2021 Fiscal Year Final Research Report
Study on high quality and high efficiency GMA welding utilizing external magnetic field
Project/Area Number |
19K04107
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Multi-year Fund |
Section | 一般 |
Review Section |
Basic Section 18020:Manufacturing and production engineering-related
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Research Institution | University of the Ryukyus |
Principal Investigator |
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Project Period (FY) |
2019-04-01 – 2022-03-31
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Keywords | ガスメタルアーク溶接 / 外部磁場 / 電磁力 |
Outline of Final Research Achievements |
Gas metal arc (GMA) welding is a highly efficient welding method, but since the welding wire also serves as an electrode (heat source), the heat source fluctuates temporally and spatially, so the arc is unstable. Therefore, it has the disadvantage that welding defects such as humping beads are likely to occur. In this study, we tried to reduce welding defects by stabilizing the arc and molten metal flow by using the electromagnetic force generated in the arc and the molten pool by adding an external magnetic field. Even when a DC magnetic field was applied to GMA welding, the arc fluctuated back and forth in the welding direction, but extreme arc deflection and welding defects were suppressed. Furthermore, when a high-frequency AC magnetic field was applied to GMA welding, the fluctuation of arc and molten pool was further suppressed, and although the range of application was still narrow, welding with few welding defects has become possible while maintaining a high welding efficiency.
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Free Research Field |
熱工学、材料加工
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Academic Significance and Societal Importance of the Research Achievements |
ガスメタルアーク(GMA)溶接は、入熱が大きく高効率な溶接法であるが熱源が変動するためアークが不安定で溶接欠陥が生じやすい欠点がある。これまでに、アークを安定させるために、一般的には溶接電流のパルス化や特殊なワイヤや混合ガス等が使われているが、どれも高価であるため、使用範囲が限られていた。 本研究では磁場の付加により、アークや溶融池内に生じる電磁力を用いてアークや溶融池流れを安定化することにより溶接欠陥の低減を試みた。その結果、高周波の交流磁場をGMA溶接に付加した場合、極端なアークの偏向や溶接欠陥が大幅に抑制され、まだ適用範囲が狭いが高い溶接効率を保ちつつ、溶接欠陥の少ない溶接が可能になった。
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