isothermal transformation


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isothermal transformation

[¦ī·sə¦thər·məl ‚tranz·fər′mā·shən]
(metallurgy)
(thermodynamics)
Any transformation of a substance which takes place at a constant temperature.
References in periodicals archive ?
A transformation of this type is said to be athermal, in contrast to one that will occur at constant temperature (isothermal transformation).
These curves also serve another useful purpose because they demonstrate the interrelation between the athermal and isothermal transformations. The intersection of each isothermal curve with the ordinate axis gives the amount of martensite formed on the quench to the holding temperature.
where X is the transformation volumetric fraction; [X.sup.e] is the thermodynamic equilibrium fraction related to compositions and temperature of the steel; t is the time of isothermal transformation, s; B, k, and n are related to the compositions and temperature of the steel; D[gamma] is the austenite grain size, [micro]m; and [DELTA][epsilon] is the residual strain.
The process of isothermal transformation is simulated using (7) and (8).
Shakeout and isothermal transformation temperatures have a major influence on the final microstructure.
The isothermal transformation was defined as 90 minutes for all the samples.
The time-temperature dependence of the bainite transformation may also be represented on the isothermal transformation diagram.
The collective consensus is that the Nakamura model, which relates the isothermal transformation kinetics to the dynamically cooled crystallization kinetics, is the one that fits the experimental observations best.
At last, the isothermal transformation curves of both the conventional aging and the LDEPC added aging were derived.
Further, the isothermal transformation curve of both the regular aging and the LDEPC added aging can be derived to reflect the effects of pulse current intuitively.
Isothermal Transformation Diagrams in a Heavy Section High Alloy Ductile Cast Iron (90-126) D.J.
"Isothermal Transformation Diagrams in a Heavy Section High Alloy Ductile Cast Iron" dealt with the I-T diagrams for heavy section high alloy ductile cast iron (90-126).