Carbo-austempering

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:389736

Keough, W R ^[1]

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1. CK Engineering, Bloomfield Hills, MI (United States)

Carbo-Austempering is a heat treat process in which carburized parts are quenched at a temperature above the martensite start temperature (MS). While austempering is commonly used on through hardened parts, it is not usually considered for use with low carbon parts. However, a low carbon core with a high carbon case gives a Carbo-Austempered surface and a low carbon martensite core. With this process a unique combination of properties is developed. This paper points out the substantial advantages of combining carburizing and austempering. The carburizing process is the same for both the Carbo-Austemper and the carburize, quench, and temper process. Endothermic based atmospheres, or nitrogen-methanol based atmospheres, with or without other gas additions, are used. The only differences are in the quenching temperature and the possibility of eliminating tempering. A number of benefits will be discussed. These benefits include a reduction in distorting and the elimination of cracking on complex shaped parts, superior physical properties, elimination of the cost of tempering and the cost of washing compounds, the cost of treating waste wash water emulsions, and a reduction in the cost of the quenching medium. Comparisons of conventional case hardening with the Carbo-Austempering processes will be presented. Cost comparisons/advantages will be included.

• OSTI ID: 389736
• Report Number(s): CONF-951222--; ISBN 0-87170-561-3
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BAINITE
CARBON STEELS
CARBURIZATION
CRYSTAL-PHASE TRANSFORMATIONS
ELONGATION
FATIGUE
FRACTURES
HARDNESS
IMPACT STRENGTH
MARTENSITE
MECHANICAL PROPERTIES
QUENCHING
SURFACES
TEMPERING
TENSILE PROPERTIES
WEAR RESISTANCE