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The rough criteria for distinguishing short crack (affected by notch root radius) and long crack in the notches with 60° angle has been proposed.
The mechanical properties are listed in Tab. 2.
Table 1 Chemical composition of spring steel Element C Si Mn Cr Ni Mo V Cu P S % wieght 0.44 0.28 0.56 0.87 1.41 0.26 0.11 0.12 0.009 0.002 Table 2 Mechanical properties of spring steel UTS Rm [MPa] Yield strength Rp0,2 [MPa] Torsion limit τe [MPa] Shear modulus G [GPa] Modulus E [GPa] Hardness HRc 2010 1570 800 75 193 52 - 55 Material for specimens were prepared at the same technological procedure as regular spring production.
Therefore, in order to compare equivalent stress intensity factors by using Eq.(1) we used only torque M5=238.67 Nm.
The rough criteria for distinguishing short crack (affected by notch root radius) and long crack in the notches with 60° angle has been proposed.

Mechanical properties Tensile test at room temperature was conducted on SANS WE600 hydraulic universal test machine, the results of which were shown in Table. 3.
It was obvious that, ①the mechanical properties of two steels tested both met the requirements, with a large strength surplus; ②the elongation of 2# steel was larger than 1# steel.
The mainly factors affecting the yield strength of steels were as follows [3]: large precipitation, inclusion, band shaped structure, the content of pearlite, the size and homogeneity of grain, and steel surface condition.
Large precipitation of liquid chromatography TiN formed in steel led to local stress concentration, becoming nucleation resources, thereby resulting in a decrease of mechanical properties.
The mechanical properties of both two steels met the requirements.

These requirements are mechanical properties, physical properties and as well as chemical stability and adhesion of protective coating to substrate.
Quantitative metallography is used for structure and mechanical properties relation evaluation [3, 4].
The surface corrosion products, oxide phases, penetrate deep into coating and affecting of outside mechanical loading was ripped out.
The degradation is caused with highest temperature and mechanical factors on this particulate area.
Vaško, Analysis of the factors influencing microstructure and mechanical properties of austempered ductile iron, Communications, 11, No. 4, (2009) 43-47

Effect of Annealing Temperature on Mechanical Properties of Cold Drawn Pearlitic Steel Wires Won Jong Nam 1,a, Hyung Rak Song1 and Kyung Tae Park 2,b 1 Department of Advanced Materials Engineering, Kookmin University, Seoul, Korea 2 Department of Materials Science and Engineering, Hanbat University, Daejeon, Korea awjnam@kookmin.ac.kr, b ktpark@hanbat.ac.kr Keywords: annealing, wire drawing, pearlite, cementite, steel Abstract.
The effects of annealing temperature and annealing time on mechanical properties of cold drawn pearlitic steel wires containing 0.84wt% of silicon were investigated.
In this work, it is attempted to investigate the effects of annealing temperature and annealing time on mechanical properties in cold drawn high carbon steel wires containing 0.84wt%Si.
Thus, the strain age hardening and the age softening are main factors to control tensile strength of annealed steel wires.
Summary The effects of annealing temperature and annealing time on mechanical properties of cold drawn pearlitic steel wires containing 0.84wt% of silicon were investigated.

High-speed high-precision CNC processing technology plays a very important position in the CNC machining industry,machine disturbance,however,an important factor affecting the machining accuracy,the ball screw feed drive as an important part of the machine directly affects the operating characteristics of the machine.Ball screw drive system,Solidworks,Ansys,Adams the establishment of machine tool,rigid-flexible couping the multibody dynamics model,the dynamic characteristic curve of the machine.Compared with the rigid body model simulation results verify the feasibility of rigid-flexible coupling modeling method,optimized to provide the basis of the structural design of the machine components.
In fact, due to their material properties, as well as the influence of the coupling mode, mechanism often have a certain flexibility which will affect the dynamic characteristics of the element, to produce the noise and vibration.
(2)Define the entity model unit type, material properties, real constants meshing, and the establishment of a flexible body and rigid body coupling at the interface nodes point.
Figure 8 , transmission speed of workbench is uniform in the process of movement, but the drive components due to deformation appear go fast or go slow and jump movement .Thereby affecting the smooth machine tools processing and machining accuracy.
Mechanical Engineering and Automation, Vol.3 (2009),p.37-39,(In Chinese)

Residual stresses generated in milling process affect the performance of machined components.
The chemical composition and the mechanical properties of the material are presented in Table 1 and Table 2, respectively.
In the cutting speed region from 300~1500mm/min, the dominative factor which affects the surface residual stress is changing due to the temperature increasing, that is, from the mechanical loading in the low speed cutting to the thermal loading in higher cutting speed.
(2) The dominative factor affects surface residual stresses is changing from the mechanical loading to thermal during the cutting speed range 300~1500mm/min.
(4) The observed residual stresses values show that the residual stresses in both the feed direction and the normal direction are generated in the milling process and their properties and values are almost the same.

In this case, the criterion parameters of the deformation and strength of structural materials are such standard characteristics of the mechanical properties of the material as elastic modulus E, yield strength σт and tensile strength σв.
(1) As the basic characteristics of the mechanical properties, the yield strength sT, the tensile strength sB, the endurance limit витривалості s-1, the long-term strength sls, the tensile strength Sк, the ultimate ductility yк, the critical stress intensity factors KIc and KIec deformations are used: (2) Derivatives of mechanical properties, structural forms and loading conditions are such material characteristics as long-term ductility yкt,, effective stress concentration factors Ks, sensitivity to absolute sizes es and cycle asymmetry ys, coefficient of variation us, crack growth rate dl/dN in the number of cycles and dN/dt in time, sensitivity to the external environment bс.
In some cases, to establish the distribution curves of the basic characteristics of the mechanical properties sB, yк, s-1, sls, tests were carried out from 10 to 2000 samples in one of the load conditions.
This crack growth is determined by their velocities dl/dN, dl/dt, which in turn depend on the magnitude of the stress intensity factors DKI or deformations DKIe.
and their dose loads affecting people and other objects of the biosphere: R3 – the probability that these levels of fields and loads will lead to certain damage.

Previous studies only show the individual impact of these concrete recycled materials on mechanical and durability properties.
The experiments were carried out to test mechanical properties like compressive, tensile and flexural strengths by mixing constituent materials of concrete in a mechanical mixer.
Material and Mixture properties.
Mechanical and durability properties of recycled aggregate concrete with ternary binder system and optimized mix pr. 
Abrasion resistance and mechanical properties of Roller Compacted Concrete with GGBS. 

This may affect the mechanical property, corrosion sensitivity and other service properties.
If these are not controlled, weldment may develop unweldly structural and mechanical properties that may lead to failure.
This leads to poor mechanical property in the welds [11].
All other factors being equal, as carbon content increases so does the difficulty in weldability.
A.: Effect of Preheat and Postweld Thermal Treatment on the Mechanical Properties of Ni/Cr Steel Weldment.

Physical-Chemical Properties of Molybdenum Films Prepared with Magnetron Sputtering N.A.
The causes that lower protective properties of the coating and lead to the penetration of HF solution can be divided into the following groups: 1) External factors (quality of the preparation and substrate roughness); 2) Physical and mechanical parameters of the film (especially the structure and thickness of the coating, mechanical stress).
Protective coating properties also depend on its structure.
The question of the coating thickness influence on its protective properties requires more detailed studies.
The data indicate the existence of additional factors, which lead to pinhole formation on the glass surface.