Volume and Surface Properties of Antimony-Containing Nickel Melts

A decrease in the detrimental effect of an antimony impurity in nickel is considered using structure-sensitive parameters, namely, density and surface tension. Samples of experimental heats containing 0.01–0.05 wt % Sb are prepared from a preliminarily cast master alloy. Antimony additions are found to increase the density of the nickel melt substantially. A negative density hysteresis appears in the temperature dependences recorded upon cooling. Antimony in the nickel melt is found to have a high surface activity and to decrease its surface tension strongly. When the melt is heated, its surface tension increases, which is accompanied by the passage of antimony into the volume and by changes in the volume and surface solution compositions.     

Effect of Secondary Melt Refining on the Properties of an EP602 Nickel Superalloy

The influence of argon blowing of the EP602 alloy melt in a ladle is considered. Ladle treatment during the manufacture of nickel superalloys is shown to form a more equilibrium and homogeneous structure of a melt, which leads to changes in the structure and properties of the solid metal.     

高镍锌白铜的性能研究

采用水平连铸－拉拔－轧制生产工艺锌白铜异材，对高镍锌白铜的金相组织，机械性能及退火工艺进行了研究。研究表明α单相高镍锌白铜具有优良的机械性能，适宜冷热加工，退火温度为７００－７５０℃，颜色为银白色。该材料完全能满足高档眼镜用异形材料的要求。     

用P507从硫酸镍溶液中萃取分离钙镁的研究

研究了用P507从硫酸镍溶液中萃取分离钙、镁，给出了萃取分离的最佳工艺条件为：温度60摄氏度，水相平衡pH6.00，相比1：1，P507的体积分数10％，皂化率20％，在此条件下，以P507和磺化煤油组成的有机相萃取分离效果较好。     

一种用于钴、镍分离的全界面接触高效萃取设备

介绍了一种全界面高效萃取分离钴、镍的新设备。利用自主研发的多相流涡轮增压反应器切割混合水相和有机相,使两相物料以微米级形态接触,增大了萃取反应相内接触表面积和反应动力学,克服了机械混合的缺点,使两相分离速度加快,而且不产生第三相,萃取反应级数从传统的9级降为3级,设备投入减少。优化后的镍、钴萃取分离工艺试验结果表明:在萃取剂与硫酸镍溶液体积比为1∶3、萃取剂皂化率50%~55%、反应温度45℃、3级逆流萃取条件下,钴萃取率达99.9%,萃余液中钴离子质量浓度达到要求(1mg/L)。     

Modeling of Melt Flow and Surface Standing Waves in a Continuous Casting Mold

Majority of surface and subsurface defects in the continuously cast steel may be attributed to surface standing waves and turbulence. A lot of work has been done on surface defects and on understanding the behavior of the surface waves but there is a dearth of literature connecting the two. Also 3‐D modeling of surface waves with heat transfer and solidification has received little attention. In the present study, a 3‐dimensional mathematical model incorporating turbulent fluid flow, heat transfer, and solidification using a commercial code, FLOW3D, was developed. Using the model, the applicability of Froude criterion for scaling down industrial flow systems was analyzed. Although the small scale models, using this criterion, correctly predict the general fluid flow but the prediction of surface waves is not very accurate. Also, the effect of temperature is difficult to incorporate in water models. The model was used to study the effect of temperature on surface waves and verify the water modeling results. The effects of casting and SEN parameters on the fluid flow and surface waves were studied.     

Use of a Reducing Melt to Treat the Surface of High-Alloy Steels and Alloys

The technological advantages of reducing melts are readily apparent. Such melts can dissolve certain acidic oxides (Si, Mo, W, Ti), and they reduce not only the oxides dissolved in the melt (ferrates, ferrites), but also those on the surface of the steel. A reaction involving sodium hydride completely reduces oxides of iron, nickel, cobalt, and copper and partially reduces oxides of chromium, manganese, vanadium, and titanium. Pickling schemes that have been developed reduce acid consumption and metal loss during pickling and prevent over-pickling of the surface. The technology as a whole is particularly suited for metallurgical plants that produce a wide range of steels. __________ Translated from Metallurg, No. 5, pp. 63–64, May, 2005.     

钨镍(W-Ni)的焊接性能及工艺

异种金属的有效连接在高新技术领域具有实际意义,采用电阻点焊方法焊接稀有金属钨片和镍丝.用SEM,HRTEM表征焊接接头的组织形貌,用拉伸试验机测定焊接件的抗剪切力.采用如下焊接工艺:第一阶段:预压力是100 N,使钨镍良好接触;第二阶段:保持预压力不变,施以预热电流1.1KA,400 ms,然后再施以焊接电流1.7KA...     

MLCC内电极用超细镍粉表面改性研究

利用还原法对超细镍粉进行表面改性，形成Ni—BO体系，从而提高镍粉的抗氧化性能。文章着重研究了NaBH4的用量、反应温度、PH值对超细镍粉抗氧化性的影响。最终确定了最佳条件。利用热重分析法DTA—TGA对镍粉的抗氧化性进行检测。研究表明，改性后镍粉的抗氧化性得到明显的改善。     

Relationship Between Degree of Homogeneity and Physical and Mechanical Properties of a Sintered Nickel Steel

Abstract

Commercial production of low-alloy steel components from blended mixtures of the constituents in powder form involves the use of sintering times which are too short to allow the production of a chemically homogeneous material. This has prompted an investigation into the relationships between the degree of homogeneity, microstructure, and mechanical properties in a sintered and heat-treated low-alloy steel, prepared in this way. A quantitative assessment has been made of the degree of homogeneity by measuring the nickel content of a large number of small areas within a complete cross-section of the specimen and this has been compared with plated and pre-alloyed material with the same overall composition but greater homogeneity prior to sintering. Provided the degree of homogenization was greater than a certain critical value the relationship between tensile strength and porosity fitted well with previously published work. The production of small quantities of non-martensitic phases from austenite during quenching was not detrimental in such alloys but, in quenched specimens of less homogenous alloys, residual austenite had a very detrimental effect on tensile strength, particularly when the austenite was distributed as a thin interparticle network. The relationship between tensile strength and porosity in these heterogeneous alloys did not agree with any of the accepted equations that represent this relationship.     

A Novel Heat Treatment Process for Surface Hardening of Steel: Metal Melt Surface Hardening

A novel heat treatment process for surface hardening of steel has been demonstrated and named as “metal melt surface hardening (MMSH).” A surface layer with a thickness of about 400 μm and a hardness of about 700 HV has been achieved by ejecting AISI 304 stainless steel melt at a temperature of about 1783 K (1510 °C) onto the 40Cr steel surface. This proposed MMSH provides a very promising application for surface hardening of steel.     

Preparation and Properties of Iron Powder Plated with Nickel and Cobalt

The magnetic properties (magnetic induction and coercive force) of iron powder coated with nickel and cobalt as a result of chemical deposition from hypophosphite electrolytes are studied. Thermogravimetry, differential thermal and x-ray phase analyses are used to study in detail the kinetics and mechanism of high-temperature oxidation in air (up to 1200°C) for the original and coated powders. The phase composition of oxide films on specimens annealed at all temperatures of the DTA-curve peaks is determined. The possibility of increasing the high-temperature oxidation resistance of iron powder coated with nickel or cobalt is demonstrated.     

镍熔炼渣物理化学性能研究及生态化利用前景

本文在分析镍熔炼渣的物理化学性能指标、研究方法以及分析检测手段的基础上,对目前镍渣物理化学性能研究现状进行了概述。针对镍熔炼渣的熔炼特点和废渣处理现状,探讨了镍渣固体废弃物的综合利用途径,并提出了生态化利用的可行工艺和方法。     

Electrode Process of Y~(3 )Ion on Molybdenum and Nickel Electrodes in YCl_3-NaCl-KCl Melt

The electrode process of Y~(3 )ion on molybdenum and nickel electrodes has been studied by cyclicvoltammetry and chronopotentiometry in the YCl_3-NaCl-KCl melt.The overall charge transfer process is atwo-step reaction:Y~(3 ) e=Y~(2 );Y~(2 ) 2e=Y.Yttrium reduced on the nickel electrode can form a series of Ni-Yalloys.X-ray diffraction analysis was employed to determine the alloy compositions formed under different con-ditions.     

金属间化合物Al3Fe熔体结构的计算机模拟

本文利用ＴＢ模型对Ａｌ３Ｆｅ熔体结构进行了分子动力学计算机模拟，详细考察了在快速弟固条件下Ａｌ３Ｆｅ熔体结构的温度变化特征，计算了不同温度下的偶分布函数，分析了在快速凝固条件下Ａｌ３Ｆｅ合金熔体的结构特点。     

Physical Properties and Solidification Structure of Al－SiEutectic Alloy Melt with Cerium Modification

ＰｈｙｓｉｃａｌＰｒｏｐｅｒｔｉｅｓａｎｄＳｏｌｉｄｉｆｉｃａｔｉｏｎＳｔｒｕｃｔｕｒｅｏｆＡｌ－ＳｉＥｕｔｅｃｔｉｃＡｌｌｏｙＭｅｌｔｗｉｔｈＣｅｒｉｕｍＭｏｄｉｆｉｃａｔｉｏｎＬｉＰｅｉｊｉｅ（李培杰）；ＧｕｏＪｉｎｇｊｉｅ（郭景杰）；ＪｉａＪｕ...     

Thermodynamic Properties and Mixing Thermodynamic Parameter of Binary Metallic Melt Involving Compound Formation

Massactionlaw,formulatedbyGuldbergand Waagein1864,showsthattheequilibriumconstant (ΔGθ)ofachemicalreactionisafunctionoftemper atureonly,andindependentfromtheconcentration ofreactantsandproducts.Itisanimportantsubject forallmonographsinthefieldofmetallu…     

Morphology and Magnetic Properties of Electrodeposited Iron and Nickel Based Alloy Foils

An alternative to conventional process for the preparation of soft magnetic metal foils of Fe, Fe-Ni, Fe-Co and Fe-Ni-Co by electroforming was described. The microstructure and magnetic properties were observed. The results showed that the crystal size of the iron-based alloy foil is less than 10μm, while that of nickel-based alloy foil is about 2μm. Moreover, the electroformed Fe-Ni foil has better magnetic properties than the conventional milled permalloy 1J79 foil.