简介:BasedonAPISTD1104-2005andCSAZ662-2007,fieldgirthweldingtestsandgirthweldabilityevaluationswereexecutedforthreetypesofwallthicknessX70UOEpipeline,inwhichthemostpopularmainlinegirthweldingmethod,single-wireautomaticgasmetalarcwelding(GMAW),wasused.Theweldingprocedurespecificationwasoptimizedtoachieveagoodqualityandcold-crack-freegirthweldjointwithoutpreheatingorpost-weldheattreatment.Inaddition,porosities,inclusions,andincompletefusiondefectswereavoided.Thetensilestrength,bending,Vickershardness,CharpyV-notchimpacttoughness,andcracktipopeningdisplacementfracturetoughnessofthegirthweldjointwereevaluated,andthejointexhibitedgoodmechanicalperformance.Thus,thefieldgirthweldabilityofBaosteel’sX70UOEpipelineisexcellentforautomaticGMAW.
简介:介绍ER70S-6X焊丝钢的生产情况。通过化学成分及残余元素控制、精炼脱氧制度优化、连铸保护浇注和铸温铸速的稳定控制等工艺措施的实施,使EK70S-6X焊丝钢的产品质量和综合性能得到了稳定提升。
简介:Separationisacommonlyobservedphenomenonduringdropweightteartestinginhigh-toughnesslinepipesteels.Severeseparationisharmfulbecauseitmaycausefracturingorburstingofpipes.Inthisstudy,aquantitativemeasurementofseparationwasproposed,andusingthisnewmethod,arelationshipbetweentheseparationandmicrostructurewasdeterminedanddiscussed.Themicrostructuresobservedusingopticalandscanningelectronmicroscopyrevealedthattheseparationwasrelatedtothemixedferriticandbainiticmicrostructures,orrather,itwasrelatedtothecarbonenrichmentinbainite.