内孔焊接在低压反应水冷凝器制造中的应用

本文概述了内孔焊技术的特点及其应甩,着重介绍了内孔焊接工艺参数的选择。以低压反应水冷凝器管子管板内孔焊为例,叙述了不锈钢管子与管板内孔焊接的工艺试验和产品焊接。     

换热器类管与管板内孔焊

国营五二四厂对管与管板内孔焊的研究、生产已有二十几年，该技术现已被广泛用于换热器类设备的制造中。换热器类管与管板的焊接，通常采用端面焊，即将管子插入管板孔内，在管板的外侧将管子与管板焊接在一起（图1、2）。该结构型式简单易行，但也有其致命的不足，如管子与管板间的间隙内沉淀积垢后会产生间隙腐蚀，胀管产生的残余应力会引起应力腐蚀。而管与管板内孔焊，则消除了间隙腐蚀，减少了应力腐蚀，延长了设备的使用寿命。所谓内孔焊，是将管子置于管板的内侧，管子与管板形成内孔对接焊缝（通常采用的接头型式，（见图3）或内孔…     

换热器管子与管板的内孔焊接

为了解决换热器管子的应力腐蚀断裂问题,我们于1974年开始开展内孔焊的试验研究工作。第一阶段试验内容,已刊登在《化工与通用机械》,1975,№9,本文介绍内孔焊枪的进一步改进和换热器模拟体的焊接。一、内孔焊枪的改进工作我们在第一阶段的工作中,φ25×2管子与管板的内孔焊枪(包括对接和搭接两种接头型式)及内孔焊的试验工作进展比较顺利,工艺试验也比较满意。关于φ13×1.25管子与管板的内孔对接焊枪,虽然已能实现内径为10.5毫米的内孔对接焊,但是还存在一些问     

压力容器胀接公式的选择

胀接广泛用于管——板结合,是靠管子和管板(即在板料上冲翻孔,以下同)变形来达到密封和紧固的一种机械连接。采用不同的方法(如机械、爆炸和液压等方法)扩张管子内径,使管子塑性变形,管板孔壁弹性变形,利用管板孔的回弹对管子施加径向压力,使胀口达到以下质量指标:     

换热器管子管板封口焊试验及应用

以碳钢换热管与不锈钢堆焊层的管子管板的封口焊为例，介绍了管子管板封口焊的焊接工艺制定及其产品的焊接。并通过一系列焊接工艺试验，确定采用管子内缩管板和高铬镍焊材及自动脉冲钨极氩弧焊方法，提高了管子管板的焊接质量和可靠性。     

关于钢制列管式换热器技术条件中几个问题的探讨

本文对列管式换热器管子与管板的胀接联接结构中的几个技术问题,如管子与管板的硬度差及管端退火、管板孔的尺寸、管桥距与胀管率等问题进行了探讨,指出原标准中的不合理之处。     

管子-管板的内孔旋转氩弧焊

针对管子一管板采用内孔旋转氩弧焊的接头型式,从装配、设备、焊接、检验等方面作了详细的介绍,为有应力倩蚀工况换热设备的管头质量提供了保障。     

管板孔开槽液压胀接接头性能的三维有限元分析（一）——管板孔开槽时液压胀接接头处的等效应力及残余接触压力的分布

采用三维弹塑性有限元方法对换热器管板孔开槽的液压胀接接头进行分析,研究了管子和管板材料都具有非线性应变硬化性质时,胀接接头处的等效应力和管子—管板之间接触压力与残余接触压力的分布状况,以及它们随胀接压力大小而变化的规律。     

换热管远距离深孔焊

70年代末从国外引进换热器内孔焊技术,相继从国外又引进了高性能的管子、管板专用焊接设备。国内也研制出类似的焊机。由于焊枪结构的限制,内孔焊接深度一般在200mm左右(见图1),更远距离的内孔焊工艺在国内还未见报导。为解决更远距离的内孔焊接,我们     

转化气蒸汽发生器内孔焊技术

主要介绍我国重质原油加工技术中转化气蒸汽发生器的研制,通过整体制造工艺研发,并采用标准TIG20-160机头配合管子内孔对接焊接的特殊焊炬及定位机构,实现入口侧管板与换热管的内孔对接焊,保证了对接接头质量,攻克了相关制造难点,为该类转化气蒸汽发生器的国产化制造积累经验。     

发动机活塞销孔结构强度分析及改善对策研究

运用ANSYS分析软件计算活塞的机械应力与变形,得出活塞销孔内侧应力集中,变形较大.并在此基础上,提出了活塞的结构改进措施,采用了在活塞销孔内嵌入铸铝青铜衬套.使得活塞销孔内侧的应力趋向均匀,改善了销孔的应力集中现象,降低了销孔表面应力峰值,达到了预期的效果.     

Measurement of the shape in the radioactive area by ultrasonic wave sensor

The HANARO (High-flux Advanced Neutron Application Reactor) has been operated since 1995. The Cold Neutron (CN) hole was implanted in the reflector tank from the design stage. Before a vacuum chamber and a moderator cell for the cold neutron source are installed into the CN hole, it is necessary to measure exactly the size of the inside diameter and thickness of the CN hole to prevent the interference problem. Due to inaccessibility and high radiation field in the CN hole, a mechanical measurement method is not permitted. The immersed ultrasonic technique is considered as the best way to measure the thickness and the diameter of the CN hole. The 4-Axis manipulator was designed and fabricated for locating the ultrasonic sensors. The transducer of an ultrasonic sensor having 10 MHz frequency leads to high resolution as much as 0.03mm. The inside diameter and thickness of 550 points of the CN hole were measured using 2 channel ultrasonic sensors. The results show that the thickness and inside diameter of the CN hole is in the range of 3.3 - 6.7mm and 0 156-165mm, respectively. This data will be a good reference for the design of the cold neutron source facility.     

中小孔径内螺纹快速强力加工方法

介绍了中小孔径内螺纹的加工方法。通过改进刀具角度及操作方法,提高了加工效率,解决了内螺纹加工的难点。     

一种内孔脉冲滚压工具的设计

孔的挤压加工是成批加工较小尺寸精密孔的一种简单和可靠的方法。运用脉冲滚压原理,设计制造了内孔挤压工具。经使用效果良好,被加工零件表面粗糙度、表面硬度和精度都有显著提高。     

液体中气泡生成影响因素的试验研究

为了提高浆态床反应器内的气含率,提高反应速率,利用高速摄影技术,研究了气泡在液体中形成的特性,在不同气孔内径、不同气体流量下分别考察了平面孔、内伸孔2种进气方式对气泡在水中生成的影响,测算了气泡脱离时的大小及生成所用时间;并考察了内伸孔高度、水温对气泡生成的影响。结果表明:相同试验条件下,生成气泡大小分别随着气孔内径、气体流量的增大而增大,内伸孔进气生成的气泡体积小,用时短,且与内伸孔的内伸高度有关;高温水中气泡生成用时较短,体积较小。     

Electro-elastic fields of piezoelectric materials with an elliptic hole under uniform internal shearing forces

The existing investigations on piezoelectric materials containing an elliptic hole mainly focus on remote uniform tensile loads. In order to have a better understanding of the fracture behavior of piezoelectric materials under different loading conditions, theoretical and numerical solutions are presented for an elliptic hole in transversely isotropic piezoelectric materials subjected to uniform internal shearing forces based on the complex potential approach. By solving ten variable linear equations, the analytical solutions inside and outside the hole satisfying the permeable electric boundary conditions are obtained. Taking PZT-4 ceramic into consideration, numerical results of electro-elastic fields along the edge of the hole and axes, and the electric displacements in the hole are presented. Comparison with stresses in transverse isotropic elastic materials shows that the hoop stress at the ends of major axis in two kinds of material equals zero for the various ratios of major to minor axis lengths; If the ratio is greater than 1, the hoop stress in piezoelectric materials is smaller than that in elastic materials, and if the ratio is smaller than 1, the hoop stress in piezoelectric materials is greater than that in elastic materials; When it is a circle hole, the shearing stress in two materials along axes is the same. The distribution of electric displacement components shows that the vertical electric displacement in the hole and along axes in the material is always zero though under the permeable electric boundary condition; The horizontal and vertical electric displacement components along the edge of the hole are symmetrical and antisymmetrical about horizontal axis, respectively. The stress and electric displacement distribution tends to zero at distances far from the elliptical hole, which conforms to the conclusion usually made on the basis of Saint-Venant’s principle. Unlike the existing work, uniform shearing forces acting on the edge of the hole, and the distribution of electro-elastic fields     

巧用宏程序加工椭圆

在数控编程的实际应用中,常见的是直线插补和圆弧插补,没有椭圆插补,但在实际生产中,往往遇到许多椭圆的零件需要加工,如果手工常规编程就无法编制出椭圆的加工程序,为了解决这个问题,在数控编程中有宏程序可以做到椭圆的加工,本文按HCNC-21T系统（在其他系统只不过是宏程序的格式不同而已）对椭圆做内、外的加工编程举例,还在内椭圆的加工中先加工一个工艺孔,巧妙利用椭圆的参数方程来编写宏程序,用宏程序来解决一些实际的工作问题。     

Exact solutions for piezoelectric materials with an elliptic hole or a crack under uniform internal pressure

The existing investigations on piezoelectric materials containing an elliptic hole or a crack mainly focus on remote uniform tensile loads.In order to have a better understanding for the fracture behavior of piezoelectric materials under different loading conditions,theoretical and numerical solutions are presented for an elliptic hole or a crack in transversely isotropic piezoelectric materials subjected to uniform internal pressure and remote electro-mechanical loads.On the basis of the complex variable approach,analytical solutions of the elastic and electric fields inside and outside the defect are derived by satisfying permeable electric boundary condition at the surface of the elliptical hole.As an example of PZT-4 ceramics,numerical results of electro-elastic fields inside and outside the crack under various electric boundary conditions and electro-mechanical loads are given,and graphs of the electro-elastic fields in the vicinity of the crack tip are presented.The non-singular term is compared to the asymptotic one in the figures.It is shown that the dielectric constant of the air in the crack has no effect on the electric displacement component perpendicular to the crack,and the stresses in the piezoelectric material depend on the material properties and the mechanical loads on the crack surface and at infinity,but not on the electric loads at infinity.The figures obtained are strikingly similar to the available results.Unlike the existing work,the existence of electric fields inside an elliptic hole or a crack is considered,and the piezoelectric solid is subjected to complicated electro-mechanical loads.     

Recovery of distal hole axis in intramedullary nail trajectory planning

In intramedullary nail (IMN) surgical operations, one of the main efforts for surgeons is to find the axes of two distal holes. Two distal holes on an IMN, which are inside the intramedullary canal of a patient's femur, can only be seen in a lateral X-ray view. For the standard surgical procedure, the localization of the distal hole axes is a trial-and-error process which results in a long surgical time and large dose of X-ray exposure. In this paper, an algorithm to derive the three-dimensional position and orientation of the distal hole axis was developed. The algorithm first derives the nail axis through two X-ray images. Then the distal hole axis is calculated through projecting back the hole boundary on the X-ray image from a lateral view to three-dimensional space. A least-squares method is used to determine the centres of the front hole and the back hole through iteration. The algorithm has been tested with real data and it was robust.     

轻量化阶梯孔结构电解加工试验研究

针对内大外小轻量化阶梯孔结构特点与加工难点,采用固定阴极电解加工方式实现其内孔加工。以某飞机起落架转轴中心阶梯孔为例,为提高其加工质量及加工效率,基于数值分析和试验验证的方法优化了阴极结构,结合实际生产需要,提出了阶梯式变电压加工方法。在上述基础上修正阴极锥度并进行工艺试验,最终加工出合格件,该方法加工质量稳定,满足批量生产需要。