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It can be seen from Figure 1 without the pulsed electric field processing of solidification, center grains are coarse , the direction of growth are disorder, right side are mostly small equiaxed grains.
It can be seen from Figure 2 that the pulsed electric field processing of samples solidified, center grains are coarse, the right end are much more tightly packed columnar grains, the direction of growth of columnar crystal are same in the cooling direction.
When the liquid metal was connected with the anode of the pulse, Fe, Mn, Cr atoms will rapidly close to the solid - liquid interface at the role of electric field moment, yet Si atoms will be away from the solid - liquid interface, with the number of solute atoms declining, the number of solute atoms are fewer, nucleation rate has dropped, the resulting grain size to slightly larger.
Thus by the pulsed electric field treated samples, the number of martensite are increased, the number of ε → γ transformation are increased after heat back, which increased the amount of shape recovery. (2) Solidification of pulsed electric field treated are most columnar crystals, most non-treated solidification are nearly equiaxed.
Pulsed electric field is benefit to Fe-Mn-Si-Cr alloys grain refinement.

The slip bands have a complex internal structure formed by a number of short slip lines which become coarser after the subsequent cyclic tests.
If the slip bands are parallel to laths, the lengths of the slip bands reach the dimensions of some grains.
The bends mostly are parallel to the boundary of the former austenite grain (Fig.3).
The same was observed in the case of the steel 13X11H2B2MФ, however, plastic deformation in this steel is mainly localized on the boundaries of the former austenite grains rather than on the packets inside the grains (Fig. 2-3).
Atthe individual sites (joints of grains and packets) the localized slip bands are formed. 2.

Currently, most authors and researchers tend to favour on of the growth selection theories, in particular the Σ9 grain boundary theory, and a number of striking proofs for its validity have been presented.
In the case of Goss grain growth a number of specific theories on oriented nucleation and growth selection have been proposed.
The numbers in the fields correspond to the depth in the sheet.
Up to a temperature of 800°C, when still no abnormal grain growth is observed the numbers do not change significantly.
These numbers suggest that actually Σ9 boundaries do not show any increased mobility which would lead to a decrease of their density.

The results have indeed shown that IFC can shorten the HP and reduce austenite grain growth and its variation across thick plate.
This technique has been successfully adopted in a number of industrial plate mills.
The prior austenite grain sizes from the as-quenched PSC samples were revealed by etching in saturated picric acid and grain sizes were measured by the linear intercept method.
Fifthly, the steel B with Ti and Nb microalloying elements had the finest prior austenite grain size after 3 roughing passes, as shown in the Fig. 5, which indicates that the Ti restricted the austenite grain growth during the high temperature deformation.
The refinement of austenite grain size is due to the IFC lowered austenite grain growth temperature and to a much shorter waiting time during the HP.

Fig. 2 Transfer of the larger angle grain boundary with grain growing up.
As shown in Fig. 2, grain boundary migration is achieved by the stepwise reduction of the lattice orientation difference in the grains.
As a result, the number of grain boundaries decreases, the grain boundary surface energy decreases, So that the organization in a more stable thermodynamic state.
In this case, the coarser fibrous structure will be due to the disappearance of grain boundaries within the region and into the strip grain, the original strip grain is likely due to the same reason to become larger size equiaxed grains, Which to a certain extent, eliminating the previous stage due to ruminal extrusion deformation caused by the grain.
The recrystallization process of the surface metal has a periodic characteristic of recovery, recrystallization and grain growth The violent vibration at the time of firing of the gun resulted in a large increase in the number of nuclei and accelerated the formation of recrystallized tissue, which was one of the important reasons for limiting the grain size.

Measurements were performed at room and at 100 °C, 200 °C and 250 °C on each grain.
These grains were subjected to the nanoindentation measurements. 9 indentations have been carried out for each grain at each temperature in array of 3x3 with spacing of 25 μm.
As one can see, indentation hardness slightly decreases with increasing temperature for grain D from room temperature up to 250 °C from 2.9 GPa to 2.3 GPa, for grain G from 2.8 GPa to 2.1 GPa and for grain C for 2.7 GPa to 2.1 GPa.
This differences between individual grains can be related to various number of active slip system in grains [7].
This can be explained with various number of active slip system in the individual grains.

In mathematics, a Voronoi diagram is a way of dividing space into a number of regions without overlaps and gaps.
As mentioned above, polycrystalline microstructures in metallic alloys are represented using Voronoi tessellations in a significant number of researches due to their similar properties.
As is shown in the figure, the deviation of overall stress with 1000 elements and 27000 elements is less than 3.5%, while the average number of elements per grain of the latter is 27 times as the former.
The aggregates with 1000 C3D8 elements and 10000 C3D4 elements, or aggregates with 8000 C3D8 elements and 66000 C3D4 elements have nearly the same number of average integration points per grain, but the deviations of overall stress when strain is 0.1 between them are 5.1% and 5.3%, respectively.
(c)and(d) Regular mesh and free mesh with nearly the same number of integration points.

Experimental Investigation of Brittle to Ductile Transition of Single Crystal Silicon by Single Grain Grinding F.W.
Grinding is a very complex manufacturing process which is involved with a great number of variables, such as wheel type, wheel condition, operating parameters, coolant condition and machine characteristics.
conducted single grain grinding experiments on a modified wafer grinding machine [6].
Fig. 3 3D image of single grain grinding groove shown in Fig. 2(b) Material response based on subsurface damage.
Therefore, below a critical depth of cut, cracks will fail to form around the cutting grain.

The fine NbC precipitated in the crystal and grain boundary enhanced strength of grain at high temperature, which resulted plastic deformation or slip at high temperature were mainly concentrated in the grain boundary, and high temperature plasticity of HAZ were decreased.
Test Materials and Methods Two commercial seamless steel tubes of TP347H stainless steel were selected as test materials, with specifications of OD76 × 6(mm) and OD57 × 9(mm), numbers D and X, respectively.
Number C Si Mn Cr Ni Nb S P Tube X 0.040 0.31 1.48 18.00 10.77 0.61 0.001 0.026 Tube D 0.041 0.44 1.45 17.57 9.05 0.72 0.002 0.026 Fig.1 Heat Cycle Curve of Simulated HAZ of Welded Joint.
Under optical microscope, twin austenite structure and grain grade 4-6 were observed for the section N of X6 sample, and win austenite structure and grain grade 5-7 for section N of D7 sample.
Grain strength is enhanced by the precipitation of fine NbC in the grain boundary and grain boundary under the welding thermal cycle, plastic deformation and slip at high temperature mainly concentrate on the grain boundary, which lead to the decrease of high temperature plasticity of thermal cycle area.

The use of metal materials with a gradient structure [11-16], where the grain size from the coarse-grained state in the central part of the workpiece decreases to the ultra-fine-grained state on the surface, is an effective way to solve the problem of increasing the plasticity of metal products in general.
From the edge to the depth of 0.75 radius (figure 1a,b), an ultra-fine-grained structure with equiaxial grains of 200-700 nm in size prevails.
At the same time, the special state of the borders with a large number of grain boundary dislocations, necessary for the formation of special properties of the UFG structure, will be preserved.
If the set of reflexes from the polycrystalline region is uniformly distributed over the corresponding circles as in figure 1f, then the crystal lattice in the grains is oriented randomly in each grain.
Song, A good combination of strength and ductility of ultra-coarse-grained Cu-Al alloy with coarse-grained surface layer via pre-torsional treatment, Micron, 129 (2020) 102783