Transmission electron microscopy examination of hardening and toughening phenomena in Aermet 100

Journal Article · Wed Sep 01 00:00:00 EDT 1993 · Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States)

DOI:https://doi.org/10.1007/BF02666329· OSTI ID:6051589

Ayer, R ^[1]; Machmeier, P M ^[2]

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1. STEM, Inc., Woodbridge, CT (United States)
2. Snap-on Tools Corp., Kenosha, WI (United States)

The effect of tempering on the microstructure and mechanical properties of ultrahigh strength Aermet 100 steel was examined. In the as-quenched condition, the steel contained a dispersion of relatively fine, undissolved, (CrTiFeMo)C and (CrFeMo)[sub 23]C[sub 6] carbides in a martensitic matrix. Upon tempering at 427 C, the martensite decomposed to form a high density of cementite particles concomitant with a significant drop in toughness. Tempering at 454 C resulted in peak strength (yield strength [approx] 1,756 MPa) due to the precipitation of coherent zones of fine carbides. The peak in toughness (170 MPa[radical]m), attained at a tempering temperature of 482 C, was attributed to both the absence of cementite and the formation of reverted, stable austenite. Tempering at higher temperatures resulted in loss of both strength and toughness, which was suggested to be the result of precipitate coarsening and formation of unstable austenite, respectively. The details of the electron microscopy studies and mechanism of strengthening and toughening are discussed in light of the current understanding of this subject.

• OSTI ID: 6051589
• Journal Information: Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States), Journal Name: Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States) Vol. 24:9; ISSN 0360-2133; ISSN MTTABN
• 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
CARBIDES
CARBON ADDITIONS
CARBON COMPOUNDS
CEMENTITE
CHROMIUM CARBIDES
CHROMIUM COMPOUNDS
DATA
ELECTRON MICROSCOPY
EXPERIMENTAL DATA
FRACTURE PROPERTIES
HARDENING
HEAT TREATMENTS
INFORMATION
INTERMETALLIC COMPOUNDS
IRON ALLOYS
IRON BASE ALLOYS
IRON CARBIDES
IRON COMPOUNDS
MARTENSITE
MECHANICAL PROPERTIES
MICROSCOPY
MICROSTRUCTURE
MOLYBDENUM CARBIDES
MOLYBDENUM COMPOUNDS
NUMERICAL DATA
PHASE TRANSFORMATIONS
PRECIPITATION HARDENING
REFRACTORY METAL COMPOUNDS
STEELS
TEMPERING
TITANIUM CARBIDES
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
TRANSMISSION ELECTRON MICROSCOPY
YIELD STRENGTH