Journal of Welding and Joining

9: J Weld Join. 2015;33(5):14-19. Published online October 30, 2015.
DOI: https://doi.org/10.5781/JWJ.2015.33.5.14; Analysis of Adhesive Slag Formed on Weld Metal Surface of GTAW Welding after Flux Cored Multi-Pass Welding; Jung-Min Kim^*, Nam-Kyu Kim^*, Gi-Dong Kim^*, Ji-Hong Park^*; Corresponding author: Jung-Min Kim ,Email: kjm85@kims.re.kr

Abstract: This study has been performed to investigate the adhesive slag at GTAW weld zone after FCAW multi-pass welding. The cause of adhesive slag formation was examined using optical microscope, field emission scanning electron microscope(FE-SEM) and XRD analysis. The results obtained in this experiment are summarized as follows. Slag of GTAW weld zone surface during welding were formed by mixing the presence of slag in FCAW weld zone. While the slag cools, Cr-spinel phase were formed due to reactions in slag/metal interface. Also, a Cr moves form the weld metal to the slag to strong affinity between oxide atoms and Cr atoms. Hence, detachability of slag was exacerbated by decreasing the interfacial tensions between slag and weld metal.

Keywords :GTAW, FCAW, Adhesive slag, Inclusion, Cr-spinel phase, Interfacial tension