共查询到20条相似文献,搜索用时 234 毫秒
1.
2.
采用有限元法计算了真空加压气淬炉封头的应力分布,指出了真空加压气淬炉封头作应力分析的方法和必要性。通过对球形封头和椭球形封头的应力分析,最后得出了椭球形封头更适合于真空加压气淬炉的结论。说明了球形封头与椭球形封头的应力分布规律。 相似文献
3.
4.
本文根据对流换热理论,分析了影响真空高压气淬炉中换热器换热强度的因素,指出了强化换热的途径,最后排荐了换热计算的经验公式。 相似文献
5.
6.
王运玲 《理化检验(物理分册)》2009,(11):675-677
研究了真空高压气淬热处理工艺对2Crl3钢的组织和性能的影响。结果表明:随着气淬压力的升高,2Crl3钢的强度和硬度有所提高,伸长率和冲击韧度有所降低,断面收缩率和淬透性的变化不大;采用真空高压气淬工艺处理试样的组织为均匀细小的板条状淬火马氏体组织,力学性能及淬透性满足标准要求;而且试样表面光洁,呈银亮色,可免除淬火后的清洗;可替代现有的真空油淬工艺。 相似文献
7.
8.
本文采用标准的k-ε三维紊流模型,利用FLUENT软件对喷嘴型真空高压气淬炉中空炉冷态流场和工件满装炉量下气固耦合流动传热过程进行了数值模拟计算.建立了符合实际的控制方程和简化物理模型,对空炉冷态下炉内的气体流动特征点进行流速测量,通过实测值与计算机模拟结果进行对比,验证了流场模拟计算的准确性和适用性;预测了满炉状态下炉区内的气体流动和工件温度分布,实测了指定工件的冷却曲线,比模拟冷却时间慢,误差在10%以内. 相似文献
9.
用高压气淬真空炉对模具和刀具的硬化处理与日俱增,现已成功地对冷加工钢或热加工钢制成的大小锻铸件进行了硬化。较大尺寸的高速钢刀具气淬后也得到了高的热硬性、好的韧性、极好的耐磨性。 本文重点强调高压气淬所能得到的淬火速度,同时也论述了它在实践中的特殊用途。 高压气淬真空炉的各种性能已经得到了证实,现在又做了进一步改进,即将原来的气体流动系统改进成可以在炉腔内从顶部和底部或者顶底结合交替地对负载进行淬火,这就使得整个负载温差最小,负载淬火均匀。其循环气流强度可随时调到所需要的值。 本文还对该新型炉的某些实验给以讨论。 相似文献
10.
11.
针对高温锻钢闸阀的设计要求,基于美国机械工程师协会(American Society of Mechanical Engineers,ASME)标准规范和有限元分析方法,研究闸阀的虚拟性能评估技术。为了保证闸阀在高温条件下安全可靠运行,提出一种应用有限元软件Ansys计算高温锻钢闸阀温度场和应力场的方法。首先对高温锻钢闸阀的温度场和总应力场进行定量计算及分析,然后完成应力评定并对结构性能进行分析和评价。结果表明:该闸阀的阀盖圆筒高度足够,散热板设计面积合理,承压边界部件能够满足强度要求,具有良好的工程实用价值。 相似文献
12.
某电站高调门阀后热电偶套管在正常运行中多次发生断裂,使用最短的只有3个月。对断裂套管进行了断口宏、微观分析,并对失效套管固有频率进行了分析计算。结果表明,套管断裂是微动疲劳和整体疲劳相互作用的结果,过热蒸汽在套管背面流动变化引发的周期性压力波动是产生微动疲劳和整体疲劳的主要因素,套管固有频率处于蒸汽作用在套管上压力谱的频率范围内,加剧了热电偶套管的微动疲劳和整体疲劳。 相似文献
13.
Dongsheng He Gehong Liu Lingling Lu Kang Zhao Dong Guo Yang Zhang 《Journal of Failure Analysis and Prevention》2018,18(2):265-273
This article is from the cooperation projects of Tarim Oilfield—the sidetracking feasibility analysis of lateral drilling. It analyzed the buckling behavior of non-cementing casing string in the borehole by means of theoretical analysis and modeling analysis. When free section of casing string occurs buckling, casing string bends along the sidewall, leads to additional force and additional bending moment. If casing string’s deformation is too large, it reduces the ability to resist broken of casing string. The study of non-cementing casing string buckling is important to the feasibility of lateral drilling. The free section of casing string is the research objective of this paper. Considering the factors such as self weight of casing string, fluid pressure inside and outside casing, downhole temperature and contact frictional force between casing and shaft lining, the differential equation of buckling is derived by the energy method. The solution of the buckling differential equation has been solved, and the analytical solution of the sinusoidal and spiral buckling of the casing string along the tube column has been obtained. This article analyzed the buckling behavior of non-cementing casing string in the borehole by means of theoretical analysis and finite element analysis. The results show that the difference of the analytical solution and simulation results of the buckling differential equation is <15%. 相似文献
14.
本文研分析了各类真空阀门的特点,并结合某高超声速风洞工程工艺的特殊要求,设计了适合该工艺要求的大口径真空插板阀。研究了阀板动作机构特点,通过阀门全开、全闭、任意位置驻停等动作,实现真空系统压力和流量控制。设计了阀板的独特压紧和释放结构,实现阀门的可靠性和密封动作。对阀门结构进行了模拟、计算和验证,工程应用证明阀门适合风洞工艺要求,可以作为吹吸式高超声速风洞真空系统的主要启闭部件。 相似文献
15.
Materials substitution should be performed as part of an integrated activity where redesign, processing and cost are analysed simultaneously. The paper illustrates this approach by analysing the substitution of the material of a steam control valve gate. The selection is narrowed to two candidate materials, each with its alternative design and sequence of manufacturing processes. A simpler design requiring a less complex manufacturing sequence is associated with the Haynes Alloy R-41, thus making it economically more attractive than type S42200 stainless steel, which requires a more complex design and manufacturing sequence. However, there has been no experience of using the Haynes Alloy as valve gate material. 相似文献
16.
This paper discusses basic concepts of failure analysis and gives advice on how to interpret, e.g., function, failure, failure mode, failure cause, and failure effect, using a gate valve as an example. A general approach to identification and classification of functions and failure modes is presented and the various steps of failure analysis are discussed. The OREDA (Offshore Reliability Data) database is used to illustrate the interpretation of the basic concepts. Limitations in the use of OREDA are pointed out and proposals for enhancements of this database are given. 相似文献
17.
目的 加强组合式车桥减速器壳盖刚性和密封性,对其进行设计优化。方法 针对减速器壳盖刚性问题,在常用车桥减速器壳盖结构的基础上,对减速器壳盖周边进行翻边处理,并通过建立有限元模型对减速器壳盖刚性进行了分析计算。针对减速器壳盖渗透问题,采用了CAE分析技术对减速器壳盖进行密封性分析。为满足减速器壳盖与减速器接触平面度要求,在减速器壳盖周边接触面设计凸起压痕。结果 最终优化后减速器壳盖最大应力为155.4 MPa,小于材料屈服强度,刚性满足强度设计要求。采用CAE分析技术对减速器壳盖进行密封性分析,得出使用12个螺栓时渗漏处工作间隙为0.03 mm为最好的解决方案。结论 翻边处理后的减速器壳盖刚度高于未处理的减速器壳盖。减速器壳盖接触面设计凸起压痕,用12个螺栓拧紧减速器壳盖很好地解决了密封性和拆解问题。 相似文献
18.
19.
The service life of the casing is one of the technical problems affecting heavy oil recovery efficiency. Plastic limit analysis of the defective casing can effectively prevent casing failure and improve the comprehensive service life in high temperature and pressure thermal recovery wells. In this paper, the analysis of such influencing parameters as defect shape, defect depth, defect circumferential spread, defect number and defect distribution are conducted respectively and it is proven that defect depth and circumferential spread are the main controlling factor to the plastic limit load of defective casing. Furthermore, plastic limit load mathematical model of defective casing caused by the combination of high temperature and high steam injection pressure is presented through the classical formula of plastic limit load for ideal circular tube. The model is then amended by the numerical calculation results and proven to be in good agreement with the data gained from the defective casing blasting failure experiment. Hence, the presented mathematical model can accurately predict the plastic limit load of defective casing in thermal recovery wells. 相似文献
20.
L. Hodulak J. G. Blauel Ch. Berger J. Saß 《Fatigue & Fracture of Engineering Materials & Structures》1992,15(3):277-289
Abstract— The possibilities and limitations of failure predictions, based on the determination of defect size and shape by NDE, on material characterization using standard testing methods and on calculations using a failure assessment program for personal computers have been investigated for a control valve casing by comparing analytical calculations with component tests. 相似文献