Bohler Edelstahl Gmbh

Boehler Gesellschaft M.b.h.

Bohler Ybbstalwerke Gmbh

Erema Engineering Recycling Maschinen Und Anlagen Gesellschaft M.b.h.

Böhler Edelstahl Gmbh & Co Kg

Gerhard Hackl

Klaus Feichtinger

Gerhard Wendelin

Gabriele Saller

Raimund Huber

Manfred Gstettner

Bruno Hribernik

Karl Leban

Gunter Hochortler

Rupert Winkelmeier

Michael Stromberger

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. Plunger pistons and piston rings of the above alloy, may optionally contain superficial hard layers, have especially advantageous usage properties.

Nitrogen-bearing iron-based alloy for machine parts subject to sliding

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-%,

Iron-based alloy for plastic molds

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. When necessary, it is further created by diffusion annealing of the powder in a medium containing carbon or hydrocarbon compounds and/or nitrogen or nitrogen compounds; and powder with a minimum carbide and/or carbonitride content of 10 percent by volume is processed to produce work pieces in a manner known in the prior art, when necessary after mixing two or more kinds of powders containing different amounts of carbon and nitrogen made according to the process of this invention. Work pieces, particularly tools, produced according to this process have a content of at least two elements selected from the group consisting of vanadium, niobium, titanium, zirconium, hafnium or tantalum, with a carbide and/or carbonitride content of at least 6 percent by volume, and a maximum carbide and/or carbonitride granule size of 5 .mu.m diameter.

Process for the powder metallurgical production of working pieces or

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Kapfenberg, Austria

Gerhard Hackl