CO_2气体保护焊电弧稳定性评价指标研究

Study on Arc Stability Evaluation Index of CO_2 Arc Welding Process

本试验采用汉诺威焊接质量分析仪对电弧电压和焊接电流信号进行采集,并自动生成电压电流波形图、电弧电压和焊接电流的概率密度分布图(PDD图)及短路时间、燃弧时间、加权燃弧时间、短路周期的频次分布图(CFD图),并分析电弧过程的电特性,找到熔滴过渡以及焊缝成形的主要影响因素。结果表明:电弧电压和电流对短路过渡有明显影响。电弧电压影响电弧稳定性、飞溅大小、焊缝熔宽等。电压偏低,过渡过程不稳定,飞溅较大;电压偏高,将会出现混合过渡;当电弧电压在18V时,电弧稳定性较好。焊接电流影响焊丝熔化速度、过渡频率、飞溅大小、焊缝质量等。电流偏低,出现断弧现象,焊缝成形差;电流过高,飞溅大,电弧不稳定,出现无效短路;焊接电流在160 A左右焊接电弧较稳定,飞溅少,焊缝成形好。

The Hannover analyzer was used to acquire the signal result of voltage and current. The voltage-current waveform, probability distribution diagram of voltage and current（PDD） and frequency distribution of short-circuit time,arcing time, weighted arcing time, and the short-circuit cycle time（CFD） were automatically generated. The main influenced factors of arc droplet transfer and weld seam formation based on the analysis of the electrical characteristics of the arc process were obtained. The results show that the main factors which influence the arc process characteristics and weld appearance are weld current and arc voltage. Arc voltage influences the droplet diameter, stability of arc, spatter and the width of weld. When the arc voltage is lower, the transition process is unstable and the spatter is bigger. When the arc voltage is higher, mixed transition appears. When the arc voltage is 18 V, the stability of arc is better. The welding current can affect wire melting speed, the frequency of transition, spatter, and weld seam quality and so on. When the current is lower, the broken arc phenomenon appears, and the fromation of weld seam is bad. While the higher welding current, the bigger spatter and the bad stability of the arc, and the invalid short circuit appear. When the welding current is 160 A,smaller spatter and better weld seam formation can be obtained.