(1) Basic situation of foundry industry in China

According to the analysis and estimation of relevant data, there are more than 20,000 casting sites in China, employing about 6,543.8+0.2 million people, with an annual output of about 6,543.8+0.2 million tons of castings and an output value of more than 40 billion yuan, ranking second in the world. 194 exported about 550,000 tons of castings with a total value of $330 million. From the perspective of industrial structure, there are a large number of foundry branches or workshops belonging to the main engine factory or company; In the process of promoting specialized production, a large number of independent professional foundries have also been developed (mainly focusing on process specialization); There are also a large number of small foundries established in towns and villages since the reform and opening up. In terms of scale and level, there are large foundries with advanced technology and high mechanization, with an annual output of tens of thousands of tons of castings; There are also small foundries with backward technology, simple equipment and basically manual operation, with an annual output of castings 100 tons. Taking iron castings as an example, the overall labor productivity is about 8~ 10 ton/person-year. The energy consumption per ton of iron castings and steel castings in a general foundry is 550 ~ 650kg standard coal and 900 ~ 1000kg standard coal respectively. In recent ten years, a number of enterprises have made great progress and improved through technical transformation, and a number of advanced foundry backbone factories have been formed. However, on the whole, China's foundry industry is still facing problems such as poor economic benefits, low casting quality, high energy and material consumption, poor working conditions and serious environmental pollution.

The statistical analysis of 1989- 1992 shows that the market demand for castings is booming. According to alloy types, China's casting output accounts for 8 1%~83%, steel castings account for 13%~ 15%, and non-ferrous alloy castings account for 3.5%. The annual output of investment casting is 6.5438+0.7 million tons, and that of die casting is about 250,000 tons, accounting for 2%.

During the period of 1994, the output of various castings in China is shown in table1-kloc-0/,and the output of various castings in various regions is shown in table 1-2.

(2) The technological progress and development of China foundry industry in recent 5- 10 years.

With the reform and opening-up, as well as the technical transformation in the Seventh Five-Year Plan and the Eighth Five-Year Plan, many changes have taken place in China foundry industry. The casting process, technical level and casting quality level have been improved to some extent compared with the previous 10 year, and a number of key foundries with international standards in the 1980s have emerged. The technological progress and development of China foundry industry are mainly manifested in:

The application of new equipment has improved the mechanization level of foundry production in China.

-More than 80 resin sand production lines have been put into mass production in machine tools, petroleum, general and heavy machinery industries. At the same time, the application of resin sand technology and equipment with the capacity of 5~20 tons/hour in China has formed a number of castings mainly based on tree finger sand technology, which has improved the technical level of casting production, and made the dimensional accuracy of large and medium-sized castings in China reach CT9- 1 1, the surface roughness reach Ra 12.5~50μm, and the quality is close to the international level in the 1980s. At present, China has formed an annual production capacity of more than 700,000 tons of resin sand castings, and successfully produced resin sand steel castings 150 tons. Some domestic factories have been able to meet the requirements of the international market and produce export machine tool castings and other castings by resin sand process.

-3 1 stamping line has been introduced into mass flow production in automobile, internal combustion engine and other industries. On the basis of digestion and absorption, China has independently developed 29 air impact molding machines and production lines. With the production of these automatic molding lines and the cleaning of high-quality fine steel pellets, a number of factories have been formed in China to produce advanced castings, which make the dimensional accuracy of castings such as cylinder block, cylinder head and box body produced by some foundries reach ISOCT 6-8 grade, and the surface roughness reaches Ra 12.5~25μm, which is close to the quality level of similar castings abroad. In addition, China has introduced more than 70 advanced molding production lines such as vertical and horizontal parting high pressure, injection pressure, extrusion static pressure and "V" method, which has played a significant role in improving the quality level of high-strength thin-walled castings in China.

── Due to the advantages of high dimensional accuracy (up to 0.2 mm), smooth surface (Ra 5 ~ 6 μ m), low production cost and low investment, EPC has developed rapidly in Europe and America in recent years. China uses EPC technology to produce aluminum alloy intake pipes for automobiles, as well as cast iron parts such as valves and pipe fittings.

-About 10 sets of centrifugal casting equipment for medium-sized ductile iron pipes with a diameter below 1m have been introduced for cast iron pipes, and the production capacity of each factory is 30,000-50,000 tons/year. At the same time, China also developed water-cooled metal centrifuges and various auxiliary machines. It is predicted that the annual output of centrifugal ductile iron pipes in China will increase rapidly in the next 2~3 years.

—— Heavy machinery industry has introduced refining technology and equipment outside the furnace such as AOD and VOD, and has advanced equipment such as 80-ton large electric arc furnace with automatic control, which greatly improves the internal quality of high-grade alloy steel castings.

-In recent years, China has introduced various core-making machines 1 10 sets. China has been able to mass-produce various types and models of hot box machines and shell-core machines. Triethylamine cold box equipment and core-making unit have been successfully developed or put into use after digestion and absorption. The core-making level has been greatly improved.

—— In recent years, more than 0/00 sets of die casting machines have been introduced and independently developed/0/6000 KN die casting machines. The level of aluminum die casting has also been greatly improved.

2) The development and application of new materials improve the service life and reliability of the whole machine.

China's rich rare earth resources are widely used in foundry production. Rare earth magnesium nodular cast iron has been widely used in mechanical products such as automobiles and diesel engines. Rare earth medium-carbon low-alloy cast steel and heat-resistant cast steel have been well applied in mechanical and metallurgical products, and considerable technical and economic benefits have been achieved.

Gray cast iron with high strength and high elastic modulus has been successfully applied to machine tool castings, which improves the accuracy of machine tools. With the application of high-strength thin-walled gray cast iron casting technology, the thinnest hardness difference between cylinder block and cylinder head casting is only 4~6 mm HB.

-Vermicular graphite cast iron has been used in automobile exhaust pipes and cylinder heads of high-power diesel engines, which has improved the service life of automobile exhaust pipes by 4-5 times, reaching more than 10 Wan Li.

High phosphorus boron vanadium titanium wear-resistant cast iron has been widely used in machine tool guide rail, cylinder head and piston ring, and its wear resistance and service life have been improved by 1~2 times. High chromium and low chromium wear-resistant cast iron have been widely used in wear-resistant parts, and their service life is 8~ 10 times and 2~3 times that of raw materials respectively.

-New aviation materials such as ZL206 high-temperature heat-resistant aluminum alloy and ZM6 heat-resistant high-strength rare earth magnesium alloy have been developed.

3) The popularization and application of new technology has promoted the level of casting technology and the internal and external quality of castings.

After more than ten years of research and development, China has formed its own series of inoculants, nodularizers and vermicularizers, and gradually formed a production base for commercial supply of three agents according to national standards, which has effectively promoted the improvement of the internal quality of iron castings in China.

-In recent years, all kinds of advanced cast iron smelting equipment have been developed and popularized, which further improves the temperature of molten iron and reduces the oxidation of molten iron. External hot blast cupola (air temperature 500~600) has been applied in China, making the temperature of hot metal reach 1500. Cupola-electric furnace duplex melting process has been widely used in mass production.

-Screen technology is applied to mass production of high-strength thin-walled castings such as cylinder block and cylinder head, which improves the internal quality of castings and reduces slag hole defects.

── Coated sand permanent mold casting technology has been successfully applied to diesel engine crankshaft, effectively improving the quality and yield of crankshaft.

—— Successfully produced 600,000 kilowatts of high and medium pressure cylinder of steam turbine, stainless steel blades of water turbine12.5 ~170,000 kilowatts, large steel castings with gross weight of 330 tons and large aluminum alloy castings with gross weight of 5 tons and net weight of 2.7 tons.

Advanced resin sand core-making technologies such as hot core box, shell core box and cold core box have been widely used in castings of automobile, internal combustion engine, tractor, machine tool and other industries, greatly improving the dimensional accuracy of castings.

-China has successfully developed horizontal continuous casting technology and equipment, and produced 60~200 and 40×40 ~ 200×200 sections of ink cast iron and gray cast iron. This material has a series of advantages such as compact structure, high strength, pressure resistance, high dimensional accuracy and smooth surface.

China's investment casting technology has made great progress, and the near-net forming technology is used to produce aero-engine blades without allowance, reaching the international level in the 1980 s. At present, the production capacity of stainless steel investment castings has reached 6.5438+0 million tons/year, and the dimensional accuracy and surface roughness have reached the international level, meeting the export requirements.

4) The supply of raw and auxiliary materials began to improve.

The quality and supply of casting raw and auxiliary materials have long restricted the development of China's casting industry and the improvement of casting quality. After more than 40 years of appeals and hard work by foundry workers, this situation began to improve.

-A systematic investigation and basic work have been carried out on resources such as raw sand and bentonite for casting. Under the unified planning, more than 30 sand mining sites, such as Dalin, Bahuta, Dongchangchang, Zheng 'an, Fujian Dongshan and Pingtan, have all realized the elutriation of raw sand, making the mud content of raw sand lower than 0.8%. At present, the annual output of sand washing in these sand mining sites is1.50 ~ 2 million tons, and the annual output of scrubbed sand is over 500,000 tons.

-China has been able to mass-produce and commercially supply various resins, hardeners and auxiliary materials for molding and core-making of resin sand, and commercially supply coated sand.

-Various auxiliary materials, such as coatings and adhesives, have been imported and commercialized, laying a foundation for future system development.

-Foundry coke required for producing high-temperature and high-quality molten iron has been initially established in China, forming a certain scale, which has created favorable conditions for stabilizing the quality of ductile iron castings and high-strength gray iron castings.

5) Advanced detection means and electronic technology have been applied and developed in foundry production.

—— In recent years, direct-reading spectrometers and thermal analyzers have been widely used in many key foundries that are unemployed. The accounting of molten metal and impurity elements in front of the furnace has been quickly and effectively controlled, and the quality of castings has been controlled by means of audio and sound velocity detection, thus ensuring the reliability and stability of the internal quality of castings.

Three-coordinate measuring instruments have been applied in a few large foundries, effectively ensuring the dimensional accuracy of molds, core boxes and even castings.

-Electronic computers have been used in foundry production. At present, it has been applied to production management and various data processing, automatic control of production process and casting process aided design.

-Manipulators and robots have been used in the sand dropping and cleaning process in casting production, as well as investment casting in die casting.

1.2 market demand analysis

(1) Analysis of casting demand based on casting production status and output growth trend.

According to the overall development plan of China's national economy, China's gross national product will increase by 8%~9% in the 1990s. The scale of economic construction will continue to expand and the export volume of castings will also increase. It is expected that the output of castings in China will continue to increase. At the same time, due to technical progress factors, such as improving the dimensional accuracy of castings, reducing the wall thickness of castings, prolonging the service life of castings, expanding the application of light alloy castings, and using engineering plastics to punch and weld structural parts, it is expected that the output of castings will continue to increase at an average annual rate of about 4%. By 2000, the annual output of castings in China will reach13.5 million tons.

(2) Looking at the demand analysis of castings from the development of key host products.

Automobile castings have increased greatly. By the year 2000, the annual consumption of automobile castings will reach 654.38+500,000 tons.

-Due to the prosperity of the construction industry and the country's vigorous development of pipeline transportation of water, oil and gas, the output of cast iron pipes will increase at a relatively fast speed and will exceed 2.3 million tons by 2000. Among them, due to the introduction of nearly 10 sets of main engines, the output of centrifugal ductile iron pipes will exceed 500,000 tons by 2000, and its proportion in cast iron pipes will increase from the current 5% to 20%~25%.

-Due to the tilt of state investment in infrastructure, railway locomotives, power generation equipment, metallurgical mines and various professional machinery have increased substantially. It is predicted that by the year 2000, the output will increase by more than 30% compared with the present, and the output of castings will also increase.

-the output of agricultural machinery and internal combustion engine castings will continue to grow steadily, and it is estimated that the output will exceed 2 million tons by the year 2000.

-The output of machine tools, valves and hydraulic castings will also increase to a certain extent. Due to the application of resin sand, the export volume of such castings will increase. The proportion of machine tool castings to the total weight of castings may still be around 7%.

(3) Demand analysis of various casting alloys from the development of key mainframe products.

1) the output of iron castings continues to increase, but its proportion in the total output of castings remains at about 80%~82%, and its internal composition ratio will change greatly.

-Ductile iron castings have greatly increased due to the rapid increase of automobile production and the continuous production of nearly 65,438+00 sets of centrifugal ink cast iron pipe production lines, and further replaced some steel castings and malleable iron castings. It is predicted that by the year 2000, the proportion of ink iron castings of China team will exceed 15%, with an annual output of 2 million tons.

Although malleable cast iron still has a certain market in pipe joints, fasteners, circuit accessories and other products, its consumption in the automobile industry has been greatly reduced. It is predicted that by the year 2000, its proportion will be reduced to 2%~3%, with an annual output of 300,000 ~ 400,000 tons.

Gray cast iron castings are still widely used in automobiles, diesel engines, tractors, machine tools and various professional machinery, and the output will continue to increase. It is predicted that by the year 2000, the annual output will reach 9 million tons, accounting for a slight decrease in the weight of all castings, about 65%.

2) The output and specific gravity of non-ferrous alloy castings have been greatly increased.

-due to the rapid growth of the output of automobiles, motorcycles and leisure office supplies in China in the next 5~ 10 years, the output of aluminum alloy castings and aluminum-zinc alloy die castings in China will increase substantially. It is estimated that by 2000, the output of aluminum alloy castings may reach about 800,000 tons, accounting for 6% of the total output of castings. Due to the limitation of colored production, the growth rate will also be limited.

-The output of copper alloy castings will not change much, but its proportion will decrease.

3) The annual output of steel castings will be reduced to about 6.5438+0.2 million tons, and its proportion in all castings will be slightly reduced, but the demand for alloy steel castings will be further increased, making its proportion in all steel castings rise to 25%~30%.

(4) Analysis of international market demand

In recent years, the annual output of castings in the world has been stable, generally between 70 million and 75 million tons, in which ductile iron castings and aluminum alloy castings have increased greatly, while gray iron castings, malleable iron castings and steel castings have decreased. Due to the influence of energy, labor price and environment, the output of castings in western industrialized countries will gradually decrease. They will purchase ordinary castings from developing countries, but at the same time they will export high-quality castings with high added value and high technology content to developing countries. If the average annual growth rate of China's casting exports is 15% from 1990 to 1993, the export volume of China's castings may reach 1 000000 tons by 2000, which is more than1times higher than now.

1.3 revitalization goal

(1) Overall goal of revitalization

It is conceivable that it will take fifteen years or even longer to fundamentally change the backward situation of foundry production in China, strive to basically meet the needs of national pillar industries-machinery industry, automobile industry and high-tech industry for high-quality castings, as well as the needs of national economic infrastructure and people's lives, and make the overall technical level of China's foundry industry close to the world level.

Before 2000, it was the first stage of revitalization. While accelerating the digestion and absorption of imported technologies and equipment, and combining with China's specific production conditions and resources, we will actively develop new casting processes, new materials, new technologies and new equipment, effectively solve the commercialization of casting raw and auxiliary materials, make their quality and variety meet the requirements of casting technology development, and form a group of competitive backbone casting production enterprises in the international market. Improve the quality and reliability of domestic foundry machinery and process equipment, so as to promote the high quality, low consumption, high efficiency and less pollution of foundry production in China and lay the foundation for revitalizing the overall goal.

The second revitalization stage is 200 1 to 20 10. The performance, quality and reliability of the main casting products reached the international level at that time, and a relatively complete supply system of raw and auxiliary materials and a self-developed casting machinery and process equipment system were formed in China.

(2) immediate goals

It is predicted that by the year 2000, the foundry output in China will reach13.5 million tons. The main contradiction is to improve the casting quality, technical and economic benefits and solve the problems of working conditions and environmental pollution. During the Ninth Five-Year Plan or a longer period, through market competition, survival of the fittest, deepening system reform and macro-control, China's foundry sites will be gradually adjusted to a more reasonable level, and a basic team of casting sites with about 6,000 employees ranging from 600,000 to 800,000 will be formed, in which 1/4 will become a key foundry to achieve economies of scale. 10% (about 150) of these key foundries have become the backbone factories of various industries, reaching or approaching the production technology level of industrialized countries in the late 1980s and early 1990s. 90% (about 1400) of key foundries have reached the level of industrialized countries in the mid-1980s.

1.4 Short-term development goals of large-scale economic production

According to the different means and methods of product production, the development goal of scale economic production in the backbone foundry of various castings is:

1) mass production of automobiles, internal combustion engines, tractor castings and cast iron pipes, with economies of scale1.5 ~ 20,000 tons/year? Above the factory. Among them, some large foundries (group companies) and centrifugal ductile iron pipe factories should reach 50,000 tons/year? Above the factory. First of all, during the Ninth Five-Year Plan period, the unemployed automobile foundry has further improved its casting quality, mechanization and automation, technological level, personnel quality and environmental protection quality. The overall production level has reached the level of developed countries in the late 1980 s and some in the early 1990 s, and it is competitive in the international market.

2) Mass-produced machine tools, valves, railway locomotives and general special machinery castings, with economies of scale of 700,000 tons/year? Above the factory. Resin sand technology should be popularized in technology and equipment, so that this kind of castings can reach the current international standards in internal quality, dimensional accuracy and surface roughness, and the overall production level, including mechanization, can reach the level of developed countries in the early 1990s, and the environmental protection quality can reach the national standards, and an export base for this kind of castings has been established.

3) Heavy and large mechanical castings such as mines, power stations and metallurgy. If a single piece is produced in small batches, it should produce 7000 tons/year? Above the factory. The level of technical equipment and environmental protection quality reached the level of developed countries in the late 1980s and early 1990s. It can provide high-quality and reliable castings for key equipment of major national engineering projects and is competitive in the international market.

4) Mass production of precision small castings (such as hydraulic components, small compressors, high-tech castings, etc.). ) should be concentrated as much as possible according to the process requirements, and the scale economy batch should reach 1000~2000 tons/year? Above the factory; On the basis of relatively centralized and specialized production, investment casting strives to increase the economic scale to 500 tons/year? Above the factory. By applying the international advanced technology, materials and equipment at that time, the problem of rough quality of hydraulic parts was completely solved, and the precision and surface roughness of investment castings reached the international level of similar products. The quality of environmental protection has reached the national standard, and some casting export bases with high added value have been established.

5) The scale economy batch of aluminum alloy castings should be 500~ 1000 tons/year? Above the factory. The quality and economic benefit of castings should reach the level of advanced industrial countries in the early 1990s, meet the needs of automobile, instrument and other industries, and the environmental protection quality should meet the national standards.

(3) Long-term goals

By 20 10, advanced casting technology and equipment suitable for China's national conditions will be adopted to form a relatively complete supply system of casting raw and auxiliary materials and a casting machinery and technical equipment system that can be independently developed. The quantity and quality of castings can fully meet the needs of machinery industry, and some middle and high-grade castings are exported. Adjust the number of foundry enterprises to 5000, so that 60% (about 3000) of them will become key foundry enterprises, and 30% (about 900) of them will be backbone enterprises. Their production technology level, casting product performance and environmental protection quality reached the international level at that time, and 70% (about 2,000 vehicles) reached the level of industrialized countries in the late 1990s.