Estimation of the System Free Energy of the Lath Martensite Phase in High Cr Ferritic Steels

2006 ◽  
Vol 15-17 ◽  
pp. 690-695 ◽  
Author(s):  
Tomonori Kunieda ◽  
Kensuke Akada ◽  
Yoshinori Murata ◽  
Toshiyuki Koyama ◽  
Masahiko Morinaga
Keyword(s):  
Free Energy ◽  
Ternary Alloy ◽  
Elastic Strain ◽  
Lath Martensite ◽  
Elastic Strain Energy ◽  
Martensite Phase ◽  
Interfacial Energies ◽  
Martensite Packet ◽  
Chemical Free Energy ◽  
Martensite Microstructure

The system free energy was estimated for the martensite phase of an Fe-Cr-C ternary alloy, 12Cr2W and 12Cr2W0.5Re steels. The system free energy of the martensite phase is defined as, Gsys = G0 + Estr + Esurf , where G0 is the chemical free energy, Esurf is the interfacial energy for the boundaries in the martensite microstructure, and Estr is the elastic strain energy due to the dislocations in the martensite phase. From the experimental results on SEM/EBSD, the total interfacial energies were estimated to be 0.83J/mol for the ternary alloy and 4.8J/mol for both 12Cr2W and 12Cr2W0.5Re steels in the as-quenched state. Also, the elastic strain energies were estimated to be 7.1J/mol for the ternary alloy, 9.6J/mol for 12Cr2W steel and 9.8J/mol for 12Cr2W0.5Re steel in the as-quenched state. So, the system free energy was about 7.9J/mol for ternary alloy. On the other hand, the system free energy was about 14.4J/mol for 12Cr2W steel and 14.6J/mol for 12Cr2W0.5Re steel. So, these microstructural energies operate as a driving force for the microstructure evolution, e.g., recovery of dislocations and the coarsening of the sub-structures such as martensite-packet, -block and -lath.

Stress Dependence of Microstructural Evolution in Heat Resistant Steels

2010 ◽  
Vol 654-656 ◽  
pp. 190-193
Author(s):  
Yoshinori Murata ◽  
Yoshihiro Saoto ◽  
Yuhki Tsukada ◽  
Toshiyuki Koyama ◽  
Masahiko Morinaga ◽  
...  
Keyword(s):  
Free Energy ◽  
Relaxation Time ◽  
Surface Energy ◽  
Elastic Strain ◽  
Strain Energy ◽  
Elastic Strain Energy ◽  
Stress Dependence ◽  
Heat Resistant ◽  
Chemical Free Energy ◽  
Heat Resistant Steels

The state of the microstructure of ferritic heat resistant steels during creep was evaluate by the system free energy, which composes mainly chemical free energy, surface energy and elastic strain energy, and its stress dependence was expressed quantitatively by using a relaxation time. The steels used in this study were P91 (9Cr-1Mo-C-N-V-Nb) steel and P92 (9Cr-Mo-W-C-N-V-Nb-B) steel. The obtained results are as follows: (1) the relaxation time of elastic strain energy was expressed as a function of stress and temperature, (2) surface energy of P92 scarcely decreased during creep due to the formation of the Laves phase, and (3) the relaxation time of the chemical free energy in P92 was larger than that in P91.

The role of chemical free energy and elastic strain in the nucleation of zirconium hydride

2013 ◽  
Vol 441 (1-3) ◽  
pp. 395-401 ◽  
Author(s):  
A.T.W. Barrow ◽  
C. Toffolon-Masclet ◽  
J. Almer ◽  
M.R. Daymond
Keyword(s):  
Free Energy ◽  
Elastic Strain ◽  
Zirconium Hydride ◽  
Chemical Free Energy

Estimation of the System Free Energy of the Lath Martensite Phase in High Cr Ferritic Steels

2006 ◽  
pp. 690-695
Author(s):  
Tomonori Kunieda ◽  
Kensuke Akada ◽  
Yoshinori Murata ◽  
Toshiyuki Koyama ◽  
Masahiko Morinaga
Keyword(s):  
Free Energy ◽  
Lath Martensite ◽  
Martensite Phase ◽  
Ferritic Steels

scholarly journals Estimation of the System Free Energy of Martensite Phase in an Fe-Cr-C Ternary Alloy

2005 ◽  
Vol 45 (12) ◽  
pp. 1909-1914 ◽  
Author(s):  
Tomonori KUNIEDA ◽  
Masaaki NAKAI ◽  
Yoshinori MURATA ◽  
Toshiyuki KOYAMA ◽  
Masahiko MORINAGA
Keyword(s):  
Free Energy ◽  
Ternary Alloy ◽  
Martensite Phase

scholarly journals Finite-strain thermoelasticity based on multiplicative decomposition of deformation gradient

2002 ◽  
pp. 379-399 ◽  
Author(s):  
L. Vujosevic ◽  
V.A. Lubarda
Keyword(s):  
Free Energy ◽  
Elastic Strain ◽  
Strain Energy ◽  
Finite Strain ◽  
Helmholtz Free Energy ◽  
Deformation Gradient ◽  
Elastic Strain Energy ◽  
Multiplicative Decomposition ◽  
Latent Heats ◽  
Constitutive Formulation

The constitutive formulation of the finite-strain thermoelasticity is revisited within the thermodynamic framework and the multiplicative decomposition of the deformation gradient into its elastic and thermal parts. An appealing structure of the Helmholtz free energy is proposed. The corresponding stress response and the entropy expressions are derived. The results are specified in the case of quadratic dependence of the elastic strain energy on the finite elastic strain. The specific and latent heats are discussed, and the comparison with the results of the classical thermoelasticity are given. .

Do muscles function as adaptable locomotor springs?

2002 ◽  
Vol 205 (15) ◽  
pp. 2211-2216 ◽  
Author(s):  
Stan L. Lindstedt ◽  
Trude E. Reich ◽  
Paul Keim ◽  
Paul C. LaStayo
Keyword(s):  
Skeletal Muscle ◽  
Elastic Strain ◽  
Strain Energy ◽  
Elastic Strain Energy ◽  
Normal Animal ◽  
Eccentric Contractions ◽  
Normal Muscle ◽  
Energetic Costs ◽  
Locomotor Muscles ◽  
Power Outputs

SUMMARYDuring normal animal movements, the forces produced by the locomotor muscles may be greater than, equal to or less than the forces acting on those muscles, the consequences of which significantly affect both the maximum force produced and the energy consumed by the muscles. Lengthening (eccentric)contractions result in the greatest muscle forces at the lowest relative energetic costs. Eccentric contractions play a key role in storing elastic strain energy which, when recovered in subsequent contractions, has been shown to result in enhanced force, work or power outputs. We present data that support the concept that this ability of muscle to store and recover elastic strain energy is an adaptable property of skeletal muscle. Further, we speculate that a crucial element in that muscle spring may be the protein titin. It too seems to adapt to muscle use, and its stiffness seems to be`tuned' to the frequency of normal muscle use.

The Elastostatic Axisymmetric Problem of a Cracked Sphere Embedded in a Dissimilar Matrix

1980 ◽  
Vol 47 (3) ◽  
pp. 545-550 ◽  
Author(s):  
R. Kant ◽  
D. B. Bogy
Keyword(s):  
Elastic Strain ◽  
Strain Energy ◽  
Elastic Strain Energy ◽  
Companion Paper ◽  
Infinite Medium ◽  
Applied Mechanics ◽  
Axisymmetric Solution ◽  
Material Parameters ◽  
The Difference ◽  
Elastostatic Problem

The axisymmetric elastostatic problem of a cracked sphere embedded in a dissimilar matrix is solved by using the solution for a spherical cavity in an infinite medium together with the axisymmetric solution for a cracked sphere given in the companion paper in this issue of the Journal of Applied Mechanics, Pages 538-544. Numerical results are presented for (a) interface stress for various composites (b) dependence of the stress-intensity factor on the material parameters and ratios of crack to sphere radii, (c) the difference in the elastic strain energy for a cracked and uncracked composite.

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