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The higher hardness was attributed to fine-grained microstructures in the as-rolled CSP strips.
As CSP process has a number of its own distinct features and its products have a much difference between conventional continuous casting process products.
TEM analyses of carbide precipitation show that a large number of small carbide precipitates are distributed in the tempered specimens, as illustrated in Fig. 4.
However, for the specimen produced by CSP, carbides were precipitated not only in the matrix, but also along grain boundaries and sub-grain boundaries because it has much more boundaries owing to its ultra-fine grains.
Therefore, CSP products have more fine-grained and uniform microstructures compared with conventional process [2-5].

Table 1: Required values for the documentation of forging strokes · Timestamp · Number of pass · Number of stroke · Die length · Die radius · Length before/after stroke · Width before/after stroke · Height before/after stroke · Position of the manipulator · Rotation angle of the manipulator · Transportation time to press · Indicator for length measurement · Furnace temperature · Surface temperature The data management in FAST is split into three arrays.
During the cooling process, grain growth takes place, increasing the average austenitic grain size to about 135 µm.
At the faster cooling edges, the resulting grain size is lower.
Fig. 9: Recrystallized microstructure fractions and grain size after the 1st pass of process 1 in the core fibre of the ingot (node number corresponding to position in the workpiece) As the data in FAST is stored for every stroke in the process, a point tracking can easily be extracted from the calculated data.
It can be concluded, that some strokes are influencing the minimum grain size, others do only have a slight influence on the average grain size, which is a result of the low fraction part of the newly recrystallized grains.

The paper presents the abrasive grain motion equations, removal rate model,grinding force model and grinding force ratio model.According to the grinding force model, the grinding force will decrease as the spindle speed, vibration amplitude and vibration frequency increase.
The kinematics analysis of UAG Fig. 1 The motion model of axial ultrasonic vibration assisted grinding [2] As shown in Fig. 1, there arethree kinds of grain motion such as grinding wheel rotational circular motion,grinding wheel feed movement and the simple harmonic oscillation.Based on the UAG kinematics analysis, establish the single abrasive grain trajectory model.
x=(vw+vs)t1 (1) y=Asin(2πft1+Ø0) (2) z =R-Rcosωt1 (3) Wherevs is grinding wheel speed,t1 is grinding time of single grain, ω is grinding wheel angular velocity, vw is feed rate,f is ultrasonic frequency, R is grinding wheel radius, Ø0 is ultrasonic vibration initial phase, A is ultrasonic amplitude.According to the single abrasive grain trajectory model can get the grain trajectory curve: Fig. 2 (a) (b) (a) Grain trajectory in single rotation period of grinding wheel (b) The trajectory of single grain contact with the workpiece Assume the ultrasonic vibration initial phaseØ0=0, the trajectory length of single grain contact with material in single rotation period can be defined as follow: (4) UAG material removal rate modeling Fig. 3 Abrasive grain pressed depth Fig.3 shows pressed depth of single abrasive grain.
The depth of grain pressed into the material is ag, cone apex angle is θ, and the grain trajectory groove width Ø can be deduced as follow: (5) The cross sectional area of grain pressed into the material can be found: (6) Single grain material removal volume is defined as follow: (7) Assume that the distributing density of the dynamic grain on the wheel surface is Nds，the grain number through the dynamic grinding area in unit time is N=Ndsbvs，Whole material removal for volume in unit time can be defined as follow: (8) The average chip cross section area in AUAG is: (9) Average grain pressed depth is: (10) The grinding force modeling of UAG Fig.4 Grinding force distribution of single grain The grinding force produced by chip deformation As Fig.4 shows, agis grain average cutting depth.There is an angle Øbetweengrinding direction and OAB .The area of OAB is ds.Grinding forcedF is vertical to the conical surface
Thenwe can deduce: (12) ρis cone length, can be found: (13) Put (13) into (12),can be obtained: (14) Substitute (14) into (11),can be found: ; (15) The grinding forceof single grain: ; (16) The total grinding force: ;

In order to deform the material to a large total strain, the billet is pressed through the die a number of times, since its cross sectional area remains unchanged during ECAE.
Second, the initial grain size was smaller (200 µm) and the authors did not report the presence of recovered grains in the starting condition.
TD ED 0 10 20 30 40 50 60 70 0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.18 Number fraction Misorientation angle (deg) as-deformed 400°C for 15 min Fig. 5.
Fine equiaxed grains coexist with coarser areas where grain fragmentation is less pronounced.
The mean grain size in the deformed state is 650 nm.

Inclusions which located near the prior austenite grain boundary couldn't induce the nucleation of IAF, only the ones inside the prior austenite grain can promote IAF's growth.
Furthermore, prior austenite grain size is also an important factor affecting the nuclei of IAF [4-5].
Utilizing the intergranular ferrite which had outlined the prior austenite grains, we measured the prior austenite grain size, and the statistic histogram is shown in Fig. 5.
The size of prior austenite grain is about 50~70 micron during the three simulated weld thermal cycles.
The grain size would increase as the phase cooling time extend.

Grains induced by dynamic recrystallization are immediately included into the process of forming.
The nuclei that develop mainly at the grain boundaries are still aligned according to the basal character of the old grain [5].
Considering the area of cold forming, other effects such as the insufficient number of slip systems are predominant, which affects the general formability in a negative way.
Due to the previous deformation of structure the nucleus orientation is unlikely to cause a basal texture in the newly formed grains.
After annealing the microstructure in both layers is completely recrystallized with a slight grain growth in the center.

Fig. 2(b) indicates that the large <111> and <001> grains involve sub-grain boundaries, and some <001> grains have crytallographic orientations nearly identical to those of the neighboring <111> grains in the directions normal to extrusion.
However, the grain size and the fraction of <111> grains increased by the re-solution treatments, as shown in Table 3.
The average grain size and the fraction of <111> grains.
In T7 temper, the coarsening of η precipitates (MgZn2) occurs in grains as well as along grain boundaries, which is associated with the widening of precipitate free zones (PFZ) along grain boundaries [5].
The curves in this figure are drawn by using a phenomenological equation, sa = sao + k{(Nf/Nfo)-m - 1}, where sa and Nf are the stress amplitude and the number of cycles to failure, respectively, Nfo is a reference number of cycles (=107 cycles in the present analysis), sao is the fatigue strength at Nfo, and k and m are constants [3].

Due to the f(amin) represents the number of the boxes of the same maximum height probability (NPmax(e) = Namin(e) ~ e--f(amin)), while f(amax) reflects the number of the minimum one (NPmin(e) = Namax(e) ~ e--f(amax)), the Df describes the ratio of the number of the maximum probability and that of the minimum one: NPmax(e)/NPmin(e) = e -Df.
Experimental results indicate that the number of lowest valleys of all HfO2 films is larger than that of the highest peaks (at e = 1/512, NHmax/ NHmin » 3, 77, 11, 29 for HfO2 grown at RT, 200 oC, 400 oC and 600 oC, respectively).
The grain sizes become larger with the increasing temperature.
As listed in table1, it is important to recognize that d spacing (d-111) decreases with increasing grain size below 7 nm, but becomes larger with grain size of 14.8 nm.
Fig.3 (b) also shows the relationship of Da and the grain size of HfO2 films.

That Allows MH grain nucleation rate is less than the growth rate, Larger MH grain generated in system.
At this time, the nucleation rate is greater than the growth rate, a large number of fine grain were generated, it lead to the grain reunion in the solution and make the size bigger.
With higher temperature, ion activity increase further, a large number of fine grains were generated in the solution, lead to a serious of particle aggregation occurred.
Speed of NaOH precipitation reaction is quickly, generate a large number of slow growth microcrystalline in short time.
Long carbon chains of SDS easily adsorbed on MH surface, thus prevented the bulky hydrated Mg2+ ions enter grain zone to grow.

The precipitation occurs at not only grain boundaries but also twin grain boundaries in the experimental steel.
The grain boundaries are clean, straight and thin.
This can be considered as follows: Large numbers of defects exist in material after cold deformation.
Cold deformation may cause dislocation pile-up at grain boundaries, and increase the distortion energy of grain boundaries, which can nucleate σ phase at grain boundaries and defect microstructures (deformation twin and slip band) accelerate the precipitation of σ phase inside grain.
The precipitation occurs at not only grain boundaries but also twin grain boundaries in cold-deformed Fe-18Cr-12Mn-0.48N steel