Metallurgical Transactions A

, Volume 24, Issue 9, pp 1943–1955 | Cite as

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

  • Raghavan Ayer
  • P. M. Machmeier
Transformations
Received:

Abstract

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)23C6 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 ∼ 1756 MPa) due to the precipitation of coherent zones of fine carbides. The peak in toughness (170 MPa√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.

Keywords

Austenite Martensite Metallurgical Transaction Cementite Cementite Particle 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
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Copyright information

© The Minerals, Metals and Materials Society, and ASM International 1993

Authors and Affiliations

  • Raghavan Ayer
    • 1
  • P. M. Machmeier
    • 2
  1. 1.STEM, Inc.Woodbridge
  2. 2.Snap-on Tools Corp.Kenosha

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