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Ni-based alloy welding material has been widely used in the welding and post-welding repair of high-temperature materials. The effect of temperature on the cyclic stress amplitude of ENiCrFe-1 Ni-base alloy electrode was studied under the same strain condition. The results showed that when the temperature was lower than 400 °C, it presented the characteristics of cyclic hardening and then cyclic softening. When the temperature was higher than 500 °C, it presented the characteristics of cyclic hardening and then cyclic stability. The main reason is that with the temperature increase, the dislocation structure changed more and more stable. The results not only enrich the internal mechanism of fatigue behavior of nickel-based alloy welding materials, but also have important reference value for improving the structural safety of welded joints.

In recent years, the oil and gas well casing is confronted with more complex service environment, and the casing is subjected to higher service load and temperature. In this study, the strength and plasticity of Cr - Mo low alloy casing steel of 80, 90 and 110 steel grades commonly used under high temperature service conditions was studied. The results show that with the increase of temperature, the yield strength and tensile strength of casing steel decreased. The sensitivity of high steel grade to temperature change was higher than that of lower steel grade; with the increase of steel grade, the fracture mechanism of casing steel changed from microporous polymerization fracture induced by large size second phase particles to shear propagation fracture induced by sub grain boundary microporous polymerization. This study has important guiding significance for the service safety and strain design of high grade steel under high temperature conditions.

During heavy oil production, the performance of casing varies with temperature in the service environment. The tensile test of N80Q Steel and 80SH Steel were carried out to evaluate the mechanical properties during the service. The results indicated that the grain size of 80SH steel was relatively uniform and the grain boundary was relatively obvious compared with N80Q steel. A qualitative analysis was performance by relating the tensile properties with different temperature. The results showed that the yield strength, the tensile strength and elongation of N80Q and 80SH steels decreased with increasing temperature, but the degree of decline was limited. The observation of the tensile fracture revealed that the characteristics of the radiation zone of N80Q steel were obvious compared with 80SH steel at 20°C.

The main exploitation process of heavy oil is cyclic steam huff and puff. Cyclic operation causes cumulative damage to thermal recovery casing and causes a large number of failures. Failure analysis shows that the main failure factor of thermal recovery casing is the low cycle fatigue process caused by thermal cycle, which results in the decrease of strength of casing material, thus causing casing fracture and failure. Based on the failure analysis results, the low cycle fatigue tests of 80SH thermal recovery casing steel under different temperature, strain, pre-strain and other conditions were carried out. The influencing factors, life prediction model and criterion of service safety of casing materials under thermal recovery service conditions were first proposed, which provides a strong theoretical basis for the service safety design theory of thermal recovery casing materials. The research shows that the strain limit and low cycle fatigue life are the two core issues of service life. Life predictions need to satisfy two criteria. The first is the strain criterion. The strain limit should be lower than the total strain during the long service life. And the second is the low cycle fatigue criterion, which satisfies the expectation of low cycle fatigue life under double conditions of strain amplitude and mean strain.

The service conditions of thermal recovery wells make the casing repeatedly bear the tension and compression load and form low cycle fatigue. Meanwhile, many factors, such as pre-strain and creep, lead to the formation of asymmetrical low cycle fatigue (R≠-1), which is the low cycle fatigue behavior under the influence of mean strain. This work studied the effect of mean strain on low cycle fatigue behavior of N80Q steel. Different strain amplitude conditions were selected for low cycle fatigue test, which were 0.5%, 0.7%, 1.0%, 1.5% and 2.0% respectively. Then tests at mean strains of-0.8%, 0%, 0.5% and 1.0% were conducted under constant strain amplitude. And the microstructure and fracture surface of the material after the tests were characterized using scanning electron microscopy and transmission electron microscopy, respectively. The results show that the mean strain makes the fatigue life reduce significantly under the condition of constant strain amplitude, and is related to the amplitude of the mean strain. The value of the mean strain and the strain amplitude will ultimately affect the fatigue life. And the fatigue life is related to the maximum absolute value of strain and has a linear relationship in the double logarithmic coordinate system. The SEM results of fracture morphology show that the brittleness feature of the crack growth area with high mean strain decreases significantly. And the fracture cross-section observation shows that the crack propagation is transgranular propagation. The TEM results show that a large number of dislocations pile-up is formed at lath subgrain boundary.

Enantioselective partitioning of racemic omeprazole enantiomers was studied using a biphasic recognition chiral extraction system. Hydrophilic hydroxypropyl-ڂ-cyclodextrin in aqueous phase and hydrophobic D-tartaric acid hexyl ester in organic phase as chiral selectors which preferentially recognize (R)-omeprazole enantiomer and (S)-omeprazole enantiomer, respectively. Different experimental variable parameters could affect the chiral extraction efficiency. The largest distribution coefficientskS,kRand separation factorځwere obtained at concentrations o f 0.1 mol/L HP-ڂ-CD and 0.2 mol/L D-tartaric acid hexyl ester, which were 47.38, 58.65 and 1.24, respectively.kRis always larger thankSwhen using different kinds of tartaric acid derivatives as chiral selectors in organic phase. The present study also reveal the mechanism of biphasic recognition chiral extraction forR,S-omeprazole enantiomers.

This paper summarizes the land-use experience of the major international airports at home and abroad. First of all, the paper studies the regular pattern of the major international airports at home and abroad land-use on total amount and land using area on every unit. Secondly, the paper summarizes the experience on runway amount of the airport, and studies passenger amount that a single independent runway can carry and how many times the plane can take off and land. On the basis of above experience, the paper brings forward some inspiration about land-use and runway layout.

After processed the signals obtained from monitoring system, one theory of condition evaluation was proposed on basis of a new evaluation parameter—index variation. One new condition grade division method was proposed from approximate statistic distribution of index variation, and as per the concept of confidence degree and confidence interval. Because the monitoring data and the standard of condition grade division were all interval numbers, interval extension evaluation theory was adopted to establish the model of condition evaluation. Set-Valued Statistics and gravity center based decision theory were introduced to divide weight into subjective weight and objective weight to make calculation. This evaluation method was found to be reasonable and had good project practicability.

Aiming at the phenomenon that the production line of the strip steel’s detection is fast speed and detection quantity of data is large, which are difficult for worker to detect on line, we put forward a detecting system on defect area of the strip steel’s surface. Using CCD camera regularly to collect the images of the strip steel’s surface and to reflect it back to the detecting device on defect of the strip steel’s surface, and adopting specific arithmetic to analyze and handle images, what can accurately sound a warning while it detects the defected image. It is convenient for worker to take corresponding measures right away. This system has simple structure, low cost, and high defect detection rate, which has the great promotional value.

Emergency evacuation is an important issue in fire safety. In this study, a cellular automaton (CA) model in which the human behaviour termed ‘flow with the stream’ is considered is proposed to simulate the procedure of emergency evacuation. Based on the CA model, the influence of the number of guiders to the evacuation from a large compartment is analyzed through numerical test. The result shows that the proposed CA model is a promising tool that may be used in fire safety design.

Each related index was compared in three specifications, including Fundamental code for design on railway bridge and culvert, Code for rating existing railway bridges, and Code for design of high speed railway. The reasons of the difference existed in indexes was revealed, especially between high speed railway bridge and normal speed railway bridge.

In order to filter the impulse noise existing in the weld surface defect images, the traditional median filtering will dim image, even destroy some details in the image, We put forward a new filtering algorithm based on dual threshold Criterion. This way distinguishes the noise point and signal location in the first, and it only doing median filter to the noise point. Lastly, it solves the image’s boundary. We can find it when compared to the traditional median filtering and modified extremum median filtering, the way in this article can be good for filtration, and can keep the image’s details, which have obvious advantage.

The disturbance phenomena and its characteristics of electromagnetic field are studied in this paper, based on the observational data in satellite and ground station during the magnetic storm occurred from 21 to 23 July, 2009. The results showed that: (1) the synchronous disturbances are seen from the two kinds of electromagnetic data in the same magnetic storm, especially during the active phase. (2)The disturbances performance are different: from electromagnetic data of revisited orbit in satellite, the disturbances of storm and non-storm are distinguished effectively in the main phase stage; the evolution trend of magnetic storm can be found from the data of continuous orbit. The geoelectric and geomagnetism data is a time sequence for a fixed location, therefore the full evolution of magnetic storm can be reflected. (3) The features and advantages of the two kinds data can play a better role, if they are comprehensive applied.

Because the fusion rules which are based on coefficient of a single point and coefficient of region has one-sidedness and are easy to make blending images lack fidelity, a new fusion rule is put forward. When this fusion rule fuses the low frequency sub-band resolved by wavelet method, it adequately consider the local areas regional energy and the regional energys similarity of the image which is need to fuse, and it use threshold to choose appropriate fusion rule. Experimental result indicated that this way can preferably keep detail features of the image, and it has some engineering application value.

Concrete strength theory under complex stress is mostly expressed by stress. However, the destruction of concrete depends mainly on strain; failure criterion based on strain space can essentially describe the failure mechanism of concrete. It is also the basis for concrete constitutive strain space. This paper studies the strength failure criterion based on strain space and proposes directions for future research, which has guiding significance for theoretical research.

In the actual structure, the concrete materials are mainly in multi-axial stress state. Because of the rapid development of concrete structures and the continuous improvement of structural engineering analysis theory, engineers have put forward higher requirements for concrete performance under multi-axial stress research. Based on stress space, this paper studies strength failure criterion of concrete, analyzed its limitations, and proposed concrete strength failure criterion research directions. It plays a strong practical role in scientific research.

A 3-D thermal-mechanical model was built to simulate the hot rolling process of medium plate, with the aid of nonlinear commercial FE code MSC.SuperForm on a company's actual process parameters. The hot rolling process of single-pass which slab thickness is 180mm was simulated, and the influence of pass reduction on metal flow, stress-strain field, contact stress and rolling force were researched. The study revealed that pass reduction should be at least 20% by increase depress in pass in addition to rolling efficiency. As that, rolling efficiency be increased, roll contact stress be brought down, and its service life be prolonged. And metal plastic strain enhanced, metal flow increased, but its strain field non-uniformly distributed, metal flow and plastic deformation would be strengthen by increase pass reduction, and the lateral broadening in the head is bigger than that in the tail.

In the light of the shortcoming that gears traditional measurement methods not only consume time and labor, but also have a great contrived factor, a new methods of total accumulative pitch errors measurement based on the coordination measurement machine is put forward, which can scan tooth profile coordinates automatically and quickly within the effective work scope of tooth profile, conduct the data processing directly and obtain the deviation through the involutes deviation to achieve online measurements. The theoretical analysis and experimental results show that the measurement method has many advantages, such as simple, non-contact and efficient.

The kind and extent of defect can be identified through image processing. First, the weld defect detection device should be constructed, and then the defect imaged should be obtained through rational way, in order to enhance the image quality, image filter and image enhancement method should be use. To ensure the real-time system, the weld region need to segment from the image. After that, the needed defect features need to determine and extract. Finally, the kind, the location and the size of the defect can be defined.

In the conditions of rationally selecting of the measure tooth number, this paper puts forward a new method to calculate the common normal length variation, which is based on coordinate measurement machine to collect the data of bilateral modification gear's outline. Firstly, the addendum modification coefficient and tangential modification coefficient are used to determine the optimum measure tooth number, and then the common normal length variation is determined according to the definition. The experiment has shown that this way has a lot of advantages, such as the intensive data of sample points, less human intervention and high measurement accuracy.

There is a set of 6 degrees of freedom (6-DOF) loading system with the simulated border for the application of material structural strength and reliability tests. This is a novel equipment for the tests of structural mechanical properties and reliability in different materials. This study showed a three-dimensional structure model, introduced the definition of the test of the 6-DOF loading system with the simulated border, and discussed the primary theory of the system and technical performance. Based on the matrix of direction cosine of the system, the solutions of inverse kinematics of 6-DOF loading system were given. The system of control was introduced as well.

The structure of a 3-DOF parallel manipulator is presented. The methodologies of multiple-mode negative impulses input shaping is introduced, which can decrease the delay time of the system response while the residual vibration is suppressed. The parameters of two-mode negative impulses and positive impulses input shapers of the 3-DOF manipulator are presented. The sensitivity analysis of these input shapers are carried out through numerical simulations, and the robust of the input shapers are presented and compared.

A variable gear measuring method was put forward in order to define the error of eccentricity of the zero-tooth-difference internal gear, which was based on the three-coordinate measuring machine. This method can scan the coordinate of tooth profile automatically and fleetly, then by calculating the difference of the tooth profile curve between the theory and reality, and achieving the measure on line about geared ring radial runout to define the error of eccentricity. The results of this experiment and theoretic analysis showed that the method which was putted forward has many advantages, like the density of sampling is big, the calculation is simple, the measure is accurate, and the human factors are very little.

The methodologies and application of multiple-mode negative impulses input shaping of a 3-DOF parallel manipulator with flexible intermediate linkages are presented in this paper. First, the structural system and the dynamic equations are expressed for a 3-DOF manipulator. Second, the multiple-mode negative impulses input shaping is introduced to reduce the residual vibration of the multiple-mode system and decrease the delay time of the system response at the same time. Finally, the theory of the multiple-mode ZV, ZVD and EI negative impulses input shapers are presented, and the two-mode negative impulses input shapers of a 3-DOF manipulator are established and compared with the positive impulses input shapers.

To prepare shape-stabilized phase change material applicable in digester insulation, firstly to prepare composite phase change material by sol-gel method. Shape material was obtained by sol-gel with TEOS, in which phase change material was lauric acid/cetyl alcohol binary eutectic phase change materials. T he result s showed that the descending order of the influencing factors: ester-PCM ratio, ester -water ratio, pH, the react ion temperature, aging temperature. The best technology is: the ester -water ratio1:8, ester-PCM ratio1:2.3, pH3, aging temperature 85°C, the react ion temperature 60°C. When composite phase change material was prepared with the best technology, phase transition temperature of composite phase change material is 34°C, phase change enthalpy can reach 122.4J/g when the mass fraction of phase change material is 64%.

Double field detection method can effectively solve missing detection and mistake detection problems. But because the image data is two times as single field detection, and therefore the detection speed is slow. A new Processing flow is put forward. Firstly, the suspected defect images are filtered out, and only the images that contain defects can be processed in the follow programs. Secondly, the retained suspected defect images are divided into two categories. Different categories are handled by different process. The simulation experiment result shows that: it not only makes full use of the advantages of the double field method, and greatly reduces the image data quantity, at the same time ensuring the real-time of the system.

Vibration characteristics of the thin-walled cylindrical pipe are affected by the liquid within the pipe. The natural frequencies and vibration modes of the pipe without liquid are analyzed by the theory of beam bending vibration and finite element model, which is based on the Timoshenko beam model. The first three natural frequencies and vibration modes of the pipe with or without liquid are acquired by experiments. As shown in the experiment results, the natural frequencies of the containing liquid pipe are lower than the natural frequencies of the pipe without liquid.

The lumped mass on the cylindrical pipe affects the natural frequency of the cylindrical pipe. The first-three order natural frequencies and vibration modes of the cylindrical pipe with different lumped masses are analyzed by the bending vibration theory and finite element analysis, respectively. The results with different lumped masses are obtained by experiments. As shown in the results, the natural frequencies of the cylindrical pipe with lumped mass are lower than those without lumped mass. The greater the lumped mass is, the smaller the natural frequencies of the pipe are.

Put forward a method that use scatter points which got in different places to measure the involution cylindrical gears, give a mathematical model that use the discrete points to sure the total deviation of gear tooth profile. The experience results show that this way is of high precision in measurement points, measurement an error data processing less intervention, etc.

An integrated system to measure mechanical functions of material or structure is introduced. This system is able to provide more detection methods and experiment environments. And it can discover the characteristics and mechanisms of damnification and breakage in materials, considering the effects of loading and environments. Material functions were analyzed in many aspects, including loading, strain, light, sound, temperature and infrared to ensure the safety of materials and configuration of unmanned plane. Current study has laid a foundation for realizing optimal design of unmanned plane. In this paper, theory, components, and function of the system were discussed, as well as signal acquisition and analysis.

The liquid within a cylindrical pipe affects the vibration characteristics of the pipe. Furthermore, these vibration characteristics are affected by lumped mass on the pipe. The natural frequencies and the vibration modes of the cylindrical pipe with different lumped masses can be obtained by finite element analysis. The natural frequencies of the containing liquid cylindrical pipe are obtained by experiments. The experimental results show that the natural frequencies of the containing liquid pipe are affected by the lumped mass. The greater the lumped mass is, the smaller the natural frequencies of the pipe are.

In this essay, the charactristc index of the humidity controlling material is breifly illuminated, based on which, an observing experiment in a small enclosed box is made. According to the experimental phenomenon and the basic principles of the thermodynamics, the formulation of the humidity parameter in a closed space of greenhouse is derived, from the angle of two-phase equilibrium. We assert that the purpose of using B,the charateristic parameter, is to ensure that the temperature of the subjest is zero. So when the temperature is not zero, using this parameter will cause error. Since the imperfection of B, it is necessary to use another parameter, BT, which is derived according to the temperature of the subject and proved more reasonable, to reply the former one. Both parameters can reflect the combination of the material and the moisture, which relate to the binding energy. The humidity controlling character proves better, if the binding energy becomes closer to that of two pure water molecules.

The classic multi-mode negative impulses input shapers can suppress the residual vibration of the multi-mode system effectively. But when these several frequencies bandwidths and amplitudes of vibration modes are greatly different, the time delay and the suppression performances of input shapers are decreased. However, the hybrid multi-mode negative impulses input shapers can overcome the disadvantage. The hybrid double-mode negative impulses input shapers of a 3-DOF parallel manipulator and are constructed and compared with the classic multi-mode negative impulses input shapers. And the numerical simulations are shown out, for different frequencies bandwidths and amplitudes of vibration, and the hybrid multi-mode negative impulses input shapers can increase the total suppression performance of input shaper.

The effect of compound modification and various kinds of heat treatment on microstructure and mechanical properties of the low chromium white cast iron was studied.The results showed that,after modification,the carbide morphology in cast iron has been greatly improved;the annealed modified cast iron is suitable for machining;both martensitic quenching and austempering can cause the hardness and the impact toughness of modified cast iron increase greatly.

The effect of austenitizing temperature, heating time and tempering temperature on hardness and impact toughness of low chromium white cast iron was studied by orthogonal test. The optical microstructure was used to analyze the reasons of changes on mechanical properties. The results showed that the hardness increases at beginning and then decreases with the increase of each parameter, high impact toughness can be obtained at high tempering temperature and high austenitizing temperature, the descending order of influence on hardness and impact toughness is austenitizing temperature, heating time, tempering temperature.

Ten mixed fuels were prepared using soybean biodiesel and 0# diesel oil with different blend ratios (in vol %). The effects of the blending ratio on physical-chemical properties of biodiesel-diesel mixed fuels and engine power were investigated. The results shows that, with the increase of the blending ratio, a increase in gelatine, carbon residue, acidity and ash content is found and a decrease in sulfur content and mechanical impurities appears. Furthermore, no distinct affection of the blending ratio on engine power is found.

The moisture absorption characteristic of the humidity-controlled materials at different relative humidity was studied by experiment and the moisture equilibrium content under different humidity condition was obtained. At the same time, the humidity-controlled composite building blocks in greenhouse were successfully developed. The experiment of the humidity-controlled composite building blocks shows that the humidity-controlled composite building blocks can realize the humidity control without the high power consumption, operation inconvenience or polluted the environment etc. compared with the traditional dehumidification method. The humidity-controlled composite building blocks in greenhouse have the very good application prospects.

According to internal heat and moisture transfer coupling equations for the humidity-controlled composite materials in greenhouse, the analytical solutions are obtained under the steady periodic conditions, then the moisture desorption and adsorption properties of humidity-controlled composite materials in a closed space are investigated. It shows that the air humidity ratio in the closed space changes periodically in consistent with the air temperature. The ratio of the absolute humidity amplitude to the air temperature amplitude is a constant, which can be taken as a criterion to evaluate the humidity control performance of the material. A simple method, the close box and heat impulse method is put forward to measure the constant value. It can directly embody humidity-controlled traits of materials under the condition of periodic heat and moisture.

There are lots of theories and methods about condition assessment for highway bridge, and gradual perfection for normal-speed railway bridge, but only little for high-speed railway bridge, especially large-span and special structures. After studying on the contents, methods, theories and evaluation indexes of highway bridge and normal-speed railway bridge, combined with the characteristics of high-speed railway bridge, index system for high-speed railway bridge(medium and small span, large-span or special bridge structures) was conceived and discussed, which laid the foundation for the development of condition assessment of high-speed railway bridge.

The methodologies and application of hybrid multi-mode positive impulses input shaping of a 3-DOF flexible parallel manipulator in this paper. First, the structural system and the dynamic equations are expressed for a 3-DOF manipulator. Second, the hybrid multi-mode positive impulses input shaping is introduced to reduce the residual vibration of the multi-mode system or to decrease the time-delay of the system response at the same time. The theory of the hybrid multi-mode positive impulses input shapers are presented, and the hybrid two-mode positive impulses input shapers of a 3-DOF manipulator are established and compared with the classic multi-mode positive impulses input shapers. Finally, the numerical simulations are made, and the robust of the input shapers are presented and compared.

With the aid of commercial FE code MSC.SuperForm, the structural steel tube continuous rolling process of a typical hollow tube specification 152.5×12.5mm is simulated based on Bao Steel 152.5 main pass sequence of 140mm 8-stand mandrel mill, and the distribution characteristics of stress/strain, outline lateral spread, temperature changes of workpiece in continuous rolling process and distribution of stress/strain, friction of workpiece in deformation zone are analyzed. Analysis results indicate that deformation of workpiece along the width of the groove, especially at the top and the bottom of the groove is highly inhomogeneous due to the unequal draught and the longitudinal stress of special position (the top and the bottom of the groove) of workpiece is always an alternate state, in a tensile-compressive-tensile manner, and has a distinct rule. In the first stand, outline dimension of workpiece gradually increases during reducing process and early stage of wall thickness reduction, but it gradually decreases during middle-late stage of wall thickness reduction and tends towards stability at last. It is inhomogeneous that distribution of unit compressive stress and longitudinal strain of workpiece in deformation zone, and contact stress and total equivalent plastic strain are maximal in inner surface of workpiece contacting with mandrel. Temperature difference between the outer and the inner surfaces of workpiece is obvious.

The novel Fomichev plug described in this paper is of characteristic producing equal unit-reduction of wall thickness along its perforation section during seamless tube piercing, which designed on the base of the roll opening of Julong piercer, taking into account for both feed angle and toe angle of a cone type piercer. Then a 3-D thermal-mechanical coupled numerical simulation on performance characteristic of novel Fomichev plug is presented with the aid of commercial FE code MSC.SuperForm, according to practical process parameters of piercing and rolling for steel grade P91 on Julong piercer in Yangzhou Chengde Steel Pipe Co., Ltd. By comparison with conventional plugs, as FE simulation result shows that the new plug reduces the damage value of the workpiece, thus decreases the tendency of lamination defects. What’s more, the axial resistance of novel Fomichev plug is smaller than the conventional, which is in favor of biting condition and increases piercing efficiency. Furthermore, the newly-designed plug’s temperature field is more uniform, which can alleviate failure of piercing plug caused by overtop local temperature, prolong its working life, and improve the quality of hollow shells.

With the aid of commercial FE code MSC.SuperForm, the rolling process of Accu-Roll mill is simulated and the influence of guide disc postposition on the value of outside diameter expansion of elongated shell, force parameters and twist deformation of the workpiece are analyzed in detail. Analysis results indicate that the value of outside diameter expansion of elongated shell, guide disc force and the axial force of mandrel decrease when the value of guide disc postposition increases, but separating force and twist deformation of the workpiece increase, which provides scientific guidance for designing Accu-Roll mill and setting adjustment parameters.

The key issues in the theory of interval number fuzzy comprehensive evaluation are discussed in this paper, which includes weight interval calculation, quantitative index dimensionless method and etc. Due to the deficiency of “line method” for interval number formation, one improved method is given to increase the stability of interval number. Then the existing problems of several initial evaluation models are discussed, and the probability theory is introduced to improve evaluation model combined with coefficient of variable weight method. This improved interval number fuzzy evaluation method is adopted on one concrete cable-stayed bridge to general evaluate its safety and durability. The result shows that this improved fuzzy evaluation method can well reflect the general working status of the bridge and have good feasibility and practicality.

The Fomichev plug is of characteristic producing equal unit-reduction of wall thickness along its perforation section during seamless tube piercing. This paper introduces the design of a novel Fomichev plug based upon the analysis of roll opening, taking into account for both feed angle and toe angle of a cone type piercer, then presents a 3-D coupled thermo-mechanical simulation of the novel Fomichev Plug’s performance characteristic during cone-roll piercing process, with the aid of FE code MSC.SuperForm. In comparison with conventional plugs, as FEM simulation result shows that the new plug makes the metal deformation distribute uniformly along its perforation section, which brings about well-distributed plug wear. The novel Fomichev plug is able to decrease the slip between the roll and workpiece and avoid rolling block owing to its smaller plug force, which can increase piercing efficiency so, moreover, analyzing stress distribution, it’s more suitable for metal deformation with fewer defects in tube piercing, makes resistance to metal elongation smaller, reduces wedge cleaving to tube billet, and prevents lamination defects during piercing high-alloy billet.

Concerning the 3-roll skew rolling process of round billets, a 3-D thermo-mechanical coupled simulation is performed with the aid of commercial FE code MSC.SuperForm. The influence of the feed angle and inlet cone angle of the roll on the strain and damage filed are investigated. It is found that the distribution pattern of the equivalent plastic strain in the longitudinal section of the billet presents U-shape, and that the feed angle and inlet cone angle of the roll make difference in the gradient of deformation intensity in radial direction of round billet. The ring-shaped distribution of the damage field in transverse cross section of the billet indicates a high tendency for the ring-shaped inner crack to occur, instead of the center crack appearing in 2-roll skew rolling of round billet. The results show that the critical parameters to control the ring-shaped crack during the 3-roll skew rolling process are the feed angle and inlet surface cone angle of the roll. It should be avoided to use too large feed angles so as to reduce the tendency of annular inner crack in the actual rolling of high-alloy steels with poor hot workability.

Base on the study of the light reflectivity of steel surfaces, the interaction of CCD Camera and Illumination is investigated through experience. A new bright-dark filed defect recognition method which combines bright-filed mode and dark-filed mode is proposed. The bright-filed defect and dark-field defect on the surface of the strip steel can be detected at the same time through this new way, and the quantity of the defect information is increased. Therefore, the recognized defect type is twice the tradition way. A new algorithm of defect detection which is proper to bright-dark filed mode is proposed, too. This method is based on the image fusion. Experiment results show that detection rate of defects is more than 95% while classification rate of defects is over 85%.