Phase chemistry and precipitation reactions in maraging steels: Part 2. Co-free T-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/BF02668191· OSTI ID:6311463

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). Department of Materials

This article describes studies of phase transformations during aging in a commercial Co-free T-300 maraging steel. Atom-probe field-ion microscopy (APFIM) was the main research technique employed. Thermochemical calculation was used to aid the interpretation of results. The composition and morphology of precipitates were compared in the same maraging system aged at different temperatures for different times to investigate the aging sequence. Ni[sub 3]Ti and Fe[sub 7]Mo[sub 6] have been found to contribute to age hardening. The formation of the Fe[sub 7]Mo[sub 6] phase took place at a much later stage of aging in the Co-free steel than in the equivalent Co-containing material. The matrix concentration of Mo was correspondingly higher at earlier stages of aging. No reverted austenite has been found during APFIM and transmission electron microscopy (TEM) examinations of specimens heat-treated at 510 [degree]C, even after 360 hours of aging.

• OSTI ID: 6311463
• 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
HEAT TREATMENTS
INTERMETALLIC COMPOUNDS
ION MICROSCOPY
IRON ALLOYS
IRON BASE ALLOYS
MARTENSITIC STEELS
METALLURGICAL EFFECTS
METALS
MICROSCOPY
MOLYBDENUM ALLOYS
MORPHOLOGY
NICKEL ALLOYS
PHASE TRANSFORMATIONS
PRECIPITATION
SEPARATION PROCESSES
STEELS
TITANIUM ALLOYS
TRANSITION ELEMENTS
TRANSMISSION ELECTRON MICROSCOPY