集箱短管接头角焊缝埋弧焊工艺试验研究

为提高锅炉集箱短管角接接头焊接机械化程度及角焊缝质量,上海锅炉厂有限公司创新性地采用"内孔氩弧焊+埋弧焊"工艺方法,并与合作方联合开发"集箱短管接头角焊缝埋弧焊设备"。通过对高端材料、几种规格和不同坡口型式的短管接头进行的大量焊接试验,最终确定了最佳的坡口型式及焊接工艺规范参数,且获得了焊缝表面成型美观、接头质量可靠等性质优良的焊接接头,生产效率大大提升,为工厂生产应用和大面积推广打下了基础。     

骑座式焊接接头坡口型式与加工

介绍了一种新型骑座式接接头的坡口型式与加工方法     

窄间隙脉冲热丝TIG焊在集箱环缝焊接中的应用

本文介绍了窄间隙脉冲热丝TIG焊在集箱环缝焊接中技术难点、工艺试验情况，并通过试验确定了合适的坡口型式，得到了合理的焊接工艺规范，选择了匹配的焊接材料，焊接质量较好，目前已在生产中推广应用。     

13MnNiMo54钢板窄间隙焊正火工艺试验研究

本文介绍了窄间隙埋弧焊应用于13MnNiMo54钢板焊接的情况，通过试验确定了合适的坡口型式，选择了匹配的焊接材料，得到了较为合理的焊接及热处理规范；对热处理对焊缝性能影响的规律有了一定了解。     

三通管相贯件数控加工专机

在锅炉、石油化工管道中有许多三通管接头。为保证三通管接头的强度与加工工效,对三通管接头应选择合理的坡口型式并采用数控专机加工相贯线坡口并施焊。1 三通管相贯件的坡口型式     

对伸出式换热管与管板TIG焊接头检验及评判要求的探讨

换热器产品中的换热管与管板的焊接接头是影响产品质量和性能的关键工序。本文针对此类接头结构之一的伸出式坡口角焊缝形式进行研究,目的是结合标准要求与试验条件,确定接头外观选型、有效焊缝厚度及合适的评判要求,以便制定更加合理、实用的焊接工艺来满足设计要求,并对优化和改进此类接头的坡口设计结构提供参考意见。     

奥氏体不锈钢DP-TIG焊接工艺及接头性能研究

通过焊接工艺试验研究了各工艺因素对奥氏体体不锈钢DP-TIG焊缝成形的影响,并按照压水堆核电厂机械设备焊接工艺评定的要求对成形良好的焊接接头进行了金相分析和力学性能分析.试验结果表明焊接电流、焊接电压、焊接速度是影响DP-TIG焊缝成形的关键因素,母材厚度、种类及装配质量也影响DP-TIG焊缝成形,焊接接头的各项性能均...     

铸铝燃气热水锅炉用铝材焊接工艺试验

通过对铸铝材料EN AC-Al Si10Mg(a)的焊接性分析及焊接工艺评定试验,证明选用交流TIG焊接方法及铝硅系合金焊丝,焊接接头热影响区虽有软化,但接头强度仍然大于母材标准下限值。配合焊接技术,焊缝质量可以达到RT-Ⅰ级。铸铝锅炉壳体的清砂工艺孔按此工艺焊接,经验证性水压试验及一定期限的实际应用,强度及密封性均能满足设计要求。该焊接方法简化了工序,对推广节能环保的冷凝式铸铝燃气锅炉有积极意义。     

压力容器焊接质量控制

焊接接头的质量，对压力容器的寿命和安全运行起着关键作用，一定程度上，压力容器的质量就是其焊接的质量。焊接接头的质量控制主要包括对焊接材料、焊接工艺、焊工管理及焊接检验等方面的控制。     

马鞍型埋弧焊机的特点及应用

采用骑座式马鞍型埋弧焊机进行了焊接工艺试验,并在锅炉汽包上应用,改善了焊缝质量,提高了工效。生产实践证明,采用骑座式马鞍型埋弧焊机进行汽包管接头焊缝的焊接,是一种先进的工艺方法。     

T/P91焊接质量控制

T/P91钢焊接质量控制至关重要,从影响焊接质量的5个因素着手,结合多年来的焊接实践经验,分别阐述了人员、设备、材料、工艺、环境等方面的控制要点,指出了容易产生缺陷的关键点,并对不同焊接方法的质量控制过程进行了详述,分析了焊接工艺对接头性能的影响,最后对预防和消除不合格焊缝提出了控制措施.     

一起锅炉爆炸事故引起的思考

焊接是锅炉压力容器制造过程中的重要环节,焊接质量决定着锅炉压力容器制造质量,锅炉压力容器制造单位特别要重视角焊缝的焊接质量。     

电站锅炉异种钢焊接接头失效问题浅析

本文对电站锅炉受热面部件中奥氏体与铁素体异种钢焊接接头的失效案例进行了总结分析,认为设计结构因素、焊接质量问题、运行环境是促进异种钢失效的主要外因,并从全过程质量控制的角度提出了降低失效风险的应对方法.     

不锈钢中厚板激光全熔透焊的有限元模拟

运用有限元计算软件ABAQUS对16mm厚不锈钢板的激光全熔透焊的温度场和应力场进行了模拟.采用一体两面的复合焊接热源模型来刻画激光全熔透焊过程中的热输入特征,以柱状体热源代表焊接小孔传热模式,以2个超高斯面热源代表等离子体/金属蒸气云对熔池的辐射传热模式.结果表明:温度场模拟结果得到了与实验结果相一致的"沙漏状"焊缝;钢板内纵向残余应力最大,横向应力次之,板厚方向横向应力最小;纵向拉应力主要分布在焊缝两侧约25mm的区域内,最大值已超过材料的屈服强度;经测算,钢板焊后的角变形量仅为0.35°,这是由于激光焊接能量输入高且集中、可不用开坡口而一次性将钢板焊透.     

球罐小直径支柱埋弧自动焊焊剂托架设计

一种球罐小直径支柱埋弧自动焊焊剂托架包括漏斗、薄弧板、挡板、橡胶密封垫、连接板和支座,其方法是将一些焊剂放置于薄弧板上面,然后将该托架放置于支柱焊缝正下方,使焊剂与外圆环向焊缝之间紧密贴合,从而解决了球罐小直径支柱内部环向焊缝无法直接采用埋弧自动焊焊接的问题。     

FCAW process to avoid the use of post weld heat treatment

Post weld heat treatment (PWHT) is the most common technique employed for relieving residual stresses after general repair welding. Besides, the primary purpose of reducing the effect of stresses induced by welding, PWHT is also intended to temper the metallurgical structure of the heat-affected zone (HAZ). Unfortunately, there are significant difficulties in carrying out post weld heat treatment such as; the complexity of weld geometry, the possibility of distortion in the case of any mechanical loads, difficulty in heating symmetrically, and also PWHT may cause degradation of the material properties (especially creep and tensile strength in the case of multi PWHT cycles). Most of the repairs in industry are performed with manual metal arc welding (MMAW), however, the benefits of the flux cored arc welding (FCAW) process have been appreciated by industry for many years.     

Optimization of girth welded joint in a high-pressure hydrogen storage tank based on residual stress considerations

The cylinder sections in a high-pressure hydrogen storage tank are usually connected by girth welded joints. However, due to the ultra-thick wall of the cylinder, the weld geometry has a significant influence on the residual stress distributions, which are very difficult to be fully determined by experimental methods. Therefore, in this paper, four sequential coupling two-dimensional (2D) axisymmetric finite element (FE) models with different weld geometries have been developed to study the effects of weld groove shape on the residual stresses. In addition, the effects of working pressure (75 MPa) on the welding residual stress distributions have been investigated. The results demonstrate that different weld groove shapes bring different residual stress distributions, leading to different influences on structural integrity. Among the four types of welded joints, V and U types have similar residual stress distributions, and X and d-U types have similar distributions, but the latter two types have large tensile residual stresses at their inner surfaces, which have a greater risk of generating hydrogen induced cracking (HIC). After introducing a working pressure of 75 MPa, the welding residual stresses are redistributed, and the weld regions of the four types of welded joints are all fully yielded and plasticized. Based on the residual stress considerations, using V-shape groove can obtain the best residual stress distributions in an ultra-thick girth welded joint, which provides a reference for the welding and fabrication of a high-pressure hydrogen storage tank.     

螺旋翅片管组件制造工艺的改进及应用

通过对联合循环余热锅炉螺旋翅片管与集箱焊接的组件的制造工艺进行改进，降低了装配难度。采用组合焊接操作技术，即保证了焊缝焊接质量要求，又大大节约了制造成本，并缩短了制造周期。     

Effect of the weld groove shape and pass number on residual stresses in butt-welded pipes

This study used finite element techniques to analyze the thermo-mechanical behaviour and residual stresses in butt-welded pipes. The residual stresses were also measured in some welds by using the Hole-Drilling method. The results of the finite element analysis were compared with experimentally measured data to evaluate the accuracy of the finite element modelling. Based on this study, a finite element modelling procedure with reasonable accuracy was developed. The developed FE modelling was used to study the effects of weld groove shape and weld pass number on welding residual stresses in butt-welded pipes. The hoop and axial residual stresses in pipe joints of 6 and 10 mm thickness of different groove shapes and pass number were studied. It is shown that these two parameters may have significant effects on magnitude and distribution of residual stresses in welded pipes.