Current status and problems in the foundry industry

In the history of our country, there has been a brilliant and brilliant casting industry. The exquisite beauty of the bronzes of the Xia, Shang and Wednesday dynasties has amazed the world. However, in modern times, the gap between China’s foundry industry and the world’s advanced level is also worrying.

In the history of our country, there has been a brilliant and brilliant casting industry. The exquisite beauty of the bronzes of the Xia, Shang and Wednesday dynasties has amazed the world. However, in modern times, the gap between China’s foundry industry and the world’s advanced level is also worrying. From October 8th to 12th this year, China Foundry Week will be held in Dalian. The main content is to carry out technical exchanges and discuss the trend and future of the foundry industry. The foundry industry is an important part of the manufacturing industry and plays an important role in the development of the national economy, and the foundry technology is an important part of the manufacturing technology. Although China has become a major foundry country in the world, and its output has ranked first in the world for three consecutive years, it is far from a powerful foundry country. What is the gap between China’s foundry industry and the international advanced level, where will the foundry industry go, and many issues affecting the quality of foundry products need to be considered by people who are concerned about “Made in China”. This newspaper will adopt this set of reports from today to reflect this.

The foundry industry is an important part of the manufacturing industry and plays an important role in the development of the national economy and the enhancement of national defense capabilities. Casting is the foundation of pillar industries such as automobiles, petrochemicals, steel, electric power, shipbuilding, textiles, and equipment manufacturing, while advanced casting technology is an important part of advanced manufacturing technology. Relevant statistics show that in 2002, my country’s casting output was 16.26 million tons, ranking first in the world for three consecutive years. Although my country’s casting output has leapt to a major foundry country, it is far from a foundry power in terms of comprehensive quality, material structure, cost, energy consumption, efficiency and clean production.

Since the founding of the People’s Republic of China, after more than 50 years of construction, the manufacturing industry has laid a good foundation. The industrial added value of the manufacturing industry accounts for 35.75% of **P. At present, my country is a major manufacturing country second only to the United States, Japan, and Germany. Compared with developed countries, there is still a big gap. Professor Liu Jingyuan, a senior engineer from the Shenyang Foundry Research Institute, pointed out that in order to build my country into a manufacturing power, the level of casting and other blank production technology must enter the world’s advanced ranks. Experts pointed out that the gap between my country’s foundry industry and developed countries is mainly manifested in basic conditions such as comprehensive quality of castings, casting production technology and technical equipment. In terms of dimensional accuracy, castings in my country are generally 1 to 3 levels lower than those of developed countries, and their surface roughness is also 1 to 2 levels coarser than those of developed countries. For example, the roughness of the engine block is 25 microns to 100 microns in my country, and 12.5 microns to 25 microns in foreign countries. In terms of the composition of casting materials, the proportion of ductile iron in cast iron products is an important indicator to measure the comprehensive structural quality of castings in a country. The ratio of the total output of ductile iron to cast iron in my country is far behind that of developed countries. For example, ductile iron in the United States accounted for 39.1% of total cast iron output in 1996, and 16.4% in my country. In 2001, it was 43.3% in the United States and 22.45% in my country. Although the gap has been narrowing in recent years, the ratio of ductile iron to total cast iron output is still There is a big gap with developed countries represented by the United States. The chemical composition, metallographic structure and performance level, and stability of casting materials are generally lower than those of developed countries. In terms of the appearance of castings, there is also a large gap between my country and developed countries.

In terms of basic conditions such as foundry technology and equipment, my country generally has a relatively large gap with developed countries. In terms of smelting, foundry coke is commonly used in cast iron cupolas in developed countries, and the proportion in my country is very low. The baking temperature in foreign countries is 1500 degrees Celsius, and it is generally at 1380 degrees Celsius in my country. In terms of modeling and core making, most of the molds for mass production of medium and small castings in developed countries use high compaction rate high-efficiency, high-speed, injection-pressure and other high-efficiency assembly lines, and resin sand cores are used. There are only a few large-scale enterprises in my country that adopt foreign advanced modeling and core-making techniques. Due to the technological gap, our country’s precision castings are not refined, and there is a big gap between the technology of casting with almost no margin in developed countries, and the gap between special and precision molding technology and developed countries is even greater.

In terms of process design, mold processing, and foundry machinery, developed countries generally use CAD, CAM and other software integration technologies. Except for large-scale enterprises and some medium-sized enterprises, most small and medium-sized enterprises still rely on the experience of craftsmen to design with manual and simple methods. Mainly machinery, the level of casting mechanization and mold accuracy, performance, matching, and reliability are much lower than those of developed countries. Many key parts and molds need to be imported.

In terms of the quality and variety of casting raw and auxiliary materials, as well as the supply of socialization, specialization and commercialization, there is also a big gap between the developed countries. The quality of casting raw and auxiliary materials directly affects the quality of castings. Take foundry coke as an example. my country’s carbon content is 80%, developed countries’ 90%, and my country’s ash content is more than twice that of developed countries. There are many impurities in pig iron in our country, the composition is fluctuating, and it is not easy to supply fixed-point, high-quality scrap is lacking and the price is high. The quality, variety, price, technical standards, scientific research and development of modifiers, purifiers, raw sand, additives and high-temperature refractory materials used in foundry in developed countries have become a system. Europe has even established a transnational service system. At present, although there are many specialized factories producing various raw and auxiliary materials for foundry in my country, the equipment is simple, the technology is backward, the detection methods are short, the raw and auxiliary materials are incomplete, and the quality is poor. In particular, some high-tech products are still unable to be produced. Shanghai is still at a low-level, disorderly supply-oriented stage, such as long-life refractories are still being imported. Due to the technological gap, the energy and material consumption is higher than that of developed countries. Similar castings in my country are 10% to 20% heavier than developed countries. The production rate of castings in my country is 55% for cast steel, 64% for cast iron, 70% for non-ferrous alloys, and 60%, 68% and 80% for industrialized countries. %. There are about 24,000 foundry companies in my country. Compared with developed countries, there are more companies with low degree of specialization, low degree of intensification, and low labor productivity. The average annual output per capita in my country is 10 tons, and individual labor productivity is 30 tons. The U.S. and Germany are 46 tons to 60 tons, and Japan is 60 tons to 85 tons. The difference is obvious. The average annual output of castings per plant in my country is more than 500 tons, compared with 4700 tons in Japan, 4300 tons in Germany and 4280 tons in the United States. Although our country has a glorious history of casting, the Si Mu Wu Da Fang Ding of the Shang Dynasty is admired by the world. However, in the face of the development of the world’s foundry industry, we should face up to the domestic status quo and problems, take a series of effective measures based on the national conditions, shorten the gap with developed countries, and catch up with the international advanced level.