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Measurements on the mean grain size and the distribution of grain size were carried out.
The results indicated that the mean grain size of 0# steel was 5.67μm, but that of the Q345B with RE was 5.01μm.
Meanwhile, standard deviation of grain size of the former steel was 1.98, lower than that of the latter steel 2.10.
The limitation of grain refining capability could be due to the agglomeration of the nucleating particles, and formation of complex compounds in presence of the higher RE contents which results in a coarse columnar grain structure.
But, the differences of grain distribution and grain size are very slight

.% Cr content and guaranteed pitting resistance equivalent (PRE) number in the range 40 ≤ PRE ≤ 45.
The effect of strain, strain rate and temperature on flow stress can be described by a number of constitutive equations.
It also appears that in addition the average ferrite grain size also increases per unit area, as well as the phase volume fraction.
Cr-nitride precipitation also reveals the presence of a clear cellular sub-grain structure in the ferrite phase.
Consequently, quenched-in nano-scale chromium nitride particles form and become finely dispersed within coarse ferrite grains.

Influencing time of electric current frequency is longer, dynamic (the velocity of the molecules) is bigger, it is easy to gain status of destruction of hydrogen bonds, so that the number of hydrogen bonds reduce leading to viscosity of liquid also reduces.
Due to the increased number of elements, the liquid is also leaded to increase by time, and the special weight of the liquid is reduced by time.
Impact of changes of physicochemical properties of water to the growth of grains: (a) testing sample uses deionized distilled water; (b) testing sample uses deion distilled water after impact of TR-1 within 30 minutes As the results above shown that, under the impact of power line frequency, hydrogen bridges links is weaker, water elements are easily converted into free and flexible, leading to penetration and impact to grain is faster.
Results leading to stimulation of the growth of grain also happens faster.
Researches to the growth of grain show that, research results have high potential in application in agriculture crops and water treatment.

It was found that the main role of Al is binding TiC grains whose size decreased with an increase of the amount of Al added.
However, The more Al powder content in the initial mixture, the less number of pores are observed in the coating.
In addition, the liquid metals Al surrounding the TiC grains increases and leads to an increase in diffusion path and decreases the driving force for grain growth of TiC and discourages the coalescence of TiC grains to form larger grains.
Due to the action of the hard reinforcement phases and the grain refinement, the micro-hardness of the ceramic layer was 2-3 times greater than that of the Ti-6Al-4V substrate.
Furthermore, the more Al powder content in the initial mixture, the less number of pores are observed on the coating.

During heating, recrystallization of the material occurs if the stored energy is sufficient, and this produces small grains with high-energy grain boundaries.
Above the solidus temperature, these grain boundaries melt and small solid globules formed.
Fig. 4 (d) shows the liquid content is increasing and the number of α-Al particles is decreasing.
Meanwhile, the atom reprecipitation and aggregation of grain colonies cause the segregation of liquid.
With increasing the temperature, liquid fraction increases and the number of particle decreases.

The average particle size was about 500 nm and the primary grain size was 50 nm for Al2O3.
Grain size.
The average grain diameter of the sample can be estimated by Scherrer equation [15] and the calculated results show that the grain size is about 40-60nm.
The growth of grain size seems to be rarely happened because of the little high temperature sintering time.
Acknowledgements This work was supported by the Key Natural Science Foundation of Jiangsu Province under grant number BK2004005.

It can be seen clearly in Fig.1 that grain boundary were blurry and obvious connection were existence between the minor parts of grains.
When the temperature exceeding this number, the resultants N2 and SiO could break through SiO2 protective film on the surface, resulting the materials were out of protection.
In this picture, the shape of SiC grains kept fairly well and the grain boundary line is obvious, only the matrix part had some binding reactions.
Most SiC grains had been completely oxidized.
And it’s hard to find a SiC grain in good condition right here.

During creep, the precipitate on the PAG (prior austenite grain) boundaries and martensite lath boundaries coarsened.
In the present study, we examined statistically and quantitatively the microstructural changes, such as the size of the precipitates, the number of precipitates per unit area and the martensite lath width, during the creep of 11Cr-3.5W-3Co steel.
The BSE (backscattered electron) image was used to distinguish between the Fe2W phases and M23C6 phases, due to the atomic number contrast provided by the distinct yields of the BSE signals from the various phases [4].
Previous researchers reported that the major precipitates of 9-12 wt.% high Cr tempered martensitic steels were the M23C6 ((Cr, Fe)23C6) phases on the PAG boundaries and MX (Nb,V(C,N)) phases on the martensite lath boundaries and inside the grains [1,2].
Number of precipitates vs. size of precipitates after different creep times.

The implication is that if a critical minimum amount of strain is required for hot tearing, the strain experienced by a liquid film at any grain boundary would decrease as the number of grains increases, thereby lowering the possibility of tearing [1].
“Shape hardening” arises because the plate-shaped and rod-shaped precipitates result in 2 and 1.75 times more strengthening, respectively than the equivalent number of spherical precipitates of the same volume [6].
Development of as-cast grain structure in (a) 7449, (b) & (c) 7449 containing Sc.
(a) (b) (c) Grain Refinement: The combined action of Sc and Zr is known to bring about considerable grain refinement in Al and many of its alloys [14].
Figures 14(b)-(d) represent optical micrographs showing changes in the weld grain structure from columnar to equiaxed and there is considerable refinement of the grains in both cases [2,3].

Fine grained soils such as clay and silt can be modeled by the C-C model.
Coarse grained soil, for containing and not containing excavation, may be represented using the M-C model considering strain softening and the normal M-C model.
The proper direction toward model research and model selection lies in the following requirements [9] : i) it can reflect the main character of soil under the loading case researched; ii) it must consider soil sort and the character of geotechnical engineering; and iii) simplicity and a small number of parameters.
In the horizontal direction from west to east, the diameter of the soil grain and the thickness of Quaternary stratum decreases and increases gradually.
Coarse grain soil is usually buried deep and in a dense state.