Abstract: In section bars and shaped bodies made of nickel-base superalloys having a structure consisting of columnar grains, a complete recrystallization cannot be effected unless the heating-up rate is kept below a maximum heating-up rate T.sub.max, which depends on the ratio V of one or more of the metal carbide-forming elements hafnium, niobium, tantalum, titanium and zirconium to one or both of the metal carbide-forming elements tungsten and molybdenum.

Abstract: The invention relates to high speed tool steels produced by powder metallurgy; to parts subject to heavy wear which are fabricated from such steel; and to a method of such fabrication. According to the invention, the part subject to heavy wear contains Nb in the amount of 2-15 wt. % and V in the amount of 1-4 wt. %, and further contains metal carbides in the amount of 10-30 vol. %; and that the lower limit of the carbon content is given by the formulaC.sub.min =0.45+0.1(%Nb)+0.20(%V),and the upper limit of the carbon content is given by the formulaC.sub.max =1.0+0.15(%Nb)+0.24(%V).In manufacturing the steel the melt of the alloying components is subjected to atomization in an overheated state (substantially above the liquidus temperature), to produce a powder.

Abstract: A method for powder metallurgical production of bar stock from an iron, nickel or cobalt based alloy comprises the steps of introducing a powder of the desired alloy into a tubular container together with a reducing agent and an oxygen getter, sealing the container without evacuating it, heating the sealed container and the powder therein, compacting the heated container by progressive forging and rolling the forged blank. Equipment for forging the container includes a tool having upper and lower dies defining between them an open-ended forging cavity which tapers from an entrance end towards an exit end and through which the container is fed in step-wise manner.