Journal Published Online: 01 May 1985
Volume 13, Issue 3

A Positron Study of the Quench and Tempering Process in AISI 4340 Steel



Dopper broadening measurements of the gamma-ray spectra produced by positron annihilation have been made on an AISI 4340 (Unified Numbering System [UNS] G43400) steel as a function of both isochronal tempering over the temperature range of 150 to 700°C and isothermal tempering at 250°C for times ranging from 1 to 1100 min. Changes in the positron annihilation line shape parameter S are correlated with the corresponding structural transformations that accompany tempering of the as-quenched steel. Of particular significance is the increase in the S parameter in the temper embrittlement regime. This increase in S parameter is postulated to be related to the precipitation of a transition iron carbide that alters the defect structure of the surrounding ferrite phase.

Author Information

Moore, KD
Duke University, Durham, NC
Jones, PL
Duke University, Durham, NC
Pages: 3
Price: $25.00
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Stock #: JTE10782J
ISSN: 0090-3973
DOI: 10.1520/JTE10782J