Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1573979 | Materials Science and Engineering: A | 2015 | 9 Pages |
Abstract
A dense intra-granular dispersion of small secondary Nb(C, N) precipitates in commercial TP347 Nb-stabilized austenitic steel was formed during a short-term hardening heat treatment in the temperature window ÎT=1050-950 °C, starting with isothermal annealing at 1050 °C and followed by continuous cooling from 1050 °C to 950 °C. The precipitates are semi-coherent in cube-on-cube orientation relationship with the austenitic matrix, of characteristic faceted octahedral shape with {111} facets and typically d=15±4.6 nm in size. The experimentally determined volume fraction f=1.4±0.2·10â3 correlates well with thermodynamic calculations. The precipitation gives a significant strengthening of the steel from Ïy initial~529±42 MPa to Ïy hardened~703±39 MPa, corresponding to a strength increment ÎÏy~174 MPa (~33%) in good agreement with the prediction for Orowan strengthening. The present work is relevant to the exploration of the application potential of short term hardening heat treatments for precipitation strengthening austenitic steels.
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Physical Sciences and Engineering
Materials Science
Materials Science (General)
Authors
Christian Solenthaler, Mageshwaran Ramesh, Peter J. Uggowitzer, Ralph Spolenak,