The Exploration Of LFC Automobile Panel Dies Steel Casting Based On The CNC Processing Foam Patterns

As we know, it always has been a difficult problem to produce high internal and external quality of steel castings with lost foam process. In actual production of lost foam steel castings, it is real hard to control the rate of foam decomposition and the velocity of relevant product escaping from the mould. It will easily form slag and porosity if the foam’s decomposition product is involved in the liquid metal. Otherwise, the surface carburization of EPC steel castings is almost impossible to avoid. As a result, the surface carburization will increase casting’ hardness, make the casting difficult to machine,deteriorate casting’ welding performance, change parts of the casting’ mechanical properties and so on. This paper had made explorations and research on how to produce LFC steel casting with high quality.In order to reduce production cost, increase efficiency, improve the working environment, a lost foam casting experimental line has been designed, according to the company’s production program and existing conditions, to gradually replace the original resin sand casting production line. After specified the relevant production details, qualified steel castings had been produced and high quality castings can stably been produced on this line.First,As the level of foam’s surface quality determines the appearance roughness,dimensional accuracy of castings, the surface of low roughness and high dimensional accuracy is a prerequisite to obtain high-quality castings. In this paper, after selected high-quality foam, advanced CNC milling machine, used the special cutting tool of foam with proper speed and feed rate,eventually the car foam mold had been carved out with high quality.Second,a better internal quality of lost foam steel castings has been the focus of domestic and foreign researcher. After optimizing and determining the final casting process with using the casting simulation software in a unique way, the author tried to apply “burning foam before pouring metal” process on the production of more complex automotive panel die castings. Many aided measures and process had been taken to avoid the collapse problems. Eventually the automotive punching die castings with good internaland external quality has been successfully cast out combining with the vibration crystallization process. After tested, the dimensional accuracy is high, the surface is without carburization, the relevant internal defects have not been founded in machining areas.