Thyssen Edelstahlwerke Ag

Helmut Brandis

Wolfgang Spyra

Serosh Engineer

Bernd Huchtemann

Hans-Joachim Fleischer

Albert Von Den Steinen

Kurt Bohnke

Rainer Thielmann

Peter Schuler

Hans H Weigand

Paul Gumpel

Rudolf Oppenheim

Heinrich Frinken

Gustav Lennartz

Dietrich Werner

Heinrich Kiesheyer

Hans-Heinrich Domalski

Boron-containing steel products having boron contents of up to 200 ppm are obtained by an annealing process in the temperature range of between 850.degree. and 1050.degree. C. The characterizing feature of the invention is that the products are annealed in the state of equilibrium in a non-oxidizing gaseous atmosphere with a boron potential supplied by a pulverulent boron oxide source having a value such that the products retain or adsorb their boron content. The boron source is quantitatively about 100 g of B.sub.2 O.sub.3 per m.sup.3 of annealing space. In an annealing gas atmosphere mainly consisting of hydrogen, the steam partial pressure can be adjusted at atmospheric pressure in the presence of B.sub.2 O.sub.3 to the required boron activity within the range of between 10.sup.-3 to 10.sup.-5. The products can also be simultaneously case hardened during annealing. The case hardening agent can be mixed with pulverulent boron oxide as the boron source.

Process for annealing boron-containing steels and product thereof

A ferritic, heat-resistant steel whose behavior at high application temperatures is improved by the combined addition of oxygen affinitive elements. Apart from stabilizing the electric resistance of heating elements by addition of zirconium, titanium and rare earth metal, also the creep elongation of the steel is considerably reduced under load at temperatures above 900.degree. C., the thermal stress capacity thus being increased. The resulting complex oxide coating increases the protective function with regard to preserving the metallic cross-section in continuous and/or cyclic heat treatments. The steel is composed of:

Semi-finished products of ferritic steel and catalytic substrate

A martensite steel, especially for plastic molds, of the following compositions:

Age hardenable maetensitic steel

An alloy is proposed for use in making permanent magnets. The alloy has the following composition by weight:

Method of manufacturing permanent magnets

Disclosed herein is a highly wear-resistant, corrosion-resistant steel having high thermal resistance and tempering stability which consists of Fe; 0.7-1.7%C; 0.01-0.08%N; 0.02-1.5%B; 0.01-1.5% Si; 0.01-1.0% Mn; 5.0-15.0% Co; 3.0-7.0% Cr; 13.0-20.0% Mo; 0.02-2.0% Nb and/or Ta. The steel may additionally contain up to 10.0% W and up to 5.0% V.

High-speed steel

Described herein is a ferritic chrome-molybdenum-nickel steel, containing specified amounts of niobium, zirconium and aluminum, of high chemical resistance against general and intercrystalline corrosion attack, as well as against pitting, crevice and stress corrosion in chloride-containing solutions. The described steel is useful for the fabrication of articles which must exhibit a 0.2-limit of at least 520 N/mm.sup.2 at room temperature; a notched bar impact strength of at least 40 J at 0.degree. C. and at least 70 J at 20.degree. C. in 3-mm U-notch impact specimens; and guaranteed for flat stock such as sheet or strip material up to at least 10 mm thickness and for bar material of at least 60 mm diameter, round of square.

Corrosion-resistant ferritic chrome-molybdenum-nickel steel

Parts made of a heat-treated alloy steel having a minimum tensile strength of 700 N/mm.sup.2 and a notch toughness of at least 55 joules, wherein the alloy steel is a Mn/Cr/Nb alloy steel of lower alloy content than has hitherto been used to provide the desired strength/toughness properties.

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Krefeld, Germany

Helmut Brandis