Abstract: A process for making and using machine parts which in their function are exposed to severe stress from sliding superficial friction and machine parts produced thereby are described. The parts are made from an iron-based alloy which includes the following elements, in weight %: 0.35 to 1.0, preferably 0.4 to 0.8% C; up to 1.0% Si; up to 1.6%, preferably 0.3 to 1.4% Mn; 0.10 to 0.35, preferably 0.12 to 0.29% N; up to 1.0, preferably up to 0.8% Al; up to 2.8% Co; 14.0 to 25.0, preferably 16.0 to 19.0% Cr; 0.5 to 3.0, preferably 0.8 to 1.5% Mo; up to 3.0, preferably up to 1.5% Ni; 0.04 to 0.4, preferably 0.05 to 0.2% V; up to 3.0% W; up to 0.18% Nb; and up to 0.20% Ti. The total concentration of carbon and nitrogen results in a value of at least 0.5% and at most 1.2%, preferably at least 0.61% and at most 0.95%, with the remainder being iron and metallurgically required admixtures for the production of machine parts.

Abstract: The use of a chromium-containing martensitic alloy for plastic molds is described. The use properties of a thermally treated plastic mold of a hardness of at least 45 Rockwell C are improved by an iron-based alloy including, in weight-%,______________________________________ C 0.25 to 1.0, preferably 0.4 to 0.8; N 0.10 to 0.35, preferably 0.12 to 0.29; Cr 14.0 to 25.0, preferably 16.0 to 19.0; Mo 0.5 to 3.0, preferably 0.8 to 1.5; and V 0.04 to 0.4, preferably 0.05 to 0.2, ______________________________________where the sum of the concentration of carbon and nitrogen results in a value of, in weight-%, at least 0.5 and no more than 1.2, preferably at least 0.61 and no more than 0.95, the remainder including iron and melt-related impurities.

Abstract: Process for the powder-metallurgical production of work pieces, particularly tools, containing high-melting point carbides and/or carbonitrides homogeneously distributed in a matrix, in which an amount of elements of the IVa and Va groups, or secondary groups, of the periodic table is adjusted to at least 3 weight percent of the alloy, a low carbon and/or nitrogen concentration is established, and primary precipitates are prevented; and a desired carbon and/or nitrogen content is created by atomization of the melt into powder vaporizing medium.