Effect of the first and second stages of tempering on microcracking in martensite of an Fe-1. 22 C alloy

Journal Article · Thu Jan 01 04:00:00 EST 1976 · Metall. Trans., A; (United States)

DOI:https://doi.org/10.1007/BF02644043· OSTI ID:7364476

Balliett, T A; Krauss, G

The effect of tempering on microcracking in the plate martensite of an Fe-1.22 C alloy was investigated by isothermal heat treatments in the temperature range between 180 and 225/sup 0/C. The second stage of tempering, followed by x-ray measurement of retained austenite, was confirmed to depend upon the diffusion of C in austenite, and the transformation product was found to consist of very closely spaced cementite lamellae in ferrite. Microcracking, despite the volume expansion that accompanies the transformation of the retained austenite, decreased only slightly with time during the second stage. The major decrease in microcracking occurred during the first stage, a result attributed to the plastic deformation that accompanies the dimensional changes caused by the reduction of the lattice tetragonality of the high carbon martensite in the first stage. Metallographic observations of surface relief and etching effects associated with martensite plates provided evidence of the first-stage plastic flow.

• Research Organization: Lehigh Univ., Bethlehem, PA
• OSTI ID: 7364476
• Journal Information: Metall. Trans., A; (United States), Journal Name: Metall. Trans., A; (United States) Vol. 7A:1; ISSN MTTAB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
ALLOYS
CARBON ADDITIONS
CARBON STEELS
CRACKS
DEFORMATION
ETCHING
HEAT TREATMENTS
HIGH TEMPERATURE
IRON ALLOYS
IRON BASE ALLOYS
MARTENSITE
METALLOGRAPHY
PLATES
QUENCHING
STEELS
SURFACE FINISHING
TEMPERING