risk and decide, based on the simulation results, where such released mold particle can end its path through the metal stream. One of the most important behavior for any casting is its solidification pattern. Casting technologist have to have at least minimum level of experience to be able to design suitable casting technology with respect to wanted solidification pattern Numerical simulation can help to find biggest hot spots of the casting body and even calculate exact value of thermal modulus Casting engineer is then simply able to select proper feeder from the catalog Of course, situation is usually not so easy, especially if the casted material is cast iron or ductile iron, where so many different phenomena entering the casting process. To predict such complex behavior, simulation software must have proper functions In ProCAST, most important module to handle different aspects of every possible material is a special thermo-dynamic material database Computherm Based on alloy chemical composition, software is able to create all material parameters which are needed to perform the calculation Such tool allows also to see effect of various chemical composition on the final solidification/porosity results. Speaking about porosity prediction. As mentioned above cast iron is not simple material Many different aspects can have big influence on final metal quality and therefor on shrinkage porosity Beside of described thermos-dynamic database, software ProCAST implemented special features to handle material quality. Those features can consider level of inoculation and modification, fading effect of such treatment or the way how it was done during the process. Finally, concerning cast iron and ductile iron materials, question of huge importance is also final material microstructure and related mechanical properties. Software ProCAST contains special "'Microstructure module" which allows user to determine distribution of mechanical properties across the casting body. This module is fully connected with above mentioned thermo-dynamical material database. Every kind of cast iron material can be then investigated. All this virtual steps and features mentioned above give casting engineer great opportunity to know many information about casting process even before real production starts It allows him to validate casting design and technology from many different perspectives This is what in Odlewnie Polskie know well and that is why simulation is valid part of the casting production process.