Issue 50

K. Singh et alii, Frattura ed Integrità Strutturale, 50 (2019) 319-330; DOI: 10.3221/IGF-ESIS.50.27

[18] Estrin, Y., Mecking, H. (1984). A unified phenomenological description of work hardening and creep based on one parameter model, Acta Metallurgica, vol 32, pp. 57-70. DOI: 10.1016/0001-6160(84)90202-5. [19] Gururaj, K., Robertson, C., Fivel, M. (2015). Post-irradiation plastic deformation in bcc fe grains investigated by means of 3d dislocation simulations, Journal of Nuclear Materials, 459, pp. 194-204. DOI: 10.1016/j.jnucmat.2015.01.031. [20] Thomas, H., Bruno, M., Jean-Michel, P., Maxime, S., Jerome, S., Michel, C. (2015). Introducing the open-source mfront code generator: Application to mechanical behaviours and material knowledge management within the PLEIADES fuel element modelling platform, Computers & Mathematics with Applications, 70, pp. 994–1023. DOI: 10.1016/j.camwa.2015.06.027 [21] Spitzig, W. (1973). The effect of orientation, temperature and strain rate on deformation of Fe-0.16 wt.% Ti single crystals, Material Science and Engineering, 12, pp. 191–202. DOI: 10.1016/0025-5416(73)90010-4. [22] Quesnel, D., Sato, A., Meshii, M. (1975). Solution softening and hardening in the iron-carbon system, Material Science and Engineering, 18, pp. 199–208. DOI: 10.1016/0025-5416(75)90170-6. [23] Kuramoto, E., Aono, Y., Kitajima, K. (1979). Thermally activated slip deformation of high purity iron single crystals between 4.2 k and 300 k, Scripta Metallurgica, 13, pp. 1039–1042. DOI: 10.1016/0036-9748(79)90199-6. [24] Vincent, L., Libert, M., Marini, B., Rey, C. (2010). Towards a modelling of RPV steel brittle fracture using crystal plasticity computations on polycrystalline aggregates, Journal of Nuclear Materials, 406, pp. 91-96. DOI: 10.1016/j.jnucmat.2010.07.022. [25] Vincent, L., Gelebart, L., Dakhlaoui, R., Marini, B. (2011). Stress localization in BCC polycrystals and its implications on the probability of brittle fracture, Materials Science and Engineering A, 528, pp. 5861-5870. DOI: 10.1016/j.msea.2011.04.003. [26] Libert, M., Rey, C., Vincent, L., Marini, B. (2011). Temperature dependant polycrystal model application to bainitic steel behavior under tri-axial loading in the ductile–brittle transition, International Journal of Solids and Structures, 48, pp. 2196-2208. DOI: 10.1016/j.ijsolstr.2011.03.026. [27] N’Guyen, C.N., Barbe, F., Osipov, N., Cailletaud, G., Marini, B., Petry, C. (2012). Micromechanical local approach to brittle failure in bainite high resolution polycrystals: A short presentation, Computational Materials Science, 64, pp. 62 65. DOI: 10.1016/j.commatsci.2012.03.034.

N OMENCLATURE



T

Absolute temperature

Peirels shear stress at 0 K

0



Mobile dislocation density (m-2)



Effective resolved shear stress on the slip plane Resolved shear stress on the slip plane

m

eff



Total obstacles (forest dislocation and irradiation loops)

obs



RSS



Dislocation density on same slip system

self



Critical resolved shear stress

c

F 



Forest dislocation density

Same slip system’s dislocations induced stress

self



Irradiation defect density Strain rate on slip system

irr





Line tension resistance

LT



Shear modulus

AF 

Interaction coefficient of system A with obstacle system F Average obstacle strength based on a quadratic average rule Obstacle strength between same slip system

0 H  Pair activation enthalpy at 0 K



k

Boltzmann constant

B

N

Irradiation defects (interstitial loop) number density Irradiation defects (interstitial loop) diameter

irr



self

d

irr

Magnitude of Burger’s vector Distance between Peierls valleys Phonon/viscous drag coefficient

b h

X

 Distance swept by kink pair before its annihilation y Dynamic recovery parameter

B



Average obstacle spacing

329