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The Belleville springs, installed in a pre-loaded package, were subjected to a cyclic load in the range of 100kN-160kN, with the number of cycles C = 9000.
The grain size was assessed according to the GOST 5639 scales, the microstructure - according to the 9-point scale OST 92-9465-81.
Based on the results of short-term compression, the dependences of the total number of pulses (N) on the ordinal number of loads (n) for 3 groups of BS were constructed (Fig. 2).
It can be assumed that under conditions of hindered diffusion and a large number of nucleation sites of the secondary α-phase, its particles are separated by an intermediate mechanism and are very dispersed, and in some cases, grain coarsening occurs, because the degree of coagulation of the secondary α-phase is higher.
Thus, to reduce the tendency to relaxation, it is necessary that the α-phase and β-phase in the alloy are fine-grained and dispersed, the grains of the secondary α-phase are less coagulated, and the β-phase is more dispersed [4].

As the holding time longer, the number of precipitates in micro alloyed increase gradually, but very little change in size.
In the picture can see, when the holding time is short, because the cooling speed is fast after deformation, number and size of precipitates change less.
As holding time longer, numbers of precipitates gradually increase, but changing in size of precipitates is very small due to low temperature.
Figure 3 are morphology and distribution of precipitates after insulation 100s and 1000s getting by extraction replica method, can see with increase of holding time number of precipitate increasing, distribution is more uniform.
(3) When the holding time is short, because the cooling speed is fast after deformation, number and size of precipitates change less.

Fairly reproducible and equiaxed grains were obtained from the heat treatment, and the average linear intercept grain size obtained from a statistical sample size of grains was ≅ 10 μm.
It is found that the primary sub-grains become elongated in the transition region between power-law and exponential creep, and they often contain fewer secondary sub-boundaries, larger numbers of coarse-walled cells and a higher dislocation density in comparison to their equiaxed neighbors [1].
The volume fraction of sub-grains near the boundary is fc.
If grain boundaries migrate only, the value of fc becomes zero.
The internal stresses within elongated sub-grains are expected to be higher than that within equiaxed sub-grain, and this difference can lead to sub-boundary migration if the sub-boundaries are mobile.

The reduction of the grain size is also reflected in an enhancement of the hardness.
From the micrograph, a grain size of ~ 20-100 nm is estimated whereat a few larger grains are also visible.
From the micrograph, grain sizes of about ~ 20-50 nm are estimated and the grains seem to be more equiaxed in this case.
Therefore, the grain size of the Cu and Fe phases are further reduced.
Acknowledgments The financial support by the Austrian Fonds zur Förderung der wissenschaftlichen Forschung (Project number: S10402-N16) is gratefully acknowledged.

It can be easily seen the grain boundaries of prior austenite, prior austenite grain were almost equiaxed and the grain size was larger than 10μm.
Bainite lath grows from the prior austenite grain boundaries and the lath is thin and long even penetrated whole grain.
Because of high temperature tempering, partial lath was connected and coarsened, many sub-grains which consisted of dislocation wall could be seen. 2# steel, it can be clearly seen several fine ferrite grains and bainite which are characterized by granular and lath-type.
Discussions Quenching from the full austenitic region for 1# steel, the microstructure was typical bainite lath with high ration of length/with, a large number of poor mobility dislocation generated by phase transformation during quenching.
The sub-grain exhibited effective resistance to the cracks propagation[8].

The low volume fraction of recrystallized grains (< 0.1) in ODS-Eurofer steel annealed at 800oC can be explained by nucleation at prior grain boundaries and around large M23C6 particles.
In spite of differences between hardness of both steels after cold rolling, these numbers clearly indicate that the amount of softening is influenced by the presence of nanoparticles in ODS-Eurofer steel.
The corresponding volume fraction of recrystallized grains is below 0.1.
The recrystallized grain size is about 3 mm.
The stored energy at prior grain boundaries is larger than the one found in the interior of the grains which helps to sustain the growth of the recrystallization nuclei.

Aluminum alloy with high strength, corrosion resistance, easy molding, thermal stability and regeneration a number of advantages to meet the special needs of military and civilian, and thus far, aluminum is still a lightweight material of choice.
Many studies have found that the grain size will have an impact, the mechanical properties of materials commonly used method of grain refinement, adding refiner, rapid solidification and crystallization under pressure to achieve.Modification of the rare earth has a unique physical and chemical properties [2-8].
RE modificatior of grain processing more than ternary modificatior fine grain size distribution is more uniform.
Join the cast structure of rare earth alloy, alloy grain size is significantly reduced, the secondary dendrite arm spacing refinement, the alloying elements of the rare earth complexes with Al, Mg and Si, the formation of intermetallic compounds were spherical and short rod-like distribution at the grain boundaries or sector, the tissue distribution of a large number of dislocations, when the rare earth content is greater than 0.3%, an existing form dominant.
In this way, regardless of the direction of grain growth, is not dominant.

The grain orientation of cold rolled high nitrogen alloy with 0% deformation is equiaxed grain with random distribution.
The grain boundary is large angle grain boundary.
It can also be seen in large angle grain boundaries (15° orientation difference or less) and small angle grain boundaries (2° or less orientation difference<15°) in Fig. 1(c)-(e).
A large number of deformation twins appear, and the width of twins will decrease with the increase of rolling deformation.
For the high nitrogen alloy with rolling deformation of 30%, a large number of micro-twins parallel to the interface are found (as shown in Fig. 2(c)).

In this model, grain size and variation in flow stress of each grain as aspect of mesoscopic material information were considered for modeling of material inhomogeneity.
In this model, grain size and variation in flow stress of each grain as aspect of mesoscopic material information were considered for modeling of material inhomogeneity.
Material Young modulus E [GPa] K value [MPa] n value e0 Average grain size dg [μm] Grain number in thickness t0/dg C1020-O 110 532 0.44 0.019 16.7 3.0 Inhomogeneous FE Material Modeling In this model, grain size and variation in flow stress of each grain as aspect of mesoscopic material information were considered for inhomogeneous FE material modeling.
For each grain, different flow stress was input.
In this model, the class k was 7 and the grain size dg was 16.7μm and the ratio of thickness to grain size t0/dg was 3 obtained from microstracture observation of pure copper foil C1020-O.

But the surface morphology in Fig.1(b) is difference from Fig.1(a), presenting elliptic ball grain instead of tetrahedron, and its grain size significantly decreases and coating surface becomes smooth.
It shows that nanoCr2O3 not only refines the grain size of pure Ni, but also changes the shape of the grain.
Current peak is also formed deprived from nucleation/grain growth under higher overpotential.
Therefore, it results in that the number of active nucleation sites which the Ni electro-deposition needs increases and the nucleation potential reduces.
Conclusions (1)The grain size of Ni-Cr2O3 composite coating is much smaller than that of the pure Ni,the Cr2O3 powder refines the grain of Ni, and also makes the coating surface smoother