T、K、Y管节点焊缝超声波探伤——第一讲 技术特征与影响因素

由于T、K、Y管节点焊缝复杂的结构特点,其焊缝截面的形状随着其相贯线上的位置不同而发生变化,加之主支管的壁厚均较大,难以用射线照相法进行检验。目前国内外主要采用超声波方法进行探伤。本讲侧重研究T、K、Y管节点焊缝超声波探伤的因素及技术特征。 1 T、K、Y管节点焊缝的几何学特点 1.1 管节点的基本形式 管节点主要有T、K、Y三种(图1),其中,以Y型管节点最具代表意义。     

T、K、Y管节点焊缝超声波探伤——第二讲 探伤方法与验收标准

根据T、K、Y管节点焊缝超声波探伤的技术特征,结合涠11-4平台上部结构建造的探伤实践以及试验研究,对工艺方法、缺陷定位定量方法以及验收标准等进行了较系统的分析与探讨。 1 探伤前准备工作 1.1 目视检查与尺寸测量 当探伤人员在接到焊接检查人员的超声波申请单以后,须检查工件的名称、编号、结构等是否符合申请内容,焊件应力延迟时间是否足够,并要求外观目视复查。复查的内容包括对探伤有影响的飞溅、油污清理情况,表面有无裂纹、锈蚀、表面焊渣、焊肉高度、咬边、超边、凹坑及烧穿等。 节点的实际尺寸往往与图纸的标准值有较大的偏差,探伤前必须实测。用超声波测厚仪在主、支管上分别选择四个位置(通常选择0、3、6及9点钟四个点),在每一个位置作出标记,测量三次后取平均值,分别予以记录并与图纸的数据相对照。不圆度的测取须借助专用设备。 1.2 探测面的标记与修整 1.2.1 焊缝根部的标记 在焊管坡口加工后尚未焊接前,对待扫查的构件应在离开根部的探测面上用划痕或打冲印的方法做标记,以保证焊后根部位置的准确。API标准中非常强调做这些标记,因为,在焊缝成形后通过其它方法对这些节点根部位置的测量将会很困难或不可能。离根部表面至划线或打印标记线的距离可任选,但应注意使标记离坡口边缘有     

焊接专利

<正>专利名称:T型管堆焊焊接技术专利申请号:CN201310458459.1公开号:CN103480943A申请日:2013.10.02公开日:2014.01.01申请人:黑龙江宏宇电站设备有限公司T型管堆焊焊接技术。目前,在国内散热器T型管相贯线的焊接工艺上,多采用人工焊接方式,人工焊接存在焊接质量不稳定、生产效率低等缺点。本发明包括:上位机,上位机通过以太网接口连接下位机,下位机包括6K4多轴运动控制器和MCS51单片机;6K4多轴运动控制器通过电机驱动     

Y型管节点焊缝超声波检测缺陷的计算机辅助定位

针对Y型管节点焊缝的特点,为解决在Y型管节点焊缝超声波检测中的缺陷定位困难、方法繁琐和耗时严重等问题,结合计算机辅助软件,设计了Y型管节点焊缝超声相控阵检测工艺,并对该类焊缝进行试验研究。试验证实:采用计算机辅助超声相控阵技术检测Y型管节点焊缝有利于该类焊缝检测效率的提高,可以有效地避免常规方法频繁移动探头的检测方式。     

压力容器C、D类焊缝接头形式及施焊工艺分析

压力容器设备中法兰与筒体、法兰与接管连接处的C类焊缝和封头端部、筒上马鞍形的D类焊缝是最为不规则的且施焊工艺最为复杂的焊缝.着重讨论C、D类焊缝的T形接头形式和角接接头形式的焊接工艺,尤其是对施焊难度高的D类焊缝的接头坡口形式、优缺点以适用场合进行了分析.通过分析得出其合理的T型接头形式和施焊方法,为压力容器中此类焊缝的焊接提供参考作用.     

海洋平台导管架Y形节点焊接冷裂性评价

海洋平台结构的不均匀性与焊接技术的局限性导致焊接接头位置易产生焊接冷裂纹等缺陷进而导致开裂。针对该问题,文中基于SYSWELD软件对海洋平台E36高强钢材质的导管架典型Y形管节点位置处的焊缝进行建模并对其焊接过程进行了数值模拟。根据焊后应力场获得焊后拘束应力,从而实现对其冷裂性的定量评价。通过热源校核得到的热循环曲线实现热源模型的施加,进而分别对管内壁焊根处和管外壁焊趾处的轴向、周向及径向拘束应力沿着相贯线的变化进行了分析,并将各方向的危险点拘束应力与材料的临界拘束应力进行了对比。结果表明,导管架Y形管节点的焊后最大拘束应力为492 MPa,小于E36高强钢的临界拘束应力,即导管架Y形管节点的焊根和焊趾处均不会发生焊接延迟开裂。     

钢管节点相贯焊缝超声检测技术研究

针对异径钢管焊接接头几何形状复杂．所形成的“T、K、Y”形节点相贯焊缝超声检测相对困难，国内目前尚无相应标准。探讨了利用GB11345—89对相贯焊缝进行检测的可行性(增加熔深检测内容)，并介绍了一种在海洋结构件管状T、K、Y接头中广泛应用的缺陷定位方法。     

海洋平台TYK节点自动焊接技术可行性研究

海洋平台TYK节点焊接过程复杂,焊接时焊枪的位置和姿态要不断进行连续调整,国内外对海洋工程中大直径、大壁厚管道TYK节点自动焊接的研究仍是空白.为使研究便于开展,选取φ508mm×19mm交φ610mm×25mm钢管T形和Y形接头作为试验对象,通过Motoman UP20弧焊机器人进行模拟试验,与现行半自动CO2气体保护焊对比研究,对TYK节点自动焊接方案、可行性、效率等进行了评估和分析.试验结果对后续TYK节点自动焊接研究有非常重要借鉴意义.     

导管架主腿及钢桩关键焊接节点的安全性评估

我国海洋采油事业发展迅速,工作重心逐渐向深海发展,这对导管架的安全性要求越来越高。目前国际上普遍采用焊后热处理的方法提高接头性能,而由于导管架结构庞大,热处理难度极大,因此,通过ECA(Engineering Critical Assessment,工程临界评估)实际工程案例,结合CTOD(Crack Tip Opening Displacement)试验,给出了T/K/Y形焊接节点免除焊后热处理的可靠证据,为提高工程结构安全性和降低工程难度提供了保证。     

海上平台管节点6GR位置焊接工艺方法

在海洋工程结构的构件中主要有T形、K形和Y形管节点,这些管节点中以6GR位置难度最大,6GR为带有障碍环的管子倾斜4 5°固定焊,其管子的轴线与水平面成4 5°角,位置固定不允许变动,障碍环的外径比厚壁管的外径约大30 0mm ,且安装在厚壁管外缘,距两管接缝及厚壁管端面的距离≤13mm。我们在培训中总结归纳了一套6GR焊接的操作工艺方法及其要点,供同行参考。1　焊接工艺及参数管材选用2 0无缝钢管,设备选用山东奥太ZX7-40 0STG逆变式焊机,直流反接电源,打底焊条为日本产单面焊双面成形用焊条LB - 5 2U ,3.2mm ,填充及盖面焊条为四川自贡…     

Inspection system for welded tubular joint based on ultrasonic phased array

A manual inspection of large-diameter tubular joints is difficult. As a result a scanner with three degrees of freedom (DOFs) was developed based on the scanning principle of ultrasonic phased array. The weld tracing is realized by a 2D0F motion of scanner. The pose of ultrasonic probe is controlled by the third one. The control strategy is put forward based on a programmable multi-axis controller. Four kinds of scanning modes can be implemented simultaneously employing this ultrasonic inspection system. Experiments on reference blocks of tubular joints reveal that the automatic ultrasonic phased array inspection system has the same inspection accuracy as a manual ultrasonic inspection. This system is superior to the manual ultrasonic system in terms of reliability and repeatability. The artificial defects of weld at tubular joint can be detected accurately with the presented inspection system.     

海上平台结构管节点焊缝的超声波检测

海上平台结构管的节点形式以T型、K型和Y型为主,管节点焊缝的超声波检测是探伤中的一个难点。从检测前的准备、检测的实施、缺陷的定位以及缺陷的判断等方面做了详细的论述,并充分说明了检测技巧和注意要点,有效地解决了现场施工难题,为管节点焊缝的超声波检测提供了很好的借鉴意义。     

计算机辅助在TKY管节点焊缝超声相控阵检测中的应用

采用解析几何理论与方法,对TKY管节点焊缝进行了数学模型的构建.在获得管节点焊缝截面图形基础上,按照规定尺寸绘制焊缝接头,并依据实物尺寸绘制相控阵探头轮廓和超声波的声束线.运用计算机辅助技术实现了焊接接头声束覆盖范围可视化效果,较好地指导了相控阵检测工艺设计,能够对TKY管节点焊缝超声检测盲区进行评估,从而克服了相控阵超声检测参数设置的盲目性.对人工设计的Y形管节点焊缝试样检测表明,利用超声相控阵成像技术和计算机辅助技术相结合手段有助于管节点焊缝作快速检测和评价.     

惯性摩擦焊超声相控阵检测工艺

由GH4169高温合金盘采用惯性摩擦焊焊接成的整体转子鼓筒,必须对焊接接头的质量进行无损检测。通过对比试件和专用吊具的研制,利用R／DTech超声水浸检测系统对鼓筒惯性摩擦焊接头超声相控阵检测进行了应用研究,通过分析和试验,证明了采用超声相控阵技术检测GH4169高温合金鼓筒惯性摩擦焊接头质量的可行性和可靠性。     

K4169高温合金机匣的精密脉冲弧焊修复技术

精密脉冲弧焊技术具有适应性强、灵活简便、可精确控制热输入等优势,采用该工艺对3 mm厚K4169板材进行焊接试验。结果表明,焊缝组织呈细枝晶形态,并析出细小均匀的沉淀强化相,X射线检测结果表明焊缝内无缺陷形成,接头中焊缝处硬度较母材低,接头室温拉伸性能、高温抗拉强度均与母材相当。采用该工艺对机匣零件裂纹缺陷进行了修复试验,检测结果表明修复质量满足使用要求,即精密脉冲弧焊技术可以应用于机匣零件的裂纹修复。     

Microstructure analysis and mechanical characteristics of tungsten inert gas and metal inert gas welded AA6082-T6 tubular joint: A comparative study

The present study is aimed to compare the microstructure characteristics and mechanical properties of AA6082 in T6 condition of tubular joints fabricated by tungsten inert gas welding (TIG) and metal inert gas welding (MIG) processes. The effect of welding processes was analysed based on optical microscopy image, tensile testing, and Vickers micro-hardness measurements. The results showed that the tensile strengths of the TIG-welded joints were better than those of the MIG-welded joints, due to the contribution of fine equiaxed grains formation with narrower spacing arms. In terms of joint efficiency, the TIG process produced more reliable strength, which was about 25% higher compared to the MIG-joint. A significant decay of hardness was recorded in the adjacent of the weld bead zone, shown in both joints, related to phase transformation, induced by high temperatures experienced by material. A very low hardness, which was about 1.08 GPa, was recorded in the MIG-welded specimens. The extent of the heat-affected-zone (HAZ) in the MIG-welded joints was slightly wider than those of the TIG-welded specimens, which corresponded with a higher heat input per unit length.     

Influence of welding consumables on high cycle fatigue life of flux cored Arc welded high strength,quenched and tempered steel joints

Quenched and tempered (Q&T) steels are prone to hydrogen induced cracking after welding. Austenitic stainless steel (ASS) welding consumables are traditionally used for welding of high hardness, Q&T steels as they have higher solubility for hydrogen in the austenitic phase. The use of stainless steel consumables for a non stainless steel base metal is not economical. Hence, in the present work, an attempt was made to explore alternate consumables for welding Q&T steels. Flux cored arc welding process was used to fabricate the joints using austenitic stainless steel and low hydrogen ferritic steel consumables. The joints fabricated using low hydrogen ferritic steel consumables exhibited superior fatigue performances than the joints fabricated using ASS consumables.     

基于自动脉冲TIG焊的核级阀门管道焊接工艺

针对核电厂运行期间核一级手动截止阀唇边焊易发生泄露的风险,要求阀门需要进行整体更换,分别对核级阀门两种规格的接头开展自动脉冲TIG焊接工艺研究,并对焊后的试件进行渗透、X射线探伤等无损检验和拉伸、弯曲、金相、化学分析和晶间腐蚀等破坏性检验。试验结果表明,壁厚2.77 mm的焊接接头拉伸力平均值为564 MPa,断后伸长率平均值为39.25%;壁厚8.7 mm的焊接接头拉伸力平均值为612 MPa,断后伸长率平均值为46.75%,两种壁厚的焊接接头均具有良好的力学性能,面弯试验和背弯试验均未发现裂纹,弯曲性能良好;壁厚2.77 mm接头的金相组织主要是板条状铁素体,壁厚8.7 mm接头的金相组织主要以树枝状铁素体为主;两种壁厚的焊接接头中熔敷金属的化学成分经检验均满足技术条件的规定;采用弯曲法进行晶间腐蚀试验,经检验两种规格的接头均无晶间腐蚀倾向。     

FATIGUE STRENGTH DETERMINATION OF BUTT WELDED JOINTS BY FEM

1.IntroductionThe design of welded constructions subjected to alternating stresses, taking into account their fatiguestrength,wasbasedtillnowonthestress(S)-cycle number (N) relations (S-NWohler curves). Unfortunately,thismethodhassomelimitationsduetonotmakingallowancefortheinfluenceofthegeometricshapeofthejointonthefatiguestrengthoftheweldedstructure,especiallyatthetoeoftheweld(transitionfromtheweldfacetotheparentmaterial).Toassessthefatiguelifeofweldedconstructions,the"localapproach"hasbeen…     

The synchronized tandem wire welding process applied to the welding of structural plates*

As part of a European research project, partially funded by the Steel Research Fund (RFS-CR-03049), the potential benefits derived from the use of synchronized tandem wire welding (STW) technology applied to structural plates, in place of the currently used arc techniques, have been evaluated.

In particular, two welded joint types have been investigated: T joints and butt joints in S355 grade structural plate, 6 and 12 mm thick. Considering the variables that characterize the process, also depending on the type of tandem torch, i.e. variable or fixed electrode configuration, the influence of the distance between the electrodes, stick-out, the type of arc and weld speed on the process characteristics have been examined.

The joints obtained have been compared with those produced using traditional technology in terms of overall joint deformation, structural integrity, microstructural analysis and mechanical performance (toughness and fatigue strength).

The results have demonstrated that the STW process is an effective technology for increasing both the weld speed, at the same penetration and the quantity of metal deposited, by about 50% compared to GMAW welding, with only slightly higher but relatively modest heat input (1 kJ/mm). These operating conditions have allowed the preservation of a level of joint quality (EN ISO 5817 quality level B) and structural integrity, comparable with those of GMAW and SAW welded joints, in addition to significant reductions in distortion. Furthermore, the fatigue strength of STW joints has also been in compliance with the reference class (butt joint, FAT class 100).

The objective of the project (RFS-CR-03049), partially supported by the Research Fund for Coal and Steel, was to explore and quantify the benefits of STW applied to structural steels as an alternative technology to established arc welding technologies.

T joints and butt joints of 6 and 12 mm steel grade S355 plates have been investigated using two different types of welding gun configuration, i.e. fixed electrodes and variable electrodes configuration. The influence of electrodes distance, stick-out, arc types and welding speed have been examined. The optimized joints have been characterized in terms of structural integrity, microstructure, mechanical performance (impact fracture toughness and fatigue resistance), total deformation and compared to traditional arc welding joints.

STW technology allowed an increase of about 50% in both the welding speed, at the same penetration and deposited metal compared to GMAW with a not much greater heat input (1 kJ/mm) maintaining the same level of joint quality (EN ISO 5817 quality level B) and structural integrity with a reduction of joint distortion. In addition, fatigue resistance of STW joints was in compliance with the requirement (FAT Class 100 MPa).