PSI - Issue 14

Ritam Chatterjee et al. / Procedia Structural Integrity 14 (2019) 251–258 Author name / Structural Integrity Procedia 00 (2018) 000 – 000

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A few important simulation parameters are shown in Table 2. Table 2: A few important simulation parameters N grains T (K) ̇ (s -1 ) w rel 1000 1173 0.001 0.001

incr 0.01

N steps crit (m 30

P

-2 )

random

0.37*10 14 0.5 N grains refers to the initial number of grains in the microstructure, T is the operating temperature and ̇ is the strain rate imposed under compressive loading. The volume of grains is realised in simulation via a parameter called relative volume weight i.e. w rel which is the volume occupied by a grain in the microstructure and is represented by using crystallographic texture. The strain is incremented by in each deformation step and the total strain imposed equals 0.3 for N steps . The critical dislocation density has been arbitrarily chosen to be 0.37*10 14 m -2 . 3. Results and Discussion

The major results from the simulation are shown in Fig. 2 (a) to (d):

(b)

(a)

(d)

(c)

Fig. 2. (a) Flow stress variation with strain for DRX vs non-DRX (b) evolution in average dislocation density for DRX vs non-DRX (c) new DRX grains and total grains (d) percentage of DRX grains and grain size evolution with deformation

From Fig. 2 (a) and (c), the flow stress is shown to decrease as soon as new grains start forming at total strain ~ 0.2. At peak stress, rate of dislocation storage due to strain hardening exactly balances rate of dislocation annihilation due