简介：Drillpipeproductsarethemostcriticalservicerequirement,thehighestperformancerequirementandthehighestqualityreliabilityOCTGproducts.Throughthecontinuousresearchonsteelmaking,upset,hearttreatment,straighteningandfrictionwelding,Baosteelimprovesthekeytechnicalparameterswhichaffectthequalityofdrillpipe,suchasmaterialpurity,Miuofinternalupsettransitionarea,toughnessandstraightness.Baosteeldrillpipeproductshavemetthedemandingrequirementofdrillingoperations.ByBRPdephosphorizationandLFdesulfurization,theP,ScontentofBaosteeldrillpipeisverylow.TheScontentofS-135drillpipecanbecontrolledinlessthan10ppm.Baosteeldesignsanewclosed-loopcontrolsystemofupsetendinductionheatingsystem.Thesystemusetemperaturemeasurementinsidetheovenandclosed-loopcontrol.Thetemperatureaccuracyofthesystemcanbeguaranteedwithinthe±15℃togetastableupsetquality.TheupsettingprocessofthedrillpipeisoptimizedbyusingpatentedtechnologyandmadetheMiufrom100mmto140mm.Thismakeasubstantialincreaseinfatiguelifeofthedrillpipe.Toimprovetheimpacttoughnessofthedrillpipebody,thedrillpipebodymaterialischangedfromCr-Ni-MosystemtoCr-Mo-Vsystemandtheheattreatmentischangedfromoilquenchingtowaterquenching.Toimprovetheimpacttoughnessofthetooljoint,thetooljointfurnaceisupgradedtoimproveheatingcapacity.Toimprovetheimpacttoughnessoftheweldzone,anewfuzzycontrolsystemofweldzoneheattreatmentisdeveloped.Thetemperatureaccuracyofthesystemcanbeguaranteedwithinthe±5℃togetastableheattreatmentquality.Anewdrillpipestraightnessautomaticdetectiondevicesandself-learningmethodofstraighteningaredevelopedtoachieveautomatedstraightening.Aweldingprocesswithhighspeed,single-stagepressureandhighforgingforceisappliedtoinertiafrictionwelding.Aweldingprocesswithlowspeed,three-stagepressureandlowforgingforceisappli