Open AccessUnderwater Pulse-Current FCAW - Part 1: Waveform and Process Features
Author(s) -
Chuanbao Jia,
Chuansong Wu,
Yanfei Han,
Yong Zhang,
Qingyuan Yang,
Wu Chen
Publication year - 2020
Publication title -
welding journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.27
H-Index - 71
eISSN - 2689-0445
pISSN - 0043-2296
DOI - 10.29391/2020.99.013
Subject(s) - welding , waveform , materials science , current (fluid) , underwater , pulse (music) , voltage , arc (geometry) , process (computing) , acoustics , electrical engineering , metallurgy , mechanical engineering , engineering , computer science , oceanography , geology , physics , operating system
The typical metal transfer mode in conventional underwater wet flux cored arc welding (FCAW) delivers large droplet repulsive transfer with low frequency. The process stability and the weld quality are seriously deteriorated with significant spatter and frequent arc extinctions. It is thought the repulsive forces applied on droplets can be reduced by rapidly decreasing the welding current, making the droplets sag and oscillate. A novel underwater pulsecurrent FCAW was proposed to periodically regulate the forces applied on droplets. The experimental system was developed with specially designed pulse current and reliable arc length control. Visual and electrical signals were collected simultaneously to study the process features. It was found that the maximum droplet diameter decreased to less than 5 mm; the temporary arc-extinguishing frequency decreased significantly; there was almost no short-circuit transfer and surface-tension transfer; and the stability of the welding process was significantly improved.