Incoloy 800波纹管膨胀节开裂失效分析

金属波纹管膨胀节具有热补偿功能,应用越来越广,同时其失效开裂问题也日益显现.为此,从宏观形貌、化学成分、金相显微组织、SEM微现形貌方面,对开裂的Incoloy 800波纹管膨胀节进行了分析.结果表明,波纹管膨胀节开裂的原因是高轴向拉应力条件下的材料失稳破裂,并提出了相应的改进措施.     

波纹管膨胀节实际应用中的腐蚀分析与防护对策

腐蚀破坏是波纹管膨胀节失效的一个重要原因。通过对催化裂化装置用波纹管膨胀节及城市区域供热用外压波纹管膨胀节的腐蚀破坏情况进行分析 ,探讨其腐蚀机理 ,提出了相应的防护对策。     

316L不锈钢波纹管膨胀节开裂原因分析与预防

某厂的316L不锈钢波纹管膨胀节在使用近3a(年)发生了穿透性开裂。采用化学成分分析、宏观及微观检验等方法对该波纹管膨胀节开裂的原因进行了分析。结果表明:氯化物应力腐蚀开裂是该波纹管开裂的主要原因,并提出了相应的预防措施。     

固冲推力测量进气管路振动特征研究

针对冲压发动机地面直连式试验推力测量数据振动现象,利用LabWindows/CVI编程对实际推力测量试验数据进行了频谱分析;探讨了进气管路失稳条件,给出了横向振动固有频率,采用有限元方法对波纹管进行了模态计算。分析表明所述振动问题主要诱因为垂向波纹管的横向振动与轴向波纹管轴向振动,提出了改进方案,多次发动机热试验验证了分析结果的正确性。     

金属波纹管膨胀节的新发展

<正> 金属波纹管膨胀节从80年代初至今已被广泛用于国民经济建设中。洛阳船舶材料研究所经过20多年的研制生产,目前已具相当规模。建成了比较完整的科研、生产、检测、试验的一体化生产线。 1992年完成了“高压波纹管的研究”、“直埋式膨胀节的研究”、“波纹管选材研究”、“烟机旋转接头用S形波纹管的研究”等研究项目。其中直埋式膨胀节已     

浅析空调供热（冷）管道波纹管补偿器失效及支架破坏

空调水系统室外管道(冷热两用),采用波纹管膨胀节消除热胀冷缩产生的位移,本文针对运行过程中波纹管膨胀节失效及管路支架损坏的情况进行了原因分析,并结合某高层建筑工程实际,提出了解决问题的方法和建议,以保证空调水系统能正常安全地运行。     

波纹管膨胀节在石油化工码头上的应用

石油化工码头管线建设中,膨胀节的设置是必要的。本文从波纹管膨胀节的选型、管架布置及安装要求作一阐述,以供同行借鉴。     

外压型不锈钢波纹管膨胀节开裂分析

奥氏体不锈钢外压轴向型波纹管膨胀节在使用较短时间后发生了开裂。采用化学成分分析、金相检验和断口分析等方法对开裂的原因进行了分析。结果表明:波纹管膨胀节的工作介质过热蒸汽中含有腐蚀性氯离子,在服役环境下受到拉伸应力的作用,导致其发生了应力腐蚀开裂。     

不锈钢波形膨胀节简介

一、概述 金属波纹管系一种减振防噪、缓冲的机械元件,也可以用于管路上作为管道热胀冷缩的补偿元件,因而广泛应用于造船、石油化工及动力等工业部门的设备和管道系统。随着我国工业建设的发展,对金属波纹管的研究、试制和生产也受到应有的重视。本文简要介绍无锡减震器厂生产的柴油机排气管路用的不锈钢波形膨胀节(以下简称膨胀节),并以此为例介绍波形膨胀节的结构和设计计算。     

波纹管膨胀节变形精确解

对工程实际中所遇到的典型单平面Ｚ型管段及两平面空间Ｚ型管段中所布置的波纹管膨胀节的变形状态进行了分析，并通过代数和几何方法求出了各波纹管膨胀节的变形精确解。通过实例，将精确解的计算结果与近似解的计算结果进行了比较。     

Estimation of Parameters of Universal Distribution of Moments of Failure of Products

A method is proposed for estimating the parameters of a mixture of exponential and Weibull distributions for which the accuracy of preliminary estimates obtained by graphical analysis is refined in accordance with the criterion of maximum likelihood. The efficiency of the proposed method is supported by the results of statistical modeling.     

Analysis of the rate of propagation of the wave of change of boiling modes

An approximate analytical expression is derived for the velocity of the front of the wave of change of boiling modes on a rod and on a plate. The impact of the Thomson effect and of the heater orientation in the gravity field is included. Adequate agreement is demonstrated between the derived relations and experimental data.     

Evaluation of optical properties of highly scattering media by moments of distributions of times of flight of photons

A novel method for the determination of the optical properties of tissue from time-domain measurements is presented. The data analysis is based on the evaluation of the first moment and the second centralized moment, i.e., the mean time of flight and the variance of the measured distribution of times of flight (DTOF) of photons injected by short (picosecond) laser pulses. Analytical expressions are derived for calculation of absorption and of reduced scattering coefficients from these moments by application of diffusion theory for infinite and semi-infinite homogeneous media. The proposed method was tested on experimental data obtained with phantoms, and results for absorption and reduced scattering coefficients obtained by the proposed method are compared with those obtained by fitting of the same data with analytical solutions of the diffusion equation. Furthermore, the accuracy of the moment analysis was investigated for a range of integration limits of the DTOF. The moment analysis may serve as a comparatively fast method for evaluating optical properties with sufficient accuracy and can be used, e.g., for on-line monitoring of optical properties of biological tissue.     

可燃气体检测报警器测量结果的不确定度评定

本文详细介绍了可燃气体检测报警器示值误差测量结果的不确定度评定方法。     

水三相点复现的不确定度评定

水三相点是开尔文热力学温度的唯一基准点，也是ITS-90国际温标重要的定义固定点。因此，水三相点不确定度分析对整个温标的建立、温度量值传递起着至关重要的作用。近3年来，中国计量科学研究院研制出一系列高质量的水三相点容器，加强了水三相点的研究，为不确定度的分析提供了更为可靠的实验依据。同时，不确定度的分析也是客观评价新研制容器性能的一个重要指标。因此，根据实验结果对新研制容器所复现的水三相点进行了不确定度评定。评定结果表明，其扩展不确定度为0．16mK(k=2．69，P=0．99)。     

心电图机电压测量示值误差测量值的不确定度评定

本文介绍了心电图机电压测量示值误差测量值的不确定度评定与表示方法。     

Estimation of potentialities of methods of summation of direct measurement errors

Conventional methods for summation of direct measurement errors are considered. Conditions under which these methods provide consistent results are stated. It is proposed to utilize for characteristic of the total error, its interval estimator or the half-sum of the value obtained by adding up its arithmetic and geometric random errors.Translated from Izmeritel'naya Tekhnika, No. 4, pp. 10–12, April, 1995.