The influence of rotating speed on metal transfer and the wire metal speed was studied in the high rotating speed arc narrow gap welding.The results indicate that the high rotating speed arc has benefit on the metal t...The influence of rotating speed on metal transfer and the wire metal speed was studied in the high rotating speed arc narrow gap welding.The results indicate that the high rotating speed arc has benefit on the metal transfer,and that with the rotating speed increasing,the droplet volume decreases.It is shown that the rotating speed has little influence on the wire metal speed with DC electrode positive polarity(DCEP),but the melting speed decreases with increasing of rotating speed in DC electrode negative polarity(DCEN).展开更多
The effect of laser power on metal transfer is studied under conditions of alternating combustion of double arcs in order to develop the welding process of the laser-double arcs pulsed metal active gas （P-MAG） hybri...The effect of laser power on metal transfer is studied under conditions of alternating combustion of double arcs in order to develop the welding process of the laser-double arcs pulsed metal active gas （P-MAG） hybrid welding with single power. Different laser power corresponds to different interactive mechanisms of laser and arc and to different methods of metal transfer in the hybrid welding. When the laser power ascends from 500 W to 1 500 W, the methods of metal transfer change from the complex transfer of one droplet per pulse, one droplet two pulses and one droplet much more pulses during the mixture of globular and projected transfer of the lead wire, and from one droplet two pulses and one droplet three pulses during globular transfer of the follow wire to the methods of the metal transfer of both lead wire and follow wire are stable one droplet two pulses and one droplet three pulses when the metal transfer is mainly globular. The arc sharps and pressure of droplet are altered with the laser power changing. The compression of the arcs is strengthened by the laser and the offset of the center of droplet mass is much more obvious with the increasing of the laser power.展开更多
电弧-侧壁距离控制是保证窄间隙熔化极活性气体保护焊（Narrow gap metal active gas welding, NG-MAG）侧壁熔合良好的关键。通过对NG-MAG脉冲立焊过程中电弧声的预处理和分析，发现其时域波形呈周期性“振铃”衰减特性，频率与焊接电...电弧-侧壁距离控制是保证窄间隙熔化极活性气体保护焊（Narrow gap metal active gas welding, NG-MAG）侧壁熔合良好的关键。通过对NG-MAG脉冲立焊过程中电弧声的预处理和分析，发现其时域波形呈周期性“振铃”衰减特性，频率与焊接电源脉冲频率相同；电弧声能量的频域分布范围为0.3～12.0 kHz，且能量主要集中在0.3～3.0 kHz和9.0～12.0 kHz两个频带，频谱分布与电弧-侧壁距离高度相关。在此基础上，采用小波变换（Wavelet transform, WT）和联合时频分析（Joint time-frequency analysis, JTFA）实现对电弧声信号的降噪处理和时频分析，结果发现，伴随电弧-侧壁距离的逐渐增大，电弧声能量的低频分布始终存在，呈现“断续-连续-断续”分布特征；而高频分布出现在电弧-侧壁距离2.6 mm以上，呈现“断续-连续”分布特征。利用 NG-MAG 脉冲立焊电弧声的时频分布规律可实现对电弧作用位置的监测预警，为 NG-MAG 焊接过程状态监控提供一种途径。展开更多
文摘The influence of rotating speed on metal transfer and the wire metal speed was studied in the high rotating speed arc narrow gap welding.The results indicate that the high rotating speed arc has benefit on the metal transfer,and that with the rotating speed increasing,the droplet volume decreases.It is shown that the rotating speed has little influence on the wire metal speed with DC electrode positive polarity(DCEP),but the melting speed decreases with increasing of rotating speed in DC electrode negative polarity(DCEN).
基金This paper is supported by National Natural Science Foundation of China （Grant No. 51175374） , the Application of Basic ＆ Frontier Technology Program of Tianjin （Grant No. OgJCYBJC05000） and the Science ＆ Technology Pillar Program of Tianjin （Grant No. 10ZCKFSF00200）.
文摘The effect of laser power on metal transfer is studied under conditions of alternating combustion of double arcs in order to develop the welding process of the laser-double arcs pulsed metal active gas （P-MAG） hybrid welding with single power. Different laser power corresponds to different interactive mechanisms of laser and arc and to different methods of metal transfer in the hybrid welding. When the laser power ascends from 500 W to 1 500 W, the methods of metal transfer change from the complex transfer of one droplet per pulse, one droplet two pulses and one droplet much more pulses during the mixture of globular and projected transfer of the lead wire, and from one droplet two pulses and one droplet three pulses during globular transfer of the follow wire to the methods of the metal transfer of both lead wire and follow wire are stable one droplet two pulses and one droplet three pulses when the metal transfer is mainly globular. The arc sharps and pressure of droplet are altered with the laser power changing. The compression of the arcs is strengthened by the laser and the offset of the center of droplet mass is much more obvious with the increasing of the laser power.
文摘电弧-侧壁距离控制是保证窄间隙熔化极活性气体保护焊（Narrow gap metal active gas welding, NG-MAG）侧壁熔合良好的关键。通过对NG-MAG脉冲立焊过程中电弧声的预处理和分析，发现其时域波形呈周期性“振铃”衰减特性，频率与焊接电源脉冲频率相同；电弧声能量的频域分布范围为0.3～12.0 kHz，且能量主要集中在0.3～3.0 kHz和9.0～12.0 kHz两个频带，频谱分布与电弧-侧壁距离高度相关。在此基础上，采用小波变换（Wavelet transform, WT）和联合时频分析（Joint time-frequency analysis, JTFA）实现对电弧声信号的降噪处理和时频分析，结果发现，伴随电弧-侧壁距离的逐渐增大，电弧声能量的低频分布始终存在，呈现“断续-连续-断续”分布特征；而高频分布出现在电弧-侧壁距离2.6 mm以上，呈现“断续-连续”分布特征。利用 NG-MAG 脉冲立焊电弧声的时频分布规律可实现对电弧作用位置的监测预警，为 NG-MAG 焊接过程状态监控提供一种途径。
