scholarly journals Effect of Initial Composition Distribution on the Phase Transformation Behavior in the Fe-Cr-Ni System

1995 ◽  
Vol 398 ◽  
Author(s):  
J. M. Vitek ◽  
S. A. David
Keyword(s):  
Phase Transformation ◽  
Solid State ◽  
Transformation Kinetics ◽  
Transformation Behavior ◽  
Initial Composition ◽  
Composition Distribution ◽  
Subsequent Transformation ◽  
Diffusion Controlled ◽  
Solid State Phase Transformation ◽  
The Impact

ABSTRACTA finite-difference implicit numerical model was used to study the diffusion-controlled α-γ solid-state phase transformation in the Fe-Cr-Ni system. The influence of a non-uniform initial composition distribution was examined in order to assess the impact that non-uniform solute profiles resulting from solidification may have on subsequent transformation behavior in weldments and castings. A significant impact on the transformation kinetics and transformation path was found in some cases. The factors that affect the degree of influence are discussed.

scholarly journals Solid state phase transformation kinetics in Zr-base alloys

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
A. R. Massih ◽  
Lars O. Jernkvist
Keyword(s):  
Phase Transformation ◽  
Solid State ◽  
Zirconium Alloys ◽  
Excess Oxygen ◽  
Transformation Kinetics ◽  
Fuel Cladding ◽  
Reactor Accident ◽  
Phase Transformation Kinetics ◽  
Solid State Phase Transformation ◽  
Water Reactors

AbstractWe present a kinetic model for solid state phase transformation ($$\alpha \rightleftharpoons \beta$$ α ⇌ β ) of common zirconium alloys used as fuel cladding material in light water reactors. The model computes the relative amounts of $$\beta$$ β or $$\alpha$$ α phase fraction as a function of time or temperature in the alloys. The model accounts for the influence of excess oxygen (due to oxidation) and hydrogen concentration (due to hydrogen pickup) on phase transformation kinetics. Two variants of the model denoted by A and B are presented. Model A is suitable for simulation of laboratory experiments in which the heating/cooling rate is constant and is prescribed. Model B is more generic. We compare the results of our model computations, for both A and B variants, with accessible experimental data reported in the literature covering heating/cooling rates of up to 100 K/s. The results of our comparison are satisfactory, especially for model A. Our model B is intended for implementation in fuel rod behavior computer programs, applicable to a reactor accident situation, in which the Zr-based fuel cladding may go through $$\alpha \rightleftharpoons \beta$$ α ⇌ β phase transformation.

Phase Field Study of Concurrent Nucleation and Growth in a Diffusion-Controlled Solid-State Phase Transformation

2012 ◽  
Vol 490-495 ◽  
pp. 1140-1144 ◽  
Author(s):  
Gang Wang ◽  
De Chang Zeng ◽  
Zhong Wu Liu
Keyword(s):  
Phase Transformation ◽  
Phase Field ◽  
Phase Field Model ◽  
Field Method ◽  
Nucleation And Growth ◽  
Phase Field Method ◽  
Model Alloy ◽  
Transformation Kinetics ◽  
Diffusion Controlled ◽  
Solid State Phase Transformation

The concurrent nucleation and growth in a diffusion-controlled phase transformation is studied using the quantitative phase field method, and the transformation kinetics is obtained for a model alloy. The simulation results show that the simultaneous nucleation and growth of new phase can be described very well in the phase field model, and that the phase transformation is governed by the diffusion of solute atoms. The competition between nucleation and coarsening is also observed. The phase transformation kinetics is found to obey the JMAK equation.

Continuous Cooling Transformation Behavior of a Ti Addition Steel

2014 ◽  
Vol 556-562 ◽  
pp. 480-483
Author(s):  
Chen Zhang ◽  
Guang Xu ◽  
Zhang Wei Hu ◽  
Hai Lin Yang
Keyword(s):  
Phase Transformation ◽  
Solid State ◽  
Cooling Rate ◽  
Transformation Behavior ◽  
Cooling Rates ◽  
Continuous Cooling Transformation ◽  
Continuous Cooling ◽  
Cct Curve ◽  
Solid State Phase Transformation ◽  
Ti Addition

The continuous cooling transformation (CCT) behavior of a Ti attached steel was studied through thermal simulation tests, and the influences of different cooling rates on the microstructure and transformation were investigated. The results show that the microstructure changes with the cooling rate, and the CCT curve of studied steel is plotted, which indicates that the solid-state phase transformation mainly consists of four regions. The CCT diagram made it possible to predict the microstructures of studied steel with different cooling rates.

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