bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Annealing Treatment on the Microstructure and Magnetic Properties of FeSiBAlNi(C, Ce) High Entropy Alloys
Authors: Xu Jing , Zhao Zheng Feng , Wang Yan
Published: March 2016

In this paper, the effects of annealing treatment on the microstructure, thermal property and magnetic properties of mechanical alloyed FeSiBAlNiC and FeSiBAlNiCe amorphous high entropy alloys has been systematically investigated using X-ray diffraction, differential scanning calorimetry, field emission scanning electron microscopy and alternation gradient magnetometry. The results showed that annealing at different temperature range induced the pronounced microstructural evolution from the amorphous phase to a mixture of amorphous phase and intermetallics but without any formation of solid solutions. In addition, the thermal stability and heat resistance were enhanced with increasing the annealing temperature. Similarly, annealing treatment also had significant effect on the particle morphology, making the particles evolve from near-round shape to plate-like shape. Furthermore, subsequent annealing of W6-Ce amorphous HEAs enhanced the saturation magnetization (Ms) remarkably (from 0.6 emu/g of 140 h as-milled W6-Ce to 20.17 emu/g). But for the Ms values of the 140 h as-milled amorphous W6-C HEAs, annealing in different temperature range all exhibited a slightly decreased effect.
The Microstructure and Mechanical Properties of Heat Treated NiCr20TiAl Superalloy
Authors: Wei Ran , Wu Hui Yun , Zhang Qing Quan , Li Ming Yang , Cao Yu , Li Zhen Rui
Published: March 2016

NiCr20TiAl is a typical age-hardening superalloy with Ni-Cr as matrix and γ′ as strengthening phase. The microstructure and mechanical properties of nickel base superalloy NiCr20TiAl under different heat treatment were examined by scanning electron microscope (SEM), energy dispersive spectrometer (EDS), optical microscope (OM) and mechanical tester. The results showed that superior comprehensive mechanical performance of NiCr20TiAl cast alloy was achieved by 1050°C/8h, air cool (AC) +700°C/16h, AC treatment. The edge cracks problem was resolved by 1150°C/1h, water quench (WQ) solid solution treatment before cold rolling process. The vickers hardness of the alloy decreases from 308 to 148. The vickers hardness of the NiCr20TiAl alloy could be controlled below 250 by 1080°C/2min treatment.
Glass Formation and Thermal Stability of Mechanically Alloyed Al75Ni10Ti10Zr5  Amorphous Composites with Graphene Addition
Authors: Wang Tong Yang , Sun Zhen Xi , Zhang Lan Xiang , Wang Yan
Published: March 2016

In this study, the influence of 0.5 wt.% graphene (Gr) addition on the glass formation and thermal stability of the Al75Ni10Ti10Zr5 alloy during mechanical alloying (MA) process has been investigated. The as-milled products consist of the amorphous phase and a small amount of the AlNi nanocrystals. The results showed that the 0.5 wt.% Gr addition could shorten the amorphization process, indicating the enhancement of the glass forming ability. Moreover, the onset crystallization temperature (Tx1) slightly decreased with prolonging milling time for the as-milled alloys. However, it is worth noting that the Gr addition effectively increased the Tx1 of the as-milled Al-based amorphous composites for the long duration of MA time. The Tx1 values of the as-milled AlNiTiZrGr amorphous composites were more than 1120 K, exhibiting the highly thermal stability.
Microstructure and Properties of W-Cu Composites Fabricated by Laser Cladding Forming
Authors: Wang Guang Yuan , Gu Sai Nan , Qin Yuan , Yang Sen
Published: March 2016

In this paper, the rapid prototyping of W-Cu composites by laser cladding was reported. The influence of the mass ratio of W and Cu on the structure and properties were investigated. Ni and Co were added to the W-Cu composites to promote the sintering densification. The effect of the elements on the structure, phase composition and properties of W-Cu composites was investigated by using X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray spectrometer (EDX) and hardness test. The results showed that when Cu content increases to 60 wt.%, W particles were distributed around Cu agglomerates. When Ni content increases to 3.0 wt.%, γ-Ni phase could be observed. It was found that Co was concentrated at the interface between W and Cu phase and enhance the diffusion of W in Cu phase. Both Ni and Co could increase the density of the W-Cu composites greatly.
Effect of Trace Strontium Addition on Microstructure and Room Temperature Fracture Toughness of Nb-12Si-22Ti Alloys
Authors: Wu Mei Ling , Guo Feng Wei , Li Ming , Han Ya Fang
Published: March 2016

The effect of strontium (Sr) addition (0.2 at.%) on the microstructure and mechanical properties of Nb-12Si-22Ti alloys were studied. Microstructure of the alloys was observed by scanning electron microscope, and their phase compositions were analyzed with X-ray diffraction and Electro-Probe Microanalyzer. The room temperature fracture toughness was measured. The results indicated that the phases of Nbss and Nb3Si were presented in Nb-12Si-22Ti alloys. However, with the Al and Sr addition, the alloys were composed of Nbss and β-Nb5Si3. Compared with the Nb-12Si-22Ti alloys, the value of room temperature fracture toughness increased about 46% and 73% with the addition of Al and Sr alloy, respectively. The relationship between the microstructure and the mechanical properties was discussed.
Microstructure and Properties of Fe Base Coatings Reinforced by In Situ TiC Particles Using Plasma Jet Surface Metallurgy
Authors: Chen Hao , Zhang Yang Rong , Huang Zhu
Published: March 2016

By plasma jet surface metallurgy, the thick composite coatings reinforced by in-situ TiC were produced on low carbon steel. Composition, microstructures and performance were characterized by scanning electron microscope (SEM), energy dispersive X-ray (EDX), X-ray diffraction (XRD), micro-hardness tester and wear tester. The results showed that the excellent bonding between the coating and the carbon steel substrate was achieved by strong metallurgical interface. The microstructure of the coating is mainly composed of γ-(Fe, Ni) dendrite, M23C6, CrB and in-situ synthesized TiC ceramic particle. Because of the particulate reinforcement, the dispersion strengthening, refinement strengthening, micro-hardness and wear resistant of Fe-based coating can be enhanced.
In Situ Synthesis and Oxidation Behavior of Ti-Al-Ag Ternary Coatings
Authors: Yang Lei , Li Hua , Liu He Zhou , Zhang Yang Yang
Published: March 2016

Mixture powders with different ratio of Ag/γ-TiAl were deposited on titanium alloy by low presure plasma spray and thermal treatment was applied to convert the mixture coatings into Ti-Al-Ag ternary ones. The experimental results indicated that the oxidation resistance of ternary coatings was better than sheer γ-TiAl coating and increased with increasing Ag from 2at.% to 4at.% at 700 and 800°C. The outside oxide scale consisted of alumina and a small amount of rutile due to the insufficient diffusion of Ag in γ-TiAl.
Influence of Annealing Treatment on Microstructure and Mechanical Properties of Fe-Cu-Si-Al Amorphous Composites
Authors: Zhao Yan Chun , Ma Wen Long , Yuan Xiao Peng , Zhao Zhi Ping , Huang Ming Yuan , Kou Sheng Zhong , Li Chun Yan
Published: March 2016

In this study, the bulk amorphous alloys with 3mm in diameter were prepared at different voltages adopting copper mould suction casting method by adding microelement Al to Fe-Cu-Si based amorphous alloy respectively. The microstructures, glass-forming ability, mechanical compressive properties of (Fe0.34Cu0.47Si0.19)95Al5 amorphous composites annealed in different temperature were investigated. The results showed that re-melting of master alloy refined the solidified microstructure and homogenize the composition and microstructure. Moreover, the microstructure was stable with the increase of re-melting times. After relaxation and annealing at low temperature the majority of residual thermal stress was released during annealing at low temperature, with the enlargement of short-range order of amorphous microstructure and the decrease of the most adjacent inter-atomic distance. After proper annealing treatment the hardness and thermal stability of alloy were improved, indicating that the annealing treatment could improve the properties of amorphous alloy.
Preparation and Properties of Aluminum Boron Composite
Authors: Chen Shuai , Sun Yong , Duan Yong Hua , Huang Bo , Peng Ming Jun
Published: March 2016

Al/B composite is a new structural-functional integration material, which has a promising potential in future application due to their good combination of neutron shielding property and mechanical property. In order to obtain sintering process parameters of Al/B composite, the mold pressure, sintering temperature and the composition of powders were investigated and the physical properties of Al/B composite also systematically studied. In addition, the surface morphology of Al/B composite was analyzed. The experimental results indicate that the relative density will be higher when the mold pressure was bigger in appropriate pressure intervals, and when the mold pressure was more than 144MPa, the composites was difficult for molding because of the great internal stress. From the analysis of morphology, it shows that the best sinter temperature interval is 550-580°C. From the studies of composition of powders, it has been found that the percentage of Al affect the density and hardness. The density will be higher if the percentage of Al is higher.
Analysis of Shear Banding in Zr-Based Metallic Glass under Laser Shock Peening and Bending
Authors: Fu Jie , Zhu Yun Hu , Zheng Chao , Ji Zhong , Shi Hui Gang
Published: March 2016

Metallic glasses have been expected to be used as structural materials since their high strength and high hardness. Unfortunately, their catastrophic brittle fracture behavior with poor plasticity becomes the major weakness for structural application. It has been recognized that the mechanism of plastic deformation in metallic glasses is through the formation of shear bands, which provide them with limited ductility. Laser shock peening (LSP) is an innovative surface treatment technique which can introduce deep compressive residual stress layer to materials for improving their mechanical behavior. In this work, a finite-element model has been developed to numerically simulate the pure bending process, LSP and subsequent bending process. An advanced constitutive equation was established based on the large deformation theory of nonlinear mechanics, the free volume model and the Coulomb-Mohr yield criterion. The model is able to capture the following results: (i) for a given bending deflection, the shear band spacing increases with increasing plate thickness; (ii) for a given plate thickness, the free volume increases with the bending deflection; (iii) for a given thickness and a given deflection, the shear bands increase under the effect of LSP.
Preparation and Magnetic Properties of Nanocrystalline FeSiAl Powder Produced with Strip Cast Ingot Process
Authors: Xu Lin Hao , Yu Hai Chen , Zhang Hong Ping
Published: March 2016

FeSiAl magnetic powder contains high cost-performance as inductance components, which is widely used in various fields. In the present investigation the structure, magnetic properties and properties of magnetic powder cores prepared by strip cast ingot process were studied, and then compared with FeSiAl magnetic powder prepared by ingot cast broken process. The results show that strip cast sheet contained much little grain which surround with big grain, while the ingot cast broken has big grain connect with each other. For FeSiAl magnetic powder prepared by strip cast ingot process, the bigger grains were strip, the smaller grains were irregular shape, the surface of the powder was coarse, the powder prepared by strip cast ingot process was good for keeping the insulation film perfectly. For FeSiAl magnetic powder prepared by ingot cast broken, much of the powder was irregular bulk shape, and the grain corner was sharp, which is not good for insulation coating. Compared the patterns of strip cast ingot powder with the patterns of ingot cast broken powder, the diffraction peak of the patterns of strip cast ingot process powder became broaden. The initial magnetization curves of FeSiAl were obtained by vibrating sample magnetometer (VSM), observing that the saturation magnetization of strip cast magnetic powder was greater than that of ingot cast broken.
Effect of High Energy Ball Milling on Structures and Properties of Atomization Fe-Based Nanocrystalline Soft Magnetic Powders
Authors: Zhou Juan , Chen Yong , Zhu Hong Mei , Fan Xiang Fang
Published: March 2016

The microstructure and strain of gas atomization and water collection Fe73Si3B24 soft magnetic alloy powder treated by high energy ball milling were investigated via SEM and X-ray diffraction. And the magnetic properties of those powders were studied via VSM (Vibrating Sample Magnetometer). The results show that the atomization powders almost exhibited spheric or ellipsoidal shape. The averaged particle size was 104.94 μm. The main phases were composed of α-Fe (Si) and amorphous phase. As ball milling time went on, the interplanar space, amount of amorphous and crystal microstrain of the powders increased, while the grain size decreased. The peak for the (110) crystal plane of α-Fe (Si) phase widened, while the peaks for (200), (211) crystal planes weakened. These three peaks shifted towards to small angle direction. The saturation magnetic induction of treated powders was steady, and the coercivity of samples increased.
Analysis on Fracture Toughness of the L415MS/N08825 Bimetallic Composite Pipe Welded Joint
Authors: Wang Bin , Lei Bo Bo , Wang Liang , Xu Ming
Published: March 2016

Crack tip opening displacement (CTOD) tests were conducted on the weld and heat affected zone (HAZ) of L415MS/N08825 bimetallic composite pipe welded joint according to BS7448, ISO12135(2002) and ISO15653(2010) standards at room temperature. The fracture toughness of weld and HAZ were studied and analyzed. The fracture surface and inclusions were characterized using scanning electron microscopy (SEM) and energy-dispersive X-ray spectrometry (EDS), respectively. The results showed that the average CTOD value of the weld was less than HAZ, CTOD values of HAZ exhibited larger discrete, which was mainly caused by Pop-in effect in P-V curve of HAZ samples. CTOD value of sample with Pop-in effect dropped several times than sample without Pop-in effect. The fracture surfaces of the weld and HAZ showed tough fracture to a certain extent, and the fracture surface of HAZ sample with Pop-in effect exhibited significant quasi-cleavage feature.
Effects of Processing Temperature on Release of Bisphenol A from PC: A Multi-Technique Analytical Study
Authors: Sun Zhuo Jun , Li Chun Ping , Gao Jian , Pan Shu Zhen , Zhang Shu Li , Yang Lun Hua , Song Xiao Yun , Gao Jian Guo
Published: March 2016

The degradation of polycarbonate (PC) food contact materials was studied based on analysis with GC-MS, FTIR, UV-Vis and TG techniques. It was evident that the processing temperature of the materials significantly enhanced the release of bisphenol A, an endocrine disruptor. Investigation of the redshift of UV band also revealed that high temperatures accelerated the aging degradation of PC.
Microstructure Evolution and Constitutive Modeling Based on Flow Behavior of 2297 Al-Cu-Li Alloy
Authors: Yang Sheng Li , Shen Jian , Li Xi Wu , Yan Xiao Dong , Mao Bai Ping
Published: March 2016

Flow behavior and microstructure evolution of 2297 Al-Cu-Li alloy were investigated by isothermal compression tests conducted at the deformation temperature of 300-500°C and strain rates of 0.001-10s-1. The results demonstrate that the characteristics of stress-strain curves depended on the interaction of work hardening and dynamic softening. The true stress increased with the decreasing of temperature and the increasing of the strain rate. At a given deformation condition, the flow curve consisted of three stages: stage I (work hardening stage), stage II (softening stage) and stage III (steady stage). Deformation temperature and strain rate had a great influence on microstructure evolution. 2297 alloy deformed at low temperature (300°C) and high strain rate (10s-1) showed a DRV characteristic. As deformed at high temperature (500°C) and low strain rate (0.001s-1), DRX gradually become the main softening mechanism. The measured flow stress was friction corrected and then employed to develop constitutive equations on the basis of the Arrhenius-type equation by considering the effect of the strain on material constants by a sixth orders polynomials. Flow stress value of 2297 alloy predicted by the proposed constitutive equations shows a good agreement with experimental results, thereby confirming the validity of the developed constitutive relation.
Diffusion Behavior of Carbon Atoms in Austenite Region of SCM435 Steel
Authors: Xu Dong , Zheng Bing , Gao Xing Liang , Zhu Miao Yong
Published: March 2016

The research on the decarbonizing behavior of the austenite region of SCM435 steel was carried out. And the experimental results shewed that the relationship between the diffusion coefficient and temperature totally agreed with the Arrhenius equation and that the diffusion constant and the diffusion activation energy were uniform within the temperature range of 900-1100°C. However, when the austenite reached certain temperature, the carbon diffusion coefficient decreased significantly as temperature increased and its relationship with temperature no longer agreed with the Arrhenius equation.
Thermodynamic Calculations of the Rare Earth Permanent Magnets: Fe-RE Binary Systems
Authors: Chen Tai Li , Wang Jiang , Rong Mao Hua , Rao Guang Hui , Zhou Huai Ying
Published: March 2016

As the key sub-binary systems in the rare-earth (RE) permanent magnetic materials with excellent magnetic properties (e.g. Nd-Fe-B, Sm-Fe-N magnets), the Fe-RE binary systems were investigated widely due to the industrial applications of permanent magnets. In this work, the experimental data of phase equilibria and thermodynamic properties of the Fe-RE binary systems (RE=La, Ce, Pr, Nd) in the published literature are reviewed firstly. Based on available phase equilibria data and thermodynamic data, the Fe-RE binary systems are assessed thermodynamically using the CALPHAD method. As a result, further experimental information and thermodynamic calculations will be both required in order to develop thermodynamic database of the RE-Fe-B ternary systems, which is very useful to study the relations between alloy composition, microstructure and magnetic properties of novel Nd-Fe-B-based permanent magnets.
Experimental and Numerical Study of Macrosegregation in a 160 Steel Ingot
Authors: Duan Zhen Hu , Du Xuan , Shen Hou Fa , Liu Bai Cheng
Published: March 2016

Large steel ingots are the important material for the equipment manufacturing industry. It is still difficult to predict and control the macrosegregation in ingot. In this paper, the cooling curves at the surface of ingot and temperature variation of the mold were measured. The carbon distribution was measured through the local region dissection of ingot. Then, based on the definite the heat transfer coefficient at the interface of mold/ingot, a two-phase model with consideration of the motion of equiaxed grains is applied for the prediction of macrosegregation in 160-t steel ingot formed during the solidification. The results indicate that the heat transfer coefficient at the interface of mold/ingot decreases sharply after starting solidification and then varies slowly. Negative segregation at the bottom of ingot forms due to the interaction of solidification interface and equiaxed grains deposition during solidification. The positive segregation appears in the riser with thanks to the solidification shrinkage and the floating enriched solute. Finally, the results of the predicted and the measured are in good agreement.
A Model for Prediction of Yield Stress of Heat Treated Al-7Si-Mg Cast Alloys
Authors: Xu Qing Yan , Chen Rui , Shi Yu Feng , Liu Bai Cheng
Published: March 2016

In the present investigation, a physically based numerical model was developed to predict the yield stress of Al-7Si-Mg cast alloy during processing. It covered the integrated unit step models of the physical metallurgy of solidification, solid-state of homogenization, and structural hardening of precipitation. The as-cast microstructure of Al-7Si-Mg alloy was calculated based on the cellular automaton method and the evolution of the precipitated phase during aging process was achieved by a precipitation kinetic model involved nucleation, growth and coarsening. The yield stress prediction was achieved by a strengthening model including the effects of as-cast microstructure, solution strengthening and precipitate hardening. The predictions of this model were verified by comparing with experimental measured yield stress which shows that this model is successfully applied to predict the yield stress evolution of Al-7Si-Mg cast alloy.
Effect of Annealing Time on the Formability of a Ultra Purified Ferritic Stainless Steel Containing Copper
Authors: Yin Hong Xiang , Zhao Ai Min , Zhao Zheng Zhi , Wang Xu Ming , Zhou Kai Chun , Sun Shao Heng
Published: March 2016

For developing of a ultra-purified ferritic anti-bacterial stainless steel, 1.4 Cu % was added in 21% Cr ferritic stainless steel. The effect of annealing time on the formability was analyzed. The micro texture of steel was measured by using electron back scattering diffraction analysis. The Cu precipitates through different annealing periods were investigated by means of transmission electron microscopy. Average plastic strain ratio was calculated by the r values at 0, 45°and 90° directions measured by tensile testing. The results shows that with the extension of annealing time, the morphology of the Cu precipitates became into rod from spherical and the size increased. Average plastic strain ratio increased first and then decreased, while the change trend of anisotropy index was opposite. The higher formability is due to the {111} texture components increase significantly, while more {001}<110> component at 60 min was adverse for the formability. And anisotropy index was determined by γ components and {110}<110> components.
Effects of Homogenization Temperature on Microstructure of 2A66 Al-Cu-Li Alloy
Authors: Wu Yue , Wang Xu Dong , Li Jiong Li , Feng Zhao Hui
Published: March 2016

The microstructure evolution during homogenization of 2A66 Al-Cu-Li alloy was investigated by optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX), transmission electron microscopy (TEM) and differential scanning calorimeter (DSC). The results showed that the dendritic segregation can be found in the ingot of experimental alloy. Numerous eutectic phases can be observed in the grain boundary, and the distribution of the main elements along the interdendritic region varied asymmetrically. It was found that the main secondary phase was Al2Cu. Differential scanning calorimeter (DSC) results showed that the over-burnt temperature of 2A66 Al-Cu-Li alloy was 515°C. With the increase of homogenization temperature in the area of 480°C~510°C, the boundaries of experimental alloy became sharp and the most of secondary phase dissolved into the matrix. The experimental alloy heat treated at 520°C was over-burnt. The Al3Zr precipitated and α (Al) super-lattice was observed by TEM in the experimental alloy after homogenization.
The Effects of Two-Stage Aging on the Microstructure and Mechanical Properties of the New Al-Si-Cu-Mg Alloy
Authors: Zheng Yan , Xu Cong , Xiao Wen Long , Yamagata Hiroshi , Ji Guo Fu , Yang Ming Juan , Ma Chao Li
Published: March 2016

Two-stage aging treatments were applied to Al-6Si-2Cu-0.5Mg casting alloy, and the influence of aging treatment parameters on the microstructure and mechanical properties was investigated. The experimental results indicated that the microstructure and mechanical properties of Al-6Si-2Cu-0.5Mg alloy were significantly influenced by the aging time and temperature, and the elongation remarkably increased with the aging time increasing before 7 h. In the case of the alloy aged at 200°Cfor 2h, higher hardness and tensile strength were obtained, which may be attributed to precipitation of a large amount of Cu-rich phases. However, the higher elongation was achieved in the alloy under 200°C aging treatment for 5h, while its hardness and tensile strength slightly decreased. It is mainly due to the amount of the Cu-rich phases decrease slightly, but the morphology of the phases evolved from plate-like to bulk-like structure.
Experimental and Numerical Simulation of Surface Segregation in Two-Phase Zone Continuous Casting Cu–Sn Alloy
Authors: Luo Ji Hui , Liu Xue Feng , Shi Lai Xin , Cheng Chang Fei
Published: March 2016

Surface segregation exists in two-phase zone continuous casting (TZCC) alloy with wide solid–liquid two phase zone. The surface segregation formation cannot be explained by the traditional solidification theories. ProCAST software was used to simulate the TZCC process for preparing the Cu–4.7 wt%Sn alloy with wide solid–liquid two phase zone. The Sn solute distribution in TZCC Cu–4.7 wt%Sn alloy was investigated, and the surface segregation mechanism of TZCC Cu–4.7 wt%Sn alloy was analyzed. The results showed that numerical simulation results were agreed with that of experimental. TZCC Cu–4.7 wt%Sn alloy in the center firstly started to solidify and resulted in “Λ” shape inclined solid/liquid (S/L) interface near the mold. Therefore, a narrow gap between the wall of the two-phase zone mold and the S/L interface formed. On the one hand, while Cu–4.7 wt%Sn alloy solidified along the opposite continuous casting direction, the solute redistribution between the solid and the liquid occurred, which lead to Sn solute decreased in solid and enriched in front of S/L interface. Because the narrow gap lies in front of inclined S/L interface near the two-phase zone mold, Sn solute enriches in liquid of the narrow gap. On the other hand, during the TZCC process, solid grains nucleate on the wall of the two-phase zone mold, while the melt feeds into the two-phase zone mold which the temperature is in the two-phase zone of the Cu–4.7 wt%Sn alloy. The solute redistribution also occurs while the solid grains grow, thus lead to Sn content increases in front of S/L interface near the wall of the two-phase zone mold. The enriched Sn solute is too late to diffuse, and will quickly flows into the narrow gap, resulting in further increasing of Sn content in the narrow gap. The liquid with enriched Sn solute in the narrow gap will become the surface layer after solidification, which lead to surface segregation layer during the TZCC Cu–4.7 wt%Sn alloy.
Principle and Model of Phase Transformation in Ultra-High Strength Steel for Cone Crusher
Authors: Wang Wei , Song Ren Bo , Peng Shi Guang , Zheng Ru Wen , Tan Zhi Dong , Guo Ke , Wang Zhong Hong
Published: March 2016

The principle of phase transformation in ultra-high strength steel for cone crusher was studied by DIL805 thermal mechanical simulate, and the critical temperature was determined. The Austenite continuous cooling transformation (CCT) diagram of the steel was confirmed by thermal expansion curve, dilatometry and metallography. The phase transformation model was established and offered a theory for deciding parameters of heat treatment process. The results proved that: when the cooling rate was under 0.5 °C/s, the structure was mainly Pearlite and Bainite. With the increase of cooling rate, the content of lower Bainite increased. When it came to 1°C/s , Martensite start to transform from Austenite. When the cooling rate is 5°C/s, Pearlite disappears, Bainite and Martensite were in the majority. Meanwhile, the mathematical equations of phase transformation have high degree to fit the experimental results, and the phase transformation model is feasible.
Inoculation and Fading of Sr-Modified A356.2 Aluminum Alloy in Squeeze Casting
Authors: Niu Jian Wei , Li Lie Jun , Liu Hai Jun , Gao Ji Xiang , Ren Chuan Dong
Published: March 2016

The inoculation and fading behavior of Sr-modified aluminum alloy A356. 2 were studied for air bag bracket produced by squeeze casting. The effects of Sr, P, B contents and casting temperature on the microstructure and eutectic silicon morphology in different periods of inoculation were investigated by SEM and direct-reading Spectrometer. The influence of inoculation fading rate and addition of Sr on the casting mechanical properties and hydrogen absorption was studied. The experimental results showed that the inoculation process was completed in 1 h, and the eutectic silicon morphology can be maintained in almost subsequent 40 h after the addition of Sr. The fading rate decreased appreciably with the increase of casing temperature, P and B contents. The deleterious effect of the inoculation fading of Sr on the casting mechanical property can be compensated by the squeeze casting.
Design and Optimization of Conformal Cooling System of an Injection Molding Chimney
Authors: Li He , Mei Yi , Lin Bo , Xiao Hua Qiang
Published: March 2016

Cooling system is important in the quality and the efficiency of forming plastic parts. The heat transfer model for conformal chimney cavity and straight pipe cooling system was developed employing thermal analysis module of UG software. The temperature field distributions of two cavities were analyzed. The differences in chimney forming warping deformations, shrinkage and freeze times for the two types of cooling systems were analyzed quantitatively by Moldflow software. The results showed that the temperature field distribution of the conformal cooling system was more homogeneous and the forming quality and efficiency of molding for the plastic parts was better. Finally, the cooling system parameters were optimized through orthogonal test and range analysis method.
Determination of Migration of Hazardous Elements from Non-Stick Pan Materials in Five Food Simulants by ICP-MS
Authors: Gao Jian Guo , Zhao Fu Wen , Li Chun Ping , Sun Zhuo Jun , Zhang Shuai , Gao Jian , Zhang Qian Qian , Song Xiao Yun
Published: March 2016

A method for the determination of seven hazardous elements in Non-stick Pan Materials in five food simulants by inductively coupled plasma mass spectrometry (ICP-MS) was established. Using this method, the experiments were carried out on the samples of imitated migratory elements (Cr、Mn、Ni、Cu、As、Pb、Cd) in food simulants of water, 4%(W/V) acetic acid solution, 10%(V/V) ethanol solution, 2g/L sodium chloride solution and olive oil. The sample preparation method of five food simulants was confirmed through experiment. Experiments by resolution, stability, sensitivity and other parameters were adjusted tuning instrument to determine the instrument to achieve the best working condition. The linear range of this methods was 0.1~50ng/ml. For all elements, the correlation coefficient of the calibration curves was above 0.9990 and the detection limits were within the range of 0.008~0.12ng/ml. Most of the recoveries at 1ng/ml concentration level was from 85.34%~112.3%, while the RSD was from 0.37%~4.1%.
Effect of Cold Rolling and Heat Treatment on Properties and Microstructure of Cu-24wt%Ag Alloys
Authors: Gao Xue Cheng , Wang Qiang Song , Xie Guo Liang , Liu Dong Mei , Xie Wei Bin , Li Yang
Published: March 2016

Sheets of Cu-24wt.%Ag alloy were prepared through the process of forging, cold rolling and heat treatment to reveal the evolution of microstructures, mechanical properties and electrical conductivity. The experimental results showed that nanomultilayered structure of Cu and Ag phases arranged alternatively was obtained, with numerous nanoscale Ag precipitate-fibers embedded in Cu matrix. The lamellas in longitudinal section became curved gradually and shear bands appeared when the deformation exceeded 90.79%. With the increase of rolling strain, the average layer thickness and spacing decreased progressively and reached to less than 200 nm as the strain surpassed 96%, resulting in rapid enhancement of the hardness. The heat treatment at 250°C markedly improved electrical conductivity of the alloy, with little decline of the hardness. The anisotropy of the alloy reduced with rising temperature. Local spheroidization occurred when the alloy was heat treated at 300°C. Hardening of this Cu-Ag alloy is predominated by Cu/Ag interface in strain stage of 80%~99%, leaning mainly upon layer thickness and spacing.
Toughness of X80 Grade Pipe Steel Girth Welds by Curved Wide Plate Testing
Authors: Yao Deng Zun , Zhang Long , Fan Yu Ran , Wang Tian Qi , Zhou Yan
Published: March 2016

To confirm pipeline designs and validate the weld toughness, extensively works of Curved Wide Plate (CWP) test methods was carried out. The method of Two Clip Gauge-CTOD was firstly introduced in CWP test in this paper. The test results of CWP analyzed by Two Clip Gauge-CTOD method and Compliance—J method was compared. The CTOD-R curves achieved by these methods showed the good consistence with each other. Furthermore, the difference of the test results among SENB(single edge-notched bend), SENT(single edge-notched tensile) and CWP was discussed. It shows that the toughness obtained by SENB is relatively conservative, and CWP and SENT are recommend to be chosen for pipeline steel welds toughness test.
Bending and Tempering Process of L415M Hot Induction Bend Used in Low Temperatures Areas
Authors: Yan Li Jun , Li Yu Zhuo , Zhu Peng , Shi Jia , Liu Jin Sheng , Zhang Long
Published: March 2016

Test bends of L415M hot induction bend of 508 mm OD×14.3 mm WT used in –45°C areas were conducted. The bending and tempering process parameters were designed, the influences of bending and tempering process parameters on impact toughness at –45°C and microstructure of tangent weld and bend weld were investigated. Hot induction bend was produced by the process of local induction heating+fast water quenching. After tempering treatment, the weld contained martensite-austenite (M-A) islands, carbide precipitations, welded column crystal structure and little pearlite (P), and the brittle fracture surface contained S segregation, the temper brittleness of the weld occurred, which lead to impact energy of bend weld to be lower than 40 J at –45°C. Without post-bending tempering treatment, the microstructures of bend weld was a composite of polygonal ferrite (PF) and granular bainite (GB) with small size and uniform distribution, the coarse column structure and acicular ferrite (AF) disappeared in the weld, so the impact energy of bend weld was higher than 70 J at –45°C, but the impact energy of tangent weld was very poor. It suggests that the process of overall induction of heating + fast water quenching + no tempering treatment is more reasonable, the process ensures that the impact toughness at –45°C, strength and other properties of bend meet the requirements of CDP-S-OGP-PL-016-2011-2.
Experimental Research and Production of Heavy Gauge DNV 485FDU for Deep Water Trunkline Project
Authors: Li Shao Po , Ding Wen Hua , Wang Li Feng
Published: March 2016

In this paper, an overview of experimental research and production of 40.5mm DNV 485FDU heavy wall thickness pipeline steel for deep water trunkline project was introduced and analyzed systematically. Alloy design of the steel was introduced. Continuous cooling phase transformation behavior of the steel under deforming condition was investigated. The microstructure of the steel at different cooling rates was observed by the microscope. An optimized cooling process (OCP) after finish rolling was developed in Shouqin Steel Co., Ltd. (SQS). The optimized cooling process guaranteed the steady control of the final bainitic microstructure with optimum polygonal ferrite (PF) for heavy gauge DNV 485FDU plates. The plates produced by this process achieved good tensile strength and excellent lower temperature toughness. The pipes were produced via the JCOE pipe production process and had favorable forming properties and good weldability. Plate mechanical properties successfully met the required final pipe mechanical properties due to the ideal microstructure from the alloy/OCP design.
Failure Analysis on a Non-Occupation Refined-Oil Pipeline
Authors: Wang Feng , Feng Bin , Chu Bao Min , Fan Yu Ran , Sun Qiao Fei , Gao Yu Hai
Published: March 2016

In this paper, the failure analysis was conducted on a non-occupation refined-oil pipeline, in which corrosion perforation occurs when the pipeline was filled with 1.2 MPa air for more than 1 year, and the material of the corrosion pipeline was L245. To find out the reason of the corrosion, some tests such as XRD analysis for corrosion products, corrosion pits analysis, inclusions and microstructure inspection, as well as corrosion simulation trial were conducted. The experimental results showed that the failure was caused by electro-chemical corrosion because of the dissolved oxygen, while the existence of 1.2 MPa inner air and non-metallic inclusions accelerated the corrosion.
Effects of Finish Cooling Temperature on Microstructure and Properties of X100 Pipeline Steels
Authors: Jia Shu Jun , Liu Qing You , Li Ba , Hao Hong Mei
Published: March 2016

The effect of finish cooling temperature on microstructure and mechanical properties of X100 pipeline steels were investigated through SEM, TEM and mechanical tests. The results showed that the effect of finish cooling temperature on tensile strength of studied steels were slight in the temperature range of 180°C~500°C. The yield ratio, yield strength and impact toughness all presented peak value when the finish cooling temperature was 360°C, however, both the volume fraction and particle size of MA component at 360°C finish cooling temperature had the minimum values. As a brittle hardening phase in bainite the increased number and enlarged size of the MA component were the key factor of the decrease of the yield ratio and toughness. Therefore, rational choosing finish cooling temperature could optimize the morphology and distribution of MA component to make sure the required strength and toughness for the X100 pipeline steel production.
Optimal Controller for Active Vehicle Suspension Disturbed by Sinusoidal Signals
Authors: Sibielak Marek , Rączka Waldemar , Konieczny Jarosław , Kowal Janusz
Published: March 2016

The problem of optimal control of systems disturbed by sinusoidal signals for infinite control time is considered in the paper. The control laws described in [1] is base of a modified mean-square performance index with an infinite control time. The performance index was formulated in such a way that each sinusoidal component corresponds to a separate weight matrix. This allows energy constraints on the control signals to be differentiated based on frequency. An optimal solution to the optimization problem was found.
In the paper the problem of the impact of time on the identification of sinusoidal disturbance on vibration isolation system frequency characteristic. The controller was synthesized for slow-active vehicle suspension [2,3]. The model of suspension, synthesis of the controller and implementation of the system was described. The results of simulations of the designed vehicle active suspension system are presented.
An Analysis of Axial Vibration in Face Packing Seals
Authors: Gudkov Sergii , Martsynkovskyy Volodymyr , Kundera Czeslaw
Published: March 2016

This paper deals with the dynamics of face packing seals, in which one of the sealing rings is made of elastic sealant. The study involved analyzing the axial vibration of the flexible ring for two configurations of its housing in the seal and determining the frequency characteristics and the condition of maintaining face-to-face contact between the sealing rings with considerably different elastic properties subjected to two types of external excitations. The derived analytical relationships were verified using a calculation example for real operating conditions of face packing seals in two pumps.
Discrete Preisach Model of a Shape Memory Alloy Actuator
Authors: Rączka Waldemar , Konieczny Jarosław , Sibielak Marek , Kowal Janusz
Published: March 2016

Shape Memory Alloy is a material used to designing actuators. These actuators have many advantages. They are light, strong and silent. They are building in laboratory and tested because beside advantages they have disadvantages too. SMA actuators have nonlinear characteristics with hysteresis loop.In the first part of the paper Shape Memory Alloys are shortly described. Next mathematical model was formulated. In the paper the Preisach model was developed. Discrete form of the model was considered and implemented. After parameter identification model was implemented in LabView. Tests of the model were conducted and results were worked. Obtained characteristics of the SMA actuator are shown in the paper. At the end of the paper the conclusions were formulated.
Employment of Double-Panel Casing for Active Reduction of Device Noise
Authors: Wrona Stanislaw , Pawelczyk Marek
Published: March 2016

The idea of active casing is an approach to reduce device and machinery noise by controlling vibration of casing walls. The sound insulation efficiency of this technique for a single-plate casing was confirmed by the authors in previous publications. However, under specific circumstances, a dedicated double-panel structure can yield even higher noise reduction.
The aim of this paper is to propose and evaluate by means of laboratory experiments the performance of a double-panel casing in comparison with a single-panel casing. An adaptive control strategy based on the Least Mean Square (LMS) algorithm is used to update control filter parameters. A low-frequency noise in the range up to 250 Hz is considered. Obtained results are reported, discussed, and conclusions for future research are drawn.
Vibration Measurements for Active Noise Control in a HVAC System with a Passive Absorber
Authors: Szumski Karol , Pawelczyk Marek
Published: March 2016

A hybrid active-passive noise control system for a HVAC duct combines both a physicalnoise absorber and an active system. Due to the presence of the passive component, requirements forthe active system can be relaxed, removing the need for detecting and suppressing noise in the frequencyrange already covered by the passive elements. A typical noise measurement system adaptedto working in airflow usually uses a microphone with a housing designed to reduce the noise generateddue to local turbulent flow introduced by the housing itself. Alternatively, there are microphonesspecifically designed to work in the airflow.During work on the hybrid active-passive noise control system both a microphone designed forairflow and a microphone with special housing were tested. While these solutions can be used forresearch, both have issues making them impractical when designing a commercial product. This, alongwith the required narrow frequency range motivated the authors to consider vibration measurementsperformed by appropriately installed accelerometers. An audio signal is then synthesized using thosemeasurements and it is confronted with signals obtained at the same time with microphones.In the paper the proposed method is presented and validated with a laboratory HVAC installation ofa large cross-section and an originally designed passive absorber. Obtained results encourage further research.
Testing and History of Composite Repair Systems for Subsea Pipeline Repair
Authors: Liew Shann Ching , Green Matthew A.
Published: March 2016

A composite is a combination of two or more materials, differing in form or composition, which retain their individual identities while acting in concert.

Two Components: Reinforcing fibers (carbon, glass or synthetic). The high tensile strength of the fiber is used to handle the loads in the hoop, axial, flexural, compression, & shearPolymeric matrix (epoxy, vinyl ester, urethane). Matrix material binds the fibers into shapes and provides bond strength to substrates for load transfer.

Composites can be designed to share the loads & stresses with the host pipe, tank or concrete structure. Composites can also be designed to neglect the host strength of the host pipe, tank or structure for internal corrosion or erosion reinforcements needs.
Flow Assurance and Hydrate Prevention Methods Enabled by Medium Voltage Electric Heating Technology
Authors: Molnar C. , Riley M.
Published: March 2016

Offshore production facilities utilize a variety of process heating equipment to help start-up production and operate efficiently. Applications include glycol reboiling, oil and gas conditioning, knock-out drum heating, molecular sieve regeneration, sea or potable water, and fuel/lube oil maintenance. In addition, oil producers have long investigated downhole and subsea heating solutions capable of decreasing viscosity, preventing wax and hydrate buildup, and providing localized heating for improved productivity. The types of heating solutions are problematic due to the large capacity and extreme environmental and process conditions involved, especially with the downhole and subsea applications. Until recently, low voltage (below 1000V) heating elements and low power heating cables have been the typical solutions for downhole and subsea electric heating applications. These traditional solutions have limitations that prevent them from significant adoption and utilization.

This paper discusses the benefits of using medium voltage technology for flow assurance and hydrate prevention applications. The focus will be on the reduction of installation, maintenance, and operational costs, as well as the reduction of electrical power consumption and line loss associated with using medium voltage technology for such applications. For large heating loads, the physical size and footprint of medium voltage electric heating systems are more compact than traditional low voltage systems. This is especially relevant on newly designed platforms offering medium voltage power distribution.

Finally, medium voltage electric heating technology opens the door for completely new solutions in downhole, subsea and offshore heating, as well as other process heating, in the oil and gas industry that were not possible before. It is important to present such innovation to the marketplace so that producers and operators are aware of new solutions to existing problems.