Phase chemistry and precipitation reactions in maraging steels: Part 1. Introduction and study of Co-containing C-300 steel

Journal Article · Tue Jun 01 04:00:00 EDT 1993 · Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States)

DOI:https://doi.org/10.1007/BF02668190· OSTI ID:6311485

Sha, W ^[1]; Cerezo, A; Smith, G D.W. ^[2]

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1. Cambridge Univ. (United Kingdom)
2. Univ. of Oxford (United Kingdom)

This article introduces a series of studies of phase transformations in maraging steels. Atom-probe field-ion microscopy (APFIM) was the main research technique employed. Hardness measurements, transmission electron microscopy (TEM), and thermochemical calculations were also used. The composition and morphology of precipitates in the commercial-grade C-300 steel were compared for different aging times at 510[degree]C to investigate the aging sequence. Both Ni[sub 3]Ti and Fe[sub 7]Mo[sub 6] were found to contribute to age hardening. The decomposition starts with the formation of small Mo-enriched Ni[sub 3]Ti particles at very short aging times. The Fe[sub 7]Mo[sub 6] phase forms at a later stage of aging. The matrix concentrations of both Ti and Mo were measured and were found to be low after standard aging conditions. The observation of the Fe[sub 7]Mo[sub 6] [mu] phase is supported by thermochemical calculations, Austenite reversion has been found at the aging temperature, and its composition approaches the predicted equilibrium composition after 8 hours of aging.

• OSTI ID: 6311485
• 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. 24A:6; 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
AGE HARDENING
AGING
ALLOYS
AUSTENITE
CARBON ADDITIONS
CHEMICAL COMPOSITION
COBALT
ELECTRON MICROSCOPY
ELEMENTS
HARDENING
HARDNESS
INTERMETALLIC COMPOUNDS
ION MICROSCOPY
IRON ALLOYS
IRON BASE ALLOYS
MARTENSITIC STEELS
MECHANICAL PROPERTIES
METALLURGICAL EFFECTS
METALS
MICROSCOPY
MOLYBDENUM ALLOYS
MORPHOLOGY
NICKEL ALLOYS
PHASE STUDIES
PHASE TRANSFORMATIONS
PRECIPITATION
SEPARATION PROCESSES
STEELS
TITANIUM ALLOYS
TRANSITION ELEMENTS
TRANSMISSION ELECTRON MICROSCOPY