Carburizing method

• Main Authors: TIPPS JERRY A, BYRNES LARRY E
• Format: Patent
• Language: English
• Published: 06.11.2003
• Edition: 7
• Subjects: CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; METALLURGY; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION

The present invention provides a carburizing method that involves heating a steel component quickly to a relatively high carburizing temperature (e.g. 1900 degrees F. and above), contacting the component at the relatively high carburizing temperature with a methane-containing carburization atmosphere for time to form a carbon-enriched surface case on the component, and cooling the component at a relatively slow rate effective to provide a relatively soft martensite-free surface case on the component. The component then is subjected to a hardening treatment wherein the carburized component is heated to a hardening temperature in the austenitic range followed by quenching and tempering to form a tempered martensitic surface case on an underlying non-martenistic core.