Ni-W-P镀层耐地下深层高盐卤水腐蚀性能

为了探讨Ni-W-P合金镀层耐地下深层高盐卤水的腐蚀性能及机理,在N80钢表面分别化学镀和电沉积Ni-W-P合金层.采用动电位极化曲线和静态全浸腐蚀试验研究了2种镀层在地下深层高盐卤水中不同环境下的腐蚀行为;利用SEM和EDS分析了2种Ni-W-P镀层腐蚀前后的表面形貌和成分.结果表明:2种Ni-W-P镀层的腐蚀电位均比N80钢基体的高,对N80钢基体形成了阴极保护;2种Ni-W-P镀层的腐蚀都很慢,是一种性能优异的N80钢耐蚀保护镀层.     

温度对注气井P110油管钢耐蚀性能的影响

目前,对于注气工况下井筒存在的氧腐蚀问题及其影响因素研究较少。利用高温高压反应釜进行腐蚀模拟试验,辅以失重法、SEM、EDS、XRD等测试手段,研究含氧工况下温度对P110油管钢耐蚀性能的影响。结果表明:温度通过改变溶液中的氧含量、电化学反应速率、溶解氧的扩散作用以及表面产物层而影响P110钢耐蚀性能。温度升高,电化学反应加速,溶解氧扩散加快,CaCO_3垢层脱落,腐蚀速率增大;溶解氧含量下降,又会导致腐蚀速率下降。温度的双重作用导致P110腐蚀速率先增大后减小,100℃时最大,且会发生局部腐蚀。     

低成本Al-Ti-Cr高强耐海水腐蚀钢耐蚀性能研究

本工作以普碳钢为基体,添加Cr、Ti、Al等元素制备了新型低成本高强耐蚀钢,通过动电位极化、交流阻抗、周浸腐蚀实验和盐雾加速腐蚀实验研究了低成本Al-Ti-Cr高强耐蚀钢的耐海水腐蚀性能.结果表明:钢中的Cr能促进锈层向致密的α-FeOOH进行转变;Al和Ti提供阳极保护的同时,Al还能产生致密的Al2O3分散在锈层表面延缓腐蚀介质向基体的侵蚀,而Ti能够呈点状或者片状富集在锈层内部,对晶间腐蚀起到一定的保护作用,大幅度提高了耐蚀钢的耐蚀性能.     

固溶体型Fe-Co-Ni多元合金镀层在海水环境下的耐蚀性研究

采用电沉积技术,在Q235钢基体上用硫酸盐溶液制备Fe-Co-Ni多元合金镀层。研究温度、电流密度、pH值等工艺参数对该多元合金镀层在模拟海水环境下耐蚀性能的影响。采用XRD、SEM、EDS等分析手段,分别研究Fe-Co-Ni合金镀层的结构、表面形貌及其化学成分,表明该多元合金镀层由94.92%(质量分数)Ni,2.58%(质量分数)Co和1.47%(质量分数)Fe构成,为固溶体结构,且表面平整、组织致密。电化学方法研究该多元合金镀层在海水环境下的耐蚀性,结果表明其耐蚀性显著优于304不锈钢,且在pH值为3.8、电流密度为6A/dm2、温度为50℃的工艺条件下制备的合金镀层具有最好的耐蚀性能。     

淡水泥浆钻杆化学镀Ni-P层的防护性能

G105钢油田钻杆在淡水泥浆中腐蚀严重,为此,对其进行化学镀高磷Ni-P层处理.用附带能谱仪的扫描电镜观察了镀层形貌、分析了镀层成分,用测厚仪测试了镀层厚度;通过动态模拟腐蚀装置考察了流速对G105钢及Ni-P镀层腐蚀速率的影响,比较了油田现用的有机涂层和Ni-P镀层的耐高温腐蚀性能和耐磨蚀性能.结果表明:Ni-P镀层表面呈胞状,磷含量为13.23％,属高磷耐蚀镀层;流速对Ni-P镀层腐蚀速率影响较小,Ni-P镀层耐蚀性明显优于G105钢;有机涂层经10 h强化磨蚀就发生损伤,Ni-P镀层50 h基本没有变化;低流速下,有机涂层高温腐蚀10 h而鼓泡,Ni-P镀层则没有变化.     

热浸镀层的海水全浸腐蚀行为研究

在舟山站进行了锌铝合金镀层的海水全浸腐蚀试验,失重腐蚀测试结果表明,其腐蚀深度随全浸时间按抛物线规律变化。XRD和EPMA分析结果表明,镀层表面的钙质沉积层与镀层金属的腐蚀产物及其凝聚的粘土胶体一起构成的复杂的腐蚀产物层,抑制了镀层腐蚀的传质过程和受扩散控制的氧去极化作用,从而使锌铝合金镀层表现出优异的耐海水腐蚀性能。     

暂态线性极化技术研究Galfan与Galvalume的耐蚀性能

利用暂态线性极化技术测定了Zn镀层以及Galfan、Galvalume镀层在不同腐蚀介质中、不同pH下的极化电阻Rp值，以及Rp随时间的变化规律。结果表明，腐蚀刚开始时，在pH=5和pH=7的lmol／L NaCl、0．5mol／L Na2SO4、0.5mol／L NaCl 0．25mol／L Na2SO4腐蚀介质中，Galfan的Rp均约为Zn镀层的2倍，Galvalume的Rp均约为Zn镀层的3倍。腐蚀一定时间后，Zn镀层和Galfan的R，均逐渐降低，而Galvalume的Rp除在lmol／L NaCl腐蚀介质中外皆不断升高。表明Galvalume的腐蚀产物对镀层有保护作用，使其耐蚀性进一步提高。     

船用907钢表面化学镀耐冲刷腐蚀型NiMoB合金层的工艺参数优化

为提高船用907钢的耐冲刷腐蚀性能,设计了一种可与船用907钢海水管路内壁表面形成稳定化合物的NiMoB合金镀层,并采用正交试验优选了该化学镀液中NiCl_2,EDTA,Na_2MoO_4,KBH_4的浓度。采用扫描电镜观察合金镀层形貌;采用阻抗谱、极化曲线分析了合金镀层在模拟海水中的耐蚀性,并在模拟海水冲刷腐蚀环境下分析了Ni Mo B镀层的抗冲刷腐蚀特性。结果表明:不同的镀液参数对Ni Mo B镀层的性能影响较大,当NiCl_245.0g/L、EDTA 9.0 g/L、Na_2MoO_415.0 g/L、KBH_40.8 g/L,乙二胺45.0 g/L,NaOH 90.0 g/L时,NiMoB非晶态薄膜表面呈胞状物陈列,具有致密的表面形貌,镀层的耐腐蚀、抗冲刷腐蚀性能优良。     

Ni-SiC复合梯度镀层的耐腐蚀性能

Ni-SiC复合梯度镀层比普通复合镀层性能要优,应用要广,但过去对其耐蚀性研究不多.通过对电流密度、搅拌强度和镀液中Sic浓度等电镀工艺条件的优化,制备了新型Ni-SiC复合梯度镀层.采用扫描电镜对其表面和断面形貌进行了观察,并借助电化学手段研究了Ni-SiC复合镀层在3.5%Nacl腐蚀液和3.5%NaCl+0.3%H2O2腐蚀液中的耐蚀性能.结果表明:在复合镀层中,SiC微粒沿镀层生长的方向呈梯度分布,在镀层表面呈均匀弥散分布;在3.5%.NaCl腐蚀液中纯镍镀层的耐腐蚀能力与复合镀层相当;在3.5%NaCl+0.3%H2O2腐蚀液中,由于SiC微粒包裹在Ni-SiC复合镀层内,彻底改变了镀层的表面形貌和组织结构,细化了镀层晶粒,所以改善了Ni-SiC复合镀层的耐蚀性能.     

Ni-P-WC和Ni-P-SiC复合镀层的耐磨和耐蚀性能比较

为了给Ni-P-WC和Ni-P-SiC复合镀层替代传统镀铬层在液压活塞、活塞杆的应用提供依据,在Q345钢表面电镀了Ni-P-WC和Ni-P-SiC复合镀层.对比了该2种复合镀层的结合力、厚度、热处理后的显微硬度、孔隙率、表面SEM形貌以及镀层的元素组成,通过磨擦磨损试验、二氧化硫试验、中性盐雾试验、硫化氢试验和浸泡腐蚀试验比较了2种复合镀层的耐磨和耐蚀性能.     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...     

Brainstorming for ISO Strategy 2016-2020

正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from     

CNAS Passes APLAC's PTP Review

正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively.