清洁型常温锌系磷化液研究

为使磷化实现清洁生产,开发了一种用于钢铁表面涂装前处理的清洁型常温锌系磷化液,实现了磷化液的所有分子均能参加成膜反应且产物为磷化膜、水、沉渣或在磷化膜干燥过程中挥发的设计思路.该磷化液不含亚硝酸盐、重金属(除锌外),在3～40℃下快速磷化可生成膜重≥0.90g/m2、耐CuSO4溶液点滴时间达160 s的彩色磷化膜.磷化前免表面调整,磷化后免水洗.     

中温锌系磷化膜及皂化膜的组织结构研究

为深入研究磷化皂化润滑机理及改进磷化皂化工艺,利用扫描电镜(SEM)、电子探针(EPMA)、X射线衍射(XRD)等手段对中温锌系磷化膜及硬脂酸钠皂化膜的表面形貌、截面形貌、组织结构以及成分组成进行了研究.结果表明:中温锌系磷化膜主要以磷酸锌(H膜)为主,并有少量磷酸锌铁(P膜),磷化膜表面有棒状和球状两种形貌结构,磷化膜厚度约为20μm.经过皂化后膜层分为磷酸锌、硬脂酸锌和硬脂酸钠三层,硬脂酸锌和硬脂酸钠具有很好的润滑效果,皂化膜表面为棉絮状形貌.     

改性锌系磷化工艺

改性锌系磷化工艺,是在中温磷化液中,加入一种改性离子和催化剂,即可获得结晶均匀细致的磷化膜的工艺。它具有反应速度快,抗蚀性能好等优点。     

常温锌系快速彩膜磷化工艺研究

为提高磷化膜的装饰效果,开发了一种常温锌系彩色磷化工艺。探讨了磷化液中各组分及操作条件对彩色磷化膜质量的影响,并对所得到的磷化膜性能进行了测试。结果表明,用该工艺儿得的磷化膜色泽均匀、鲜艳,具有较好的装饰效果。磷化液使用寿命长、成本低、潮水上,适用于钢铁件的表面装饰和涂装的底层处理。     

新型中温锌钙系磷化工艺

已有的磷化液中含有一些添加剂,会产生大量的沉渣,对磷化液进行优选,可以提高磷化质量。研制了一种用于钢铁制品的新型锌钙系中温磷化液。讨论了游离酸度、总酸度、促进剂、磷化时间、磷化温度、某些离子和杂质对磷化膜的影响,总结出了最佳工艺条件。     

钢铁的锌系磷化

综述了钢铁锌系磷化的机理及影响因素，并对其发展趋势了展望。     

三元复合添加剂复配比例对钢铁锌钙系黑磷化的影响

已有的中温锌钙系黑色磷化膜的黑色度、均匀度、附着力及耐蚀性较差,为了克服这些缺点,在中温锌钙系黑磷化液中加入复合添加剂,研究了添加剂复配比例对黑磷化液稳定性以及磷化膜外观质量、耐蚀性、耐磨性的影响,确定了添加剂最佳复配比例,并测试了最佳复配比例时制得的磷化膜的组织结构.结果表明:当4.8 g/L柠檬酸三钠、4.0g/L EDTA-2Na和1.6 g/L硝基胍三元复配时,磷化液无沉渣,磷化膜表面黑亮光滑,孔隙少,晶粒细致均匀,耐蚀性及耐磨性良好.     

冷成型模具低温锌系磷化

研制出适用于冷成型模具高硬度表面的低温锌系磷化工艺。其中磷化液含Zn(H2 PO4 ) 2 ·2H2 O 6 0g/L ,Zn(NO3) 2 ·6H2 O 90g/L ,NaNO2 1.5g/L ,稀土促进剂 0～ 1.0g/L ,游离酸度 4～ 6点 ,总酸度 70～ 75点。该磷化液在 4 0℃下 ,处理 30～ 4 0min后可获得厚约 10 μm的磷化膜。性能测试表明 ,其减摩、润滑性能良好 ,摩擦系数约降 0 .1,与未处理试样相比磨损量下降 96 % ,附着力 1级。     

高速锌系磷化液及磷化工艺

从磷化的动力学和热力学原理出发，借助促进剂、晶粒细化剂的研究，通过正交试验等手段研制出ＰＡ３７７－３高速锌系磷化液及磷化工艺，性能测试和生产应用结果表明，该磷化液５０～５５℃时能在１０～１５ｓ内形成２～４μｍ的磷化膜，磷化膜与油漆具有优良配套性。     

高耐蚀性中温单组分锌钙系磷化液的研究

提出了高耐蚀性中温单组分锌钙系化新工艺，研究了诸因素对磷化膜耐蚀性的影响。通过定量分析，研究了化液的磷化面积以及游离酸度随面积的变化规律，并讨论了化液周期性调整的判据及以原液进行调整的可能性，为提高磷化液的稳定性提出了一种可供选择的方法。     

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.……     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

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.     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

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 ...