简介:摘要:长输油气管道大量使用大口径高钢级管线钢,西二线、西三线使用X80管线钢,管线出现缺陷修复时部分缺陷采用钢制套筒进行修复,修复时使用角焊缝焊接。由于物理因素影响,管道可能出现不同程度的物理变化,为确保钢制套筒修复后不影响管道使用,本文进行了理化分析,通过实验数据确认管道关键使用参数,用于指导后续管道的建设和运行中套筒修复的可靠性研究。
简介:High-strengthpipelinesteelandlargediameterlinepipesareoftenusedtoincreasethecapacityoftransportationandreducethecostassociatedwiththeconstructionandoperationoflong-distancegaspipelineprojects.China’sinitiativestoconstructlong-distancenaturalgaspipelineshasbroughtinnewopportunitiesforthedevelopmentofX80linepipes.BaosteelhasdesignedtheoptimumchemicalcompositionofX80withhighniobiumandlowmolybdenumcontent.Inaddition,aweldingexperimentalplatformandafiniteelementmodel(FEM)havesupportedthedevelopmentofX80UOEpipesinanefficientandeconomicalway.TheapplicationandrecentdevelopmentofX80UOEpipeswereintroducedinthispaper.TocomplywiththerequirementsoftheSecondWest-EastGasPipelineProject(2ndWEPP),X80pipelinesteelwithlowcarbonbainitemicrostructurewasdevelopedbyutilizingtheoptimizedcompositionandTMCPprocess.Thematchingweldingmaterial,weldingprocedureandUOEformingprocessesfor1219mmoutsidediameterX80UOEpipeswerealsodeveloped.Morethan340000tofX80UOEpipeswereproducedandappliedinthe2ndWEPP.Furthermore,tomeettheprospectivedemandforlong-distancegaspipelineswithanannualtransportationcapacityofover40billionm3,largersizeX80UOEpipeswith1422mmOD×30.8mmWTweretrialproducedrecently.DWTTperformance,themaintechnicalchallengeforheavierwallpipes,wasimprovedbyusingoptimizedmicrostructuraldesign.ThenewlydevelopedX80pipescanbepotentiallyusedforlargertransportationcapacitypipelinesinChina.
简介:摘要: 对不同钢厂生产的壁厚21.4mm/22mm、X80热轧卷板以及制成的螺旋焊管拉伸性能进行统计分析。结果表明,制管后屈服强度和抗拉强度均呈升高趋势,且屈服强度增加量大于抗拉强度,钢管成型和静水压试验引起的形变强化是拉伸性能变化的主要因素。建议研究不同钢厂卷板性能变化规律,合理制定卷板订货技术条件,以实现超大壁厚X80螺旋焊管优质的质量管控。
简介:Thesystematiclaboratorystudiesontherolesofsulfate-reducingbacteria(SRB)inthestresscorrosioncracking(SCC)susceptibilityofX80steelsubjectedtocathodicpotentialhavebeenconductedinanearneutralpHsoilsolutionbyslowstrainratetests.ThecathodicpotentialandSRBincreaseindividuallytheSCCsusceptibilityofthesteelinthesoilsolution.ThepositiveroleoftheSRBactivitiesinSCCsusceptibilitydependsontheprolongationofpre-incubationtime,andtheSCCsusceptibilityofthesteelincreasesundermorenegativepotentials.What’smore,theappliedpotentialsandthepresenceofSRBworktogetherinpromotingtheSCCsusceptibilityofthesteel.But,thecombinedactionbecomeslimitedwithdecreasingcathodicpotentials.Therelationshipsbetweentheplasticitylossandthepermeablehydrogenconcentrationwereestablishedforthesteelinthesoilsolution,regardlessofunderopencircuitpotentialorcathodicpotentials,inboththesterileandSRBinoculatedconditions.Therelationshipsarepracticallysignificantfortheselectionofsafecathodicprotection(CP)potentialsinthepresenceofSRBinsoilenvironment.
简介:Aself-developedelectromagneticinduction-heatingdevicewasusedtoinvestigatethevariationinthemicrostructureandpropertiesofX80pipelinesteelintherapidinductiontemperingprocessatdifferentprocessparameters.Theeffectsofthetemperingconditionontoughness,microstructure,sizeanddistributionofprecipitatesofX80pipelinesteelwereobservedusingametallographicmicroscopyandscanningelectronmicroscopy.Comparedwiththesamplespreparedviatraditionaltemperingtechniques,resultsshowthatthesamplespreparedviarapidinductiontemperinghadimprovedperformances.Whentheheatingtemperatureis590℃,ataholdingtimeof90s,itwasfoundthatacicularferritewasrefined,carboniteprecipitationwassmall,andprecipitateswereevenlydistributedinthematrix.Thelow-temperatureimpactenergy,alsoknownastheimpactabsorptionenergy,at-40℃wasfoundtobe430.5Jfortherapidinductiontemperingsamplesand323.2Jforthetraditionallytemperedsample.Thelow-temperatureimpactenergyat-60℃wasfoundtobe351.3Jfortherapidinductiontemperedsampleand312.1Jforthetraditiontemperingsample.
简介:摘要:随着我国经济的快速发展,能源需求进一步增长,为了满足国家经济建设和人民生活需要,输油输气长输管道建设作为输送石油、天然气等能源的重要工具,已成为国家重点发展的战略性工程。在长输管道建设中,大口径高钢级管线的使用已形成趋势,X80钢级长输管道因其高强度、高韧性等优点,在我国长输管道建设中得到了大力推广。其中管道焊口焊接质量是保证管道安全运行的关键因素,经多方面验证,全自动焊接技术是保证X80钢级长输管道焊接质量的必要条件。全自动焊接技术具有焊接速度快、焊接质量高、工作效率高等优点,但在实际的生产过程中,全自动焊接技术也存在一些与传统焊接类似的问题,这些问题如果不及时解决,也会严重影响到管道的质量和生产效率。
简介:摘要随着我国的社会的经济和科学技术的不断发展,越来越多的新鲜事物正在以迅猛的姿态进入到人们的生活当中,为人们的生活带来了翻天覆地的变化。尤其是在互联网科学技术的支持下,我国的很多行业也在逐渐面临着市场所赋予的机遇和挑战。而我国的石油行业的发展在近些年来也是十分的明显的,特别是在运输石油的一些管道和钢管焊接的技术上更是取得了突飞猛进的成果。而本文主要就运输石油的X80钢管进行论述,通过对X80钢管的焊接过程进行分析,进而探讨X80钢管产生冷裂纹的主要原因,最终总结出如何防止X80钢管在焊接过程中产生冷裂纹的合理适当的措施,希望对我国的石油行业的发展能够有所帮助。
简介:ConstantloadtestsinNS4solutionpurgedwithN2-5%CO2gasmixturewereconductedonAmericanPetroleumInstitute(API)X80pipelinesteelappliedinthe2ndWest-EastGasPipelineprojectwithandwithoutpreload.TheresultsshowthatcrackscouldinitiateandpropagateinX80pipelinesteelinnear-neutralpHenvironmentunderaconstantloadcondition.Thelifeofcrackinitiationandpropagationincreasedwithdecreasingappliedstress.Preloaddidnotchangeitscorrosionbehaviorobviously.However,preloadreducedthetimeforcrackinitiation.
简介:采用原位拉伸扫描电镜试验对X100级管线钢的动态塑性形变行为进行观察,并运用EBSD微观取向分析技术对形变前后管体组织的取向变化进行分析。结果表明,X100级管线钢的微观组织由针状铁素体、粒状贝氏体和M/A岛组成。在拉伸应力的作用下针状铁素体首先发生形变,随着应变的增加,针状铁素体形变累积到一定程度后,导致粒状贝氏体发生形变。针状铁素体边界和贝氏体基体上的M/A组织钉扎位错使变形不易发生。由EBSD取向可知,晶体在发生形变后轧面的{110}晶面方向沿拉伸形变方向转动。由扫描电镜照片观察到,在外加应力作用下,夹杂物成为微裂纹形核核心并随着外加应力的增加而扩展,最后连接,导致裂纹贯穿基体直至失效。