Experimental and thermodynamic study of tantalum-containing iron-base alloys reinforced by carbides: Part II — Case of (Fe, Ni, Cr)-base austenitic steels

Experiments and thermodynamic calculations were performed for three alloys based on both iron and nickel in equal quantities, containing 30 wt% of chromium, 0.2 to 0.4 wt% of carbon and 3 to 6 wt% of tantalum. Solidus and liquidus temperatures were determined for the three alloys, and the natures and fractions of the existing phases at 1000, 1100 and 1200 ring operatorC were characterized. These experimental data were compared to values calculated by Thermo-Calc, as well as to such results obtained on previous similar alloys separately based on iron or on nickel. Generally, there is a good agreement with calculations. Tantalum carbides in (Fe, Ni) base alloys are less present than in Fe-base alloys, but more present than in Ni-base alloys for the same carbon, chromium and tantalum contents.