1. The scale of China's stainless steel foundry industry in China's precision casting industry, although established in the mid-1950s, and gradually widely used, but the real rapid development in the early 1990s to the present It has been more than 10 years, especially in recent years. At present, there are two horizontal technologies in investment casting in China. The first type is the investment casting process using ventilating materials and silica sol or ethyl ester binder shells, that is, the international casting process. The second type is the use of low temperature crystallizer. And the shell process of the water glass binder, the casting dimensional accuracy and surface roughness are worse than the first one, reaching the international investment casting level. According to the situation in the mainland, there are also medium or low temperature forming dies, the surface layer is made of silica sol, and the reinforced layer is made of water glass shell composite technology, which ensures higher dimensional accuracy and surface quality to reduce costs. According to statistics, in 2001, the first type of manufacturers used exceeded 350, the annual output was 75,000 tons, and the annual output value was 3.28 billion yuan. The second type of processing enterprises (including composite processes) was over 1350. The annual output was nearly 200,000 tons, and the annual output was 15 years. 100 million yuan. In 2002, the characteristics of stainless steel casting processing, the output reached 321,000 tons, and the output value reached 5.49 billion yuan. The output in 2002 was 6.4 times that of 1988. The output was 16.6 times that of the 330 million in 1988.

2. Process level, casting quality and product type From the use and quality level, the current production of China's stainless steel casting processing is mainly: The first type of production of aviation and gas turbine castings, quality international standards, the manufacturer has 50, the annual output of 5,000 tons, the year The output value of 400 million yuan, the first and composite technology production of commercial precision castings, its quality inspection projects and standards are lower than aviation parts, about 300 years, with an annual output of 70,000 tons, with an annual output value of 2.88 billion yuan; the second type of production The casting blank with low dimensional accuracy and surface roughness requirements is about 1350, with an annual output of nearly 200,000 tons and an annual output of 1.5 billion yuan. From the distribution of the three quality levels, the proportion of castings can be seen, the production level of aviation precision castings is very low, accounting for only 1.8% of the total output, the general commercial precision castings account for 25.6%, the quality does not meet international standards, water Glass castings accounted for 72.6% of the total production. In general, investment castings have been carried out with market structures in advanced countries and regions such as the United States, the United Kingdom, Europe and Japan. There are obvious gaps, and the proportion of high-quality castings is still very low. However, China's investment casting process has made great progress in all aspects. There are many new materials, new processes and equipment development investment casting, such as water-soluble core, ceramic core, metal material improvement, large investment casting technology, Titanium alloy investment casting, directional solidification and single crystal casting, filtration technology, hot isostatic pressing, rapid prototyping technology, computer application in investment casting and mechanized automation technology can not only produce small castings, but also produce larger castings. The maximum investment size of the investment casting is close to 2m and the minimum wall thickness is less than 2mm. At the same time, the castings are also more precise, in addition to the linear tolerances, the parts can also achieve high geometric tolerances. The surface roughness of the die casting is also getting smaller and smaller, reaching Ra0.4um.

Stainless steel casting processing features

3. Due to the rapid development of the foundry industry, the supporting business has been gradually improved, which has driven the rapid development of related supporting businesses. Mainly reflected in mold processing, equipment manufacturing, raw and auxiliary materials production. According to preliminary statistics, the processing equipment is mainly specialized in manufacturing stainless steel casting and processing molds, and has been concentrated in stainless steel foundry processing plants, such as Guangdong, Shandong, Wuhan, etc., special equipment manufacturers line up; original auxiliary materials production plants and suppliers It has developed into nearly one hundred kinds, and since the first casting process requires the production of mold materials, zircon powder, abrasive belts and other accessories and some advanced equipment can not be produced domestically, se is imported from abroad every year. Some of the second and third types of process enterprises represented by manufacturers are accelerating their efforts to promote the international market in recent years, regardless of process technology level, product quality and labor productivity, and will continue to work hard to improve the level of China's precision casting industry.