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.
简介:硫化钼精矿的处理方法通常采用氧化焙烧法,但在中国,该方法存在的最大问题是低浓度SO2污染。近年来,一些可行的工艺被研究,如加压浸出(POX)-萃取(SX)工艺。北京矿冶研究总院(BGRIMM)采用该工艺进行了一系列的试验研究,研究结果表明,采用该工艺钼总回收率大于97%。加压浸出过程中有15%~20%的钼进入溶液,该部分钼可采用溶剂萃取的方法进行提取,在有机相组成N235+煤油,O/A=3/1,混合时间3min的条件下,钼的萃取率可达到98%以上,负载有机相采用25%的氨水反萃,O/A=1/3,在两级逆流萃取的条件下钼反萃率超过98%。今后在中国,POX-SX工艺在钼提取方面是一个非常具有竞争优势的工艺。