厚壁小径管对接焊缝的超声波探伤方法探讨

:2005207206:10072290X(2005)0920066203,(,510730):600MW,,,,,,,:;;;;;:TG1151285;TK223111:AUltrasonicinspectionforbuttweldsofthick2wallsmall2diametertubesGAOJie2zong,WEIJian2ping(GuangdongPowerEngineeringCorp.,Guangzhou510730,China)Abstract:Toensurethenormaloperationoftheboilerwater2cooledwallsystemof600MWunitsunderhightemperatureandhighpressure,thick2wallsmall2diametertubesareusedfortheslagscreenofthesystem.Aimingattheproblemthatthewallthicknessexceedsthestipulationofrelevantcodeduringultrasonicinspectionforbuttweldsofthick2wallsmall2diametertubes,thispaperpresentsthemethodofdirectsupersonictest.Basedonthecomputationofthenear2fieldlength,sensitivitymarginandinspectionthicknesscoverageofdifferentkindsofprobes,thefeasibilityofthemethodisapproachedandthevirtuesanddefectsareanalyzed.Keywords:ultrasonicdetection;boiler;water2cooledwallsystem;slagscreen;buttweld;supercriticalpressureunit1600MW,,,,,,,,1/3,,,,,DL/T8202002414mm,,,,,2,K1K215CTS222,1,189Vol118No1920059GUANGDONGELECTRICPOWERSep120051/MHz/mm/mm2K15466K1155466K2155566211K1,K115,K215L=Ascos/s2cos-L1tan/tan.(1)5MHz,L14mm,cs2=3230m/s,As=36mm2,s2=01648mm(1)22/mm/rad/mm/mmK112157017981898189K11511116019861199129K2158162111931208100212K1,K115,K215,33,20mm3(80%)dB/mm581520K1424038K11546443834K215403628242,K115,K215,320mm,,22mm,1124dB,2dBK1,322mm,3,2dB,4422mm(80%)dB22mm4dBK13632K1153228K2152218213K1,K215,1,=3040,=812,b=25mm,h=12mm,d,L=b+2[(10-h)tan+(d-10)tan],d=22mm,b=4mm,h=2mm,=35,=10,L20mm1,1K1,K215,h1,5,25mmL0h1K148K215516:h1=22mm-(L/2+L0)/K2769:3,5P66K215622mm,5P66K11422mmDL/T8202002,,1/4,622mm1/4(515mm),K1,;K215,K1,35mm,K1K215100%,2,,,2,,,,,,,:30%434,K1,22mm,K215,22mm,,15mm,5,,:[1]DL/T8212002,[S]1[2]DL/T8202002,[S]1[3].[M].:,1989.[4].[M].:,1994.[5],,.[M].:,2004.:(1973),,,,,(65)200mm,200mm,,,,,,C,2,,Fe3+,1116g/m2h,8112g/m2DL/T7942001(,8g/m2h,80g/m2),,Fe3+:[1]DL/T7942001,[S]1:(1966),,,,8618