国际焊接学会(IIW)第75届年会于2022年7月17～22日在日本东京召开.会议形式为线上线下融合,会议内容涵盖了焊接领域的技术交流、教育培训及认证、标准制定、焊接青年人才成长等多个方面.从年会概况、年会国际会议、年会专业委员会工作会议、年会工作机构会议、中国机械工程学会焊接分会(CWS)与IIW合作共赢5个方面进行综述,为国内学术、工业和教育界的同仁提供国际焊接领域最新发展动态.近年来的IIW年会期间,CWS持续派出了 20余位专家学者全面参与IIW的学术交流与管理工作,为中国焊接领域的国际化发展做出了重要的贡献.
In order to solve the problems such as the less addition and agglomeration of enhanced particles,a new composite interlayer was introduced to assist in brazing between SiC and Nb.The composite interlayer was braided by SiO2-fiber in three dimension with loose and porous structure(3D-SiO2-fiber).The wettability of 3 D-SiO2-fi-ber,microstructure and mechanical property of the joints were analyzed by SEM,XRD and electronic universal testing machine.The results show that,when the content of Ti increased from 4.5％to 6.0％,the wetting angle of AgCu-Ti active filler metal on the surface of 3D-SiO2-fiber interlayer decreased from 90° to 3°.The wettability was significantly improved.Moreover,the immersion depth of AgCu-Ti active filler metal in 3D-SiO2-fiber inter-layer increased continuously.With the increase of brazing temperature(950～980 ℃)and holding time(10～25 min),the reaction between 3D-SiO2-fiber and AgCu-6.0Ti active filler metal was gradually full.This method not only ensured that 3D-SiO2-fiber was able to be added to the filler metal in a large amount,but also Cu3Si,TiSi,α-Ti and Ti2Cu particles dispersed in the joint.So,the residual stress was relieved and the shear strength of joint was improved.Then the reliable joint between ceramic and metal was realized.
蛇形管高压加热器换热管与集箱管障碍焊接接头质量必须要满足100％的射线检测和渗透检测.满足探伤需求合格率是蛇形管高压加热器质量的关键,因设计结构,换热参数优胜于传统的U形管与管板.蛇型管高压加热器因自身结构管排之间空间受限,存在障碍和施焊盲区,在保证质量的前提下施焊难度大,返修难度更大.因结构形式导致换热管与集箱管的装焊顺序单一固定,焊接周期长.如果出现返修,对整个高压加热器的制造周期有严重影响.针对这种情况,进行模拟焊接,制定焊接训练计划,阶段性培训提升技能,选用手工钨极氩弧焊特制小型焊枪进行对称焊,送丝方式为内送丝.探索合理的焊接方法并进行训练,保证一次合格率,为整备产品制造周期打下良好的基础.
激光-熔化极惰性气体(Melt inert gas,MIG)复合焊过程中容易出现根部驼峰缺陷,为了实现焊接过程根部驼峰缺陷的同步预测,研究根部驼峰缺陷预测的算法并对其预测结果进行分析.采用高速摄像机进行复合焊接过程的实时视觉传感采集,提取焊接过程的正面熔池和匙孔的时序特征信息,并对这些特征信号进行小波包分解(Wavelet packet decompo-sition,WPD)与重构.应用激光扫描仪获得背部焊缝余高,以此作为驼峰状态标记的依据.再通过长短期记忆(Long short-term memory,LSTM)神经网络对焊接过程中根部驼峰状态进行预测.结果表明,WPD-LSTM算法对根部驼峰预测的准确率达到97.85％.相比其它算法,基于焊接过程正面视觉传感时序特征信息的WPD-LSTM算法预测准确率更高,且预测结果具有较高的连续性,有利于实现对焊接过程根部驼峰缺陷的同步检测与控制.
采用单钨极惰性气体保护焊(Single tungsten inert gas welding,STIG焊)、双钨极惰性气体保护焊(Double tungsten in-ert gas welding,DTIG焊)、激光-SDTIG电弧(L-SDTIG)复合焊和激光-DTIG电弧(L-DTIG)复合焊4种方式对6 mm厚TA2钛合金进行对接焊试验,实现单面焊双面成形.结果表明,L-DTIG复合焊的电弧能量更为集中,焊接速度可达680 mm/min.L-DTIG复合焊的热输入为605.5 J/mm,仅是DTIG焊的35.5％和L-SDTIG复合焊的59.0％.L-DTIG复合焊接头的焊缝区晶粒细小,显微硬度可达229.5 HV.拉伸试样在母材处断裂,接头抗拉强度优于母材.加入激光后,L-DTIG复合焊的电弧等离子体中心导电区在xOz和yOz平面电弧分别收缩51.0％,45.5％,电弧根部收缩75.0％.测得L-DTIG复合焊热源在工件上的电弧压力为3 465 Pa,分别是DTIG焊和L-SDTIG复合焊的4.17和2.25倍.较高的电弧收缩比和电弧压力可显著提高焊接效率,降低焊接热输入.
