核级波纹管密封钠截止阀的研制

介绍了核级波纹管密封钠截止阀的性能参数、结构及其主要零件的材料。分析了钠阀冷态循环、流阻、寿命试验及地震、热态试验的试验过程及其技术要求。阐述了钠阀门技术设计要点及其实践经验。     

T91+12CrlMoVG异种钢管焊接工艺的研究

文章对T91+12CrlMoV异种钢焊接工艺问题进行了研究,并对有关焊接工艺简化的可能性进行了探讨,通过对比试验和试验验证,提出了简单实用、可指导实际施工的焊接工艺。采用该工艺指导实际生产获得了良好的效果。     

硼酸镁晶须增强6061铝基复合材料的干摩擦磨损行为(英文)

研究搅拌铸造工艺制备的硼酸镁晶须增强6061铝基复合材料在干滑动条件下的摩擦磨损性能。复合材料的体积分数为2%,根据增强体种类,材料分别记为:Al基体、Mg2B2O5w/6061Al、ZnO/Mg2B2O5w/6061Al和CuO/Mg2B2O5w/6061Al;讨论磨损速率和摩擦因数之间的关系。结果表明:在4种材料中,ZnO/Mg2B2O5w/6061Al复合材料的磨损率最低。随着载荷和滑动速度的增大,基体和复合材料的摩擦因数和磨损率降低,摩擦磨损机制由轻微磨损机制转向严重磨损机制。     

视觉检测与激光精密测量在轴承加工检测中的应用

机器视觉测量技术是利用机器模拟人类视觉对待测工件的各种参数进行测量的一种新兴技术,测量速度快。利用面阵CCD传感器拍摄图像并结合相应的平面标定算法,即可测得工件的平面尺寸。此方法测量速度快,但精度相对较低。高精度激光位移传感器的测量精度较高,但测量速度相对较慢。结合以上两种视觉传感器的优点,提出一种同时具有高速、高精度特点的精密测量方法,并将其应用在精密轴承的制造、加工、检测中。     

Corrosion of nickel-chromium alloys, stainless steel and niobium at supercritical water oxidation conditions

Results of immersion tests of UNS N06625 (alloy 625), UNS S31609 (alloy 316 L), Ni-20Cr alloy and Nb coupons exposed to oxygenated ammoniacal sulphate solution at supercritical water oxidation (SCWO) conditions are presented. The corrosion behavior of the alloy 316 L (UNS S31603) SCWO reactor tubing is also presented under the same conditions. Immersion coupons corroded at a rate not exceeding 40 mm yr⁻¹ while the reactor tube itself corroded at a rate of between 160-1500 mm yr⁻¹, depending on which length of the reactor is considered to have corroded. Morphological and chemical analysis of the oxides present on the coupon samples suggest that iron oxides, which had initially precipitated on the corroding alloy 316 tube surface, were removed by heat flux-driven fluid mechanical action and transported through the reactor where they deposited on the coupons. Niobium was resistant to corrosion at the tested conditions.     

Ultrasonic evaluation of double poured rolls

Ultrasonic evaluation of the bonding characteristics in an infinitely chilled double poured rolls is carried out. During manufacturing process there are defects in the form of small holes or inclusions in these rolls. These defects act as points of stress in addition to the service stresses. By grinding, stress redistribution occurs. The shell–core interface is vulnerable to such stresses. Ultrasonic testing can be used to establish the critical points of these stress and hence predict their failure.     

泄漏检测技术在生产应用中问题的探讨

介绍了生产过程中常用的几种泄漏检测方法,对影响泄漏试验的一些因素,诸如测试容积,温度,测试压力、稳定时间及封堵形式等进行了讨论。     

浅论氮化钛涂层的硬度测量

在探讨测试涂层表面硬度正确方法的基础上,试图建立起超微负荷段试验力,硬度与涂层最小厚度之间的关系,为超薄涂层硬度测定进行试验参数的选择提供参考。介绍了一种新型超微负荷硬度计,它可以满足地进行硬度测量。     

Application of neuro-fuzzy techniques in oil pipeline ultrasonic nondestructive testing

This paper presents a novel approach to the problem of nondestructive pipeline testing using ultrasonic imaging. The identification of the flaw type and its dimensions are the most important problems in the pipeline inspection. Unlike typical methods, a decision based neural network is used for the detection of flaws. We train a generalized regression neural network to determine the dimensions of the corrosions and generate the whole image of both the internal and external walls of the oil pipeline. As an improvement to the detection algorithm, we introduce fuzzy decision-based neural network algorithms for the detection and classification of the corrosions. The simulation and experimental systems results show that these new methods outperform the existing methods.     

Microstructure and tensile properties of squeeze cast magnesium alloy AM50

High-pressure die cast magnesium alloy AM50 is currently used extensively in large and complex shaped thin-wall automotive components. For further expansion of the alloy usage in automobiles, novelmanufacturing processes need to be developed. In this study, squeeze casting of AM50 alloy with a relatively thick cross section was carried out using a hydraulic press with an applied pressure of 70 MPa. Microstructure and mechanical properties of the squeeze cast AM50 with a cross-section thickness of 10 mm were characterized in comparison with the die cast counterpart. The squeeze cast AM50 alloy exhibits virtually no porosity in the microstructure as evaluated by both optical microscopy and the density measurement technique. The results of tensile testing indicate the improved tensile properties, specifically ultimate tensile strength and elongation, for the squeeze cast samples over the conventional high-pressure die cast parts. The analysis of tensile behavior show that the strain-hardening rate during the plastic deformation of the squeeze cast specimens is constantly higher than that of the die cast specimens. The scanning electron microscopy fractography evidently reveals the ductile fracture features of the squeeze cast alloy AM50.