The effect of initial microstructure on heat-affected zone microfissuring in Incoloy 903

摘要: Abstract Studies were undertaken on electron beam welded thermomechanically processed Incology 903 with varying proportions of duplex grain size distributions, to determine quantitatively the effect variation in volume fraction fine grains warm worked heat-affected zone (HAZ) microfissuring. Extensive microfissuring was observed samples consisting primarily large grains, which, however, could be minimized by increasing proportion recrystallized outlining grains. Microfissuring also reduced decreasing welding speed for any given value current. A solidification structure composed γ/carbide eutectic reaction boundaries that developed microfissures. The devoid microfissures exhibited liquid film migration and formation niobium-enriched γ phase constituents. It is suggested one major causes minimal Incoloy due occurrence towards curvature some boundaries. existence substantial mean boundary thus factor responsible 903.