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And the grain size was 200nm when the KNN powders was synthesized at 700℃.
The powders grain cannot grew up since the grain surface is stable [24].
With the temperature increasing to 800℃, the grain size grew up to 2μm.
The grain growth is consistent with Ostwald ripening.
(°C) Fig.9 Atomic number of the KNN powders sintered at different temperature (700℃, 800℃, 900℃) The amounts of Na, K and Nbatomic ratio in typical sample calcined at different temperatures(700℃, 800℃, 900℃) were measured by XRF in Fig.9.

Average squared output error (ASE) decreases with increase of the hidden node number.
The irregular blocky carbide ((Cr0.4Mo0.2W0.2Ni0.1Ti0.08Co0.02) C(1)) with bright contrast indicates that this phase contains elements having higher atomic numbers.
During thermal exposure, particles near grain boundary merge into layer of the grain boundary, which plays the main role in the grain boundary coarsening.
Although interface between the M23C6 particles and layers is not obvious, the cores with dim contrast in the grain boundary should be M23C6 particles due to light elements having lower atomic numbers in composition.
This prevents dislocations from piling up against grain boundaries and in consequence inhibits stress concentration on grain boundaries, when dislocations move to grain boundary.

The average grains size is 7-6 index, when welding without the TMF influence and the average grains size of the weld metal corresponds to 8 index, with separate inclusions of grains with 7 index when welding with the TMF influence.
These data are summarized in monographs [1, 2] and given in a significant number of publications [3-5].
Besides in a number of publications, it is shown that the transverse magnetic field (TMF) use also allows to obtain the above-mentioned positive effects.
Thus, the data on the TMF influence on the weld crystallization in arc welding are few in number.
Electromagnetic stirring and grain refinement in stainless steel GTA welds.

The ferrite grain size number is 11.
The requirements of Nb microalloyed H beam are as fellow: yield strength is great than 365 MPa, ferrite grain size number is great than 9, charpy impact energy at -20°C is greater than 34 J.
Austenite grain size affects ferrite grain size of product.
When heating temperature are 1050°C, 1100°C, 1150°C, 1200°C, 1250°C, the corresponding austenite grain size number is 4.5, 4, 3.5, 3, 2, 1, respectively.
The microstructure consists of ferrite and pearlite, and the ferrite grain size number is 11 (see Fig 4).

The starting material had equiaxed austenite grains with mean grain size of 35 μm.
This is called grain subdivision which is the basic process of grain refinement by SPD process.
Fig. 4c shows the change in density of low angle boundaries versus number of the ARB cycles.
(b) (a) (c) Fig. 4 Relationship between the number of the ARB cycles and a) the martensite transformation starting temperature (Ms), b) the austenite grain size (boundary interval along ND), c) density of low angle boundaries (2°≤θ<15°) within the austenite.
(iii) The Ms temperature changed depending on the number of ARB cycles.

The effect of nitrogen on crystal grain for metastabl austenitic manganese steel was studied.
Table 1 lists main chemical composition of experimental steels and according crystal grain grade.
Table 1 Main chemical composition of experimental steels and crystal grain grade Heat number Main chemical composition Crystal grain grade w([N]), % w([Cr]) , % w([Ti]) , % 1 no yes no 1 2 0.120 yes no 2 3 0.070 yes no 4 4 0.055 yes no 1 5 0.050 yes no 1 6 0.067 no no 3 7 0.120 yes yes 3 By analyzing the data of nitrogen content and crystal grain grade of experimental steels listed in Table 1 and the metallographs of experimental steels showed in Fig. 2, it can be seen that the grain grade of experimental steels will be influenced by nitrogen content.
But grain grade of No.7 heat is same as No.6 heat’s alloyed with only lower content nitrogen.
The Effect of Nitrogen Element on Growing of Crystal Grain during Heat Treatment.

Fine-grained polycrystalline metals have a very high yield stress and excellent workability.
In recent years, various techniques for producing fine-grained materials with a grain size of less than 1µm have been developed.
Although many SPD processes exist [6-9], the basic grain-refinement mechanism is still unclear.
The cell sizes after the relaxation, the average grain size, and the number of atoms are given in Table 1.
Fig.1 Analysis region Fig.2 Processing route Fig.3 Initial structure Table 1 Cell sizes and number of atoms Cell size [nm] xL yL zL Average grain diameter d [nm] Number of atoms Model S 76.6 2.0 76.4 --- 1,007,160 Model P 76.5 2.0 76.7 22.6 999,356 Table 2 Relationship between processing route and shear direction Rotational angle 1st process 2nd process Zθ Yθ zxγ xzγ zxγ xzγ Route a( A ) °0 °0 - Route b( CZθ ) °180 °0 - Route c( CBYθ ) °0 °90 + Route d( CB-C YZ θθ ) °180 °90 + + Results and Discussions Time Evolution of the Defect Atoms.

Role of Mo on Static Recrystallization Kinetics in Coarse Grained Nb Microalloyed Steels B.
Although there are different rolling mill configurations, in a high number of industrial plants there are no roughing stands and the thin slab goes directly to the finishing mill.
The following parameters were quantified at each condition: the recrystallized volume fraction (X) and the grain size distributions of both recrystallized and unrecrystallized grains, being the grain size defined as the equivalent area diameter provided by the analyzer.
The number of intercepts per unit length of boundaries between recrystallized and unrecrystallized grains, , was measured to calculate the migrating boundary area per unit volume between recrystallized and unrecrystallized regions, , according to Hilliard [[] J.E.
In the table the following measurements are included: the mean austenite grain size (Dmean), the critical grain size (Dc, defined as the value for which at least a 10% of the volume fraction of grains have a greater size than that critical grain size), the amount of accumulated strain and the fraction of as-cast grains that remain before transformation.

A variety of models have been proposed to interpret this relation 1-5, and a number of experimental investigations have studied dislocation behavior in the vicinity of grain boundaries 6-10.
The grain boundary is indicated by arrow-heads.
As the indenter penetrated further, a large number of dislocations were emitted on the far side from the indenter tip (left and lower side on the micrograph) of the grain boundary into the adjacent grain.
Li: Petch relation and grain boundary sources.
(a) low-angle grain boundary and (b) high-angle grain boundary.

The transverse (sub)grain size and the number fraction of high-angle (sub)grain boundaries were about 0.2 µm and 75%, respectively.
It should be noted that the size of these fine grains is comparable with the transverse (sub)grain size in the cold worked sample.
The annealing behaviour looks similar to a normal grain coarsening with a grain growth exponent about 6.
The numbers indicate the misorientations in degrees.
The polygonization rapidly developed at an early annealing and resulted in the evolution of almost equiaxed ultra fine-grained microstructures with a grain size of about 0.3 µm, which is close the transverse size of highly elongated deformation (sub)grains.