Retained austenite and tempered martensite embrittlement in medium carbon steels
Electron microscopy, diffraction and microanalysis, X-ray diffraction, and auger spectroscopy have been used to study quenched and quenched and tempered 0.3 pct carbon low alloy steels. Some in sit fracture studies were also carried out in a high voltage electron microscope. Tempered martensite embrittlement (TME) is shown to arise primarily as a microstructural constraint associated with decomposition of interlath retained austenite into M/sub 3/C films upon tempering in the range of 250/sup 0/C to 400/sup 0/C. In addition, intralath Widmanstatten Fe/sub 3/C forms from epsilon carbide. The fracture is transgranular with respect to prior austenite. The situation is analogous to that in upper bainite This TME failure is different from temper embrittlement (TE) which occurs at higher tempering temperatures (approximately 500/sup 0/C), and is not a microstructural effect but rather due to impurity segregation (principally sulfur in the present work) to prior austenite grain boundaries leading t intergranular fracture along those boundaries. Both failures can occur in the same steels, depending on the tempering conditions.
- Research Organization:
- Memorex Corporation, Santa Clara, CA
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 5440251
- Journal Information:
- Metall. Trans., A; (United States), Vol. 14A
- Country of Publication:
- United States
- Language:
- English
Similar Records
Microstructure-mechanical property relationships of martensite and lower bainite in a 0. 3%C-3%Cr-2% Mn steel
Retained austenite and tempered martensite embrittlement
Related Subjects
CARBON STEELS
EMBRITTLEMENT
TEMPERING
AUGER ELECTRON SPECTROSCOPY
AUSTENITE
DIFFRACTION
ELECTRON MICROSCOPY
FAILURE MODE ANALYSIS
FRACTURE MECHANICS
IN-SITU PROCESSING
MARTENSITE
MICROANALYSIS
QUENCHING
X-RAY DIFFRACTION
ALLOYS
CARBON ADDITIONS
COHERENT SCATTERING
ELECTRON SPECTROSCOPY
HEAT TREATMENTS
IRON ALLOYS
IRON BASE ALLOYS
MECHANICS
MICROSCOPY
PROCESSING
SCATTERING
SPECTROSCOPY
STEELS
SYSTEM FAILURE ANALYSIS
SYSTEMS ANALYSIS
360100* - Metals & Alloys