Stainless steel precision casting industry is different from the traditional casting industry. Although China is a large casting country, precision casting is in the stage of development, and there is still a large gap with developed countries. In recent years, China has vigorously promoted industrialization and continuously improved the level of science and technology. There have been some relatively mature technical means in precision casting. At the same time, China’s demand for precision casting products is also increasing. Therefore, precision casting (especially stainless steel precision casting) will have broad development space in China.
1、 The development prospect of stainless steel precision casting is broad
Stainless steel precision casting is also called investment casting. This process minimizes or does not carry out cutting at all in the casting process. It is a casting process with little or no cutting. It is an excellent process technology in the casting industry. Its application range is very wide. It is not only suitable for casting of various types and alloys, but also produces castings with higher dimensional accuracy and surface quality than other casting methods. At the same time, investment casting can be used for castings that are resistant to high temperature and not easy to process. This casting method is more suitable for casting components in aerospace, national defense and other high-precision industries because it is not in an ultra-high temperature state in the casting process.
The earliest stainless steel precision casting can be traced back to the 1930s and 1940s of last century. The United States first used stainless steel precision casting method to cast the turbine blades in its leading aero-engine at that time. The finished products were highly praised by all aspects, which promoted this method. The R & D and application of stainless steel precision casting in China was after the founding of new China. With the development of China’s national defense industry, stainless steel precision casting research institutes or foundries have been opened in Liaoning, Guizhou, Beijing, Shaanxi, Hunan and other places. However, objectively speaking, China’s stainless steel precision casting industry is still in the development stage and can not meet the development needs of China’s aerospace, national defense industry and other industries.
The stainless steel precision casting industry is different from the traditional casting industry because the added value of stainless steel precision casting products is high. According to relevant statistics (2013 data), among the aerospace equipment and excellent engines in European and American countries, the product added value of precision casting components accounts for nearly 70% of the total added value, but the proportion in China is less than 35%. At present, although China is already the country with the largest casting volume, the casting value is still at the middle and upper reaches level and can not reach the top level. Therefore, the fundamental significance of developing stainless steel precision casting is the fundamental needs of national defense and science and technology, and the only way to develop economy.
2、 Technology continues to mature, but needs to be improved
At present, there are many mature technologies and processes in stainless steel precision casting.
Silica sol shell molding process. Silica sol shell making process is widely used in the cutting-edge internal combustion engine parts casting industry. The coating used in this method has good stability, no chemical hardening process, high temperature resistance and better deformation resistance. However, the disadvantage of this technology is that the temperature and lubricity of wax mold is poor. Although it can be improved by adding surfactant, it will increase the investment to a certain extent.
Water glass shell process. The sodium silicate shell technology was invented very early, and China also introduced the technology from the Soviet Union in the 1950s and 1960s. The technology has low cost, relatively simple operation and low requirements for raw materials. It is widely used in stainless steel precision casting. However, compared with the silica sol shell making process, the biggest problem of this technology is that the surface quality of the castings is general and the dimensional accuracy is low. However, due to its cost advantage, this technology is still used in some civil or low precision internal combustion engines in China. Since the introduction of this technology, Chinese researchers have made great improvements, mainly in improving shell coating, optimizing hardener, using composite shell and so on.
The main improvement to improve the shell coating is to add a certain amount of refractory clay to the back coating of the shell, which greatly improves the strength of the shell and realizes single shell roasting and injection. In terms of optimizing the hardener, the traditional hardener mostly uses ammonium chloride, but this material will release a large amount of ammonia and nitrogen oxide gas in the casting process, causing pollution to the atmosphere. Therefore, the hardener is changed to aluminum chloride solution and further changed to aluminum chloride crystallization. The effect of this hardener is similar to that of ammonium chloride.
In the aspect of composite mold shell, because there are some defects in the surface quality of water glass coating mold shell, many original parts are cast in the form of multi-layer mold composite, which not only saves the cost, but also improves the surface quality of castings.
In addition, in the development of new technology, the new technology that is more mature at present is self suction casting process, foam plastic mold and melting model shell casting process. However, these processes have obvious advantages and disadvantages in some aspects, which still need continuous improvement by scientific and technological workers in the future.
3、 The development trend of multi technology intersection and integration is obvious
In the future development direction, the intersection and integration of stainless steel precision casting technology will become more and more obvious. The development direction of the new round of scientific, technological and industrial revolution will not only rely on one or two disciplines or a single technology, but a high degree of intersection and deep integration of multi-disciplinary and multi-technical fields. Therefore, stainless steel precision casting should also be integrated with related technologies.
Cross use with rapid prototyping technology. The cross use of science and technology is mostly to complement each other. The design and mold manufacturing of wax mold of stainless steel precision casting are complex and need to spend a lot of time. Rapid prototyping technology can make up for this shortcoming. However, due to material limitations, rapid prototyping technology alone can not meet the requirements. Therefore, in recent years, many workers first use polymer technology to obtain the prototype of castings, and then manufacture wax molds, which are put into the stainless steel precision casting industry.
For example, light curing stereo modeling technology (SLA) and selective laser sintering technology (SLS) are relatively mature technologies used in combination with investment casting. SLA technology can provide high dimensional accuracy, especially the accuracy of the outer surface of parts; The raw material price of SLS is relatively low, and the accuracy is lower than SLA technology. In the process of using these two technologies, we must pay attention to controlling the key combination points of rapid prototyping technology and stainless steel precision casting technology, including cost control and comprehensive consideration of casting accuracy of parts. Choosing the right balance point is the key problem of the organic combination of rapid prototyping technology and investment casting.
Cross integration with computer technology. The scheme design and Optimization in the process of stainless steel precision casting is a labor-intensive and time-consuming work. In recent years, with the continuous development of computer technology, many industries that need a lot of calculation and precision calculation have introduced computer technology and developed various corresponding calculation software, such as ProCAST, Auto CAD, afsolid, AnyCasting and so on. These software can calculate or simulate the design and casting process of stainless steel precision casting, and realize the scheme optimization through data calculation, which has played a good role in promoting the development of stainless steel precision casting.
Tsinghua University has been at the forefront of the world in the development of conventional general simulation software, and has developed computer simulation software in high-end casting such as Aeroengine Parts casting simulation software and TiAI Alloy Turbine Blades; Harbin Institute of technology has carried out research on laboratory software simulation casting of important structures in aerospace casting, such as space station and rocket; Huazhong University of science and technology has developed Huazhu CAE system for medium and high-end investment casting, which has a wider range of applications. It is also a model of the cross use of China’s leading computer technology and investment casting.
However, in the current use process, we should also pay attention to the modeling applicability of computer software and the thermophysical parameters of the material itself. A good solution to these problems can greatly shorten the research and development time of stainless steel precision casting.
4、 Steady development requires multiple approaches
For a long time, China has continuously adjusted the industrial structure, and the high-tech sector is becoming more and more important in China’s scientific, technological and economic development. In such an environment, stainless steel precision casting has a broad prospect in the future, and its steady development needs to be advanced in multiple ways.
First of all, we should adhere to independent research and development and self-reliance. Although the way of technology introduction and improvement can greatly shorten the scientific and technological level gap between China and advanced countries, this way of introduction is still a way of “taking the road of others” and restricted by other countries. Therefore, under the new situation, China should adhere to the development of science and technology with its own characteristics and master the core science and technology, so as to make the continuous development and progress of China’s precision casting industry.
Secondly, we should adhere to the concept of development and set an example for enterprises. Stainless steel precision casting industry is a cutting-edge industry. Leaders and models should be selected from many enterprises to drive the development of stainless steel precision casting in China.
Finally, we should strengthen the combination of R & D and production. At present, there are not many institutions of higher learning engaged in the research of stainless steel precision casting in China, and they often do not have close contact with major manufacturers, but only carry out research and development in school laboratories. This is a disadvantage for large-scale production and promotion of China’s stainless steel precision casting industry. Therefore, manufacturers can establish a cooperative mechanism of joint R & D and production with colleges and universities, so that technology students can not only exist in the laboratory, but also be put into the production line.
Hebei Junya Precision Machinery Co., Ltd., founded in 2017, is a high-tech enterprise integrating product design, mold development, casting, processing, surface treatment, testing and inspection and sales services. The factory covers an area of 5000 square meters and is located in Huanghua economic and Technological Development Zone, Hebei Province. The company has superior geographical location and convenient transportation. After years of development, the company has introduced advanced production equipment and management experience in various industries, and trained dozens of excellent professional R & D and technical talents.
At present, the company has more than 100 employees and more than 20 technical and R & D personnel. The company’s main products are stainless steel cast pipe fittings, quick connectors, ball valves, check valves, precision accessories, marine hardware, cast auto parts, etc. The product material is mainly 304 304L 316 316L CF8M WCB 1.4408, etc. The company officially passed ISO9000 certification in 2020 and is actively preparing for TS16949 quality system certification. With its good product quality and reputation, the company has become more and more prominent in the international market, with partners all over the world.
In 2020, the export volume accounted for more than 70% of the total sales, and has established long-term and stable cooperative relations with many enterprises in Europe, the United States and Japan. The company always adheres to the business philosophy of heart, innovation and ingenuity. Based on the principle of seeking development from R & D, meeting opportunities in development, building trust in opportunities and consolidating contacts in trust, we look forward to cooperating with you. For details, please contact 18902146189
Post time: Apr-14-2022
