The manufacturing industry of large steel castings is the basic industry of national equipment manufacturing, and its development level is an important symbol to measure a country’s comprehensive national strength. There are more than 30 large steel casting production enterprises in China, most of which are large and medium-sized state-owned enterprises. At present, there are only a few enterprises that can produce steel castings of more than 200 tons, such as first heavy and second heavy. The products of the whole steel casting production industry are mainly supplied to the domestic market and a small part of them are exported. The varieties are mainly concentrated in large steel castings in power station electrical equipment, metallurgical production equipment and petrochemical equipment, marine equipment, mining equipment and aerospace equipment.
In recent years, with the strong support of the Chinese government and the joint efforts of relevant researchers, the situation of the foundry industry has changed greatly. The complete sets of large tonnage (≥ 20 t / h) resin sand equipment independently developed and produced by Chinese enterprises have been put into production in large quantities, of which 30 t / h and 40 t / h sand mixers have been applied in many large foundry enterprises. At the “Beijing International Foundry, forging and Metallurgical Industry Exhibition” in 2006, two domestic foundry equipment manufacturers exhibited their newly designed and put into operation 60 t / h lifting mobile continuous sand mixer, which is currently the largest continuous sand mixer in China. It marks a new breakthrough in the design and manufacturing capacity of casting equipment for large and extra large steel castings in China.
With the development of computer technology and the popularization of microcomputer, technicians increasingly rely on the high-speed calculation and visual drawing ability of computer in casting process design. At present, the research scope of casting process CAD is broadly divided into two parts: numerical simulation of steel casting solidification process (CAE) and computer-aided design of casting process (CAD). The numerical simulation of solidification process includes macro and micro simulation. The purpose of the research is to predict the shrinkage cavity, porosity, microstructure, residual stress and segregation that may occur in the production of steel castings, and comprehensively analyze and judge the location and size of defects, so as to optimize the process design scheme, improve the process yield and reduce the production cost. In terms of casting process CAD, China’s research began with the national key research project of “Research on Solidification Numerical Simulation and casting process CAD of large steel castings” carried out by Shenyang Casting Research Institute. The project selected five types of typical steel castings as the research objects: rolling frame, wheel shape, blade, cylinder block and valve body. Relevant R & D personnel have developed a series of software needed in the field of casting, and achieved quite good results in application. The design efficiency and the productivity of steel castings have been greatly improved. The CAD system of external cooling iron casting process uses innovative design to make large steel castings get rid of the traditional production process of adding internal cooling iron and meet the process production requirements of key steel castings.
Among colleges and universities, Tsinghua University, Dalian University of technology, Harbin University of technology and Huazhong University of science and technology have also been committed to the research and development of casting process CAD system, and have made certain achievements, which has also produced very high value in the practical application of the factory. Thfscad system developed by Tsinghua University is a CAD system completely oriented to casting process design. However, due to its poor human-computer interaction interface and backward graphic display mode based on DOS operating system and auto cadr11 platform, it has not been applied well. The metal solidification simulation laboratory of the school of materials of Huazhong University of science and technology has been engaged in the research of CAD / CAE system of casting process since 1980s. The Huazhu CAE system developed by laboratory researchers is exported to home and abroad. It is the domestic CAE software with the highest market share. Huazhu CAD products are also applied to professional casting enterprises in the field of casting process CAD. In 2001, the laboratory cooperated with Shanxi Yuci Hydraulic parts factory to develop a special process CAD system that meets the requirements of casting production. The system is customized and developed according to the actual production situation of the factory, and the riser module is designed in general, so that it can also be used in the process design of other factories. In 2006, the laboratory cooperated with Baoji Petroleum machinery factory to develop a complete set of cast steel casting process CAD system. The system is not only customized for the actual process methods of the factory, but also developed a universal module suitable for most foundries on the basis of investigating the process design of many foundries. Therefore, it is a set of special and universal cast steel casting process CAD design system.