X70鋼在役焊接熱影響區(qū)組織與性能研究.pdf

1、中國石油大學(xué)（華東）碩士學(xué)位論文X70鋼在役焊接熱影響區(qū)組織與性能研究姓名：靳海成申請學(xué)位級別：碩士專業(yè)：材料學(xué)指導(dǎo)教師：王勇20060401StudyonMicrostructureandPropertyofX70SteelHAZInserviceWeldingJINHaicheng(MaterialScience)DirectedbyProfessorWANGYongAbstract／nthispaperthedevicewasde

2、signedandsetupt0simulatetheinserviceweldingconditionsandtheweldingthermalcyclewasmeasuredwimthemeasuringdeviceofthermalcycleunderthedifferentcoolingconditions，heatinputandboardthickness，themicrostructureandpropertiesofwe

3、ldedjointwereresearchedThroughtheweldingheatsimulationtestandCharpyimpacttest，withthemicroscopeandSEM，themierostructurecharacteristic，toughnessandfractographofX70steelHAZwasstudiedTheresultsareasfollows，underthein—servic

4、ewelding，thets／5，t陰andinnerwallpeaktemperatureTpdecreaseobviouslywiththeincreasingcoolingrateofmediumWhateverthesteelboardist11ickorthin，theweldingenergyisdissipatedbythree—dimensional，andthesteelboardexistsacriticalthic

5、kness，whenitsurpassesthecriticalthickness，thechangeoft8／5andt∞isnotobvious謝tlltheincreasingofboardthickness，belowthecriticalthickness，thethinneroftheboardthickness，thesmallerofthets／5andt蚰。andthelargeroftheinnerpeaktempe

6、rature，theinnerpeaktemperaturereaches635“Cwhentheboardthicknessis4mmTheaustenitecrystalgrainiscoarseunderaircooling，thelathferritecrossesthewholeaustenite，andthehardnessislargeWiththesmallweldingheatinput，GCHAZgeneratess