Study on Stabilization of Welding Arc under Hyperbaric Condition

高压条件下焊接电弧稳定性研究

• 批准号: 02650532
• 负责人: SUGA Yasuo
• 金额: $ 1.47万
• 依托单位: Keio University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1990
• 资助国家: 日本
• 起止时间: 1990 至 1991
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02650532/
• 关键词: Welding; High pressure; Stabilization of arc; Magnetic field; Erosion of electrode; La203-tungsten electrode; Hyperbaric welding; 高圧雰囲気; 水中溶接; 磁場; GTA溶接; Welding; High pressure; Stabilization of arc; Magnetic field; Erosion of electrode; La203-tungsten electrode; Hyperbaric welding; 高圧雰囲気; 水中溶接; 磁場; GTA溶接

In hyperbaric TIG arc welding, the arc tends to be unstable and accordingly it is difficult to obtain sound welds. Therefore the effects of magnetic field and the frequency of alternating magnetic field on the arc phenomena and welding results were investigated.Main results obtained are summarized as follows : 1)Applying magnetic field to a welding arc under high pressure, the constriction of the arc is released and its diameter increases.2)Applying static field to an arc under high pressure, irregular fluctuation of arc voltage is prevented, but the arc voltage vibrates in a period of 0.5ms approximately. Accordingly, the arc may turn or vibrate in a frequency of 2 kHz.3)Applying alternating magnetic field to an arc under high pressure, fluctuation of arc voltage is prevented, but the arc voltage vibrates depending on a frequency of excitation current.4)Applying alternating magnetic field to an arc under high pressure, straight and sound welds can be obtained by a relatively stable arc. However, effect of frequency of magnetic field on welding result is not observed.5)In a higher frequency of magnetic field, a higher excitation current must be used in order to obtain a same magnetic flux density in a lower frequency. As the result, the excitation coil has a tendency to be heated in operation.6)The erosion of La2O3-W electrode is much less than that of ThO2-W electrode. At the tip of the La2O3-W electrode during welding, La2O3 exists at the surface and it makes the work function decrease and prevents superheat of the electrode tip. As the result, erosion of the electrode may become smaller than those of other electrodes.

在高压TIG电弧焊接中，弧趋于不稳定，因此很难获得声焊接。 Therefore the effects of magnetic field and the frequency of alternating magnetic field on the arc phenomena and welding results were investigated.Main results obtained are summarized as follows : 1)Applying magnetic field to a welding arc under high pressure, the constriction of the arc is released and its diameter increases.2)Applying static field to an arc under high pressure, irregular fluctuation of arc voltage is prevented, but the arc voltage vibrates在大约0.5ms的周期内。因此，弧线可能以2 kHz的频率转动或振动。3）在高压下将交替的磁场应用于电弧，防止电弧电压的波动，但是弧电压会振动，具体取决于激发电流的频率。4）在高压下将磁场施加到高压和良好的焊接中，可以使弧度相对稳定。但是，磁场频率对焊接结果的影响。5）在较高的磁场频率中，必须使用更高的激发电流才能在较低频率下获得相同的磁通密度。结果，激发线圈在操作中具有加热的趋势。6）LA2O3-W电极的侵蚀远小于THO2-W电极的侵蚀。在焊接过程中LA2O3-W电极的尖端上，LA2O3存在于表面，它使工作功能降低并防止电极尖端的过热。结果，电极的侵蚀可能比其他电极的侵蚀更小。