1、 外文资料翻译 HISTORY OF UNDERWATER WELDING TECHNOLOGY Underwater welding technology is the development of the marine, offshore oil exploitation as well as assembly, maintenance such as oil platforms, pipelines and submarine positions in large marine structures such as one of the key technologies, but als
2、o ships emergency repair, salvage, construction of bridges and other necessary technically work means. Nuclear power development is the trend of the world in nuclear power plants within the reactor pressure vessel (RPV) for long-term work in the water, susceptible to stress corrosion cracking of the
3、 damage, structural repair of nuclear power, will face many challenges. Tooften use radiation-related underwater welding method, in order to reduce the working staff. Classification of underwater welding underwater welding generally divided into three categories: wet, dry, and local dry. And the dry
4、 can be divided into high-pressure dry underwater welding and common-pressure underwater welding pressure. Local laws, including drainage cover dry type, high-pressure curtain-style, steel brush, mobile air box and plasma arc MIG local dry method. Welding method used generally coated electrode weldi
5、ng, GTAW, GMWA, and FCAW. In addition to welding underwater welding in addition there is an explosion welding and FSW (friction stitch welding friction stitch welding), these two methods are all connected by solid phase technology. Following the development of underwater welding course: 1 Underwater
6、 wet welding technology In 1802, a scholar named Humphrey pointed out that a continuous arc can burn under water, that pointed out the possibility of underwater welding, but its practical application is more than 100 years later, can not move the structure on land welding was done under the circumst
7、ances. The first published an article about underwater welding research papers in 1933, was jointly by Hibshrman Jensen and complete. 1932, Khrenov invented the thick skin of underwater medicine special electrode, the electrode surface top coat with waterproof layer, so that the stability of underwa
8、ter welding arc has been improved to some extent. To the Second World War, underwater welding technology has been in the salvage boat, etc. play an important role. In 1971, Humble Oil Company of the Gulf of Mexico drilling platforms, underwater welding repair work is the first underwater welding tec
9、hnology used in offshore oil projects. 1985 produced the first batch of accredited diving welder, and developed a depth of less than 100m underwater wet welding. In 1987, underwater wet welding stainless steel piping in nuclear power plant has been applied to the repair work. 90s of last century, wi
10、th the required repair of underwater engineering structures and the increase in the cost of increased repair dock, wet welding technology has been further developed. The development of underwater welding underwater wet welding plays an important role in the application. British Hydroweld a variety o
11、f underwater welding company achieved good practical results. U.S. Patent electrode -7018 s drug electrode layer of aluminum skin, underwater welding can produce large amounts of gas, to avoid the erosion of the weld metal. University of Hanover, Germany-based slag - gas combined protection of the m
12、etal transfer process and protective mechanism developed from the protection of double-cored electrodes. Underwater wet welding is usually the water depth of less than 100 m, the direction of current efforts is to achieve 200 m water depth of wet welding technology breakthrough. Early 50s of last ce
13、ntury, underwater wet welding arc welding had been applied in our country. 60s of last century China began developing its own dedicated underwater welding. South China University of Technology developed underwater welding rod available in 30 m water depth less than a good welding performance. 2 Unde
14、rwater dry welding technology High dry underwater welding technology High-pressure dry underwater welding, the idea is first proposed in 1954 the United States, officially for the 1966 production, mainly used for submarine pipeline repair. The maximum current is about 300 m water depth in the. The w
15、elding method, the bottom chamber is open, and through the work of deep water into the air pressure slightly larger than the pressure of the gas, the indoor air discharge water from the bottom of the openings, welding gas chamber in the dry conducted. MIG welding or commonly used, is the underwater
16、welded TIG welding quality, basically, one of the best ways to weld level can land. In the 1970s, no high pressure welding of equipment developed. Germany, Norway, the United States, Britain began in the late 90s no such research and the establishment of high-pressure welding research center. From t
17、he mid 80s of last century, a number of research centers began to study 300 500 m water depth GTAW automatic welding systems and processes, or to test 500 1000 m water depth replacement of the adaptability of the welding technology. Now France, Germany, Norway, the United States, JEM hyperbaric weld
18、ing research center operating pressure can reach the equivalent of 1000 m water depth. 90 years from the last century, the operating oil companies have begun to enter the deeper waters. The first water depth in this company should be operating under the Brazilian oil company (that is, the Brazilian
19、national oil company), its operations in the Amazon basin, and depth to 1000 m. In China, along with the development of offshore oil industry, the urgent need to develop with independent intellectual property rights of high-pressure welding technology and dry. In the 2002 863 program in there on the
20、 high-pressure dry underwater welding technology research projects. By the China Offshore Oil Engineering Corporation, Beijing Institute of Petrochemical Technology, Petroleum University, Shanghai Jiaotong University, Harbin Engineering University, the largest joint R&D Welding depth of 60 m. At pre
21、sent, the basic of the project has completed, the upcoming is sea trials. Dry underwater welding technology at atmospheric pressure Dry underwater welding pressure welding quality although better, but its limitations more, especially with the increase of water depth, increasing air pressure around t
22、he arc, easy to destroy the stability of arc welding defect arising. Achieved in the absence of fully automated welding cases, the auxiliary diving welder operation, if the water depth exceeds the limit or dive diving high costs can not be implemented. In the technical level is unable to solve these
23、 problems, in order to overcome the deficiency of underwater dry welding, 1977, create underwater atmospheric dry welding equipment. In 1977, France LPS company first used this approach in the North Sea water depth 150 m Department successfully welded 426 mm diameter submarine pipeline. China has no
24、t yet dry underwater welding equipment at atmospheric pressure. 3 Local dry underwater welding technology Local dry underwater welding technology .There are many ways. The late 70s of last century, Harbin Welding Institute maritime salvage bureau in Shanghai and Tianjin Petroleum Exploration Bureau,
25、 with the assistance of local drainage developed underwater CO2 gas shielded welding technology, referred to as LD-CO2 welding, is the local dry-type drain cover method, this method can be used to complete construction of a number of underwater tasks. High-pressure wet pad is applied by the Japanese
26、 a way to overcome some shortcomings of curtain-style, in turn the development of the Japanese steel brush.Mobile gas box in 1968, by the first put forward by British and American multinational company after applied to production. France has recently studied a rotary bell-type local dry underwater w
27、elding technology. In addition, plasma arc MIG local dry underwater welding is a promising local dry welding technology. 4 Solid-phase connection of underwater technology Explosive Welding In the late 1970s, located within the blessing of Britain, underwater pipeline engineering company has successf
28、ully developed a complete set of pipeline system, using the first explosion welding technology. Friction stitch welding British Welding Institute (TWI) in the mid 80s of last century developed a set of friction for the underwater environment, stud welding systems. The system has the equivalent of 60
29、0 m water depth pressure tested, the results show that the welding results from water depth, and has been proved that the system can effectively use the ROV (underwater robot). Recent development is the attempt to underwater friction stud welding friction welding the extension to have the stitched s
30、eam friction stitch welding. Beijing Institute of Petrochemical Technology now has started research in this area and obtained the support of National Natural Science Foundation. 5 Underwater welding technology trends in the 21st century Though, the above method of underwater welding has been since i
31、ts emergence, have to rely on their respective strengths in a particular area has been applied. But for now the research of underwater welding underwater welding can not fully meet the requirements of the future construction should be done focuses on the following aspects: (1) From the welding metal
32、lurgy and welding quality assurance point of view, dry underwater welding is most favorable, so in recent years, high-pressure dry underwater welding technology is further developed, but still can not meet the actual demand. At present, the theoretical study for high-voltage arc is not very complete
33、, multi-information fusion technology to achieve intelligent control of the welding process has become the field of high pressure dry welding a new topic. (2) Underwater welding robot as the particularity of the work environment, an increase of underwater welding robot application difficulty. The fu
34、ture of underwater welding robot should be able to complete the welding of the pretreatment, welding and weld inspection work, therefore, should strive to do, including the precise positioning of underwater robot, robot arm motion control technology, based on visual sensor spatial location of the we
35、ld system detection, tracking and underwater welding quality control aspects of the work. (3) Welding simulation technology to enable the emergence and development of welding technology is undergoing from experience to science, from qualitative to quantitative leap. In recent years, numerical simula
36、tion of welding technology in depth, breadth, but the simulation of underwater welding is relatively lagging behind, should pay attention and speed up the numerical simulation. (4) Using computer simulation technology, than in the actual physical model of the installation, commissioning, testing and
37、 so the workload is much smaller, and the cycle is short, less investment, show many advantages. In recent years, it developed in the welding process, welding equipment, control systems development and improvement of all aspects of the research application. By welding simulation, help to the idea of a new program, and can find problems early, and this is an area should be studied later. With the emergence of new requirements of underwater welding and the development of science and technology, the new method of underwater welding and welding tools will continue to emerge and
