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This procedure allows for consideration of the fine morphological features of the scale and the scale/metal interface while, at the same time, reducing the number of elements under consideration.
Assuming potential inclusion of the grain structure of the oxide scale, lubrication, generation of abrasive particles into the system, mechanical intermixing at the sub-surface layers, etc., application of traditional finite element techniques for modelling of these micro- events all at the same time becomes impossible.
Tangential viscous sliding of the oxide scale on the metal surface is allowed, arising from the shear stress transmitted from the specimen to the scale in an analogous manner to grain-boundary sliding in high-temperature creep.
Determination of the crack length is based on increment number and deactivation of the separation forces based on the crack length and J-integral value.

Introduction The rapid development of die casting production for the automotive, motorcycle large number of parts and components to provide an economical and efficient production methods.
With the number of cycles increases, the crack tip near the small hole and gradually formed micro-cracks, and began to merge to form the main crack, the crack continues to expand, and finally the formation of cracks between the interconnected network of cracks caused by mold-like failure.
Thus reducing the temperature cycle amplitude, increased material strength and toughness of die-casting mold to form the surface compressive stress, may postpone or delay the thermal fatigue crack formation and expansion, from the microscopic analysis, thermal fatigue cracks in the grain boundary carbides often, the initiation of clusters of inclusions Therefore steel clean, uniform microstructure of high-quality hot work die steel with high thermal fatigue resistance.
Methods to improve the life of die-casting mold Casting design.asting over the internal organization of thick coarse grains, the formation of pores, shrinkage, oxidation, internal cracks, and is accompanied by stress generation sources, so its strength and durability performance may be lower than secondary structure formation stiffener products.

Steel grade Yield strength, MPa Tensile strength, MPa Elongation at fracture, % Impact energy at -40 °C, J/cm2 S900 DQ 900 950 8 34 S960 DQ 960 1000 7 34 S1100 DQ 1100 1250 6 34 (tested at -20 °C) 1Tensile strength, 2Elongation to fracture with a proportional gauge length, 3Charpy V impact toughness Metallurgy of Direct-Quenched Structural Steels and Mechanisms behind the enhanced properties Typical prior austenite grain (PAG) structures of a direct quenched S960 grade steel are shown in Figure 2 a.
Patent Number US 6,2840,63.
Patent Number EP1375694 (A1), 1.2.2004
Kömi D.A Porter, Effect of austenite grain structure on the strength and toughness of direct-quenched martensite.

Face Overview Wangxingzhuang coal mine main mining 21 and 23 coal seam,the two layer distance of about 20m,  average thickness1.3m of 23  coal seam , thin, gas content relatively low, the danger of coal and gas outburst is low. 23 coal seam can be mined first as the upper protective laye of 21 coal seam.11053 face as upper protective layer face, 11051 face as the protected face.Upper protective seam face 11053 consists of fine-grained sandstone and mudstone, the floor is sandy mudstone, face of monoclinal structure, dip angle of coal seam is 8~20 °, 14 ° on average, coal seam thickness is 0.35~16.9m, average 1.3m,simple coal seam structure. 1051 face of the down 11053 is protected layer ,coal seam thickness 2.67m ~11.35m, the average thickness 4.5m, dip angle of coal seam 14° to 24°,the average is 19 °, the direction of the face is about 1497m long, 150 m long tendency.
Tab.1 Physical and mechanical property of rock Rock types Thickness /m Compressive strength /MPa Modulus of elasticity/ GPa Poisson's ratio/µ Density /g/cm3 Medium-grained Sandstone 6.92 79.94 44 0.16 2.64 Sandy mudstone 5.29 56.08 27 0.2 2.62 Mudstone 4.73 27.46 18.7 0.2 2.59 23 coal 1.3 15 9 0.3 1.28 Sandy mudstone 7.26 56.08 27 0.2 2.01 Big accounting Sandstone 10.62 78.38 36 0.25 2.64 Mudstone 1.09 27.46 18.7 0.2 2.59 21 coal 5.2 15 9 0.3 1.35 Mudstone 4.7 27.46 18.7 0.2 2.59 Sandy mudstone 3.26 56.08 27 0.2 2.62 L8 limestone 4.42 30 19 0.25 2.6 18 coal 0.3 15 9 0.3 1.36 mudstone 1.05 27.46 18.7 0.2 2.59 L7 limestone 4.98 30 25 0.2 2.61 The acoustic emission with working face advancing changes to study the deformation and failure of coal and rock mass.
When working face mining 10 m, less number of acoustic emission, cracks and elastic deformation is not obvious; When working face mining 25 m, acoustic emission frequency increases, the fracture increased obviously, in the eyes and face a stress concentration phenomenon; 40 m working face mining, the acoustic emission generated is wider; Firstly 50 m, overburden bending expanded; Mining face 70 m, bending subsidence zone further, extends to the 23 coal above 75 m far, downward influence to 21 coal below.
Number of acoustic emission in the excavation of 2, 5, 8, 10, 14, when the step is more, the mining face 5 m, 25 m, 40 m and 50 m and 70 m.

In principle, elemental concentrations are derived from the intensity ratios (K) of characteristic X-rays generated from the unknown and standard samples by incorporating atomic number (Z), absorption (A) and fluorescence (F) corrections..
The microstructure in this region exhibited considerable decarburization, large ferrite grain size and numerous dark-grey globules dispersed in the ferrite matrix.
Fig. 6: Microstructure of hot-rolled low-carbon steel sheet with edge-cracks (a) cracked edge showing decarburized ferritic region, large ferrite grain size and numerous darkgrey FeO globules (b) region away from crack end showing normal ferrite-pearlite structure; 500X.
Microstructural examination at 500X magnification [Fig.9(c)] revealed an acicular phase around the centre-line crack; the microhardness of this acicular phase was found to be 608 VPN (Vickers Pyramid Number) and was indicative of martensite.

Vanadium strengthens the steel and assists with grain refinement during heat treatment processes [1].
Mintz determined the free nitrogen content of a large number of plain carbon steels using specialised chemical analysis and developed the chart shown in Fig 1.
Fig 1 - Relationship between ∆Y and the free nitrogen content in the steel [6] Relationship between ∆∆∆∆Y and the V/N ratio A strain ageing analysis on 5.5mm rod from a number of heats of wire grade vanadium steel was undertaken to investigate the relationship between ∆Y and the V/N ratio.
The microstructure of the current steels was 80% pearlite, with the remaining 20% ferrite outlining the prior austenite grain boundaries (Fig's 6,7).

In addition, the corrosion performances depend upon a large number of factors, including the basic metal composition [6,10], environmental conditions [11], experimental process [12], and so on, which lead to difference among the rust formation mechanism, rust evolution process and rust layers.
The prior austenite grain boundary of R4 is obscure, while that of R5 is clearer due to maintaining the orientation of original martensite.
This region is thought to be the lath boundary or grain boundary.
After being amended by 18(C32+), 24(C2+), 36(C3+), the number of C is revealed in Total and atom fraction is recalculated.

Distributed localization algorithms [4], l Fine-grained v.
Coarse-grained localization algorithms [5] , l Physical v.
When an unknown node receives beacon message for a large number of anchor nodes, FTPL handle the case too simple by overlying these different circles. 4.
After large number of experiments, we found FTPL-3D-F is not always better than FTPL-3D.

A micrographic control of the grain size and distribution of the precipitates (not presented here) showed that the majority of the grains had a size varying between 75 to 210 µm with a precipitate distribution rather homogeneous.
Particle diameter / µm 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 Number of particles 0 2 4 6 8 10 12 14 Time / min 0 200 400 600 800 1000 1200 1400 1600 Specific weight gain / mg.cm2 0.00 0.05 0.10 0.15 0.20 0.25 0.30 Thickness / µm 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 T = 470°C P(O2) = 150 mbar Fig. 2.
Counting particles by image analysis of each PEC image detected a number of precipitates on a volume of 250 000 x ξ µm 3 (where ξ was the thickness of the scale).

Table 2 The basic properties of the shale ceramsite concrete Grain shape Packing density Apparent density Water absorption rate at1h Grain diameter Cylindrical compress strength Macadam 802kg/m3 1396kg/m3 4% 10~26 mm 3.4Mp Fine aggregate: natural river sand from a sand field in Kaifu District, Changsha.
Table 3 The mixing ratio of the shale ceramsite concrete Number Water absorption Time(h) Weight of ceramsite (kg) Weight of cement (kg) Weight of sand (kg) Weight of water (kg) S1 24 520 450 844.7 180 S2 24 520 400 844.7 180 S3 1 478 450 844.7 180 Experiment Scheme Test Specimens Formation and Maintenance.
The hidden layer adopts the trial method to ensure the number of neurons.