DLT3302010水电水利工程金属结构及设备焊接接头衍射时差法超生检测非正式版

DL/T330—2010I目次前言··································································································································································Ⅱ1范围·····························································································································································12规范性引用文件··········································································································································13术语和定义··················································································································································14一般规定······················································································································································35检测系统······················································································································································56试块·····························································································································································57检验等级······················································································································································78检测准备······················································································································································79检测系统设置和校准··································································································································910检测·························································································································································1011检测数据分析···········································································································································1112对非平行扫查发现的相关显示的辅助检测···························································································1213缺欠评定··················································································································································1314检测记录和报告······································································································································13附录A（资料性附录）水电水利工程常用非合金钢、低合金钢和合金钢···············································14附录B（资料性附录）参考试块·················································································································15附录C（资料性附录）缺欠深度、高度及表面盲区高度的计算······························································17附录D（资料性附录）常见焊接缺欠TOFD图像·····················································································18附录E（资料性附录）焊缝衍射时差法超声检测报告··············································································22DL/T330—2010II前言衍射时差法超声检测技术作为一种独立的无损检测方法，具有环保、对人体无伤害、缺欠检出率高、缺欠尺寸定量精度高、检测结果能图像化存储和便于实现自动扫查等优点，目前该项检测技术已经在许多大型水电站的焊缝检测中应用。本标准起草过程中通过调研、收集资料、对比试验、实践验证和分析归纳，并结合水电水利工程的特点，明确了水电水利工程金属结构及设备焊接接头衍射时差法超声检测的方法及缺欠评定要求。本标准由中国电力企业联合会提出并归口。本标准起草单位：国电大渡河流域水电开发有限公司、华电郑州机械设计研究院有限公司。本标准主要起草人：黄张豪、曹麦对、胡卫、刘雪芳、李林、杨兴斌、姚福明、王富林、李剑君、高景荣、熊剑鸣、陈刘辉、雷清华。本标准在执行过程中的意见或建议反馈至中国电力企业联合会标准化管理中心（北京市白广路二条一号，100761）。DL/T330—20101水电水利工程金属结构及设备焊接接头衍射时差法超声检测1范围本标准规定了水电水利工程金属结构及设备焊接接头衍射时差法超声检测的方法及缺欠评定要求。本标准适用于母材厚度为12mm～400mm的工程结构用非合金钢、低合金钢和合金钢对接焊接接头衍射时差法超声检测。其他类型金属材料可参照执行。2规范性引用文件下列文件对本文件是必不可少的。凡是注日期的引用文件，仅注日期的版本适用于本文件。凡是不注日期的引用文件，其最新版本（包括所有的修改单）适用于本文件。GB/T19799.1超声探伤用1号标准试块技术条件JB/T10061A型脉冲反射式超声波探伤仪通用技术条件3术语和定义下列术语和定义适用于本标准。3.1衍射时差法超声检测TOFDTimeofFlightDiffractiontechnique利用缺欠端点的衍射波信号发现缺欠和测定缺欠尺寸的一种超声检测方法，一般使用纵波斜探头，采用一发一收模式，见图1。3.2直通波lateralwave从发射探头沿工件以最短路径到达接收探头的超声波，见图1。3.3底面反射波backwallecho经底面反射到接收探头的超声波，见图1。3.4坐标定义coordinatedefinition规定检测起始参考点O点以及X、Y和Z坐标的含义，见图2。3.5探头中心间距PCSprobecenterseparation发射探头和接收探头入射点之间的距离，见图3。3.6缺欠上端点uppertipofimperfection距扫查面最近的缺欠端点，见图3。3.7缺欠下端点lowertipofimperfection距扫查面最远的缺欠端点，见图3。DL/T330—201033.8缺欠深度imperfectiondepth缺欠上端点与扫查面间的距离，见图3中的d1。3.9缺欠高度imperfectionheight在一个缺欠长度范围内，缺欠最高上端点与最低下端点在工件厚度方向上的投影距离，其中扫查面开口缺欠高度指缺欠下端点到扫查面的距离，底面开口缺欠高度指缺欠上端点到底面的距离，见图3中的h。3.10A扫描显示A-scandisplay超声波信号的射频波形显示图，一个轴代表波幅，另一个轴代表声波的传播时间。3.11TOFD图像TOFDimageTOFD数据的二维显示，是将扫查过程中采集的A扫描信号连续拼接而成，一个轴代表探头移动距离，另一个轴代表深度，一般用灰度表示A扫描信号的幅度。3.12非平行扫查non-parallelscan探头运动方向与声束方向成直角的扫查方式。也叫D扫描，见图4a）。3.13平行扫查parallelscan探头运动方向与声束方向平行的扫查方式。也叫B扫描，见图4b）。3.14偏置非平行扫查offsetnon-parallelscan在焊缝TOFD检测时，探头组主声束的交点偏离焊缝中心线的非平行扫查，见图4c）。3.15纵向平行扫查portraitscan焊缝TOFD检测时，探头组沿着焊缝方向移动的平行扫查，见图5。3.16横向非平行扫查horizontalnon-parallelscan焊缝TOFD检测时，探头组垂直于焊缝方向移动的非平行扫查，见图6。4一般规定4.1人员按照本标准进行TOFD检测、分析图像和出具报告的人员，应取得电力行业或中国无损检测学会等超声检测2级及以上资格证书和TOFD检测2级及以上专项资格证书。4.2材料本标准TOFD检测适用的材料范围参见附录A，其他金属材料在充分考虑材料的几何特性、声学特性和检测灵敏度影响的前提下可参照执行。4.3检测工艺检测前应针对被检工件的材质、厚度、坡口形式、结构特点、施工环境，以及本标准的有关要求编制检测工艺。DL/T330—201051—参考线；2—探头移动的方向；3—发射探头；4—接收探头图6横向非平行扫查5检测系统5.1检测设备5.1.1TOFD检测设备应具有线性A扫描显示，超声波发射和接收，数据自动采集、记录和显示，信号分析等功能。根据需要可使用单通道或多通道设备。5.1.2设备性能满足以下要求：a）A扫描水平线性误差不大于1％，垂直线性误差不大于5％。b）脉冲接收器带宽应大于等于探头公称的频率带宽。c）增益应在80dB以上，其步进级小于等于1dB，且连续可调。d）数字采样率至少为4倍探头公称频率，若需对原始数据进行数字信号处理，采样率应增加到探头公称频率的8倍