Weld Interface—Root Pass

Figure 11a shows the HAZ from the weld interface to base metal in the conventional GMAW specimen. Figure 11b shows the HAZ from the interface in the CW-GMAW specimen. In both specimens, the images were taken at the root pass, in a one pass weld (see Figures 8b and 9b, respectively).

**Figure 11.** Heat affected zone (HAZ) width in the GMAW specimen showing the Weld metal (WM), Coarse grain heat affected zone (CGHAZ), Fine grain heat affected zone (FGHAZ), Intercritical heat affected zone (ICHAZ), and Base metal (BM): (**a**) standard GMAW; and (**b**) CW-GMAW.

One can see that the ICHAZ is slightly narrower in CW-GMAW than in the standard GMAW. This is consistent with previous research. This seems to indicate that CW-GMAW specimens had a shorter cooling time between 800 and 500 ◦C compared to the conventional GMAW specimens. This seems to indicate that less heat was actually applied across the weld joint.
