EP 0532386 B1 19960417 - Process and apparatus for carburizing steel in an atmosphere of low pressure
Title (en)
Process and apparatus for carburizing steel in an atmosphere of low pressure
Title (de)
Verfahren und Vorrichtung zum Aufkohlen von Stahl in einer Atmosphere von niedrigem Druck
Title (fr)
Procédé et dispositif de cémentation d'un acier dans une atmosphère à basse pression
Publication
Application
Priority
FR 9111304 A 19910913
Abstract (en)
[origin: EP0532386A1] The carburising process according to the invention consists in heating the articles to be treated to a temperature of between 800 DEG C and 1100 DEG C, preferably above 900 DEG C, in an oxygen-free gaseous atmosphere maintained by pumping at a pressure of between 1 and 5 mbar and in performing a plurality of successive carbon-enrichment stages (C1, C2), each obtained by an injection for a limited period of a treatment gas containing one or a number of pure hydrocarbons, each enrichment stage (C1, C2) having a duration shorter than the time for the change of austenite into a saturation stage, these enrichment stages being separated by vacuum diffusion stages (D1, D2) of longer duration making it possible to adjust the surface carbon content. The invention makes it possible to simplify the mechanism of carbon transfer and to avoid the detrimental effects of overcarburising.
IPC 1-7
IPC 8 full level
C23C 8/22 (2006.01)
CPC (source: EP)
C23C 8/22 (2013.01)
Designated contracting state (EPC)
AT CH DE ES GB IT LI NL
DOCDB simple family (publication)
EP 0532386 A1 19930317; EP 0532386 B1 19960417; AT E136946 T1 19960515; DE 69209947 D1 19960523; FR 2681332 A1 19930319; FR 2681332 B1 19940610; JP H05195192 A 19930803; TW 225558 B 19940621
DOCDB simple family (application)
EP 92402395 A 19920903; AT 92402395 T 19920903; DE 69209947 T 19920903; FR 9111304 A 19910913; JP 24504192 A 19920914; TW 81107828 A 19921001