历史查询   



 为了更好的帮助您理解掌握查询词或其译词在地道英语中的实际用法，我们为您准备了出自英文原文的大量英语例句，供您参考。 
During one of the fabrication trials of a large pressure vessel made of 18 Ni 1800 MPa maraging steel plates, 7.8 mm thick, defects were observed in the welds which were to be repaired.


A large pressure vessel was used, which holds rock samples approx.


Part of it is a large pressure vessel containing the SF6 insulating gas at a pressure of 8 bar.




 A largescale pressure vessel, especially a spherical tank, is apt to have some defects of tsagger toes or angular distortion while it is welded assembly Such defects are even unavoidableSome additional stresses will be raised by the effect of the hastening circle due to the internal pressure. If the additional stresses are excessive, they will become one of the important causes of a disaster. Therefore, it is badly needed to deal properly with the quantitative relation between the stagger toes, the angular... A largescale pressure vessel, especially a spherical tank, is apt to have some defects of tsagger toes or angular distortion while it is welded assembly Such defects are even unavoidableSome additional stresses will be raised by the effect of the hastening circle due to the internal pressure. If the additional stresses are excessive, they will become one of the important causes of a disaster. Therefore, it is badly needed to deal properly with the quantitative relation between the stagger toes, the angular distortion and the additional stresses in order to well solve the problems of checking, repairing and using the pressure vessel safely.In this paper, the results of the determination of the additional stresses due to the stagger toes the angular distortion are described. The mechanical model for deriving the calculating formula is presented. The calculating formula of the additional stresses is derived. The structure of the formula is simple, the calculation is easy, and the calculating result is accurate. Besides, a measurement of the suitable angular distortion far the formula and the exchange relation between the numerical values determined respectively with this measurement and with the measurement set by the ministerial standard are presented.Finally, an analysis of the theory and the errors of the additional stresses is made  大型压力容器,主要是球罐,在装配焊接中产生错边、角变形的缺陷常常是不可避免的。在内压力的作用下,产生趋圆作用而引起附加应力。如附加应力过大,将会成为灾难性事故的重要因素之一。为此迫切需要解决错边量、角变形量与附加应力的定量关系问题,以便正确处理检修及安全使用压力容器问题。 本文介绍了对球罐错边、角变形引起的附加应力的测定结果,建立了力学模型并推导了附加应力计算公式。此公式结构简单,计算方便,计算结果比较准确。另外还介绍了适于公式要求的角变形量的测量方法,以及用此法所测得的数值与用部颁标准规定的测量方法测得的数值的互换关系。最后对附加应力进行了理论分析和误差分析。  More a thousand large scale pressure vessel, spherical tank, are operating in our country. Some of them have been detected.Results detected confirm that the better part of these presure vessels contain various cracks and the other welding defects. Therefore thire operation has to be arrested and they have to be repaired in some degree. It is well known that the residtal stress is produced after welding. Effect of them on performance of the vessel is very bad.Understanding residual stress peak and distribution... More a thousand large scale pressure vessel, spherical tank, are operating in our country. Some of them have been detected.Results detected confirm that the better part of these presure vessels contain various cracks and the other welding defects. Therefore thire operation has to be arrested and they have to be repaired in some degree. It is well known that the residtal stress is produced after welding. Effect of them on performance of the vessel is very bad.Understanding residual stress peak and distribution is of great realistic significance for the safe service of the pressure vessel. In this paper, the equipment and procedure of measuring residual stress on spherical tank by means of the small hole relaxation method with was investigated greatly at last few years was introduced. Quantity and distribution of residual stress in the regions measured was given out.  我国已有千余台大型压力容器——球罐在运行,一部分球罐需开罐检查,据已检查过的球罐质量看,大部分存在着较严重的裂纹和其它焊接缺陷,无法继续投产使用,需进行不同程度的检修。只要焊修便会产生焊接残余应力,它对强度、脆断及应力腐蚀等都有很大影响。因此,了解残余应力的大小及其分布规律对安全使用球罐具有重要的现实意义。 本文介绍了用近两年研究较多,破坏性很小,效果较好的小孔松驰法在球罐上测定残余应力的方法,装置及测定部位的残余应力的大小、状态和分布规律。  The engineering technicians decide construction plan for the techniqne design of heat treatment of large pressure vessel ofter welding insitu mostly based on their experiences、 utilizing the Principle of heat conduction,the author calcnlated the measured data of 10 exsarnples of local heat treatments and set up a calcniating model and relative coeffi cient that suites for engineering design.Such data and coefficients have been applied to the heat treatment after welding for large tower introduced from Japan.... The engineering technicians decide construction plan for the techniqne design of heat treatment of large pressure vessel ofter welding insitu mostly based on their experiences、 utilizing the Principle of heat conduction,the author calcnlated the measured data of 10 exsarnples of local heat treatments and set up a calcniating model and relative coeffi cient that suites for engineering design.Such data and coefficients have been applied to the heat treatment after welding for large tower introduced from Japan. In the light of analysis to the cylindrical structure the author considers;the axil heat conduction of cylindes and radial heat conduction of insulating glass wood belong to plate heat conduction.So it can be used for calcnlating with the formular of plate heat con dution.According to the rate of temperature decrease specified in specification, the thermal insulation materials can be choosen and the thickness.covering area can be calculated and decided.The required quantity of heat during increasing temperature and maintaining constant temperature are calculated according to the conditions of thermal insulation.So the suitable heater can be choosen correcfly.  对大型压力容器现场焊后局部热处理工艺设计,目前国内外工程技术人员大多根据经验来确定实施方案。作者运用工程传热原理,通过对近十处局部热处理实测数据的计算,建立了适合工程实际的设计计算模型和相关系数,并在日本引进大型塔设备的焊后局部热处理中得到应用与验证。从简体的结构分析认为:简体的轴向传热和保温棉的径向传热都属平板传热,因而可用平板传热公式计算。根据规范中规定的降温速度,计算并选取保温材料,确定其厚度及覆盖面积,再根据保温条件计算升温、恒温所需热量从而选择合适的加热器。   << 更多相关文摘 
相关查询  



