核电工程焊接无损检测管理水平的提升措施

分析了新形势下核电工程焊接无损检测的各种典型问题,提出了提升管理水平的措施。结果表明:提升核电工程的焊接无损检测管理水平是以提升工作质量为前提,应重视体系管理、绩效管理、文化氛围营造、技术管理、重过程控制等,关注无损检测人员资格、焊接返修及工序检测衔接和重要活动的无损检测策划,检测本质质量提升后可有效检测和验证焊接质量及工程质量。提升核电工程焊接无损检测管理水平可促进核安全文化在核电工程建设中的有效推广。     

相控阵检测在爆炸焊接金属复合板中的应用探究

相控阵检测技术是无损检测超声领域的新技术,将该技术应用到爆炸焊接金属复合板结合界面波纹特征的检测是一种新的尝试。介绍了相控阵检测技术的基本原理和技术特点,分析了爆炸焊接复合板界面超声波传播特点和相控阵C扫成像基本原理,并在多种材质的爆炸焊接金属复合板上进行试验性应用研究,结果发现相控阵扫查方向影响爆炸波纹的成像效果,通过相控阵检测技术,能够快速获取爆炸焊接复合板结合界面的爆炸波纹特征图像,并能够对波纹特征进行清晰识别与准确评判,有效辅助爆炸复合工艺的提升改进,提高爆炸焊接复合板产品质量,同时也实现了以无损检测方法评价爆炸焊接复合质量的新突破。     

超声无损检测技术在金属材料焊接检测中的应用

在焊接金属材料的过程中,温度变化会改变金属材料的晶粒结构,导致其内部应力分布发生变化,构件强度降低,存在安全故障隐患。因此需要对金属缺陷进行快速、准确地检测,其中无损检测法应用广泛,其包括超声波检测和射线检测。在未焊接表面裂纹缺陷检测中,辐射超声波技术具备较高的检测效率。超声无损检测(UT)技术可以在不破坏产品、构件质量的前提下,对缺陷进行检测,为确定焊缝尺寸提供参考,在生产过程中消除风险,该文对超声无损检测技术在金属材料焊接中的应用进行了研究。     

机械焊接结构的无损检测技术研究

现代机械工业的兴起与发展必然需要各种焊接技术的支持,严格控制焊接结构的生产质量以及焊接检测技术是保证各类机械正常运行、确保运行环境和人身安全的关键因素。焊接结构的无损检性检测,是对结构的非损害性检测,即在保证机械机构的原有结构和性能的前提下,获取被检测对象的缺陷或潜在缺陷资料信息而所采用的检测方法。内容针对焊接结构的典型缺陷类型运用适合的无损检测技术,并分析目前无损检测技术在实际运用中存在的优缺点进行对比研究探讨。并重点介绍了金属磁记忆焊接无损检测技术     

工程机械焊接件的外观质量控制

工程机械设备对外观质量和性能提出了较高的要求,这增加了焊接技术的压力。如何控制工程机械焊接件的外观质量是工作的重中之重。相关人员不仅要从整体把握外观质量,还要根据焊接件的结构和功能来把控。控制焊接件的外观质量,首先在选材方面要严格控制质量,而在下料成型和组对焊接成型时,要注意长度或宽度以及连接处等部位的误差,严格控制成型工艺。最后对表面进行防护处理时要严格把控涂料、涂装方面,保证焊接件外观质量符合要求。     

搅拌摩擦焊接件内部残余应力无损测试研究进展

搅拌摩擦焊是近年来发展的一种新型焊接技术,目前国内主要着力于搅拌摩擦焊工艺及应用方面的研究,但由于测试方法和相关设备的限制,关于搅拌摩擦焊接件内部残余应力的研究几乎是空白,而国外利用其先进的中子衍射和高能同步辐射装置已经开展了较多搅拌摩擦焊接件内部残余应力的无损测试。综述了近10余年来国外搅拌摩擦焊接件内部残余应力测试的研究进展,讨论了影响残余应力测试结果的各种因素;最后介绍了国内用短波长X射线衍射仪测试材料内部残余应力的探索,对未来准确、高效、经济而无损地测试搅拌摩擦焊接件内部残余应力的研究方向进行了展望。     

航空用钛的TIG焊接法

航空工业中,钛合金焊接件因比强度大、质量轻而用量越来越大,因此须开发高效的焊接技术,使焊缝区和热影响区的间隙元素(O、N、H)含量不高于母材的,焊缝区内的残余应力尽可能小,焊接件抗迟滞断裂,并有足够的塑性、韧性;消除焊接件的冶金缺陷,如缩孔,这是使钛合金焊接件疲劳极限降低的主要原因;保证焊接件和母材在焊接态及焊后热处理(退火、淬火+时效)后有良好的强度和塑性匹配.     

金属焊接件海运包装防护技术研究

目的研究新型包装防护技术对焊接件的防护效果及其对后续焊接、涂装等工艺的影响,解决常规包装无法解决的焊接部位腐蚀防护问题。方法通过自然环境暴露实验、中性盐雾实验对焊接件常规包装防护方式和改进后的新型包装防护方式,即PE袋密封包装、气相防锈袋和气相防锈袋+冷喷锌的防护效果进行对比研究。结果 30 d盐雾实验后,PE袋密封包装防护下焊接件基材、焊缝都出现了腐蚀迹象,其中焊缝部位相对于基材锈蚀更加严重。气相防锈袋密封包装防护下焊接件基材基本上无锈蚀,焊缝部位出现轻微腐蚀。气相防锈袋+冷喷锌包装防护下焊接件基材以及焊缝部位都相对完好,未出现任何锈蚀现象。结论常规的包装防护方式对焊接件基材有一定的保护作用,但是对焊接部位并不能起到较好的保护。改进后的气相防锈袋+冷喷锌包装防护方式综合了气相防锈技术和冷喷锌的双重优势,对焊接件的基材、焊缝及热影响区均具有较好的保护效果,且不影响后续的喷涂焊接工艺等,该组合型防护方式可有效应用到焊接件的海运包装防护中。     

核结构材料焊接中的无损检测技术

在核工业领域，对一些焊接结构件，必须把焊接缺陷控制在工程设计要求的水平。无损检测技术能够较为方便地识别焊接缺陷。本文重点介绍了渗透检测技术、氦质谱真空检测技术、射线探测技术和残余应力测试等几种无损检测技术，并对无损检测技术在核结构材料焊接中的应用及展望提了几点看法。     

汽车连杆类焊接专机夹紧机构设计

随着焊接技术的发展,机械产品采用焊接结构的比重日益增长。尤其是对焊接件提出了较高的精度要求,使许多焊接工作者面临着一个如何控制焊接变形,保证焊接件精度的问题。本文就焊接夹紧机构设计进行了探讨。     

电阻点焊质量检测技术研究现状

电阻点焊过程由于受到各种因素的影响,熔核区域容易出现裂纹、缩孔、未熔合等缺陷,焊点质量直接影响焊接部件的使用寿命,因此对焊点的缺陷检测与质量评定非常重要.对电阻点焊原理进行概述,总结了电阻点焊质量检测技术最新研究成果及应用,分析了焊接过程参数监控方法、焊后无损检测方法的检测机理、质量评定方法及其在实际应用中的优缺点,对...     

爆炸焊接复合板在石化装备应用中的关键技术研究

近年来随着爆炸焊接复合板在石化装备等行业中的大量运用,其复合技术及其后续制造工艺的进步愈显重要.根据爆炸焊接复合板在石化装备等工程领域中的应用状况,结合爆炸焊接复合板的可焊性窗口及特点,阐述了不同材质的爆炸焊接金属复合板在生产制造中的热处理参数及使用中焊接、无损检测等关键技术.     

板材表面质量在线检测方法概述

板材表面的质量决定了板材的使用性能、寿命、工作可靠性等一系列重要参数,因而在工程上,对于影响板材表面质量的因素以及针对板材表面质量的检测方式也越来越受重视。文中分别介绍和分析了板材常见的几种缺陷形式、板材表面质量对其使用性能的影响,并以高精度钢板为例介绍表面缺陷的传统无损检测技术、激光扫描和机器视觉技术;最后,通过各种检测方式的结果对比得出结论。     

搅拌摩擦焊残余应力研究现状及展望

搅拌摩擦焊是一种新型的固相焊接技术,目前国内外的研究主要集中在工艺、组织、力学性能等方面,而有关搅拌摩擦焊缝内部残余应力的研究相对较少。由于检测设备的限制,国内主要采用有损检测方法,无损检测方法却很少。详细综述了国内有关搅拌摩擦焊件内部残余应力测试的钻孔法、云纹干涉法,以及国内外无损检测方法中的X射线衍射法、中子衍射法和高能同步辐射法的研究概况,讨论了各种检测方法的优缺点,对未来搅拌摩擦焊残余应力的研究作了展望。     

Failure Analysis of Welded Radiant Tubes Made of Cast Heat-Resisting Steel

Radiant tubes made of cast heat-resisting steels were cracked after 4 years of operation at 1020 °C temperature in hydrocarbon cracking furnace. Optical microscopy of the tubes showed that there was extensive precipitation and intermetallic compound formation especially as brittle networks with progressive reduction in toughness and resistance to thermal and mechanical stresses. SEM and EDS analysis proved both decarburization and oxidation on interior and exterior surfaces. Apart from cracking due to long-term heating, the tubes experienced high temperature creep. HAZ cracking after welding of cracked and/or creeped tubes due to formation of brittle carbide networks was overcome by localized solution heat treatment followed by fast dry air cooling. Localized dissolution of carbide networks and intermetallic compounds resulted in lower strain microstructures and enhanced resistance of parts to thermal and mechanical stresses during repair welding. It is evident that localized solution heat treating other than lowering strains can cause the precipitates to be more uniformly and finely distributed. Fast dry air cooling rate after solution heat treating and similar cooling after welding can help to control precipitation of carbides. Detailed non-destructive testing after welding along with tensile testing proved that post-weld cracking was controlled.     

焊接过程声信号在线检测技术现状与展望

基于焊接过程声信号的声学检测技术是一种实时采集和检测缺陷的有效方法,对材料内部结构变化反映明显。概述了常规焊接缺陷无损检测方法的优缺点,对焊接过程声信号的分类和声信号采集系统进行了论述,分析总结了声发射信号和可听声信号的发声机理、检测原理和信号处理方法,并阐述其在焊接质量在线检测领域的研究现状及应用,特别是焊接缺陷、熔滴过渡形式和熔透状态的识别与预测。为了满足在线检测要求,包含声学检测在内的多传感信息融合焊接系统研究是关键,智能传感、信号处理、自动控制与人工智能技术的进一步研究能促进焊接产业的长足发展。     

Approach to net-shape preforming using textile technologies. Part I: edges

Considering cost-effective fibre-reinforced plastic (FRP) parts manufactured by resin transfer moulding (RTM) technologies, net-shape preforms can contribute to mechanical post treatment free manufacturing, hence reducing cycle-time and cost. In addition to this, RTM specific problems, such as fibre pinching when closing the tool can be avoided. The wide range of textile technologies used for FRP parts offers various possibilities to achieve net-shape parts within the preforming process including bores or inserts (see part II). The potential of the presented technologies is evaluated and discussed. Apart from standardised testing methods, a new side-impact testing was specially designed for determining the in-plane damage-tolerance of net-shape manufactured FRP parts. Folding to net-shape shows poor quality but improves mechanical properties. Rim-protections with braided inserts or over-edge stitching technologies which provide exact preform dimensions, improved mechanical performance. Especially side-impact tolerance or in-plane damage tolerance was increased. Ultra-sonic testing was successfully applied to visualise the differences in damage tolerance and propagation between these new rim technologies.     

Optimization of fused deposition modeling process parameters:a review of current research and future prospects

Fused deposition modeling(FDM) is one of the most popular additive manufacturing technologies for various engineering applications.FDM process has been introduced commercially in early 1990 s by Stratasys Inc.,USA.The quality of FDM processed parts mainly depends on careful selection of process variables.Thus,identification of the FDM process parameters that significantly affect the quality of FDM processed parts is important.In recent years,researchers have explored a number of ways to improve the mechanical properties and part quality using various experimental design techniques and concepts.This article aims to review the research carried out so far in determining and optimizing the process parameters of the FDM process.Several statistical designs of experiments and optimization techniques used for the determination of optimum process parameters have been examined.The trends for future FDM research in this area are described.     

Development of a Thermophysical Handy Tester for Non-Destructive Evaluation of Engineering Materials

Techniques of quality inspection and non-destructive diagnosis of engineering materials have been developed as procedures for determining various physical properties. The diagnostic techniques are usually based on detecting a very delicate signal concerned with changeable properties, and therefore detecting such a signal requires a great deal of experience in the procedures. In situ measurement for thermophysical properties of engineering parts is also important for judgment of the intrinsic soundness of the parts or for distinction between similar materials. The purpose of this study is the development of a thermophysical properties handy tester that can be used to simultaneously measure thermal conductivity and thermal effusivity and can be applied to the non-destructive diagnosis of numerous engineering materials. The tester consists of a portable data-acquisition unit, a probe holder equipped with a thermal probe, and a notebook computer. Measurements can be carried out by merely bringing the probe into point contact with a testing body for a period of 10 s. The thermal probe is constructed from a thin thermocouple in order to satisfy conditions based on the measurement principle. Materials that can be measured include polymeric resins, glasses, ceramics, alloys, and pure metals, among others.