| 摘要 |
<p>The method comprises forging or hot stamping a steel part, performing a quenching operation on a portion of the part such that a structure of a surface layer of the part is composed of bainite and/or martensite while the part is present at a temperature of 750-1150[deg] C, interrupting the quenching operation so that the temperature of a core of the part ensures a later self-tempering operation, and subjecting the part to the self-tempering operation to obtain a part with the surface layer of bainite and/or martensite and the ferrito-perlitic core. The method comprises forging or hot stamping a steel part, performing a quenching operation on a portion of the part such that a structure of a surface layer of the part is composed of bainite and/or martensite while the part is present at a temperature of 750-1150[deg] C, interrupting the quenching operation so that the temperature of a core of the part ensures a later self-tempering operation, and subjecting the part to the self-tempering operation to obtain a part with the surface layer of bainite and/or martensite and the ferrito-perlitic core. The method further comprises measuring a temperature of the part before the quenching operation and controlling the quenching operation according to the measured temperature of the part and time-temperature characteristics of the processing steel part. The steel part has a grain size of 3-6. The surface layer has a thickness of 5 mm. The quenching operation is interrupted using immersed tubes or pulverization tubes. The self-tempering operation is carried out in an open air from a conveyor to storage rooms such that the room temperature causes more metallurgical transformation followed by the quenching operation and not involving metallurgical processing. An independent claim is included for a hammered or stamped steel part.</p> |
