Actually, micromechanical approaches give only few references related to glide mechanisms in a lamella and especially load transfer mechanism between lamellae in pearlites. At large strains the concept of interphase barrier has to be introduced and considered as the determinant mechanism of hardening compared with the classical bulk work hardening. A micromechanical approach is used to describe a hardening mechanism related to the growth of dislocation loops inside the ferritic lamellae of pearlite and their locking at the interphase boundary. Using Eshelby-Kro¨ner’s formalism for the resolution of the field equations, the calculation of the Helmholtz free energy related to the (internal) morphological variables allows finding driving forces and the strength of interactions between loops and interfacial walls. Results exhibit a linear dependence between the critical stress and the inverse of the true interlamellar spacing, through a lattice orientation factor relative to the lamellar interphase, as observed experimentally (J. Gil Sevillano, 1991, J. Phys. III, 1, pp. 967–988; G. Langford, 1977, Metallurgical Trans A, 8A, pp. 861–875.

1.
Taylor
,
G. I.
,
1938
, “
Plastic Strains in Metals
,”
J. Inst. Met.
,
62
, p.
307
307
.
2.
Berveiller, M., and Zaoui, A., 1981, “Me´thodes Self-Consistentes en Me´canique des Solides He´te´roge`nes, Comportement Rhe´ologiques et Structure des Mate´riaux,” C. Huet and A. Zaoui, eds., p. 175.
3.
Kro¨ner
,
E.
,
1961
, “
Zur plastischen Verformung des Vielkristalls
,”
Acta Metall.
,
9
, p.
155
155
.
4.
Hill
,
R.
,
1965
,
J. Mech. Phys. Solids
,
13
, p.
89
89
.
5.
Lipinski
,
P.
, and
Berveiller
,
M.
,
1989
, “
Elastoplasticity of Micro-Inhomogeneous Metals at Large Strains
,”
Int. J. Plast.
,
5
, p.
149
149
.
6.
Lipinski
,
P.
,
Krier
,
J.
, and
Berveiller
,
M.
,
1990
, “
Elastoplasticite´ des Me´taux en Grandes De´formations: Comportement Global et E´volution de la Structure Interne
,”
Rev. Phys. Appl.
,
25
, p.
361
361
.
7.
Louchet, F., 1999, “A Few Simple Considerations on the Specific Plastic Properties of Nanoscaled Multilayers and Equivalent Systems,” Proc. in the 7th Int. Symp. on Plasticity and its Current Applications, Plasticity 99, Mexico, S. Kahn, ed., pp. 585–588.
8.
Gil Sevillano
,
J.
,
1991
, “
Substructure and Strenghtening of Heavily Deformed Single and Two Phase Metallic Materials
,”
J. Phys. III
,
1
, pp.
967
988
.
9.
Janecek, M., Louchet, F., Doisneau-Cottignies, B., Brechet, Y., and Guelton, N., Philos. Mag., to be published.
10.
Hirth
,
J. P.
,
1972
,
Metall. Trans.
,
3
, pp.
3047
3066
.
11.
Li
,
J. C. M.
, and
Chou
,
Y. T.
,
1970
,
Metall. Trans.
,
1
, pp.
1970
1145
.
12.
Eshelby
,
J. D.
,
1957
, “
The Determination of the Elastic Field of an Ellipsoidal Inclusion
,”
Proc. Roy. Soc.
,
A241
, p.
376
376
.
13.
Aubert
, (Re´gnier),
I.
, and
Berveiller
,
M.
,
1997
, “
Constrained and Unstable Expansion of Dislocation Loops Using an Invariant Formulation of the Free Energy
,”
Mechanics of Materials
,
26
, pp.
127
137
.
14.
Boehler
,
J. P.
,
1979
, “
Introduction to the Invariant Formulation of Anisotropic Constitutive Equations
,”
ZAMM
,
59
, pp.
157
167
.
15.
Mura, T., 1982, Micromechanics of Defects in Solids, M. Nijhoff Publishers.
16.
Zhou
,
D. S.
, and
Shiflet
,
G. J.
,
1992
,
Metall. Trans. A
,
23A
, pp.
1259
1269
.
17.
Langford
,
G.
,
1977
, “
Deformation of Pearlite
,”
Metall. Mater. Trans. A
,
8A
, pp.
861
875
.
18.
Embury
,
J. D.
,
1992
, “
Micromechanical Descriptions of Heavily Deformed Materials
,”
Scr. Metall. Mater.
,
27
, pp.
981
986
.
19.
Marder
,
A. R.
, and
Bramfitt
,
B. L.
,
1976
,
Metall. Trans. A
,
7A
, pp.
365
372
.
20.
Dollar
,
M.
,
Bernstein
,
I. M.
, and
Thompson
,
A. W.
,
1988
, “
Influence of Deformation Substructure on Flow and Fracture of Fully Pearlitic Steel
,”
Acta Metall.
,
36
, No.
2
, pp.
311
320
.
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