Welding process using special torch for reducing diffusible hydrogen

Diffusible hydrogen is an important factor in cold cracking, the lower its content, the better. This study focuses on the discussion and analysis of the behavior of hydrogen sources in MAG welding consumables (hereinafter, welding wires) in order to devise and develop a new process for reducing diffusible hydrogen, the process for drawing out and discharging the hydrogen sources desorbed from the welding wires. The validity of the new process has been evaluated, confirming that it renders harmless the influence of surface lubricant and moisture, which are absorbed after production, and is effective as a new technique for reducing the hydrogen. The subject welding wires include both solid wires and flux-cored wires (FCW). In the case of the latter, the initial holding moisture of the flux has been significantly reduced for seamed FCW. This effect is, however, less significant for seamless FCW. The new process has been found to be particularly effective when combined with seamed FCW. © 2018 Kobe Steel Ltd. All rights reserved.