首页 > metal
全部论文
电力论文   |   建筑论文  |  机械论文  |  化工论文  |  石油论文  |  冶金论文  |  矿产论文  |  材料论文  |  电子论文  |  航空航天论文  |  通信论文  |  计算机论文  |  水利论文  |  地质论文  |  铁道论文  |  汽车论文  |  管理论文  |  农业论文  |  食品论文  |  医学论文  |  海洋论文  |  船舶论文
  • MT 30-2000金属顶梁 u3000Metal roof beam

    本标准规定了金属顶梁(以下简称顶)的产品分类、技术要求、试验方法、检验规则、标志、包装、运输和贮存。<br>本标准适用于煤炭开采工作面支护顶板和顶梁。<br>...

    2022-06-15 09:11:48浏览:1 metal金属Meta

    查看
  • GB/T 9441-2009球墨铸铁金相检验Metallographic test for spheroidal graphite cast iron

    本标准规定了在光学显微镜下球墨铸铁显微组织的评定方法。<br>本标准对球化分级、石墨大小、石墨球数、珠光体数量、分散分布的铁素体数量、磷共晶数量和碳化物数量的评定方法作了规定,列出了相应评级图。<br>本标准适用于评定普通和低合金球墨铸铁铸态、正火态、退火态的金相组织。...

    2022-06-10 07:53:18浏览:5 metal检验graphite

    查看
  • Analysis on Width Spread of Cold Rolled Strip

    Width spread is usually considered in hot rolling, nevertheless, it can be ignore in cold rolling. In order to control the crown and flatness better simultaneously and realize the decoupling of crown and flatness, the transverse displacement function of strip is defined and deduced. The factors that affects the width spread are analyzing with the function. According to the unchanged principle of volume before and after rolling, the flatness model which considers the width spread is deduced. Through the model, the transverse metal flowing of different stands and different thickness is analyzing, it is found that the width spread is biggest in cold rolling at the No.1 stand because of the maximum thickness and reduction and the minimum deformation resistance. It gives a good foundation for the decoupling of crown and flatness....

    2020-12-06 21:11:24浏览:28 widthspreadDecouplingcoldrollingtransversemetalflowingflatness

    查看
  • Lab experiments on the innovative rapid thick strip casting process

    Rapid thick strip casting (RTSC) by Anton Hulek,Inventmetall(R),is an innovative concept for the production of hot stops with a final as-cast thickness of about 25 mm before rolling.The innovation of the mechanism consists in a vertical mould performing a caterpillar motion.This moving mould has an unconventional parallelogram-shaped cross-section.The conventional rectangular shape is formed in the shaping machine,which is placed straight below the mould.Further elements of the technology are state-of-the-art.For the investigation of this new casting system theoretical calculations were complemented with practical experiments.The investigation focused mainly on two key aspects:the characteristics of the mould and the shaping process.For the practical analysis a static mould with three pairs of elements in laboratory scale was developed and commissioned by the Dept.of Ferrous Metallurgy @RWTH Aachen University.The shaping experiments were carried out in model scale with two different materials and in variable boundary conditions.The results of these experiments delivered important mechanical as well as thermal informations about the casting system....

    2020-11-22 17:58:37浏览:23 continuouscastingRapidSolidificationstripmetalmouldsnear-net-shape

    查看
  • Effects of tool flank wear on orthogonal cutting process of aluminum alloy

    The tool flank begins to wear out as soon as cutting process proceeds. Cutting parameters such as cutting forces and cutting temperature will vary with increasing degree of flank wear. In order to reveal the relationship between them, the theoretical situations of cutting process were analyzed considering the tool flank wear effect. The variation rules of cutting force, residual stress and temperature distributions along with the tool flank wear were analyzed comparing with the sharp tool tip. Through FEM simulation method, affections of the tool flank wear value VB on cutting forces, residual stress and temperature distributions were analyzed. A special result in this simulation is that the thrust force is more sensitive to tool flank wear, which can be used as a recognition method of tool condition monitoring. The FEM simulation analysis result agrees well with the experimental measuring data in public literatures and some experiments made also by the authors....

    2020-11-22 17:58:37浏览:33 aluminumalloyOrthogonalmetalcuttingfiniteelementsimulationtoolflank

    查看
  • Numerical simulation and experimental investigation of incremental sheet forming process

    In order to investigate the process of incremental sheet forming (ISF) through both experimental and numerical approaches, a three-dimensional elasto-plastic finite element model (FEM) was developed to simulate the process and the simulated results were compared with those of experiment. The results of numerical simulations, such as the strain history and distribution, the stress state and distribution, sheet thickness distribution, etc, were discussed in details, and the influences of process parameters on these results were also analyzed. The simulated results of the radial strain and the thickness distribution are in good agreement with experimental results. The simulations reveal that the deformation is localized around the tool and constantly remains close to a plane strain state. With decreasing depth step, increasing tool diameter and wall inclination angle, the axial stress reduces, leading to less thinning and more homogeneous plastic strain and thickness distribution. During ISF, the plastic strain increases stepwise under the action of the tool. Each increase in plastic strain is accompanied by hydrostatic pressure, which explains why obtainable deformation using ISF exceeds the forming limits of conventional sheet forming....

    2020-11-11 22:33:38浏览:32 incrementalsheetForming(ISF)metalnumericalsimulationfinite

    查看
  • Effect of Metal Contamination on the Performance of Catalyst for Deep Catalytic Cracking Process

    The effect of different metal contamination levels of catalysts for Deep Catalytic Cracking (DCC) on the distribu-tion and selectivity of DCC products was investigated in a FCC pilot unit. The pilot test results showed that the effects of the metal contamination level of catalyst on the propylene yield, the coke yield, the LPG yield, the gasoline yield, the selectivity of low carbon olefins, and coke selectivity was significant, and that the influence of metal contamination level on the conversion and dry gas yield was minor....

    2020-11-11 22:33:38浏览:26 lowcarbonOlefinsmetalcontaminationcatalyticcrackingpetrochemicals

    查看
  • Analysis of damage localization for ductile metal in process of shear band propagation

    Distribution of localized damage in shear band can' t be predicted theoretically based on classical elastoplastic theory. The average damage variable in shear band was considered to be a non-local variable. Based on non-local theory, an analytical expression for the localized damage in strain-softening region of shear band in the process of shear band propagation was presented using boundary condition and symmetry of local damage variable, etc. The results show that dynamic shear softening modulus, dynamic shear strength and shear elastic modulus influence the distribution of the localized damage in shear band. Internal length of ductile metal only governs the thickness of shear band. In the strain-softening region of shear band, the local damage variable along shear band's tangential and normal directions is non-linear and highly non-uniform. The non-uniformities in the normal and tangential directions of shear band stem from the interactions and interplaying among microstructures and the non-uniform distribution of shear stress, respectively. At the tail of the strain-softening region, the maximum value of local damage variable reaches 1. This means that material at this position fractures completely. At the tip of shear band and upper as well as lower boundaries, no damage occurs. Local damage variable increases as dynamic shear softening modulus decreases or shear elastic modulus increases, leading to difficulty in identification or detection of damage for less ductile metal material at higher strain rates....

    2020-11-11 22:33:38浏览:29 ShearbandductilemetaldamageLocalizationnon-localtheorystrainrate

    查看
  • Calculation of Solidification Process of Continuous Cast Bar

    In this paper, it presents the results of calculation of solidification process of copper continuous cast bar by cross section size 120 mm×70 mm with application of ProCast 2010 software. The estimation of mould design effect on solidification process of continuos copper cast bar is completed at various speeds of casting. Profiles of liquid metal cavities and temperature allocations in the cast bar at various casting speeds are defined. The analysis of received liquid metal cavity profiles shows that a new mold construction allows significantly decrease of the length of the liquid metal cavity during continuous copper casting at HAZELETT? casting machine and the increase of maximum casting speed from 10 to 11 m/min. Adequacy of the results of copper continuous cast bar solidification process calculation is confirmed by the experimental data....

    2020-11-10 09:33:08浏览:39 continuouscastingcopperCASTbarwatercoolingmoldliquidmetalcavityheat

    查看
  • Effects of vibration and grain refiner on microstructure of semisolid slurry of hypoeutectic Al-Si a

    The effects of vibration and grain refiner on the microstructure of semisolid slurry of hypoeutectic Al-Si alloy were studied. The impact of vibration on the convection of liquid was conducted by using a system of water-particle tracer. The 356 melt at temperature of 630-660 ℃ with or without grain refiner Al-5%Ti-1%B was poured into a metal cup as the vibrating vessel, then it was cooled to 590-610 ℃ in the semisolid zone and kept for some time, subsequently vibration with different frequencies was applied. The results show that the primary α(Al) particles become finer and rounder with the increase of vibration frequency. The slurry with primary α(Al) equivalent particle diameter(EPD) of about 90 μm and average shape coefficient(ASC) of about 0.5 can be prepared under vibration of 20 Hz. With the combined action of vibration and grain refiner Al-5Ti-B, even smaller and rounder spheroids with EPD of about 85 μm and ASC of about 0.6 are obtained....

    2020-11-03 10:30:25浏览:22 mechanicalvibrationhypoeutecticAl-Sialloysemisolidmetalgrainrefiner

    查看
  • Preparation of semi-solid AlSi7Mg alloy slurry with big capability

    Semi-solid AlSi7Mg alloy slurry was prepared by low superheat pouring and weak traveling-wave electromagnetic stirring.The effects of pouring temperature and stirring power on the microstructure of AlSi7Mg alloy slurry were studied.The results show that the semi-solid AlSi7Mg alloy slurry of 5 kg can be prepared.This new technology can save energy and make the pouring process convenient.When the pouring temperature is decreased at a stirring power of 0.41 kW,the shape of primary α-Al grains gradually changes from dendritic-like to spherical.When the alloy melt is poured at temperature(630℃)with a certain superheat,the pouring process becomes easier,and the spherical microstructure of AlSi7Mg alloy slurry can be prepared by the weak traveling-wave electromagnetic stirring.When the pouring temperature is 630℃,increasing the stirring power appropriately can result in better spherical primary α-Al grains,but if the stirring power is increased to a certain value(1.72 kW),the shape of primary α-Al grains does not obviously improve when the stirring power is continually increased....

    2020-11-03 10:30:25浏览:24 aluminumalloysmetalFormingsemisolidslurryelectromagneticstirring

    查看
  • Numerical simulation on electromagnetic field, flow field and temperature field in semisolid slurry

    A two-dimensional computational model coupling an annular electromagnetic stirring(A-EMS)with a macroscopic heat and fluid flow analysis in Al-alloys semisolid slurry preparation was developed.The dynamic evolutions of the electromagnetic field,flow field,and temperature field were presented successfully by commercial soft'ware ANSYS 10.0 with corresponding experimental verification.A horizontally rotational electromagnetic field and,thereby,a more intensive velocity field were uniformly distributed in the stirred melt even at com-mercial frequency,and thus,a lower temperature difference in the stirred melt and subsequent uniformly free mierostructures were obtained compared with the normal electromagnetic stirring.The simulation results were in good agreement with experimental ones....

    2020-11-03 10:30:25浏览:27 metalFormingelectromagneticstirringnumericalAnalysissemisolidslurry

    查看
  • Erosion Characteristics of Aluminum-based Metal Matrix Composites in Slurry Environments

    The erosion resistance of the Al18B4O33 whisker reinforced AC4C Al composites in water and saline slurry were investigated using a jet-in-slit rig. Erosion tests were performed at slurry velocities between 6.4 m/s to 15.2 m/s and at normal impact angle. The detachment of flake and dislodgement of whisker were identified as the major mechanisms of material removal in slurry environments. The composites showed better erosion resistance due to the protection of the matrix by the whisker at low slurry velocities. Because of reduced fracture strain, the erosion rates of the composites were generally greater than that of the unreinforced alloy at high slurry velocities. Owing to interfacial reaction which resulted in decrease in hardness and fracture strain,the T6 treatment for the composites had a deleterious influence on the erosion resistance. By considering the material removal processes in the water slurry, a simple rationalization of the inverse dependence of slurry erosion rate on Hεf was obtained. In the saline slurry, there exists a strong synergistic effect between erosion and corrosion. The volume loss of the composites was enhanced through cracking of flakes and detaching of whisker induced by stress and corrosion....

    2020-11-03 10:30:25浏览:21 slurryerosionerosion-corrosionflow-inducedcorrosionmetalmatrixcomposites

    查看
  • Hydrogen absorption of slurry system composed of different MgNi alloy and benzene

    The hydrogen absorption amount and kinetics of the slurry formed by suspending the MgNi alloy powderin liquid benzene were studied. It is discovered that hydrogen is absorbed by both the solid phase(alloy) and liquidphase(C6 H6) and the hydrogen absorption rate varies with the temperature and the content of the Mg-Ni in the slur-ry. Most hydrogen absorption curves of the slurry fall into two regions, in which the mechanism of hydriding reac-tion in the slurry system is different. In the former region, the hydriding of the alloy proceeds with hydrogen diffu-sing through C6 H6. The part in the second region is the outcome of the hydrogenation of C6 H6. At 548 K and underthe hydrogen pressure of 4.5 MPa the saturation capacity for the slurry of 80% C6 H6 (mass fraction)+20% MgNi(mass fraction) is 5.9% (mass fraction) hydrogen, which is 97% of the theoretic capacity of the slurry system.The hydride of the alloy MgNi, which is only the hydride of Mg2Ni phase, Mg2NiH4, is an efficient catalyst for thehydrogenation of C6 H6 into C6 H12 (C6 H6 +3H2→C6 H12 ) in the slurry system....

    2020-11-03 10:30:25浏览:26 MgNialloyslurrybenzenecyclohexanemetalhydride

    查看
  • 丙烯酰胺-丙烯酸-丙烯羟肟酸共聚物乳液脱除电镀废水中的重金属离子

    采用反相乳液聚合法合成了丙烯酰胺(AM)-丙烯酸(AA)-丙烯羟肟酸(AHA)共聚物乳液.考察了该共聚物配方中丙烯羟肟酸用量,共聚物乳液的投量和pH值对电镀废水中重金属离子的脱除效果.结果表明:pH=10,丙烯羟肟酸在共聚物乳液中的用量>15%,共聚物乳液的投量为20~30 mg/L时,脱除电镀废水中重金属离子的效果最好,Cr、Cu、Ni和Zn等重金属离子的脱去率>99.5%,处理后的水中每种重金属离子浓度<0.2mg/L....

    2020-10-26 22:14:25浏览:15 反相乳液羟肟酸重金属离子脱除废水inverseemulsionhydroxamicacidmetalionsremoval

    查看
  • 支化聚乙烯的合成及结构与性能

    以[ArN=C(An)-C(An)=NAr] NiBr2[An=acenaphthyl,Ar=2,6-C6H3(iPr)2]为主催化剂,以改性甲基铝氧烷(MMAO)和常规的甲基铝氧烷(MAO)为助催化剂,研究了压力、温度和时间等条件对乙烯聚合制备支化聚乙烯的影响,采用高温核磁、高温凝胶渗透色谱(GPC)及差示扫描量热仪(DSC)等对所得的聚乙烯结构进行表征.研究发现,以MMAO为助催化剂时,催化活性比以MAO为助催化剂时高约1个数量级,达到107 g/(mol Ni·h);所得聚乙烯的支化度为(45~64)/1000C,而以MAO为助催化剂时所得聚乙烯的支化度达(82~ 88)/1000C.对支化聚乙烯的力学性能进行了分析,并与低密度聚乙烯(LDPE)和二元乙丙橡胶(EPM)进行比较.结果表明,支化聚乙烯拉伸强度达27.90 MPa,比LDPE(14.40 MPa)和EPM (5.44 MPa)高,但支化聚乙烯的弹性模量仅为2.10 MPa,与EPM(2.11 MPa)相近;支化聚乙烯的断裂伸长率为774.6%,略高于LDPE的断裂伸长率(725.6%),比EPM的断裂伸长率(1770.1%)低....

    2020-09-28 16:47:12浏览:27 后过渡金属催化剂α-二亚胺合镍配合物乙烯聚合支化聚乙烯Latetransitionmetalcatalystα-Diiminenickel

    查看
  • Characterization of 17-4PH stainless steel powders produced by supersonic gas atomization

    17-4PH stainless steel powders were prepared using a supersonic nozzle in a close-coupled gas atomization system.The characteristics of powder particles were carried out by means of a laser particle size analyzer,scanning electron microscopy (SEM),and the X-ray diffraction (XRD) technique.The results show that the mass median particle diameter is about 19.15 μm.Three main types of surface microstructures are observed in the powders:well-developed dendrite,cellular,and cellular dendrite structure.The XRD measurements show that,as the particle size decreases,the amount of fcc phase gradually decreases and that of bcc phase increases.The cooling rate is inversely related to the particle size,i.e.,it decreases with an increase in particle size....

    2020-09-15 12:28:59浏览:25 gasatomizationmetalpowderstainlesssteelinjectionmolding

    查看
  • Study on chaos in short circuit gas metal arc welding process

    Based on the chaos theory, an idea is put forward to analyze the short circuit Gas Metal Arc Welding (GMAW-S) process. The theory of phase space reconstruction and related algorithms such as mutual information and so on, are applied to analyze the chaos of the GMAW-S process. The largest Lyapunov exponents of some current time series are calculated, and the results indicate that chaos exists in the GMAW-S process. The research of the chaos in the GMAW-S process can be help to get new knowledge of the process....

    2020-09-15 12:28:59浏览:35 chaosLyapunovexponentsshortcircuitgasmetalarcwelding

    查看
  • Transformation of methane to synthesis gas over metal oxides without using catalyst

    This article reviews a new developing method in the field of metal oxide reduction in chemical and metallurgical processes, which uses methane as a reducing agent. Commonly, coal is used as the reducing agent in the reduction of metal oxide and other inorganic materials; Metal producing factories are among the most intensive and concentrated source of greenhouse gases and other pollutants such as heavy metals, sulfur dioxide and fly ash. Thermodynamically, methane has a great reducing capability and can be activated to produce synthesis gas over a metal oxide as an oxygen donor. Metal oxide reduction and methane activation, two concurrent thermochemical processes, can be combined as an efficient and energy-saving process; nowadays this kind of technologies is of great importance. This new reduction process could improve energy efficiencies and significantly decrease greenhouse gas emission compared to the conventional process; furthermore, the produced gases are synthesis gas that is more valuable than methane. In this paper, thermodynamic studies and advantages of this promising method were discussed. The major aim of this article is to introduce methane as a best and environmentally friendly reducing agent at low temperature....

    2020-09-15 12:28:59浏览:36 methanemetaloxidereactionreductiongreenhousegasessynthesisgas

    查看
  • SHELL煤气化金属滤芯的安装和检查

    Shell的粉煤气化技术在中国得到了广泛的应用,作为气化核心装置的S-1501高温高压飞灰过滤器陶瓷滤芯断裂的问题,严重影响了系统的长周期运行,力学性能更优的金属滤芯渐渐得到了更多的应用,正确的安装可以保证金属滤芯和系统的长周期运行。...

    2020-07-12 21:36:56浏览:38 Shell煤气化金属滤芯安装和检查ShellcoalgasificationprocessUnitmetalfilterelement

    查看
  • 改性煤气化灰渣吸附重金属离子的研究

    以煤气化灰渣为原料,采用酸改性法(HF酸)制备改性煤气化灰渣.通过静态实验研究了改性煤气化灰渣对溶液中Pb2、Cu2+、Cd2的吸附特性,测定了溶液pH值、吸附时间、金属离子初始浓度对吸附的影响.结果表明,二级动力学方程很好的描述溶液中重金属离子在改性煤气化灰渣上的吸附过程;吸附等温线符合Langmuir模型,Pb2+、Cu2+、Cd2的静态饱和吸附量分别为112.07,40.18,31.21 mg/g....

    2020-07-10 14:39:05浏览:33 改性煤气化灰渣重金属离子吸附modifiedcoalgasificationslagheavymetalionsadsorption

    查看
  • Effects of environmental factors on corrosion behaviors of metal-fiber porous components in a simula

    To enable the use of metallic components in direct methanol fuel cells (DMFCs), issues related to corrosion resistance must be considered because of an acid environment induced by the solid electrolyte. In this study, we report the electrochemical behaviors of metal-fiber-based porous sintered components in a simulated corrosive environment of DMFCs. Three materials were evaluated:pure copper, AISI304, and AISI316L. The environmental factors and related mechanisms affecting the corrosion behaviors were analyzed. The results demonstrated that AISI316L exhibits the best performance. A higher SO42-concentration increases the risk of material corrosion, whereas an increase in methanol concentration inhibits corrosion. The morphological features of the corroded samples were also characterized in this study....

    2020-07-08 21:52:19浏览:21 corrosionmetalfibersPoroussinteringdirectmethanolfuelcellsEnvironmental

    查看
  • THE EFFECT OF POWERFUL OXYGEN EVOLUTION METAL-OXIDE ON THE ELECTROOXIDATION OF METHANOL

    An improved thermal decomposition method is used to prepare modified titanium base anode. Some researches have been carried out to learn about the oxygen evolution properties of RuMn, RuCo, RuCe and RuEu etc. in H2SO4 solution and their effect on the electrooxidation of methanol if added into the catalytic layers of Pt/Ti electrodes. The result indicates that the Pt/Ti electrodes containing RuMn, RuCo and RuEu etc. metal oxide catalysts with the powerful evolution property exhibit a higher electro-catalytic activity towards methanol electrooxidation than Pt/Ti electrodes without composite metal oxide catalysts....

    2020-07-08 21:52:19浏览:20 directmethanolfuelcellmetaloxidecoatingoxygenevolutionactivity

    查看
  • Assessment of Cu, Pb and Hg Contamination in Bottom Sediments Of Surface Water in XuZhou

    Pollution of heavy metals Cu,Pb and Hg is assessed using geo-accumulation index in this paper. The result shows that the bottom sediments of surface water in Xuzhou is polluted by these heavy metals to deferent degrees, of which the Jinma River is the most serious, and then the Kuihe River, the abandoned Yellow River, and the Jinghang Canal. The Yunlong Lake has also been polluted by Hg. The three kinds of heavy metals in the order of concentration is Hg>Cu>Pb. The pollution degree and the type of element is closely related with industrial structure in Xuzhou....

    2020-07-08 21:52:19浏览:23 srfacewaterbottomsedimentheavymetalcontaminationindexofGeo-accumulation

    查看
  • NF3 decomposition over some metal oxides in the absence of water

    NF3 decomposition in the absence of water over Al2O3, Fe2O3, CO3O4 and NiO, and transition metal oxides (Fe2O3, CO3O4 and NiO) coated Al2O3 reagents was investigated. The results show that Al2O3 is an active reagent for NF3 decomposition with 100% conversion lasting for 8.5h at 400℃. Fe2O3, Co2O3 and NiO coated Al2O3 reagents are superior to bare Al2O3, and 5%Co2O3]Al2O3 has a high reactivity with NF3 full conversion maintaining for 10.5 h. It is suggested that the presence of transition metal oxide is beneficial to the reactivity of Al2O3,and results in a significant enhancement in the fluorination of Al2O3....

    2020-07-08 21:52:19浏览:54 NF3decompositionmetaloxidesAl2O3reactivity

    查看

能化大数据平台 ©2010-2022 All Rights Reserved.  
沪ICP备14007155号-3 网站地图 化工热词旧版本
关于我们| 会员说明| 广告合作| 联系我们| 免责声明| 投稿须知|

能源化工大数据平台-煤化工网二维码
在线客服
服务邮箱

服务邮箱

cnmhg168@163.com

微信咨询
微信
返回顶部
X我的网站名称

截屏,微信识别二维码

微信号:anquanhun

(点击微信号复制,添加好友)

  打开微信

微信号已复制,请打开微信添加咨询详情!
[!--page.stats--]