Method for the production of a tempered steel wire for spring, comprises heating the wire in continuous conduit at an austenitisation temperature and then cooling with oil, with water and subsequently with fluid and gaseous nitrogen

摘要

The method comprises heating wire in a continuous conduit at an austenitisation temperature of 920-960[deg] C and then cooling with oil, optionally subsequently with water and subsequently with fluid and gaseous nitrogen. The wire is produced from steel with a composition. A homogeneous martensitic structure is received with residual austenite of 4 vol.% and the wire is annealed. The wire is cooled in an oil bath at 40-80[deg] C, is guided from the oil bath into water bath without further treatment and then cooled at 15-30[deg] C. The method comprises heating wire in a continuous conduit at an austenitisation temperature of 920-960[deg] C and then cooling with oil, optionally subsequently with water and subsequently with fluid and gaseous nitrogen. The wire is produced from steel with a composition. A homogeneous martensitic structure is received with residual austenite of 4 vol.% and the wire is annealed. The wire is cooled in an oil bath at 40-80[deg] C, is guided from the oil bath into water bath without further treatment and then cooled at 15-30[deg] C. The wire is guided for cooling with nitrogen through a cooling tube cooled with nitrogen. A multi-walled cool tube is inserted with a central channel and coaxial external channel and the wire is guided through the central channel. The external channel is subjected with nitrogen. Oxygen evaporated in external channel is supplied together with fluid portion in moving direction of the guided wire in the central channel. The wire is cooled in cooling tube at -40[deg] C to -80[deg] C. The wire is annealed at 430-470[deg] C in a circulation lead bath. The wire is produced with a diameter of 0.1-10 mm. An independent claim is included for a tempered spring steel wire.