Joints of complex phase 780 (CP-780) advanced high strength steel (AHSS) were carried out by using an ER-CuAl-A2 filler metal for the gas metal arc welding pulsed brazing (GMAW-P- brazing) process and the ER-80S-D2 for the GMAW-P process employing two levels of heat input. The phases in the weld bead and HAZ were analyzed, and the evaporation of zinc by means of scanning electron microscopy (SEM) was also monitored. The mechanical properties of the welded joints were evaluated by tension, microhardness and vertical impact tests. It was found that there was greater surface Zn evaporation in the joints welded with the GMAW-P process as compared to the GMAW-P-brazing process. The best results in tensile strength were observed in the joints welded with GMAW-P-brazing process, which increased by ~68% with respect to those of the GMAW-P. This behavior can be attributed to the formation of an intermetallic complex compound Cu-Al-Fe in the fusion line.

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The microstructural evolution of the nickel-base superalloy Inconel 718 after exposition at 750°C for different holding times (10 min–1,000 h) was characterized and correlated with the Eddy current (EC) technique. The results showed that electrical conductivity increases with aging time. This behavior was associated with the precipitation and coarsening of the metastable γ″ phase and its transformation into the detrimental δ phase after 100 h. EC nondestructive evaluation was correlated with X-ray diffraction patterns in terms of the precipitation and growth of secondary carbides that were observed in the scanning electron microscope. Vickers microhardness values were also in agreement with microstructural changes and EC measurements, as the maximum hardened condition can be associated with the precipitation of secondary phases before the transformation of the γ″ phase into the δ phase.