Welding Industry Status and Independent Innovation Strategy

1 Position and role in equipment manufacturing

    Welding is a manufacturing technique that permanently joins materials and becomes a given functional structure. Almost all products, from hundreds of thousands of tons of giant wheels to less than one gram of microelectronic components, apply welding techniques to varying degrees in manufacturing. Welding has penetrated into all areas of manufacturing, directly affecting the quality, reliability and longevity of the product as well as the cost, efficiency and market response speed of the production.

    China's steel output reached 349 million tons in 2005, making it the world's largest steel producer and consumer. The steel used in welded structures also exceeded 130 million tons, equivalent to one year of steel production in the United States. The largest manufacturer of welded steel structures.

    From the point of view of some landmark projects completed in China in 2005, welding technology has played an important role. For example, the hydropower equipment of the Three Gorges Water Control Project is a huge welding system, including a water conduit, a volute, a runner, a large shaft, a generator base, etc., wherein the martensitic stainless steel runner has a diameter of 10.7 m and a height of 5. 4 m  440 t, the world's largest cast-welded structure runner. The runner is welded by the upper crown, the lower ring and 13 or 15 blades. The welding of each runner requires 12 t welding wire, which takes more than 4 months. The successful launch and recovery of the Shenzhou-6 spacecraft marks a tremendous advancement in China’s space industry, including the return of two astronauts. The return and orbital chambers are welded structures of aluminum alloys, and the airtightness and deformation control of the welded joints are the key to welding manufacturing. At the end of 2005, the first heavy-duty machinery group was the first hydrogen direct reactor of China's coal direct liquefaction plant manufactured by Shenhua Company. It has a diameter of 5.5 m, a length of 62 m, a thickness of 337 mm and a weight of 2 060 t, which is the largest in the world today. The heaviest forged-welded structure hydrogenation reactor adopts the automatic double-wire narrow-space submerged arc welding technology with domestic independent intellectual property rights. Each ring weld must be welded continuously for 5 days. The West-East Gas Pipeline has a length of 4 000 km and is China's first high-strength steel (X70) large-diameter long-distance pipeline. The spiral steel pipe and straight seam steel pipe used are all welded plates in the form of plate-weld. In 2005, the total tonnage of China's shipbuilding reached 12.12 million tons, accounting for 17% of the world's total shipbuilding. After Japan and South Korea, it ranked third in the world and is moving towards a world level of 25 million tons per year. The domestically produced 300,000-ton supertanker, the new 5668 TEU container ship, the 150,000-ton bulk carrier, and the 170 ships known as the "China's No. 1 Shield" for the world's attention are the pride of the Chinese shipbuilding industry. It is a typical plate-welded structure. In addition, Shanghai Zhonghaopu Bridge is the world's longest fully welded steel arch bridge; the ellipsoid dome of the National Centre for the Performing Arts is the world's heaviest steel structure dome; the bird's nest steel structure of the Olympic main stadium under construction weighs more than 40,000 tons It is also the best in the world. These large-scale structures are the largest, heaviest, longest, highest, thickest, and most recent representative and important products in China's welding manufacturing. It can be seen that welding plays a very important role in the development of national economy and national defense.

From the development projects of 20 national major technical equipments planned by the 11th Five-Year Plan, it can be seen that the nuclear power units of millions of kilowatts, ultra-supercritical thermal power generators, high-capacity super-capacity hydropower units, and large-scale pumped storage Complete sets of technical equipment for units, 30-60,000-watt circulating fluidized bed (CFB) boilers, large-scale ethylene complete sets of equipment, millions of tons of large-scale terephthalic acid complete equipment, large-scale coal-to-gas complete sets of equipment and large coal mines Among the comprehensive mining technology and equipment, welding manufacturing is one of the key manufacturing processes.

 

2 analysis of independent innovation ability of the industry

 

2.1 Industry Technology Status

    Since the founding of New China, especially since the reform and opening up 25 years ago, China has independently developed, developed and introduced some advanced welding equipment, technology and materials. At present, the mature welding methods and equipment that have been used in production in the world are also used in China, but the depth and breadth of the application are different. Chinese manufacturing companies are already using electron beam welding, laser welding, laser brazing and laser cutting, laser and arc hybrid heat source welding, monofilament or twin wire narrow gap submerged arc welding, 4 wire high speed submerged arc welding, twin wire pulse Gas shielded welding, plasma arc welding, fine plasma arc cutting, water jet cutting, CNC cutting system, robot welding system, welding flexible production line (W-FMS), variable polarity welding power supply, surface tension transition welding power supply (STT) and Digital welding power supply, etc. Even the most popular friction stir welding technology in the world has been applied to the production of products. China's welding production technology has been greatly improved, but the seriousness of the problem can not be ignored.

    Overall, China's total production of welding materials in 2004 reached 2.1 million tons, more than the combined output of welding materials in the United States, Japan, Germany, but the production of welding rods for manual welding accounted for 75%, various mechanization, automation The welding wire accounts for 25%, and the mechanization/automation rate of the welding is 35%, which is the highest ratio in the past years. However, this is only equivalent to the level of welding mechanization/automation rate in Japan in the late 1970s. In Japan, the total output of welding materials in 1979 was 400,000 tons, manual welding rods accounted for 58%, various welding wires accounted for 42%, and welding mechanization/ The automation rate is 44%.

    There are about 7,000 companies in China's manufacturing industry that use welding as their main technology, of which about 1/3 are large, large and medium-sized enterprises. Their welding mechanization/automation is obviously better than many small enterprises. Welding robots are an important way to achieve automation and flexibility of welding. According to statistics from 2001, there are 1,040 welding robots nationwide, which is expected to increase to about 2,700 by the end of 2005, mainly in the automotive, construction machinery, motorcycles, rail vehicles, boilers, metal furniture and military industries. In recent years, the automotive industry (including automobile manufacturers and parts factories) has installed and applied welding robots in large quantities, and 70% of the nation's welding robots are concentrated in the automotive industry. However, more than 90% of the joint industrial robots used for welding in the country are imported, which basically covers the varieties of industrial robots all over the world. There is only one Sino-Japanese joint venture robot manufacturer in the country, but it mainly assembles the parts produced by the Japanese parent company into robots, and lacks domestic and foreign brands. Some universities and research institutes also manufacture a small number of industrial robots, but the number is limited. It is difficult to compete with imported robots in terms of price, performance and reliability, and has gradually been marginalized in the welding field. Fortunately, there are more than a dozen welding robot application engineering development companies with certain experience in China. They use imported welding robots to design and manufacture peripheral devices according to the needs of users, and integrate them into welding robot workstations or units to complete the handover. Key works. About 20% of welding robots are currently composed of domestic engineers. However, more complex robotic welding production lines and flexible production lines, such as automobile and construction machinery welding production lines, are basically imported from foreign companies.

    The manufacture of supercritical and ultra-supercritical thermal power station boilers, nuclear power plant complete sets of equipment and hydrogenation reactors for petrochemical equipment is the need of domestic energy development. Welding plays an important role in the manufacture of these major equipment, but the key welding materials required, such as super heat-resistant steel, super-stainless steel welding materials and corrosion-resistant nickel-base alloy consumables, stainless steel surfacing The materials are basically imported. Gas shielded welding wire for high-strength steel (900 to 1 100 MPa) for construction machinery is also mainly imported. There are nearly 1,000 domestic welding material factories, and 120 large and medium-sized enterprises listed in the statistics list, and several large enterprise groups such as Tianjin, Zigong, Shanghai, Kunshan and Jinzhou have been formed. But in general, there are fewer varieties of products, weak R&D capabilities, and slow research and development. Most of them are low-end and mid-range products, and it is difficult to withstand the influx of foreign high-end welding materials. It has a serious impact on the development of major domestic technical equipment and national defense high-tech projects.

    Arc welding is still the main method of welding today. The performance of the welding power supply directly affects the stability and efficiency of the welding process as well as the material and energy consumption, and ultimately the quality consistency of the welded joint. In the past 25 years, the technical level of foreign welding machines has been rapidly improved with the development of electric power, electronic components and computer technology, from the original rotary DC welding machine to diode rectifier welding machine, thyristor (SCR) rectifier welding machine, transistor rectification Welders, inverter welders, all-digital inverter welding machines up to now. In the planned economy period, the domestic electric welding machine industry mainly played the leading role of the state-owned large enterprises such as Shanghai Electric Welding Machine Factory, Tianjin Electric Welding Machine Factory and Chengdu Electric Welding Machine Factory. Now they have all retreated, and the national electric welding machine industry has formed a situation of nearly 1,000 small enterprises. . Currently leading the Chinese electric welding machine industry are two joint ventures, the products are mainly foreign parent company brands, accounting for nearly half of the domestic electric welding machine market. The welding machines with China's independent intellectual property rights are mainly thyristor rectifier welders and simple function inverter welders. At present, the high-end welding machines used by domestic backbone equipment manufacturing enterprises, such as the STT welding machine, the all-digital inverter welding machine, and the double-wire pulse gas welding machine mentioned above, basically rely on imports. The value of these advanced welding machines is extremely high. The price of a fully digital inverter welding machine is as high as RMB 12 to 150,000. The price of ordinary thyristor rectifier welding machines of the same power is only 20,000 to 40,000 yuan. China's annual import of welding power and equipment costs about half of the national market, and nearly half of the domestically produced welding power production value is a joint venture. The output value of nearly a thousand small and medium-sized enterprises accounts for less than one-third of the domestic market share, and these market shares are mainly maintained by cheap labor and some commercial means of operation. How long this kind of competitiveness can last is worth considering.

    In summary, the welding process is not an auxiliary process. It has become a key processing tool in the manufacturing industry in recent years. It has completed many major strategic products related to national economy, people's livelihood and national defense construction. China has no suspense. The land has become the world's leading welding power. However, the key welding materials and welding equipment used in domestic welding production are heavily dependent on foreign imports. There are not many key technologies and products with independent intellectual property rights in China, and the overall R&D, innovation level and speed are not high, and the image of the welding country has formed. Huge contrast. If it continues, it will gradually become a weak link in China's economic strategic security.

2.2 Status of foreign technological innovation

     The developed countries of the world have attached great importance to the development and innovation of welding technology. American and German experts are discussing the role and direction of welding in the 21st century. Consensus that:

    (1) Welding (by 2020) will remain an important processing technology for the manufacturing industry. It is a precise, reliable, low-cost, and high-tech joining method. There are currently no other methods that can be applied more widely to metal joints than soldering, adding more added value to the soldered product.

    (2) Welding technology (including joining, cutting, coating) now and in the future has the processing method of greatest success in processing various materials into marketable products.

    (3) Welding is no longer a “call-to-call process”, it will be gradually integrated into the product's life-cycle process, from design, development, manufacturing to maintenance and recycling.

    (4) Welding will be considered a critical tool for improving the cost, quality and reliability of the product's life cycle, and will contribute significantly to improving the market competitiveness of the product.

    The major industrialized countries in the world attach great importance to the role of welding research institutions, and basically form a three-level research and development system for universities and research institutes. Welding research institutes have been established in major industrialized countries, such as the Welding Research Institute (TWI) in the United Kingdom, the Edison Welding Institute (EWI) in the United States, the FWI in France, and the JWRI in Japan. , the Polish Institute of Electric Welding (PEWI) in Ukraine, the Welding Research Institute (ISF) of the University of Aachen, Germany, and the Welding Research and Training Center (SLV) of the German Welding Society (DVS), etc., and welding in Korea. The research center is located within the KITCH of the Korea Industrial Production Technology Research Institute of the Korea Institute of Modern Science and Technology (KAIST). They are all national welding research institutions.

    The development of welding technology in foreign countries in recent years can use the following examples of industrial robots, new welding power sources and laser welding technology to briefly explain the importance of the combination of industry, university and research. After the first international oil crisis in 1972, Japan began to introduce and absorb American robotics in order to improve its competitive position in the international arena. The government funded the integration of industry, academia and research to develop its own industrial robot industry. The domestic robot manufacturing companies gave tax concessions, and soon several highly skilled electronic/electrical companies were transformed into Japanese industrial robot backbone enterprises, such as Yaskawa (motor), Matsushita (electrical), FANAC (CNC). In the 15 years from the 1970s to the end of the 1980s, Japanese industrial robots developed rapidly and surpassed the United States to become the "kingdom" of the production and application of industrial robots in the world. In 2004, it had 356,000 robots of various types, accounting for the world. 42% of the amount. The Japanese auto industry is also the industry that uses the most robots, creating its price competitive advantage. South Korea began to develop industrial robot technology in the late 1980s. Under the government's funding and guidance, Hyundai Heavy Industries Group took the lead to form its own industrial robot system in the late 1990s. The automotive industry has applied a large number of domestic robots, and already has a complete set of automotive welding robot production lines in Korea. Since the 1980s, China has invested hundreds of millions of yuan in continuous investment for nearly 20 years. However, due to the excessive academic work, there is no enterprise that can mass produce industrial robots with Chinese independent intellectual property rights. Established, forming a huge contrast.

    Lasers are considered to be new energy sources in the 21st century, and laser technology reflects the industrial level of a country. The application of laser in welding is attracting the attention of all countries. Germany, Russia, the United States, Japan, France, Italy and other countries attach great importance to the development of laser technology. Germany has applied laser welding, laser cutting, laser + arc hybrid heat source welding technology to the production of automobiles, especially the production of aluminum alloy cars, leading the development of automotive welding technology. The German government attaches great importance to the development of laser technology and has set up a special management department in the Ministry of Education and Research to coordinate the development of laser technology. In Germany, a combination of the university's  laser technology research institute  laser application engineering development company and the laser host production plant  laser parts production plant  laser application company have formed a three-dimensional overlay network. Aachen University and the Fraunhofer Laser Research Institute (ILT) and IPG jointly develop fiber lasers, FL and semiconductor lasers (DDL), and the University of Stuttgart and its Institute of Optical Processing Tools (IFSW) and Trumpf. Research and development of dish lasers. Germany's Rofin-Sina and Trumpf mainly produce CO2 lasers, HAAS mainly produces solid (NdYAG) lasers, and IPG produces new fiber lasers, and Laserline produces semiconductor lasers to form competing and complementary lasers. Technology development and production chain. Volkswagen, BMW, Mercedes-Benz and Meyer shipyards are German demonstration companies applying laser welding technology. Volkswagen in Germany has introduced laser welding technology to China and applied it to the mass production lines of Shanghai Volkswagen and FAW-Volkswagen's cars, which has promoted the application of laser welding technology in China. Germany, led by the government to form a laser technology industry-university-research chain that is developed by research, development, production, manufacturing, manufacturing, and demonstration enterprises, is worth learning in China. This kind of chain has the same effect as Japan's development of robot technology.

    Arc welding is still the main method of welding, and the advancement of arc welding technology is mainly driven by the development of power supplies. Foreign companies attach great importance to the development of welding power supplies, and combine the development of power supplies with arc physics and welding process technology. Whenever a new type of welding power source emerges, a new control method is introduced. For example, when a thyristor rectification welding power source appears, a waveform control reduces the splashing CO2 welding power source and a square wave AC welding power source; when the inverter power source appears, a variable polarity power supply, an STT short-circuit transition welding power source, etc. are introduced; and when a fully digital power supply appears After that, the double-pulse aluminum alloy welding power source and the CMT "cold metal transition" welding power source with the welding current and the voltage and the wire feeding speed are synchronously controlled. This shows that the development of welding power is not just the design of the circuit. It is related to the cooperation and cooperation of engineering and technical personnel such as electrical technology, microelectronics technology, control technology, computer technology, arc physics, process technology, etc., and requires a multidisciplinary team. The lack of leading enterprises in the domestic welding machine industry and the lack of such a team are the main reasons for the slow development of domestic welding machines and the fact that small enterprises can only survive in the production of low-end products.

    Friction stir welding is a new solid-state welding technology invented by the British Welding Research Institute in the early 1990s. It is a revolutionary innovation due to the fact that the metal does not melt, has no arc and heat radiation, consumes less energy, and is efficient. High, small deformation of the workpiece and many other advantages, and quickly promoted and applied. At present, it has been applied in the field of aluminum alloy structure manufacturing such as airplanes, rockets, speedboats, cruise ships, and train cars. Some domestic research institutes and universities have purchased UK patent technology licenses, started their own innovation activities, and partially applied to production.

    In summary, the governments of major industrialized countries in foreign countries attach great importance to the development of welding technology. They hope to use advanced welding technology to improve the production quality, improve efficiency and reduce costs, so as to work with countries with relatively low labor costs. Market competition, this is a strategic means.

2.3 Problems and gaps in domestic independent innovation capability

2.3.1 Problem

    Compared with foreign countries, in general, the level of mechanization and automation of domestic welding production is low, and the level of welding technology, welding equipment and welding materials that China needs for its own, “useful and wide-ranging” is even It is far behind abroad than cutting-edge welding technology. However, for medium and above key enterprises in the industries of automobiles, shipbuilding, rail vehicles, power station boilers, power generation equipment, heavy machinery, construction machinery, and containers, some advanced foreign welding equipments have been introduced in many technological transformations since the reform and opening up. , materials and processes, the technical level of welding production has been greatly improved, basically can reach the level of similar foreign enterprises, can produce the equipment and products needed for national economic and national defense construction, only the application and use of advanced technology. The quantity and the advanced level of technology are different from those of foreign companies. However, it must be seen that there are still more domestic advanced welding equipment, high-end welding materials and high-efficiency welding technology with independent brands. Most of the advanced welding equipment and materials used by enterprises are dependent on foreign imports. This surface of domestic welding production is brilliant, and the hollowing out of technology is a serious strategic weakness.

    There are many reasons for the low level of domestic welding innovation:

    (1) At the national level, the relevant government departments lack comprehensive and accurate understanding of the status and importance of welding technology in national economic development and national defense construction; lack of strategic development of welding technology development for economic development and market competition needs Guide planning; excessive pursuit of high-tech and sophisticated, while ignoring the innovation of basic welding technology.

    (2) From the level of higher education, before 1998, more than 50 colleges and universities in China set up welding majors, and trained thousands of welding graduates each year. After the implementation of general education, the Ministry of Education approved only one of Harbin Institute of Technology's independent welding professions, and cultivated 70 to 80 bachelor's degree in welding and 70 masters and doctors in welding every year. Most of the welding teaching and research sections of other universities have been renamed the Welding Research Institute. Under the premise of general education, some students in the Department of Materials or Mechanical Engineering are more focused on welding disciplines, but the professional courses on welding have been reduced by more than half of the original hours. Due to the lack of a system of continuing education and professional training in the country, these university graduates are required to engage in long-term in-service exercise time in the innovation and development of welding technology.

    At present, domestic universities and colleges, especially famous universities, have stronger innovation capabilities in the field of welding technology research. They are more inclined to automatic control, robotics, numerical simulation, welding of new materials, and electronics. High-tech aspects such as beam welding and laser welding. It is necessary to study these high-tech and sophisticated technologies, to solve the needs of special fields, and to obtain funding from government departments. However, these technologies are relatively narrow in application and have little impact on the development of the national economy. However, there are only a handful of universities that insist on innovative research on “conventional” welding materials, welding processes and welding power sources. For example, the annual output of Chinese manual welding rods exceeds 1.5 million tons. It is the world's largest producer of welding rods. This should be China's long term. However, due to the lack of in-depth basic theoretical research, the quality and technological level of Chinese welding rods have lagged behind foreign countries for a long time. And progress is slow. Research on electric welding machines and arc physics has been slowed down.

    (3) From the perspective of welding research institutions, China established a special welding research institute, the Harbin Welding Research Institute and the Chengdu Electric Welding Machine Research Institute, by the Ministry of Machinery Industry in the 1950s. Other industrial departments have also established corresponding welding research institutions, but most of them are located in research institutes in the form of offices and chambers, such as the welding room of the Iron and Steel Research Institute, the welding room of the Metallurgical Building Research Institute, and the Ship Technology Research Institute. Welding chamber, welding chamber of the Institute of Aeronautical Manufacturing Engineering, etc. Harbin Welding Research Institute is the only comprehensive research institute of welding technology in China. The research fields include welding materials, material weldability, welding process, welding equipment, non-destructive testing, etc.; industry service intermediary field includes the National Welding Society Secretariat, National Welding Association Secretariat, National Welding Standardization Technical Committee Secretariat, National Welding Materials Quality Supervision and Inspection Center, Welding Magazine, etc. Over the past 50 years, these research institutions have made important contributions to China's economic development and national defense construction. At the same time, they have established experimental research bases with relatively advanced research and testing instruments and equipment, and cultivated a multi-disciplinary and experienced experience. The scientific and technological team familiar with production has established a good research atmosphere. With the development of reforms, some industrial departments have been cancelled, and more than 200 research institutes have been converted into technology-based enterprises. However, how do the countries strategically locate these research institutes and what role they should play in the research and innovation of these research institutes? , relatively vague.

    (4) From the enterprise level, the 2006 National Science and Technology Conference clearly pointed out that enterprises should play a leading role in technological innovation. “Subject” does not mean to do it alone, or the company itself starts from scratch. The government should promote enterprises to take the lead, and advance the issues that need to be studied and solved, and insist on the organic joint research of production, education and research to carry out pre-study; the "subjects" must also do something different, enterprises can not fight the world, and everything must be done by themselves. The state proposes that enterprises play a leading role is a relatively long-term goal, not every company can do it right away. At present, the R&D strength of enterprises is mostly weak, and it is impossible or comprehensive. The most important thing for equipment manufacturing enterprises is to innovate in product innovation and management, and the development of common technology should rely more on the research and development of society - universities, research institutes and related professional enterprises. Between 2002 and 2003, a consulting project of the Institute of Engineering surveyed 115 medium-sized to large-scale enterprises, with only one in 2,012 welding technicians and less than 2% in master's degrees. The technicians of other processes in the enterprise may not be much better. This result is a true reflection of the current lack of process innovation capabilities in manufacturing companies.

    At present, the state should invest in the establishment of engineering technology centers in equipment manufacturing enterprises. If manufacturing enterprises establish technology centers according to the model of the original research institutes that have been transformed, it will result in more waste of research resources.

    Since the reform and opening up, many companies have introduced advanced welding equipment and production lines from abroad, which have improved the level of technology and changed the dirty, slow and poor situation of welding production in the past, but also formed a hidden rule in enterprises: all foreign countries The equipment is advanced, good, can show off, and even there is a situation where "the foreign country is more expensive to buy, and the domestic one is better." The main role of the enterprise should also include providing a stage for the country's innovative products.

    Manufacturing companies in the process of introducing foreign production equipment or newly designed products, from introduction to digestion and absorption are more closed in the enterprise to solve their own problems, and rarely organize the joint digestion and innovation of production, education and research, resulting in continuous introduction. In fact, the combination of production, study and research can provide more information and more comprehensive analysis opinions for enterprises to help enterprises master and absorb them more quickly. For universities and institutions, they can also get more, more specific and more. Detailed foreign advanced technical information will help further improvement and innovation. Enterprises should provide more platforms to fully play and reflect the role of the main body.

    South Korea is a country that has just surpassed China and ran to China. Their technological development attaches great importance to effectiveness and the promotion of the economy. The South Korean government will hold bids for science and technology projects for some equipments (products) that are in great demand and rely on imports. The government will provide funds and enterprises to support certain funds, and the combination of production, education and research will be carried out. Once the results are achieved, the state will gradually reduce imports of the products. Encourage equipment manufacturers to use domestically produced products. For example, recently South Korea imported a complete set of rail transportation aluminum alloy car welding production line. They said: "We will import this set and will not import the second set. The second set must be made in China." This pride is built in the country. Policy support. South Korea does not seek to win the "Nobel Prize," but their shipbuilding technology, steel technology, automotive technology, and IT technology have surpassed China. Therefore, it is not appropriate to excessively pursue high-tech and sophisticated, and pay due attention to the solidity of basic common technology. High-tech and sophisticated technology is built on a solid foundational common technology.

 

3 Independent innovation model and innovation road analysis

 

3.1 Analysis of innovation and innovation

    In principle, the technological innovation model can be divided into original innovation, integrated innovation, introduction, digestion and absorption, and innovation. Technological innovation should be combined with the needs of national economic development; attach importance to strategic innovation planning in the face of new challenges in the new era; pay attention to the balanced development of high-end technology and conventional common technologies; attach importance to the development of key technologies and related supporting technologies; Environmental construction for the promotion and application of results.

    The road to innovation should first be analyzed from a strategic perspective, and the practices of Japan, South Korea and Germany are worth learning. For example, in the face of the impact of the first oil crisis, Japan proposed strategic innovations to develop CO2 gas shielded welding and industrial robot technology to maintain the competitiveness of the automobile and shipbuilding industry; South Korea relies on government-led and partially funded enterprises to rely on foreign key technologies. Leading innovation in the combination of production, education and research; Germany and the European Union develop new technologies and technologies to compensate for the high-cost labor costs to improve the international competitiveness of the shipbuilding and automotive industries.

    For China's technological innovation, from the perspective of common technology development, pre-research should be carried out according to the development needs of the equipment manufacturing industry, and the government and equipment manufacturing enterprises should jointly fund the formation of joint research on production, education and research. Enterprises should pay attention to supporting China's own innovations, provide a stage for application, and promote the growth of its own innovative team. Enterprises should put forward more demands in advance, try to pass the analysis and forecast of development trends, and take more pre-orders instead of buying “spots” in order to promote targeted independent innovation. China should adopt the three-level innovation system of the enterprises of the University Research Institute for the development of common technology.

3.2 Innovation case

    Since the reform and opening up, in the 26 years since the establishment of the invention award, only a dozen of welding achievements have won the National Invention Award. It can be seen that there are not many innovations in welding in China (mainly welding materials, welding technology, welding equipment). Direct results). From the perspectives of the promotion surface, application effect, economic benefit and social benefit of the more than ten invention awards, it can be considered that the “double wire narrow gap submerged arc welding technology” of Harbin Welding Research Institute is the most outstanding. The scientific research achievements were identified in 1985. In the same year, the invention patent was filed and authorized in 1987. In 1989, it won the first prize of scientific and technological progress of the Ministry of Machinery. In 1990, it won the third prize of national invention. In 1994, it won the national outstanding patent project award. Since the introduction of the automatic narrow-gap submerged arc welding equipment in Taiyuan Heavy Machinery Plant and Harbin Boiler Plant since 1987, after more than ten years of continuous improvement, there are now 60 sets of key enterprises in China, such as the first A heavy machinery factory, second heavy machinery factory, Taiyuan Heavy Machinery Factory, Harbin Boiler Factory, Dongfang Boiler Factory, Wuhan Boiler Factory, Shanghai Power Station Auxiliary Machine Factory, Shanghai Jinshan Chemical Machinery Factory, Lanzhou Petrochemical Machinery Factory, etc. There are 4 sets, which have welded products such as 600,000 kW power station boiler steam drum, petrochemical large hydrogenation reactor, main hydraulic cylinder and plunger of large hydraulic press. The maximum thickness of welding is 400 mm, and it has become China's heavy equipment. An important welding production facility for manufacturing companies. Now the equipment has occupied the domestic market steadily. Not only is the price lower than that of similar foreign products, but the performance is better than that of foreign countries. The welding efficiency is high and the welding quality is stable. After years of practical application, the pass rate of the joint is 99. .5% or more. In 2005, the first heavy-duty machinery factory produced the Shenhua Group's first hydrogenation reactor for the first coal direct liquefaction plant. Through international bidding, it was decided to adopt all of China's own patented products - fully automatic double wire narrow gap submerged arc. Welding equipment (two sets in total). With a diameter of 5.5 m, a total length of 62 m, a wall thickness of 337 mm and a total weight of 2 060 t, the hydrogenation reactor is the most important reactor in the world. Each reactor is welded by more than ten large integral forged barrel sections. Each ring weld requires continuous welding for 5 days, and all welds are qualified for one shot.

    The project was a scientific and technological research project issued by the State Science and Technology Commission at the beginning of the sixth five-year plan in 1980. The original plan was to modernize conventional submerged arc welding equipment to meet the needs of large-scale equipment welding. The research team went deep into the Harbin Boiler Plant, the First Heavy Machinery Plant, the Taiyuan Heavy Machinery Plant and other large factories to investigate and extensively read and carefully analyze the foreign literature. The research team found that the United States and Japan conducted many years of research on different forms of narrow-gap gas shielded welding in the 1960s and 1970s. There are successful experiences and failures. The main problem is that it is difficult to achieve automated tracking when the groove is too small, and it is difficult to remove and repair once defects occur. The research team also found that Europe is developing a narrow-gap submerged arc welding method, but does not understand the details. In the Essen International Welding and Cutting Exhibition in 1981, two internationally renowned welding equipment companies were found to exhibit a single-wire narrow-gap submerged arc welding equipment. In conversations with equipment development engineers, as detailed as possible Understand the characteristics and design ideas of the device.课题组认真分析了他们设备的优、缺点，并结合以往的科研和生产实践经验，认为该设备具备一定特色，但也存在重大问题，即当提高焊接电流以增大熔敷率时，电弧对母材的热输入量也将增加，母材热影响区中的过热区会加宽、组织粗化，接头性能将明显降低。另外他们采用单侧横向跟踪和环焊缝焊接每圈的搭焊方式容易出缺陷，也有必要改进。为了解决重型装备焊接效率和质量的矛盾，课题组采用了双丝的方案，并巧妙地布置和排列了两根焊丝，使之既能保证坡口侧壁熔透，又不增加对母材的热输入；既能保证高熔敷率，又能形成薄而宽的焊道，充分利用后一道焊道焊接时的热量对前一道焊道的热影响区进行正火处理，细化其过热区的晶粒。最终找到解决焊接质量和效率矛盾的两全方法。经实际焊接检验，效率比普通埋弧焊提高效率一倍以上，比单丝窄间隙埋弧焊提高６０％，而焊接接头热影响区中过热区的冲击韧性达到接近正火＋回火的母材水平。同时改进了跟踪的方式，采用横向双侧跟踪，并且还改进了搭焊的程序。实践证明这些措施是很有必要且相当有效的，也特别适合国内企业的生产实际需要。在无需提高接头装配精度的条件下，可以保证高效率焊接和稳定的焊接质量。这项成果是中国第一个研究成功并广泛推广的窄间隙焊接方法，该方法使国内的窄间隙焊接技术达到国际先进水平。

４ 提高自主创新能力的战略目标及关键核心技术

 

４．１ 今后十年内自主创新战略目标

    １ 焊接机械化、 自动化率从目前的３５％提高到５０％，提高焊接机械化、自动化成套装备的设计与制造能力，满足７０％以上国内市场需求；

    ２ 从夯实国内焊接材料和弧焊电源的技术基础着手，提高研发能力，大力推进新型弧焊电源和高性能焊接材料的自主创新，使中国不仅是世界最大的焊接材料生产国，而且使焊接材料的质量和性能达到世界先进水平，使高端焊材的自给率达６０％以上，焊材出口量超过２５％；

    ３ 围绕国家重大技术装备，重点解决重、大、厚、长及复杂焊接结构的优质、高效、智能化焊接技术的自主创新（包括船体高效焊接、大型水轮机的高效焊接、长输管线现场高效焊接、铝合金车体优质焊接、厚壁压力容器优质焊接、大面积容器（管）的耐蚀堆焊、厚大马鞍形焊缝的高效焊接等），使重大装备产品的关键焊接技术均有国内自主知识产权；

    ４ 发展焊接新技术（包括激光、激光与其它热源复合焊接技术、搅拌摩擦焊技术等），并在重点装备制造企业中推广应用。

４．２ 关键核心技术

   焊接技术的总体发展趋势是高效、优质、低成本、环境友好、适应新材料、新结构、新功能要求，需要开展的关键核心技术有以下几个领域：

    （１）重大厚长及复杂焊接结构的优质、高效、智能化、自动化成套焊接技术关键技术主要是视觉传感技术、焊接过程的智能化和协调控制技术、工业机器人产业化与配套技术。必须重视国内工业机器人的产业化生产，缺乏自主的工业机器人系统，很难集成上述技术，并且在高端装备上受制于人。

（２）激光焊接、激光与其它热源复合焊接以及搅拌摩擦焊等新型焊接技术。关键焊接技术主要有激光与材料的作用机理、激光与其它能源的复合机理、搅拌摩擦焊的成形机理的深层次认识，以及新工艺技术在新型材料（包括铝、镁、钛合金及超高强钢等）焊接中的冶金特性。

    （３）多功能全数字化逆变弧焊电源技术。关键技术主要有针对不同电弧过渡形式中的电弧物理与工艺特征的优化控制模式，数字化逆变焊接电源的研究开发不仅仅是电路的开发与创新，必须将逆变电源的开发与工艺，特别是电弧物理相结合，开发新型的、更高性能的、更多功能的弧焊电源，推动使用量大面广的弧焊技术的发展。

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Due to its wide range of uses, there are also many varieties of hook and loop sanding disc. The most commonly used are red sanding disc, yellow/gold sanding disc, green sanding disc, and white sanding disc, etc.

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