austenite

Definitions

  • WordNet 3.6
    • n austenite a solid solution of ferric carbide or carbon in iron; cools to form pearlite or martensite
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Century Dictionary and Cyclopedia
    • n austenite A constituent of steel, obtained by quenching high carbon steel from a temperature of 1000° C. in a menstruum such as iced brine, which will produce very rapid cooling. It is probable that austenite is a true solid solution of carbon in iron, and that martensite, troostite, and sorbite are stages in the decomposition of the solid solution — that is, are intermediate steps between austenite on the one hand and pearlite on the other. On the subject of the constituents of hardened steel there exists at the present time a great deal of confusion in the nomenclature, nor is it possible to say definitely what is the true nature of any of these constituents.
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Usage

In literature:

Higher percentages of nickel change the martensitic structure to austenite, the steel then being non-magnetic.
"The Working of Steel" by Fred H. Colvin
AUSTENITE, a constituent of high-carbon steel (q.v.).
"The New Gresham Encyclopedia. Vol. 1 Part 3" by Various
Austenite may contain carbon in any proportion up to about 2.2%.
"Encyclopaedia Britannica, 11th Edition, Volume 14, Slice 7" by Various
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In news:

Revision of E975 - 03(2008)Standard Practice for X-Ray Determination of Retained Austenite in Steel with Near Random Crystallographic Orientation.
I happened to come across your article in Industrial Heating on the subject of retained austenite ("A Discussion of Retained Austenite ," March 2005).
There is a statement that says, "Given the opportunity, retained austenite will transform to martensite.".
Question on Retained Austenite Transformation.
Before specimens can be etched to reveal prior-austenitic grain boundaries, they must be prepared to a high-quality level.
It can be concluded that the remaining austenite is soft even though it is saturated with carbon.
TIG Welding Austenitic Stainless Steel.
Austenitic Stainless Steel Basics.
The question that could be asked right now is how do we cold treat, or cryogenically treat, steel for the potential decomposition of retained austenite.
Typically, steel is heated to its austenitization temperature and then cooled sufficiently fast to avoid pearlite transformation and obtain maximum hardness and strength.
The rate of diffusion of carbon into steel while in the austenite phase is concerned with carbon in solid solution in austenite.
The diffusion rate of the carbon into the austenite phase is based on.
The formation of martensite involves the structural rearrangement (by shear displacement) of the atoms from face-centered cubic (FCC) austenite into a body-centered tetragonal (BCT) martensitic structure.
When austenite is rapidly cooled (i.e.
Revision of A249 / A249M - 10a Standard Specification for Welded Austenitic Steel Boiler, Superheater , Heat-Exchanger, and Condenser Tubes.
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In science:

The parent austenite phase shows a stronger ferromagnetism than that of the martensite phase and at the martensitic transition temperature (Tm ), a sharp change in magnetization is observed in thermo-magnetization measurements.
Magnetic glass in Shape Memory Alloy : Ni45Co5Mn38Sn12
In the case of FSMAs, since the high temperature phase is ferromagnetic austenite (FM-A) while the low temperature phase is low magnetization martensite (LM-M), this reentrant transition will be seen only for the positive sign of (Hc -Hw ).
Magnetic glass in Shape Memory Alloy : Ni45Co5Mn38Sn12
The high magnetization ferromagnetic austenite (FM-A) phase transforms to the low magnetization martensite (LM-M) phase and vice versa on cooling and heating, respectively20,21 .
Magnetic glass in Shape Memory Alloy : Ni45Co5Mn38Sn12
These results signify that the fractions of coexisting metastable martensite and austenite phases not only vary with field and temperature but also depend on the path followed in the HT space.
Magnetic glass in Shape Memory Alloy : Ni45Co5Mn38Sn12
These ‘kinetically arrested states’ are due to slowing down of growth of the martensite phase from the supercooled austenite phase, similar to the viscous retardation in structural glasses.
Magnetic glass in Shape Memory Alloy : Ni45Co5Mn38Sn12
We have almost 100% LM-M phase fraction when cooled in zero field but on increasing the cooling field the ferromagnetic austenite fraction increases.
Magnetic glass in Shape Memory Alloy : Ni45Co5Mn38Sn12
This system undergoes a complete transformation below 1T (H1 ), while above 8T (H2 ) the martensite transformation is almost hindered resulting in a completely austenite phase at low temperature.
Magnetic glass in Shape Memory Alloy : Ni45Co5Mn38Sn12
However at field values between H1 and H2 , we achieve a fraction of transformed martensite phase along with an arrested austenite phase at low temperatures21 .
Magnetic glass in Shape Memory Alloy : Ni45Co5Mn38Sn12
For temperatures above 75K, the rise in magnetization in the forward field cycle followed by an opening of hysteresis indicates the onset of the martensite to austenite phase transformation, which confirms the RMT in the temperature range of 75-150K.
Magnetic glass in Shape Memory Alloy : Ni45Co5Mn38Sn12
Thereafter, due to the presence of supercooled austenite fraction △M gradually decreases and almost vanishes on heating above 150K.
Magnetic glass in Shape Memory Alloy : Ni45Co5Mn38Sn12
The single martensite variant state was obtained by applying axial compressive stress to martensite crystal or by cooling the sample through the austenite-to-martensite phase transformation under axial compressive stress .
Large Magnetic-Field-Induced Strains in Ni-Mn-Ga Alloys due to Redistribution of Martensite Variants
Further considering that austenite is metastable at the beginning of the martensitic transformation at MS temperature, it is justified in the case of |S1 | > |S2 |, to surmise that the plane with the normal N1 is distinguished, and that the anticipated orientation of macroscopic shear is close to S1 .
Physical nature of fcc-bcc martensitic transformation in iron based alloys
This procedure results in appearance of stress field when the shape memory layer is transformed to the austenitic state which brings about two-way shape memory effect.
Imprinting bias stress in functional composites
To create internal stress fields in the austenitic state, somewhat complicated training procedures such as introduction of plastic deformation, constraint aging, thermal cycling, or utilization of precipitates has to be performed [1, 2].
Imprinting bias stress in functional composites
Since the metallic layer causes recurrent stress field in the austenitic state of the shape memory layer the bimetallic composite exhibits two-way shape memory effect.
Imprinting bias stress in functional composites
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