5A06铝合金及其焊接接头的疲劳断裂行为

23220132Vol.23No.2TheChineseJournalofNonferrousMetalsFeb.20131004-0609(2013)02-0327-095A06(030024)5A065A06210699.9770.9657.4848.2041.80MPa5A06TG146.2TG113.25AFatiguefracturebehaviorof5A06aluminumalloyanditsweldedjointZHANGHong-xia,WUGuang-he,YANZhi-feng,PEIFei-fei,LIJin-yong,WANGWen-xian,LIYong-lian(CollegeofMaterialsScienceandEngineering,TaiyuanUniversityofTechnology,Taiyuan030024,China)Abstract:Fatiguetestingfracturebehaviorwasresearchedon5A06antirustaluminumalloyanditsweldedjoints.Thefatigueproperties,microstructure,fatiguecrackpropagationcharacterandfatiguefracturewereinvestigatedbyfatiguetest,opticalmicroscopy(OM)andscanningelectronicmicroscopy(SEM).Undercycletimesof2106,thefatiguestrengthsofbasemetal(BM),buttjoint(BJ),transversecrossjoint(TJ),lateralconnectionjoint(LJ)andlongitudinalcrossjoint(LCJ)are99.97,70.96,57.48,48.20and41.80MPa,respectively.Thefatiguecrackinitiationsiteisinthesmallestsectionforbasemetal,thecrackinitiationisintheweldtoeandthecrackpropagatesalongtheHAZfortheBJandTJ,thecrackinitiationisinthefilletweldlegfortheLJ,thecrackinitiationisinHAZfortheLCJ,themicro-crackpropagatesfortransgranularandintergranular.Thefatiguemacro-fractureshowsadarkgrayfibrousfracturepatternsandhassomeplasticity,themicro-fracturesurfaceconsistsofquasi-cleavagepatterns,sphericalhole,fatiguestriationanddimple,andnumeroussecondarycracksareobserved.Keywords:5A06aluminumalloy;weldedjoint;fatiguefracture;secondarycrack5A06Al-Mg[1][2−3](51175364)2012-03-292012-09-100351-6010076E-mail:[e-mail]2013232880%~90%[4−5][6][7−8][[9−10][11−12][13][14][4][15][16][17]5A065A0611.110mm5A06H1123.2mmER5356121.2TIG300GPAC/DCTIG315A06ER5356Table1Chemicalcompositionsof5A06andER5356(massfraction,%)AlloyMgMnZnFeSi5A066.00.700.200.400.40ER53565.440.1470.0110.1510.064AlloyCuTiBeOthers5A060.100.030.00020.10ER53560.00790.1290.10225A06ER5356Table2Mechanicalpropertiesof5A06andER5356atroomtemperatureAlloyTensilestrength/MPaYieldstrength/MPaElongation/%5A06220−250110−2507−8ER535623018083Table3WeldingprocessparametersJointtypeWeldingcurrent,I/AWeldingvoltage,U/VWeldingspeed,ν/(mm·s−1)BJ170−18012−152.8−3.0TJ170−18012−152.4−2.9LJ180−19012−152.4−2.9LCJ170−18012−152.5−2.91.311.4PLG−200D100kN1%0.5%FS0.5%FS−f=111~116Hzr=022.15A06223(a)3(b)32325A063292.2SNSmN=C(1)lgN=lgC−mlgS(2)SNmCN=210615A06Fig.1Versionandsizeof5A06aluminumalloyfatiguespecimen(Unit:mm):(a)Basemetal;(b)Buttjoint;(c)Transversecrossjoint;(d)Lateralconnectionjoint;(e)Longitudinalcrossjoint2013233025A06Fig.2Metallographof5A06basemetal5A06441~68~9510641~78~9510645A06SN45450%99.79MPa70.9657.4848.2041.80MPa54SN3Fig.3Metallographsof5A06aluminumalloybuttjoint:(a)Weldcenter;(b)HAZ71.1%57.6%48.3%41.9%45A06Table4Fatiguetestresultsof5A06aluminumalloyanditsweldedjointsNominalstressrange,nom/MPaCyclenumber/106DisabledpositionSampleNo.BasemetalBJTJLJLCJBasemetalBJTJLJLCJBasemetalWeldedjoint1120908075800.6350.3920.3110.5820.192IngagelengthWeldtoe2115857570701.1770.6520.3390.6870.410IngagelengthWeldtoe3110807065650.6821.0320.6850.5450.359IngagelengthWeldtoe4105756560601.0503.0780.7330.7350.594IngagelengthWeldtoe5100706055551.9581.5760.8990.8480.570IngagelengthWeldtoe690655550502.9582.0432.3891.5890.605IngagelengthWeldtoe745452.1321.198IngagelengthWeldtoe895605040405.1045.0007.5115.0001.584UnfaultedUnfaulted985355.0385.300UnfaultedUnfaulted2325A0633145A06SNFig.4SNcurvesof5A06Alalloyanditsweldedjoints55A06SNTable5ParametersofSNcurvesfor5A06aluminumalloyanditsweldedjointsMaterialconstant,mJointtypeResultDeviationMaterialconstant,CmFatiguestressrange,Δσm/MPaCorrelationcoefficient,rBasemetal7.690.174.78102199.970.901BJ6.780.197.01101870.960.895TJ6.960.153.52101857.480.958LJ3.780.144.60101248.200.953LCJ3.770.132.45101241.800.9372.32.3.15A0655Fig.5Fatiguefracturepositionofaluminumalloyanditsweldedjoint:(a)Basemetal;(b)Buttjoint;(c)Transversecrossjoint;(d)Lateralconnectionjoint;(e),(f)Longitudinalcrossjoint201323325(a)5(a)5(b)5(c)5(d)5(e)(f)2.3.25A06676(a)6(b)6(c)6(b)7[6]2.42.4.188(a)(b)(8(a))(8(b))8(c)(d)8(e)82.4.2SEM96Fig.6Microstructureshowingfatiguecrackpropagationofaluminumalloy:(a)Crack;(b)Cracktip;(c)PartiallyenlargedimageofFig.6(b)7Fig.7Microstructureshowingfatiguecrackpropagationofaluminumalloybuttjoint2325A063338Fig.8Macrostructureoffatiguefracturesofaluminumalloyweldingjoint:(a)Buttjoint;(b)Transversecrossjoint;(c),(d)Lateralconnectionjoint;(e)Longitudinalcrossjoint9SEMFig.9SEMimagesoffatiguefracturesectionsofaluminumalloyjoints:(a)Buttjoint;(b),(c),(d),(e)Transversecrossjoint;(f)Lateralconnectionjoint;(g),(h)Longitudinalcrossjoint201323349(a)9(b)~(e)9(b)9(d)9(e)9(f)9(g)(h)31)5A0699.97MPa70.9657.4848.2041.80MPa2)5A063)REFERENCES[1],,.5A06[J].,2007,37(7):34−37.PENGFei,CHUHao,YANGBing.Analysisandpreventiveoffracturein5A06aluminiumalloyfueltankwithmanualTIGweldingtechnology[J].ElectricWeldingMachine,2007,37(7):34−37.[2],.[M].:,2006:3−4.ZHOUWan-sheng,YAOJun-shan.Weldingofaluminumandaluminumalloy[M].Beijing:ChinaMachinePress,2006:3−4.[3]ZHAOTian-wen,JIANGYan-yao.Fatigueof7075-T651al