316L和Hastelloy C合金在不同温度循环废酸中的耐蚀性能

为了解316L和HastelloyC合金在不同温度的循环废酸中的耐蚀性能,利用静态挂片试验、电化学试验和扫描电镜研究了2种合金在不同温度循环废酸中的腐蚀速率及形貌。结果表明：在50℃的循环废酸中,316L和HastelloyC合金均具有优异的耐蚀性,且耐蚀性相当;316L和HastelloyC合金的腐蚀速率均随循环废酸温度的升高而增加,316L合金的增加缓慢,HastelloyC合金的增加急剧;当温度由50℃升高到80℃时,循环废酸的氧化性增加,Mo含量较高的HastelloyC合金在循环废酸中不能形成完整、致密的钝化膜,从而使其耐蚀性急剧下降。     

废硫酸综合利用新技术问世

硫酸法钛白生产所副产的废稀硫酸是最大的环保隐患之一。如何破解这一严重制约我国钛白工业发展的瓶颈？由攀钢钢研院负责的“钛白废酸制取高钛料及酸解扩大试验研究”课题取得阶段性成果，为工业试验提供了可靠的技术路线和工艺参数。[编者按]     

电石渣中和钛白废酸的试验研究

硫酸法钛白粉生产中会产生大量的废酸,废酸的处理并达到环保要求是保证企业正常生产的前提,本次试验使用车间原有装置设备,采用电石渣代替常用的石灰石(石灰)进行中和钛白废酸的试验,试验证明电石渣可以作为中和钛白废酸的原料,达到降低成本,以废治废的目的。     

扩散渗析法回收不锈钢酸洗废液中硝酸

采用扩散渗析法回收不锈钢表面酸洗废液中的硝酸.实验比较了两种扩散渗析膜用于酸回收的分离性能,考察了废酸流量、废酸浓度等对动态扩散渗析回收酸的浓度和金属离子的截留率的影响.实验结果表明:APS型阴离子交换膜的性能略优于DSV型膜,在合适的条件下,硝酸回收率大于85%,金属离子截留率大于95%.结果表明扩散渗析对于酸和金属盐的分离是一个极其有效的工艺.     

冷轧酸洗工艺自动控制原理

介绍邯宝公司2080冷轧酸轧联合机组酸洗工艺段控制,通过对储酸罐的液位控制和温度控制,喷嘴喷酸的压力控制,废酸排放控制等参数进行控制,保证酸洗的有效进行,尽最大能力的去除氧化铁皮,提高带钢表面光洁度。     

达克罗涂液研究

通过正交试验优化了达克罗涂液的组分，并研究了涂液组成对涂层耐蚀性能的影响。优选组分为：涂液中酸总量占５％￣７％（质量百分数，下同），其中铬酸占６０％，硼酸占４０％，镍与铬当量比为０．２￣０．４，酸总量与氧化锌的质量比为４￣６，酸总量与金属粉的质量比为０．２￣０．３，其中锌粉占９０％，铝粉占１０％，表面活性剂占０．５￣０．７％，乙二醇占１５％￣１８％。     

尼尔森和布林贝哥喷射硝化工艺

这种硝化甘油生产的新方法是1950年由瑞典Nitroglycerin Aktiebolaget Gyttorp工厂的尼尔森(Nilssen)和布林贝哥(Brunnbe-rg)二人发展起来的。该方法的核心是甘油用喷射器硝化,硝化甘油的分离采用一个离心分离机。硝化酸流过喷射器吸入混有空气的适量甘油。硝化甘油与废酸形成乳状液。经过冷却之后,乳状液流入离心分离机,硝化甘油从废酸中分离出来并被送往洗涤工房。从1956年在工业上应用的N.A.B.工艺的主要特征如下:     

甘草酸的不同提取方法比较

目的比较水酸法和氨水法提取甘草酸含量的变化。方法利用正交试验4因素3水平选择最佳提取条件（包括加水量、提取次数、煮沸时间、粉碎时间、溶剂量、振荡时间、氨水浓度），用紫外分光光度法在252nm波长处测定甘草酸含量。结果每lOOg甘草粗粉用水酸法提取的最佳条件为：每次加水量2000mL，提取2次，煮沸5min，粉碎20s，氨水法最佳条件为：每次加0．4%氨水2000mL，振荡2h，提取2次。最终氨水法提取率为32％，水酸法提取率为26％。结论在最佳条件下，氨水法提取的甘草酸纯度和提取率明显高于水酸法。     

NG/TEGDN混合硝酸酯废酸安全处理工艺研究

研究采用稀释后热分解法处理硝化甘油/二缩三乙二醇二硝酸酯(NG/TEGDN)混合硝酸酯合成过程中产生的废酸的工艺参数。研究表明:处理后废酸是较理想的稀释介质,处理后废酸/处理前废酸流量比为2.5~3.0、处理温度为150~180℃、真空度为0.02~0.04 MPa、流量为1.8~2.0 L/min时,废酸处理效果较好,处理后废酸中酯含量0.5%,能稳定达标排放,且不影响安全和连续化生产。     

纳米ZrO2对合成不饱和聚酯树脂的影响

用“反应法”制备纳米ZrO2／UPR．是将纳米ZrO2粉在合成不饱和聚酯时加入。用正交优选试验得到合成树脂最佳配方为：二元酸与二元醇的摩尔比是1：1，饱和酸与不饱和酸的摩尔比是1：1，纳米ZrO2含量是7％，邻苯二甲酸酐与己二酸的摩尔比是1：1，过氧化苯甲酰用量为1％。经测试．纳米ZrO2／UPR弯曲强度和冲击强度分别为121．3MPa，10．1kJ／m^2．较UPR分别提高28．4％和16．1％，得到了同时增韧增强的树脂。     

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.     

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...     

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 ...