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陈卫, 刘斌, 张琪飞, 张震, 李忠华, 毕家伟. CMT + P焊接行为及其AE特征频率[J]. 焊接学报. DOI: 10.12073/j.hjxb.20230627003
引用本文: 陈卫, 刘斌, 张琪飞, 张震, 李忠华, 毕家伟. CMT + P焊接行为及其AE特征频率[J]. 焊接学报. DOI: 10.12073/j.hjxb.20230627003
CHEN Wei, LIU Bin, ZHANG Qifei, ZHANG Zhen, LI Zhonghua, BI Jiawei. CMT + P welding behavior and AE characteristic frequency[J]. TRANSACTIONS OF THE CHINA WELDING INSTITUTION. DOI: 10.12073/j.hjxb.20230627003
Citation: CHEN Wei, LIU Bin, ZHANG Qifei, ZHANG Zhen, LI Zhonghua, BI Jiawei. CMT + P welding behavior and AE characteristic frequency[J]. TRANSACTIONS OF THE CHINA WELDING INSTITUTION. DOI: 10.12073/j.hjxb.20230627003

CMT + P焊接行为及其AE特征频率

CMT + P welding behavior and AE characteristic frequency

  • 摘要: 为了研究冷金属与脉冲复合焊(cold metal transfer and pulse, CMT + P)的焊接行为,使用PCI数据采集卡、高速相机、红外成像仪及声发射采集系统对焊接过程进行同步监测. 发现脉冲射滴过渡发生前,焊机输出电流突增,同时焊丝尖端释放猛烈电弧光,随后熔滴滴入焊道,熔池温度增加,声发射(acoustic emission, AE)信号显示出1个波峰. 发生CMT短路过渡时,焊机输出电流同时为焊丝熔化和焊丝伸出提供能量,待到焊丝尖端接触基板瞬间形成短路,熔池温度持续降低,AE信号微弱,伴随着熔滴因过热收缩而爆断,熔滴短路过渡完成. 对AE信号进行离散傅里叶变换(discrete Fourier transform, DFT)后,可通过特征频率对CMT + P各个周期及阶段进行过程识别. 结果表明,575 kHz和415 kHz可作为脉冲电弧周期和CMT短路周期的特征频率,推断180 kHz是脉冲电弧的特有频率,575 kHz的频率则是基础电弧提供,415 kHz处的频率则在CMT短路接触瞬间产生.

     

    Abstract: To investigate the welding behavior of CMT + P, a PCI data acquisition card, a high-speed camera, an infrared imager, and an acoustic emission collector were used to synchronously monitor the welding process. It was observed that prior to the occurrence of pulsed spray transfer, there was a sudden increase in the welding machine's output current, accompanied by a violent arc light emitted from the tip of the welding wire. Subsequently, the molten droplet fell into the weld bead, increasing the temperature of the molten pool, the output welding current of the welder suddenly increase, the welding machine's output current simultaneously provided energy for the melting of the welding wire and its extension. When the tip of the welding wire made contact with the substrate, a short circuit was formed, resulting in a continuous decrease in the temperature of the molten pool. The AE signal was weak, accompanied by the explosive breakage of the molten droplet due to overheating and shrinkage, completing the short-circuit transfer of the molten droplet. After performing a DFT on the AE signals, process identification of various cycles and stages of CMT + P could be achieved through characteristic frequencies. The result showed that 575 kHz and 415 kHz could be used as characteristic frequencies for the pulsed arc cycle and CMT short-circuit cycle, respectively. It was inferred that 180 kHz was a unique frequency for the pulsed arc, while the frequency of 575 kHz was provided by the base arc, and the frequency at 415 kHz was generated during the instant of CMT short-circuit contact.

     

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