Mechanical stability of retained austenite in tempered 9Ni steel

Journal Article · Wed Nov 01 04:00:00 EST 1978 · Metall. Trans., A; (United States)

DOI:https://doi.org/10.1007/BF02661946· OSTI ID:6345172

Syn, C K; Fultz, B; Morris, Jr, J W

The behavior of the thermally stable austenite in the ductile fracture surface layer of a grain-refined and tempered 9Ni steel broken at 77 K was studied through use of Moessbauer spectroscopy and transmission electron microscopy. Thin foils revealing the microstructural profile of the fracture surface layer were prepared by electroplating a thick pure iron layer on the fresh fracture surface, then thinning a profile sample through a combination of conventional twin-jet electropolishing and ion milling techniques. The results of both Moessbauer spectroscopy and TEM studies showed that the thermally stable austenite transforms to a dislocated martensite in the deformed zone adjacent to the ductile fracture surface. This result suggests that transformation of the retained austenite present in tempered 9Ni steel is compatible with low temperature toughness, at least when the transformation product is a ductile martensite.

• Research Organization: Univ. of California, Berkeley
• OSTI ID: 6345172
• Journal Information: Metall. Trans., A; (United States), Journal Name: Metall. Trans., A; (United States) Vol. 9:11; ISSN MTTAB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360101 -- Metals & Alloys-- Preparation & Fabrication
360102* -- Metals & Alloys-- Structure & Phase Studies
360103 -- Metals & Alloys-- Mechanical Properties
ALLOYS
AUSTENITE
CARBON ADDITIONS
CRYSTAL STRUCTURE
CRYSTAL-PHASE TRANSFORMATIONS
DUCTILITY
FAILURES
FRACTURES
HEAT TREATMENTS
IRON ALLOYS
IRON BASE ALLOYS
MARTENSITE
MECHANICAL PROPERTIES
MICROSTRUCTURE
NICKEL ALLOYS
NICKEL STEELS
PHASE TRANSFORMATIONS
STABILITY
STEELS
TEMPERING
TENSILE PROPERTIES