A high-power (120kV, 60kW) electron-beam welding system has been developed for the first time in the country, paving the way to the domestic production of a local vacuum** high-power electron-beam welding system***, the key equipment for the welding of small modular reactors (SMRs)*.
* A small modular reactor (SMR) is a small-sized reactor that has a power capacity of 300MW or less. It has been included in the list of the “12th national strategic technologies.” [④ Next-generation nuclear power (small modular reactor)]
** In typical electron-beam welding, the product is installed and welded inside a large vacuum chamber, which is why vacuum pumping takes a long time. On the other hand, in the case of local vacuum welding, a small chamber is used for partially vacuuming the welding spot, which can help to significantly shorten the time required for vacuum pumping and reduce the production cost of the chamber.
*** SMR pressure vessel is required for the welding of very thick materials with more than 200 mm. The electron-beam welding is capable of the welding by 1 pass processing.
For the first time in the country, the joint research team led by Principle Researcher Jeong Suh of the Department of Industrial Laser Technology at the Busan Machinery Research Center of the Korea Institute of Machinery and Materials (President Seog-Hyeon Ryu, hereinafter referred to as KIMM), an institute under the jurisdiction of the Ministry of Science and ICT, and Halla E.B.Technology Inc., the Korea Electrotechnology Research Institute, (hereinafter referred to as KERI) and Pukyong National University, has succeeded in securing the technology for the domestic production of a 120kV (60kW) high-power electron-beam welding system, as well as a highly reliable process technology for manufacturing this system.
The joint research team succeeded in the production, control, and operation of a large electron-beam welding system equipped with an electron gun and high-voltage device developed by the KERI, and also developed the technology for externally monitoring the welding process performed within a large vacuum chamber (4 m × 5.5 m × 3.2 m) as well as the weld seam tracking technology for automatically tracking the electron-beam welding line. These research outcomes have been published in five (5) domestic and international journals, and applications for three (3) patents have been filed. Additionally, the electron-beam repair welding technology using filler metal has been transferred to a corporation, contributing to the increase in technology fees.
Electron-beam welding devices have been imported from Germany, England, France, Japan, etc. Although the KIMM and specialized corporations have been striving for the domestic production of large-scale electron-beam welding systems, they have been facing challenges due to the large budget required for the development of core equipment such as electronic guns as well as the inherent technological risks associated with the process.
The joint research team has succeeded in independently designing and manufacturing an electron gun that creates an electron beam as well as a high-voltage device with high power output. Additionally, by developing the precise process technology for welding metal parts thicker than 100mm at once, the joint research team has secured price competitiveness of approximately 50 percent compared with the equipment manufactured in advanced countries. In the near future, by improving the output of electron guns and high-voltage devices, it will also be possible to domestically manufacture the welding system for SMR pressure vessel that requires electron-beam welding of materials with thickness of more than 200mm.
Dr.Jeong Suh of the KIMM was quoted as saying, “By applying the local vacuum chamber* technology currently being developed by the KIMM to the newly developed technology for the domestic production of high-power large-scale electron-beam welding system, we will be able to weld not only SMR pressure vessels but also large structures used in the defense industry such as submarines and launch vehicles. It will also be possible to create high added value by shortening the time required for welding and securing economic efficiency.”
* In general electron beam welding, the entire welded part is installed inside the vacuum chamber. Therefore, for larger parts, it is necessary to use a large-scale chamber which is larger than those parts. However, in the case of a local vacuum chamber that locally vacuums the part to be welded, the size of the chamber can be substantially reduced, and the time required for the vacuuming can also be shortened significantly.
President Seog-Hyeon Ryu of the KIMM was quoted as saying, “In connection with the “Construction of the SMR Production Support Center” that has recently been agreed upon by the KIMM, Busan Metropolitan City and the Busan Chamber of Commerce and Industry, we hope that the newly developed electron beam welding system will play a key role in the innovation of the technology for manufacturing SMRs.”
Meanwhile, this research was conducted with the support of the project for the “development of electron-beam welding equipment for advanced material parts,” one of the manufacturing-based production system technology development programs of the Ministry of Trade, Industry and Energy.
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The Korea Institute of Machinery and Materials (KIMM) is a non-profit government-funded research institute under the Ministry of Science and ICT. Since its foundation in 1976, KIMM is contributing to economic growth of the nation by performing R&D on key technologies in machinery and materials, conducting reliability test evaluation, and commercializing the developed products and technologies.
This research was conducted with the support of the project for the “development of electron-beam welding equipment for advanced material parts,” one of the manufacturing-based production system technology development programs of the Ministry of Trade, Industry and Energy.
