Search results

With the increasing of quenching temperature,the grain grows,the impact property is decreased.
Compared to the original sample and the subcritical quenching sample, in addition to differences in organizational, the grain size of its size, the degree of dispersion of various other phases have undergone great changes.
And the tempered martensite can be clearly seen from a former into a plurality of grains.
At a temperature of 950 ℃, Compared with non- temperature quenching samples, although its organization exists in the grain size decreasing trend but there is a substantial degree of uniformity improvement,as shown in Fig 3(c),4(c) and 5(c).
(c) (b) (a) Fig.5 Original sample and subcritical quenching sample crystalline phase organization chart × 1000 (a Original sample b 910℃ quenched sample c 950℃ quenched sample) 3.2 Mechanical properties and hardness results Table2 The effect of quenching temperature on the mechanical properties of EH36 number Normalizing process Yield strength Rel/MPa Tensile strength Rm/MPa Elongati-on A/% -40℃ impact energy AKV/J hardness（HRC) Grain size scale A TMCP 385.2 541.1 22.7 56.5 36.8 9 B 910℃quenched samples 372.1 510.4 35.5 72 63.1 10.5 C 950℃quenched samples 380.6 515.3 35.2 70 53.5 10 The tensile tests,impact tests and hardness tests on original samples and subcritical quenching asmples were done,the average test data was shown in table2.

· Eutectoid steels at clean austenite grain boundaries follow the Pitsch-Petch OR-RS between cementite and ferrite.
Orientation relationships: · Isaichev: (101)q//(112)α, [010]q//[111]α · Bagaryatskii: (001)q//(211)α, [100]q//[0-11]α, [010]q//[1-1-1]α · Pitsch-Petch: (001)q//(5-2-1)α, [100]q 2-3º[13-1]α, [010]q 2-3º[113]α Note: numbers in () denote planes of the crystal structures and number in [] denote crystallographic directions.
(d) shows cementite associated with alumina grains in the clogging deposit.
Figure 2 displays the phases present in the three pearlite islands measured and the different grain boundaries.
Black boundaries are fulfilling the Pitsch-Petch orientation relationship and blue are high angle grain boundaries. 4.

Species and yield At maturity, each treatment was investigated for amount of valid spikes, spike length, fruit rate, weight of 1000 grains and total weight of grains.
In the whole growth period, tillers number for drought treatment in heading stage or milky maturity stage was very close to CK (Fig. 3d and Fig. 3e).
Fig 3 Change process of the tillers number of each treatment and plant height of CK Effects of soil moisture potential controlling on rice quality The rice quality of each treatment was determined by Grain analyzer Infratec 1241 and Presentation-quality rice discriminant ES-1000.
In addition, water stress lowered the rate of brown rice, reduced the content of amylose and free fatty acid, increased the percentage of chalky grains and chalkiness degree, but had no significant effects on grain length and grain width.
The results obtained by some scholars [15] also believe that water stress had little effect on the grain shape, but increased the percentage of chalky grains and chalkiness degree, then damaged the appearance quality of rice.

Annealing at higher temperatures results in grain growth.
However in some cases, the grain growth was retarded [7] whereas in other was enhanced [8].
The first micro-grained material was obtained by a conventional plastic forming, whereas the nano-grained via HE.
This recrystallization has a discontinuous character with subgrains at the primary grain boundaries and in the most deformed areas inside primary grains.
TEM images of austenitic steel 316 LVM in as-received state and annealed at 800°C/1h a) and after HE and annealing at 800°C b), numbers indicate the boundary misorientations in degrees a) b) Fig. 7.

At the same time, it also plays a role in grain refinement to some extent.
When the molybdenum content is small (Fig. 2, (a)), abnormal grain growth was found, and the thickness in the rim phase of some abnormal growth grains is large.
While molybdenum was added in the form of pure metallic powder, the grain size distribution was wide although the size of some grains was relatively small.
The number of the irregular shape grains increased and the number of round grains was small.
Effect of carbide additions on grain growth in TiC-Ni cermets[J].

The α-lamellae cluster and the original β grain precipitate in the form of 30°/60° and form the original β - grain boundary.
The average number of grain boundary Angle is 45° in the horizontal plane specimens, which maximum grain degrees recorded is 61° constitutes 36.9% of the number fraction.
The average number of grain boundary Angle is 54° in the horizontal plane specimens, which maximum grain degrees recorded is 61° constitutes 46% of the number fraction.
The grains are α grains with the axis of [α.
The original β-grains grow along the deposition direction, and α-lamellae precipitate at 30°/60° along the β-grain boundary There are cross arranged α-lamellae in the original β-grains

Modeling of single grain grinding force The grain shape on the wheel surface is assumed to be a spherical shape.
Modeling of heat flux distribution Number of grains per unit area Ns, probability density functions of grain diameter f(x) and grain protrusion height P(x) were derived in Ref. [5].
They are expressed as: (2) (3) (4) where ω is grain density, dgx is grain diameter, x is given by x= dgx-dmean, dmean is the mean grain diameter, given by dmean=(dmean+dmean)/2, dmin and dmax are the minimum and maximum grain diameters respectively, h is grain protrusion height, hmean is the mean grain protrusion height, given by hmean=(hmean+hmean)/2, hmin and hmax are the minimum and maximum grain protrusion heights respectively.
The number of grains in each segment can be calculated from NΔ=Ns·b·Δl. h0 is defined as the minimum protrusion height of the grain, which is just contact with workpiece at position l, given by h0=hmin+hcul,max.
Statistical Calculations of Grinding Abrasive Number Based on Normal Distribution[J].

It is assumed that diffusing atoms may visit many grains and grain boundaries during a diffusion experiment Type A Kinetics Regime [9].
Smoluchowski, Theory of Grain Boundary Diffusion, Phys.
Herzig, Grain boundary diffusion: recent progress and future research, Mat.
Gust, Grain boundary diffusion: fundamentals to recent developments, Int.
Dillon, Scaling effects on grain boundary diffusivity; Au in Cu, Acta Mater. 61 (2013) 1851-1861

.%), experienced notable grain refinement.
Notably, grain refinement was enhanced significantly, reducing the average grain size of δ-ferrite from 46.3 µm in the as-cast state to 9.3 µm after forging.
In 353-steel, the number density of inclusions differs between as-cast and forged samples.
The fraction of AlN is relatively small in the number density graph but increases in the area fraction graph.
Number density and area fraction of different types of inclusions in the studied steels.

The extrusion die is designed to create additional material deformation to a defined depth, resulting in a gradient from ultra-fine grained to coarse grained microstructure.
In the near-surface area an ECAP channel is assumed with several consecutive ECAP-steps which are numbered 1 to 8.
A grain size larger than 50 µm can be observed.
Sub-structuring and reorientation of the grain can be detected.
Furthermore fragments with grain sizes larger than 10 µm can be observed.