标题：Current waveform effects on CMT welding of mild steel
作者：Chen, Maoai; Zhang, Dong; Wu, Chuansong
作者机构：[Chen, Maoai; Wu, Chuansong] Shandong Univ, Inst Mat Joining, MOE Key Lab Liquid Solid Struct Evolut & Mat Proc, Jinan 250061, Peoples R China.; [Zh 更多
通讯作者地址：[Chen, MA]Shandong Univ, Qianfoshan Campus,17923 Jingshi Rd, Jinan 250061, Peoples R China.
来源：JOURNAL OF MATERIALS PROCESSING TECHNOLOGY
关键词：CMT welding; Current waveform; Process stability; Deposition rate; Weld; bead formation
摘要：Distributions of CMT periods and short circuit times are established by analyzing the electrical waveforms and metal transfer images sensed simultaneously under different welding conditions so as to evaluate the process stability for CMT welding of mild steel. Concentrated distributions for both CMT periods and short circuit times are observed in the whole adjustable range of boost current from 250A to 320A, indicating that changing the boost current doesn't disturb the regularity and stability of CMT welding process obviously. With the boost duration ranging from 1.6 ms to 3.6 ms, the welding process is very regular and stable, and beyond this range, the process becomes unstable. The average CMT frequency changes very little with welding parameters, and fall in a narrow ranges from 80.1 Hz to 90.1 Hz. The deposition rate, average wire feed speed and droplet size increase with increasing boost current or boost duration, even the preset wire feed speed is kept constant. As the boost current or boost duration increases, the weld width and penetration increase noticeably, and the reinforcement varies very little. (C) 2017 Elsevier B.V. All rights reserved.