PROCESS FOR CHANGING THE MICROSTRUCTURE OF METALLIC RAILS

• Main Authors: SCHMEDDERS, HERBERT, KUEPPER, FRANK, WISSENBACH, KONRAD
• Format: Patent
• Language: English; French; German
• Published: 31.03.1994
• Edition: 5
• Subjects: CHEMISTRY; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUSMETALS OR ALLOYS; MACHINE TOOLS; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING OR OTHERTREATMENTS; METAL-WORKING NOT OTHERWISE PROVIDED FOR; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; PERFORMING OPERATIONS; SOLDERING OR UNSOLDERING; TRANSPORTING; WELDING; WORKING BY LASER BEAM

A process is disclosed for changing the local microstructure at the surface of the head of a metallic rail in the solid phase. The microstructure is changed by applying energy only within a limited local marginal layer located directly below the stressed running and wearing surfaces of the rail head by high-energy radiation. The amount of energy absorbed by the rail at the processing site is controlled by said high-energy radiation in such a way that the local microstructure in the marginal layer at the processing site is cooled in an adequately controlled way. L'invention concerne un procédé visant à modifier la microstructure locale à la surface d'un champignon de rail métallique dans la phase solide. La modification de la microstructure s'opère par apport d'énergie uniquement dans une couche marginale locale, limitée, située directement sous les surfaces sollicitées de roulement et d'usure du champignon de rail, par irradiation à haute énergie. Cette irradiation à haute énergie permet de contrôler la quantité d'énergie absorbée par le rail, à l'endroit du traitement, de manière à obtenir un refroidissement adéquatement contrôlé de la microstructure locale de la couche marginale à l'endroit du traitement.