Issue 50

L. Romanin et al., Frattura ed Integrità Strutturale, 50 (2019) 251-263; DOI: 10.3221/IGF-ESIS.50.21 256 Figure 5: Grain boundaries precipitates at different magnifications (10000x (a), 40000x (b)) and EDS spectra in points 1 (c) and 2 (d) Figure 6: Precipitates in PM: NbC (a), Leave’s phase (b) Microhardness profiles Two Vickers microhardness profiles across the FZ are shown in Fig. 8. The FZ extends from about -1500 μm to +1700 μm. In that region, hardness is more variable reflecting the inhomogeneous dendritic microstructure. However, microhardness results are contained around a mean value of about 243 HV. This confirms both the very narrow HAZ and the good electron beam weldability of the analyzed alloy. As a matter of fact, no microhardness profile depressions were observed that could suggest a sensitive reduction of welded joints mechanical properties compared to those of the parent metal.