PROPERTIES OF ARC-MELTED CHROMIUM-BASE ALLOYS

screened for hot workability, oxidation resistance, and hot strength using small arc-melted ingots. The alloying elements investigated included Fe, Mn, Mo, Nb, Re, Ru, Ta, Ti, W, V, Zr, and Y in amounts up to 20 wt%. Of the fabricable alloys tested, the best combinations of oxidation resistance and strength, in the range of 2000 to 2300 deg F, were found in binary alloys containing 5 wt % molybdenum, 10 wt% tungsten, and 2 wt% niobium. While yttrium additions do not contribute to the hot strength of chromium, the effectiveness of yttrium in improving the oxidation resistance of chromium is outstanding. About 1 wt% yttrium appears optimum for this purpose. Experiments with the preparation of large chromium-base alloy ingots showed that cold-mold arc melting was not suitable for preparing ingots containing over about 1 wt% of alloy addition. However, the feasibility of preparing sound, higher alloycontent ingots by induction melting and casting was demonstrated. (auth