EP 3286344 B1 20190626 - METHOD FOR THE MECHANICAL-THERMAL TREATMENT OF REDUCED-CARBON STEELS
Title (en)
METHOD FOR THE MECHANICAL-THERMAL TREATMENT OF REDUCED-CARBON STEELS
Title (de)
VERFAHREN ZUR THERMOCHEMISCH-THERMISCHEN BEHANDLUNG VON KOHLENSTOFFREDUZIERTEN STÄHLEN
Title (fr)
PROCÉDÉ DE TRAITEMENT THERMOCHIMIQUE-THERMIQUE D'ACIERS À TENEUR RÉDUITE EN CARBONE
Publication
Application
Priority
- DE 102015207111 A 20150420
- DE 2016200174 W 20160407
Abstract (en)
[origin: WO2016169560A1] The invention relates to a process involving thermomechanical-thermal treatment of reduced-carbon steels having a carbon content of 0.1 to 0.4 per cent by weight, in which an edge zone of a workpiece, especially of a ball bearing part, has been case-hardened with respect to a core, characterized by the following method steps: a) carbonitriding the edge zone of the workpiece in a fixed case hardening depth with a carbon content between 0.6 and 0.9 per cent by weight and a nitrogen content of at least 0.1 per cent by weight and at most 0.5 per cent by weight of nitrogen at a temperature between 850°C and 1000°C, b) cooling and conducting an austenitization step at a material-dependent austenitization temperature between 850°C and 1000°C, c) treating the workpiece at the lower bainite stage at a bainitization temperature of 150°C and 250°C until attainment of a volume content of bainite of at least 50 per cent by weight, d) cooling the workpiece to room temperature after attainment of a volume content of bainite of at least 50 per cent by weight.
IPC 8 full level
C21D 1/78 (2006.01); C21D 1/06 (2006.01); C22C 38/00 (2006.01)
CPC (source: EP)
C21D 1/20 (2013.01); C21D 1/785 (2013.01); C22C 38/00 (2013.01); C23C 8/32 (2013.01); C23C 8/80 (2013.01); C21D 2211/002 (2013.01); C21D 2221/10 (2013.01); C21D 2241/00 (2013.01)
Designated contracting state (EPC)
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR
DOCDB simple family (publication)
DE 102015207111 B3 20160818; EP 3286344 A1 20180228; EP 3286344 B1 20190626; WO 2016169560 A1 20161027
DOCDB simple family (application)
DE 102015207111 A 20150420; DE 2016200174 W 20160407; EP 16720336 A 20160407