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- Grain size – grain size distribution was calculated under assumption that the grain boundary misorientation limit is set to 15°.
In the first one number of EBSD points is divided by number of grains to calculate average grain size.
The second grain size statistics we will call “grain size (A)”.
Grain sizes.
Using typical grain size calculations (number of EBSD points divided by number of grains), the average grain size drops down from 140µm2 for initial state to 80µm2 for 17% deformed material (in hard direction) or 40µm2 for 16% deformed material (in soft direction).

AFM images manifest that, with the increase of deposition time, the grain size becomes larger accompanied by the decrease of the number density.
In addition, AFM images manifest that the grain size becomes larger accompanied by the decrease of the number density with increasing the deposition time.
For the film deposited in 40 minutes, large Si grains with about 35 nm in diameter is distributed among the small Si grains.
Compared Fig. 4(a) with Fig. 4(b), it is clear that, with the increase of deposition time, the grain size becomes larger accompanied by the decrease of the number density.
AFM images manifest that, with increasing the deposition time, the grain size becomes larger accompanied by the decrease of the number density.

By microcosmic orientation distribution analyse find that the new {011}<100> grains are nucleated within shear bands in the deformed {111}<112> grains, New {111}<112> grains are nucleated within deformed {111}<110> grains and new {111}<110> grains originated in the deformed {111}<112> grains .
Some grains are smooth and lightly etched whereas other grains are darkly etched.
The number and the size of the recrystallized grains generally increase as the annealing temperature increases.
It is observed that some deformed grains are completely consumed by new grains, whereas other deformed grains are partially replaced by new grains or even remain recovered without any nucleation.
Here, blue grain represent {111}<112>, green grain {111}<110> , sky blue grain {011}<100>.

From this clarification, it turned out to be clear that the number of blocks and packets per 100µm length of prior austenite grain boundary is larger at the RZ than the AWZ.
The numbers of blocks and packets were 5.3 and 2.4 at the RZ respectively.
In contrast, the numbers were 5.1 and 1.6 at the AWZ.
Since the nucleation rate from the prior austenite grain boundaries is considered to be related to the segregation of the solute elements near and at the austenite grain boundaries, Ni concentration was measured across prior austenite grain boundaries at the AWZ and the RZ by energy-dispersive X-ray spectroscopy (EDS).
It is considered that the lower Ni segregation concentration at the prior austenite grain boundaries of the RZ caused higher grain boundary energy β.

The mechanism for grain refinement is incomplete dynamic recrystallization.
The SAD patterns were arc-like, which suggests that a number of the high-angle boundaries (>15°) exist within the selected areas of Fig. 2b [5].
However, the grain size was not uniform.
The grain with diameter of 2.30 µm was observed in Fig. 5(b).
Lath martensite is a type of fine grained structure subdivided by a number of high-angle boundaries.

It is believed that the smaller grain size could improve the mechanical properties.
The process ECAP causes deformation to the separation of grains on heavy dislocation walls [3].
The Grains size significantly decline [4] [5], and dislocation density with ECAP process increased pass number for route Bc [3].
The other effect increase pass number by ECAP toughness improve significantly [9].
The effect of pass number of ECAP process Conclusions In the present work, the commercial aluminum Al-Si-Cu-Mg-Mn alloys were processed by ECAP through route (A and Bc) and the number of passes.

Finally, the original coarse equiaxed grains were replaced by new recrystallized grains and the average grain size is smaller than the original grains.
Fig. 6 Grains size and number variation: (a) one pass; (b) two pass The grain size and number variation are shown in Fig. 6 after pressing one (Fig. 6(a)) and two (Fig. 6(b)) pass.
Fig. 6(a) shows, after one pass, the microstructure was coarse equiaxed grain, average size of the grains is 2.9 and the number of grain is 84.
Fig. 6(b) shows that after pressing two pass, the grain size reduced drastically; the average size of the grains is 2.7 and the number of grain is 94, which is small equiaxed grains and distributed randomly.
Under all conditions except the involving grain refinement by ECAP, the increased number of grains was determined mainly by the recrystallization nucleation process.

It was ensured that the lines were roughly equidistant and did not intercept the same grain twice; the number of lines per image varied between 5 and 9.
The length of each line, in μm, was divided by the number of interception points along it to give the average grain size for that line,.
The mean of the average grain sizes, , was then calculated to give the approximate grain size for the specimen, as shown in Eq. 2 (where n is the number of horizontal lines on the image).According to ASTM E112-13, which illustrates the standard test methods for determining average grain size, a 95 % confidence interval should be calculated to determine the relative accuracy of the mean grain size value.
The 95 % confidence interval is calculated as shown in Eq. 4, where s is the standard deviation, n is the number of values for each image (3), and t is the value of Student’s t distribution (for p=0.025 and n-1 degrees of freedom).
Image (f) is of the specimen produced at 1000°C with a 30 minute dwell time At 800°C, although the number of primary alpha grains does not increase, the initial alpha grains grow as the dwell time increases, implying that the primary alpha volume fraction increases for increasing dwell time.

The grain size distributions after the tests are plotted in Fig. 1.
For the ultimate grain size distribution, D is always around 2.5 [6-10].
Therefore, in this condition, the Bpi is defined as the area between initial grain size distribution and ultimate grain size distribution up to 0.5 mm particle size and the Bt is defined as the area between initial grain size distribution and current grain size distribution up to 0.5 mm particle size, as shown in Fig. 3.
The conclusion further verifies that the number of broken particles increases with the increasing confining pressure during compression.
The number of the largest particles decreases with the increase in confining pressures, and the number of smaller particles increases with the increase in confining pressures.

During DIFT, the ferrite grain number per unit area increases continuously, but it decreases during continuous cooling 913K 953K 993K transformation or during isothermal transformation in a plain low carbon steel.
During this process, the ferrite grain numbers and the transformed volume fraction increase progressively.
Niobium in both the states is favorable for the DIF grain refinement.
Furthermore, it can be Number C Si Mn Nb V Ti N A 0.003 0.22 1.12 0.052 \ 0.0110 0.0012 B 0.003 0.19 1.10 0.110 \ 0.016 0.0014 C 0.086 0.16 0.57 \ \ \ \ D 0.091 0.18 0.56 \ 0.064 \ \ E 0.088 0.17 0.55 0.027 0.070 \ \ seen from Fig.2 that more fine polygonal ferrites, i.e. deformation induced ferrites are formed at lower deformation temperatures.
The role of the first pass rolling at 1000°C is to refine austenite grains by recrystallization considering that fine austenite grains will be beneficial to DIFT.