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Precipitation reactions during the early stages of aging in a Ni and Al alloyed martensitic medium carbon steel
Author(s) -
Erlach S.,
Danoix F.,
Leitner H.,
Auger P.,
Siller I.,
Clemens H.
Publication year - 2007
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.2517
Subject(s) - intermetallic , carbide , materials science , alloy , metallurgy , precipitation hardening , precipitation , atom probe , martensite , creep , nial , hardening (computing) , microstructure , composite material , layer (electronics) , physics , meteorology
Steels in hot‐work applications are exposed to a complex combination of mechanical, thermal and creep loading conditions. Advanced hot‐work tool steels combine precipitation of alloy carbides and intermetallic phases and, therefore, exhibit a higher thermal stability than conventional tool steels. The mechanical and thermophysical properties of a Fe‐0.32C‐6.5Ni‐2.5Al wt% martensitic tool steel are mainly determined by the combined precipitation of secondary hardening carbides and of intermetallic NiAl precipitates of B2‐type. This alloy shows a large and rapid hardening reaction upon aging for as short as 60 s at a temperature of 610 °C. Atom probe field ion microscopy has been used to investigate both the composition and morphology of the fine precipitates and the matrix present after aging for 0, 30 and 60 s at 610 °C. In particular, chemical composition, particle radii and number density of the precipitates have been determined as a function of the aging time. The data obtained from these initial stages of the precipitation processes were analysed by means of statistical calculations. Copyright © 2007 John Wiley & Sons, Ltd.