稀土元素在金属材料中的一些物理化学作用

针对不同金属溶液体系，采用了不同的实验方法，研究得到了铁液中Ｃｅ，Ｙ，Ｌａ，Ｎｄ，Ｓｍ分别与Ｓ，Ｏ，Ｓ＋Ｏ，Ｃ，Ｎ，Ｓｂ，Ｓｎ Ｐｂ，Ｐ，Ｃｕ，Ｔｉ，Ｎｂ，Ｖ溶质元素，镍液中Ｃｅ，Ｙ分别与Ｓ，Ｏ，Ｓ＋Ｏ溶质元素，铜液中Ｃｅ，Ｙ分别与Ｓ，Ｏ，Ｓ＋Ｏ，Ｓｎ，Ｚｎ，Ｐｂ，Ａｌ，Ｓｉ，Ｔｉ，Ｆｅ溶质元素，铝液中Ｃｅ分别与Ｍｇ，Ｔｉ，Ｍｎ，Ｚｎ，Ｆｅ，Ｓｎ，Ｐｂ，Ｎｉ，Ｃｕ，Ｓｉ，Ｓ溶质元素构成的６７个三元     

深井阳极地床的设计与施工

强制电流法阴极保护是埋在钢质管道防止腐蚀的有效方法，特别是在大口径，长距离等道施工中，得到普遍应用。强制电流法阴极保护的阳极地床是该方法的主体工程，一般采用浅埋阳极地床，但随着管道工业的飞速发展，长距离，大口径输气，输油，输水管道日益增多，如、西气东输”全长4100km输气管道正在兴建，途中的众多的管段要穿越江，河，湖，渠，管道深入地下，因此浅埋阳极地床已不能满足工程需要，必须采用深井阳极地床，才能取得优良的技术效果，本文对深井位置的选择，钻井方法，阳极组的安装，井底，井口的处理，阳极电缆敷设等工程设计和施工进行介绍。     

国外期刊题录

热处理Vol34，No3，1994热处理（日本）1994年第3期1．窒化素系现状上展望，氮化硅系陶瓷的现状和展望图5，照片2，表1，参考文献23，P119～124．2．W，Mo高温炉用情造材通用岛谷幸治，钨、钼应用于高温炉构件图4，照片2，表3，参考文献14，P，125～1303．3次元的结晶粒径分布评法松浦清隆，伊藤洋一，三维晶粒尺寸分布的评价法图5，参考文献19，P．131～1364．耐酸化性·耐热，藤田展弘，抗氧化性和耐热性优异的新型不锈钢的开发，图8，参考文献16，P．137～1425．铁系制振合金山田武海，铁系减振合金，图8，表3，参考文献11，P143～15…     

银的资源,应用与展望

本文介绍了银的矿藏资源在世界各地的分布情况，详细地叙述了近年来银在照相业，电影胶片业，电接点材料，电子工业，焊接业，能源工业，航空航天工业，超导材料，纤维复合材料，医学，货币，珠宝首饰和器具以及电镀等方面的应用开发和所占的比例，最后对银市场的供需情况进行了分析和预测。     

Hastelloy系耐蚀合金的性能及其应用

Ｈａｓｔｅｌｌｏｙ合金有Ａ，Ｂ，Ｃ，Ｄ，Ｆ，Ｅ系列，广泛用于盐酸，稀硫酸，磷酸，硝酸，有机酸，氢氟酸等介质。是化工，石油，化肥，原子能等工业中普遍使用的结构材料。对它们的研究与总结，有助于对这类材料的了解与选择。     

钨精矿中杂质元素ICP-MS测定方法的研究

采用电感耦合等离子质谱技术，研究了钨精矿中Sn，P，Ca，Nb，Ta，Mo，Cu，Pb，Zn，As，Mn，Bi，Fe，Sb 14种杂质元素含量的质谱分析方法。钨精矿样经NaOH-Na2O2碱熔后，加入硝酸，钨以钨酸的形式从溶液中沉淀而分离，消除了钨基体的干扰。在试样溶液中加入内标元素Sc，In，Tl，采用内标法进行校正，有效克服了基体效应、接口效应及仪器波动所产生的影响：通过优化仪器工作参数，选择适当的待测元素的同位素，有效地克服了因质谱干扰所带来的影响。方法的加标回收率为90．5％～101．5％，相对标准偏差为1．2％～7．8％，分析结果与按国家标准方法分析的结果相吻合，且具有快速、简便、准确等特点，可用于钨精矿及钨产品中杂质元素含量分析。     

高密度湿型的型砂性能要求

高密度造型方法对湿型砂性能的要求较普通机器造型更高，作者在文章中分别说明了高密度型砂的紧实率，含水量，透气率，湿态强度，粒度，有效膨润土量，有效煤粉量，韧性，起模性，流动性，可紧实性等性能对铸件品质的影响和控制范围，为此，作者还用附表中的工厂实际情况作为例证，在本文的最后还提出获得品质优良型砂的条件。     

新形势下中国铸造工业的战略考虑

中国经济进入新一轮增长期。自2000年起，中国铸件产量跃居世界第一，国内需求旺盛，铸件出口增加，铸件生产节奏加快，产品更新周期缩短。销售服务贯穿整个过程，环保条例更加严格，要求铸造企业思想要跟上形势，以战略目光，加强管理，提高人员素质，注重技术改造，规范原辅材料的品质，采用新技术，适应新形势，促进中国铸造业的持续发展。     

摩擦压力机操纵装置

摩擦压力机操纵装置，属于锻压机械领域，其特征在于：是由控制系统、执行系统组成的电操纵装置，控制系统由手柄，传感器，电机控制器组成，手柄与传感器相连，传感器与电机控制器相连，执行系统是由偏心部件，减速机，连杆，电机组成，电机与减速机相连，减速机与偏心部件、连杆相连。具有能耗低，可降低80％，操纵装置更协调、灵便，噪音低，改善工作环境，因避免了空气压缩机运行时产生的噪音及排放废气造成的扬尘现象等优点。     

数控凸轮磨床的驱动

关干柴油机凸轮轴的加工，以往只能采用靠模凸轮磨床来磨削，现在则采用数控加工方式，根据凸轮型线对角度座标的升程，来编制加工程序，让砂轮按型线的要求往复运动，从而磨削出合格的型线面（图1）。图1中，R为凸轮轴的基圆半径，H为对应角度D的升程，D。为升程起点，r为砂轮半径，凸轮中心A和砂轮中心B在同一水平面上，当A，B间距离为R＋r时，磨削基圆，当凸轮轴转到D。位置时，砂轮按型线要求后退，凸轮型线上升，当D超过叨度时，砂轮按型线要求前进，凸轮型线下降，如果程序恰当，就可以磨出合格的型线面。有了编辑正确的程序，还…     

The Seepage Characteristics of Heterogeneous Body With Different Spreading Solution Modes and its Applications

As the dump was a typically heterogeneous body, the seepage was different with varied spreading solution modes. The phenomenon of lamination that occured in the site was simulated using three layers in an indoor experiment, and the seepage effect comparison experiment of the inside spreading solution model and the top spreading solution model have been carried out. In the inside spreading solution mode, the phreatic planar flew without infiltration and the parallel layer motion model was used to calculate the seepage coefficient and equivalent seepage coefficient of each state respectively. In the top spreading solution model, the phreatic planar flew with an even infiltration on the surface, and the vertical layer motion model was adopted to calculate the above coefficient. The results showed that the seepage coefficient of the inside model was larger than the top model in the heterogeneous body, The ratio of them was between 1.42 and 3.07. On the basis of these results, the following new technologies were discussed: installing a few small diameter mechanical pore sand piles with every lamination in the using dump; drilling some holes one-off in the unused dump. These two methods could changed the top spreading solution into the inside model, thus the seepage in the dump was improved.     

Three-Dimensional Growth of Coherent Ferrite in Austenite: A Molecular Dynamics Study

Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

Coupled Influence of Temperature and Strain Rate on Tensile Deformation Characteristics of Hot-Extruded AZ31 Magnesium Alloy

To explore the coupled effect of temperature T and strain rate_e on the deformation features of AZ31 Mg alloy,mechanical behaviors and microstructural evolutions as well as surface deformation and damage features were systematically examined under uniaxial tension at T spanning from 298 to 523 K and_e from 10-4to 10-2s-1. The increase in T or the decrease in_e leads to the marked decrease in flow stress, the appearance of a stress quasi-plateau after an initially rapid strain hardening, and even to the occurrence of successive strain softening. Correspondingly, the plastic deformation modes of AZ31 Mg alloy transform from the predominant twinning and a limited amount of dislocation slip into the enhanced non-basal slip and the dynamic recrystallization(DRX) together with the weakened twinning. Meanwhile, the cracking modes also change from along grain boundaries(GBs) and at twin boundaries(TBs) or the end of twins into nearby GBs where the DRX has occurred. The appearance of a stress quasi-plateau, the formation of large-sized cracks nearby GBs, and the occurrence of continuous strain softening, are intimately related to the enhancement of the non-basal slip and the DRX.     

Formulas of Tension of Continuous Rolling Process

The development of computer controlled continuous rolling process calls for a mathematical expression that can express the inequality condition of "constant flow". Tension is the link of the continuous rolling process. From the condition of dynamic equilibrium, a differential equation of tension is given out. On the basis of the physical rules established from the industrial practice and experimental studies, the law of volume constancy, the linear relation of forward slip and tension, the state equation of continuous rolling, the formula of dynamic tension, and the formula of static tension have been obtained. These formulae reflect the functional relations between tensions, thickness, roll velocity, and time in the continuous rolling process. It is implied that the continuous rolling process is a gradually steady, controllable, and measurable dynamic system. An assumption of predicting the thickness of a steel plate using these tension formulae is also put forward.     

Properties of Mechanically Milled Nanocrystalline and Amorphous Mg–Y–Ni Electrode Alloys for Ni–MH Batteries

Nanocrystalline and amorphous Mg2Ni-type Mg20-xYxNi10(x = 0,1,2,3 and 4) electrode alloys were fabricated using mechanical milling.The effects of the Y content and milling time on the microstructures and electrochemical performances of the alloys were investigated in detail.X-ray diffraction and transmission electron microscopy analyses revealed that the substitution of Y for Mg yields an obvious change in the phase composition and micro morphology of the alloys.When the Y content x B 1,the substitution of Y for Mg does not change the major phase Mg2 Ni,but with a further increase in the Y content,the major phase of the alloys transforms into the YMg Ni4 YMg3 phase.A nanocrystalline and amorphous structure can be obtained by mechanical milling,and the amorphisation degree of the alloy visibly increases with increased milling time.Electrochemical measurements indicate that the discharge capacity of the alloys first increases and then decreases with increasing Y content and milling time.The substitution of Y for Mg dramatically ameliorates the cycle stability of the as-milled alloys,and the mechanical milling more or less impairs the cycle stability of the alloys.Furthermore,the high rate discharge ability,electrochemical impedance spectrum,Tafel polarisation curves and potential step measurements indicate that the electrochemical kinetic properties of the as-milled alloys first increase and then decrease with increasing Y content and milling time.     

Effect of boron and carbon on the fracture toughness of IN 718 superalloy at room temperature and 650 °C

The effect of B and C microadditions on the fracture toughness of IN 718 superalloy was investigated at room temperature (RT) and at 650 °C. At RT, the fracture toughness was observed to increase with increasing B and C concentrations. C had a relatively weak effect on the fracture toughness at 650 °C, but the influence of B was significant. At RT the highest fracture toughness value was obtained for the alloy with 29 ppm B and 225 ppm C at RT, and at 650 °C the alloy with 60 ppm B and 40 ppm C had the highest fracture toughness. An increase in the concentration of B to 100 ppm, however, resulted in a reduction in the fracture toughness at 650 °C. Fractographic observations showed that the formation and coalescence of microvoids was the predominant fracture mechanism at RT. In contrast, at 650 °C, the fracture surface exhibited intergranular cracking in the alloy with lower B concentrations and transgranular cracking coupled with fine dimples in the alloy with higher B concentrations. It is suggested that B impedes intergranular cracking by increasing the cohesion of grain boundaries and improving the grain boundary stabilization. The RT increase in the fracture toughness of the material caused by the addition of C is attributed to the formation of intergranular and intragranular carbides that increased the resistance to the plastic deformation.     

A Concordant Shift Model for Flow in Bulk Metallic Glasses

The homogeneous plastic flow in bulk metallic glasses(BMGs) must be elucidated by an appropriate atomistic mechanism. It is proposed that a so-called concordant shifting model, based on rearrangements of five-atom subclusters,can describe the plastic strain behaviour of BMGs in a temperature range from room temperature to the supercooled liquid region. To confirm the effectiveness of the atomic concordant shifting model, a comparative investigation between the vacancy/atom model and the concordant shifting model is carried out based on the estimation of the strain rate deduced from two models. Our findings suggest that the atomic concordant shifting model rather than the vacancy/atom exchange model can well predict the large strain rate in the superplasticity of BMGs.     

38CrMoAl钢螺杆氮化表面剥落原因分析

在生产螺杆过程中,螺杆表面出现剥落麻点现象,通过宏观、扫描电镜、金相显微镜和光谱等方法对螺杆氮化表面剥落原因进行分析,结果表明：螺杆表面出现剥落麻点的原因是由于氮化处理前磨削至局部螺纹棱角处时温度偏高,使棱角处及其附近的表面及浅表层产生轻微的沿晶裂纹,在后续磨削过程中,棱角处易剥落形成麻点。     

Stress Analysis of the Aperture in Compound Pipeline by FEM

There is a cyclical aperture at a certain part of the fiberglass reinforced plastic compound pipeline with a stainless steel pipe as a liner, which becomes the weakness of the conduit. The field of stress and strain of the aperture was investigated using the nonliner finite element code Marc. The results of the finite element analysis showed that there were concentrations of stress and strain in the layer of stainless steel at the part of the pipeline where the aperture existed. The method to solve these problems was also discussed.