Abstract: Very significant improvements in the hot workability of an age hardenable nickel base alloy containing 17 to 20 percent chromium, 2.9 to 5.3 percent titanium, 1.8 to 2.8 percent aluminum, 11 to 15.5 cobalt, 2.5 to 7 percent molybdenum, 0.8 to 1.5 percent tungsten, 0.004 to 0.040 percent boron, 0.02 to 0.06 percent carbon and about 52 to about 57 percent nickel are achieved by melting the raw materials under vacuum in the presence of lime, and forming a desulfurizing lime slag on the surface of the molten raw materials, and thereafter adding magnesium thereto just prior to casting the alloy, preferably while maintaining the molten raw material under an inert gas atmosphere.