Bwg Butzbacher Weichenbau Gmbh

Krupp Stahl Aktiengesellschaft

Bwg Butzbacher Weichenbau Gesellschaft Mbh & Co. Kg

Gerhard Ratz

Wilhelm Heller

Walter Kunitz

Alfred Kais

Jurgen Flugge

The invention relates to a high-strength steel track element, and process of making the steel track element by rolling and heat treating. The steel comprises: 0.3-0.6% C, 0.8-1.5% Si, 0.7-1.0% Mn, 0.9-1.4% Cr, 0.6-1.0% Mo, balance iron and smelting-related impurities. The steel has a bainitic basic structure, a tensile strength of at least 1600 N/mm,and a technical yield strength of at least 1250 N/mm,.

Method for producing high-strength track element and track element thus obtained

A process for manufacture of a railroad track part, in particular a large points part, with rail parts such as a frog point and connecting rails, and the track part obtained. The track part is made of materials of differing composition, one of which is a carbon steel and one of which is an austenitic manganese steel, which are connected by welding and are subsequently subjected to a joint heat treatment. To permit joining of the materials without negative effects on their properties, the parts are joined directly by electron beam welding or indirectly via an intermediate layer comprising a nickel-based alloy, the joined parts then being heated to a temperature T and held over a time t such that for the austenitic manganese steel, solution annealing takes place, and for the carbon steel, austenitizing takes place. The railroad track part is partially quenched after the holding time t at temperature T, such that the austenitic manganese steel is provided in an sustenitic structure and the carbon steel is in a mixed structure with at least bainite and pearlite contents.

Process for producing a permanent way component and such a component

A railway-track element is disclosed not only for normal track but also for rail points. The track element is formed of vacuum-treated steel containing at least 0.53 to 0.62% C, 0.65 to 1.1% Mn, 0.8 to 1.3% Cr, 0.05 to 0.11% Mo, 0.05 to 0.11% V and .ltoreq.0.02% P, the balance being iron plus the usual production-related impurities. The track element is in the form of a rail made of rolled pearlitic steel. If the track element is to be used for points, the starting material is a length of rolled rail with a martensitic structure produced by heat treatment at least in the rail head area.

Railway-track elements and method of manufacturing them

The present invention relates to a method for thermal treatment of pearlitic rail steel. For increasing strength and wear resistance steels with the claimed composition are produced with a fine lamellar pearlite structure by heat treatment. During the first cycle the rail head portion is heated in a sufficient depth of up to 50 mm by means of a burner or an inductive system to an austenitization temperature of about 950.degree. to 1050.degree. C. Thereafter the heated head portion is cooled by means of compressed air in such a way that in a first step by blowing a large amount of air the temperature of the rail head portion is cooled within 10 to 20 s to 650.degree. to 600.degree. C. before the area of the pearlitic transformation. In a second step with throttled blowing compared to the first step in the area of the pearlitic transformation the rail head portion is cooled within 2 to 4 minutes to about 400.degree. C. until finishing the pearlitic transformation. Then the rail head portion is again heated for 4 to 6 minutes to a temperature of about 600.degree. to 650.degree. C. and then rapidly cooled by means of water or other appropriate quenching media to a temperature of less than 100.degree. C.

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Langgöns-Oberkleen, Germany

Gerhard Ratz