Abstract: A process for the powder-metallurgical production of a workpiece by filling a binder-free and solvent-free, dry metal powder or ceramic powder into a mold, precompacting the powder by tapping and presintering it for 1/2 hour to 1 hour at 0.65 to 0.85 times the absolute melting temperature without significant shrinkage, adjacent powder particles being joined merely at their contact points by necking to give a skeletal formed body. The formed body is taken out of the mold and finish-sintered at at least 0.9 times the absolute melting temperature for at least 1 hour without additional support by a mold. Advantageously, the sintered body is additionally hot-isostatically pressed containerless in order to reach at least 98% of the theoretical density.

Abstract: A process for producing coarse, longitudinally oriented column crystals with improved temperature change resistance and ductility in the transverse direction in a workpiece of any cross-section from an oxide-dispersion-strengthened nickel-base superalloy, which exists in fine-grained form, by annealing in the temperature range between 1000.degree. and 1200.degree. C., cooling to room temperature and isothermally annealing for coarse grain in the range between 1230.degree. C. and 1280.degree. C.

Abstract: Oxide-dispersion-hardened superalloy based on nickel, which is composed of the following main constituents:______________________________________ Cr = 5-13.95 percent by weight or 14.05-22 percent by weight Al = 2.5-7 percent by weight Mo = 0-2 percent by weight W = 0-15 percent by weight Ta = 0-7 percent by weight Hf = 0-1 percent by weight Ti = 0-3 percent by weight Zr = 0.02-0.2 percent by weight Co = 0-10 percent by weight C = 0-0.2 percent by weight Y.sub.2 O.sub.3 = 1-2 percent by weight Ni = Remainder, ______________________________________and which additionally contains boron in a content of 0.026 to 0.3 percent by weight.A process for extending the temperature range of the secondary recrystallization of an oxide-dispersion-hardened nickel-base superalloy of the above composition during coarse-grain annealing and during the production of a monocrystal with a cross section of at least 5 cm.sup.2 by doping with a boron content of at least 0.011 percent by weight.

Abstract: Superalloy with oxide dispersion hardening having improved corrosion and oxidation resistance and based on nickel with the following composition:Cr=17-18% by weight,Al=6-7% by weight,Mo=2-2.5% by weight,W=3-3.5% by weight,Ta=2-2.5% by weight,Zr<0.2% by weight,B<0.02% by weight,C<0.1% by weight,Y.sub.2 O.sub.3 =1-1.5% by weight,Ni=Remainder.

Abstract: A method for zone heat treatment of metallic workpiece with a comparatively large cross-section, in which the workpiece is successively passed through a zone of higher temperature in such a way that the temperature of the workpiece initially rises steeply as a function of the displacement in the feed direction, passes through a flat maximum and then falls with a small slope. The method is carried out by passing the workpiece through a heating device equipped with a heating coil and a subsequent insulation body, or alternatively through a furnace. In a special embodiment of the method for obtaining the highest possible temperature gradient, the workpiece is drawn from a water bath and then passed through the heating coil.