简介:采用真空无压熔渗工艺制备炭纤维整体织物炭/炭-铜(C/C—Cu)复合材料,在改装的QDM150型干式摩擦性能试验机上进行载流条件下的干滑动模拟实验,研究电流及紫铜对偶盘转速对C/C—Cu复合材料摩擦磨损性能的影响规律。利用扫描电镜观察分析磨损表面及磨屑形貌。结果表明:C/C—Cu复合材料的摩擦因数随电流增大而减小,质量磨损率随电流增大而增大,接触表面的化学反应使得正极的磨损大于负极;复合材料的摩擦因数和磨损率均随着转速增大而降低。扫描电镜观察分析发现正极生成的磨屑主要以片状剥落层的形式存在,而负极的磨屑细小松散,呈等轴状。
简介:采用编织-粉料铺填法制备Cf/ZrB2预制体,经过“浸渍-炭化”制得C/C-ZrB2复合材料,研究材料的微观结构与力学性能、抗氧化性能和抗烧蚀性能。结果表明:ZrB2颗粒由树脂炭包裹,在C/C-ZrB2复合材料内部均匀分布。材料的氧化质量损失率随氧化时间延长呈线性增长,在1100℃温度下氧化10min和60min后质量损失率分别为2.67%和20.47%。该材料的抗弯强度为81.1MPa,氧化10min后抗弯强度仍保持在氧化前的80%,氧化前后均呈假塑性断裂模式。ZrB2粉体的加入可显著改善C/C复合材料的抗烧蚀性能,等离子烧蚀120s后,其质量烧蚀率和线性烧蚀率分别为0.30mg/s和8.75μm/s。玻璃态ZrO2的阻氧作用以及B2O3的挥发吸热是复合材料主要的抗烧蚀机理。
简介:以短炭纤维、Si粉、炭粉和树脂为原料,通过均匀混合、温压成形,在1500℃原位反应最终制得C/C—SiC复合材料。测试试样的开孔隙率、热扩散率及摩擦磨损性能,研究制备工艺过程中后续炭化对摩擦磨损性能的影响,并对摩擦表面及磨屑进行扫描电镜观察和X射线衍射分析。结果表明:采用树脂浸渍炭化工艺制备的C/C—SiC制动材料具有适中的摩擦因数和较低的磨损率;经后续炭化,树脂转变为树脂炭,以磨粒的形式增大摩擦力,同时有效地降低了磨损率。
简介:采用超音速等离子喷涂法在1045钢表面制备NiCr-Cr3C2涂层,分析涂层的微观结构及化学成分以及涂层的晶粒结构,利用MICROMET-6030显微硬度仪和Nano-test600纳米压痕仪测定涂层的显微硬度与弹性模量,通过油润滑微动摩擦磨损试验测试涂层的微动磨损性能。结果表明,NiCr-Cr3C2涂层为明显的层状结构,具有单晶、纳米多晶与过渡区共存的复杂晶体学结构,显微硬度HV0.3高达998,约为基体材料硬度的3倍,弹性模量为224.6GPa;涂层的微动摩擦因数随载荷增大而减小,随温度升高而增大。喷涂层的抗微动摩擦磨损性能较基体优异,摩擦因数及体积磨损量分别比基体降低36.7%和55.6%。涂层的磨损机理以磨粒磨损和疲劳剥落为主。
简介:Baosteel's60000m3/hairseparationunit(ASU)isthelargestoxygengeneratingsysteminChina.Theoperationalcostofsuchagiantsystemisveryhigh.Howtoreducetheoperationalcostisacriticalissue.Thispaperdiscussesthesystem'scharacteristics,thecurrentoperationalstatusandthedifficultiesinreducingthecost,andanalyzesrelevantindicators,suchasthetechnicalandeconomicalindicatorsofindividualunitsandsystemsaswellastheindicatorsconcerningthecosts.Therelationshipbetweenthecostandeacheconomicalindicatorandmeasurestooptimizeaneconomicaloperationoftheoxygengeneratingsystemarealsodiscussedinthispaper.
简介:Fromtheviewofthedomesticandinternationalenergy,environmentandoperationsituation,thepaperanalysestheconfrontedproblemsofironandsteelindustry,answerswhybaosteelhasbeenfulfillingenvironmentoperationstrategy,andproceedtotheintroductionofitsenvironmentmanagementpracticeandfutureoutlooks.Theenvironmentmanagementisessentiallyagreenvaluecreation,whichemergestheenvironmentalprotectionintothewholebusinessenterpriseoperatesprocessinordertocreateitsvalue.Theenvironmentmanagementisakindofmanagementcreation,isakindofactiveenvironmentmanagement,whichpromotesthemainsenseofenergyconservationandemissionmitigation.
简介:IronmakingatBaosteelhasfocusedonblastfurnacesoverthelast30years.Afterpassingthroughthestagesof'learning','tracking','usage','experimentation','innovation'and'development',Baosteel'sproductioncapacityhasgrownsteadilyanditsstandardoftechnologyisincreasing.Remarkableprogresshasbeenmadeinthetechnologiesofblendingstack,thicklayersintering,lowsiliconandhighanhydroferritesintering,coalblending,andthehighproductivitywithhighpulverizedcoalinjection(PCI)rateandlongcampaignoftheblastfurnaces.Theentireironmakingprocessisdevelopinginthedirectionofhighefficiency,lowenergyconsumption,cleanproduction,andenvironmentalprotectionbecausethezerodischargeofsolidwasteandindustrialsewagehasbeenachieved.After20yearsofdevelopment,Baosteelhasbecomeamodernizedironproducerwithanannualcapacityof28.85Mtofsinter,7.26Mtofcokeand22.50Mtofhotmetal(PugangCorexfurnaceoutputincluded),anditsmaineconomicandtechnologicalindiceshavereachedaworld-classlevel.
简介:采用高固相含量浆料浸渗法制备C/C-SiC复合坯体,通过先驱体浸渍裂解工艺(PIP)增密制得C/C-SiC复合材料。对浸渗浆料的流变行为以及C/C-SiC复合材料的微观结构、力学性能和抗烧蚀性能进行研究。结果表明:用体积分数为5%乙醇水溶液制备SiC浆料,当浆料pH值为6,聚乙烯亚胺(PEI)质量分数为0.7%,固相体积分数为40%时,浆料具有良好的流动性和渗透性。浆料浸渗后的坯体中,SiC颗粒主要分布在网胎层及针刺纤维区域。C/C-SiC复合材料具有优良的力学性能,其抗弯强度和断裂韧性分别为335.7MPa和16.2MPa·m1/2。在2000℃氧乙炔焰烧蚀条件下,SiC被氧化生成的SiO2可填充气孔、裂纹等缺陷,防止材料进一步氧化,使得C/C-SiC复合材料表现出良好的耐烧蚀性能。
简介:ThegrainrefiningmechanismofC-Mnsteelsheetoncompactstripproduction(CSP)linewasinvestigatedinthisstudy.Thegrainwasabout100μmafterF1passanddecreasedallthewayoftherollingprocess(F2-F6)to15μm.Repeatedphasetransformationexperimentwasconductedtothesteelforgrainrefinement.Thephasetransformationat860℃and920℃canrefinethegrainsizeto7.5μm.
简介:C/C复合材料在高于450℃的空气(氧化气氛)中会显著氧化,可采用基体抗氧化和涂层抗氧化来防止其氧化.作者采用在基体材料表面预先浸涂浸渍剂,再涂刷涂层并将涂层固化处理制备涂层的工艺方法,制备出抗氧化性能良好的抗氧化涂层.预浸涂处理可使材料的起始氧化温度提高近200℃.单独预浸涂以硼酸、TEOS为主的浸渍剂抗氧化效果不明显,而预浸涂以磷酸+硼酸混合液、磷酸为主的浸渍剂效果较好.其最佳抗氧化效果为900℃×2h静态氧化失重率为0.33%,900℃×4h静态氧化失重率为1.13%.对以硼酸、磷酸和TEOS及其混合液为主的浸渍剂的抗氧化机理进行了探讨.
简介:Steelmakingisenergyandmaterialintensive.Thatiswhysteelisalwaysdemonizedandconfrontedwithincriminationsandrequirementsforreductionofitsenvironmentalimpact.Thosepuredemands-likeforemissiontradingareshort-sightedastheydonotbaseonanintegratedapproach.InsteadtheymerelyconsiderCO2emissionsduringtheproductionprocess.Aforward-looking,globalclimateandenvironmentalpolicyneedsasustainablelifecycleapproach.Thereforeitmustforexamplealsotakeintoaccountthecontributionofsteeltowardscuttingemissionsinitsapplication-intheenergy.automotiveandhouseholdsectors.Steelwillplayakeyroleinclimateprotection.One-thirdoftheremainingCO2reductiontargetplannedinGermanyby2020canonlybeachievedwiththehelpofinnovativesteelproductsandtheirapplications.ThisistheconclusionofanindependentstudybyTheBostonConsultingGroup(BCG)onbehalfofSteelInstituteVDEh,andGermanSteelFederation.ThestudycomparesCO2savingsfromimportantinnovativesteelapplications(suchasmoreefficientpowerstations,windturbines,orlightervehicles)withCO2emissionscausedbysteelproduction.Byadoptingthiscomprehensiveperspective,thestudyforthefirsttimeprovidesaCO2balanceforthematerialsteelbycomparingtheCO2reductionsmadepossiblethroughinnovativesteelapplicationswiththeCO2emissionsresultingfromsteelproduction.ThebalancewascalculatedonthebasisofeightselectedinnovativesteelapplicationsinGermanyfortheperiod2007to2020,wherebytheCO2emissionscausedbysteelproductionwereconsideredthroughouttheentirelifecycleoftheparticularsteeluse.Fortheselectedexamples,theuseofinnovativesteelsresultedinatotalsavingspotentialof74MtofCO2in2020.Thecalculationsarebasedonconservativeassumptions;forexamplewithoutcountingofpotentialsbyexportedsteelorbycomparisonwithcompetitivematerials.TheproductionofsteelinGermany,includingtheextractiono
简介:Baosteeldevelopedadigitalautomaticanalysistechniqueformaceralspecificationin2002.Thisanalysissystemcombinesdigitalimageprocessing,graphics,databases,expertsystems,artificialintelligenceandotheradvancedtechnologies.After6yearsofapplicationincokeproduction,thesystemproveditselfsuccessfulincoalqualitytestingandcoalblendingguidanceonmaceral.However,duringthislongprocess,someinadequacieswerefoundthatimpactedtheprecisionandaccuracyoftheanalysis.So,in2008Baosteelbegantoworkonimprovingthecoalmaceralanalysissystem.Theimprovementsincludedthefollowing:furtherupgradingandenhancingtheanalysisperformanceofmicroscopicimages;extendingthegraylevelstoincreasethereflectancemeasurementaccuracy64times;changingthefocusmethodandeffectivelyeliminatingtheinterferenceofhalo.Inaddition,animprovedimagerecognitionmethodwasadoptedtomaketheextractionofvitrinitemoreaccurateandanewmodelofcoalconstituentalgorithmwasaddedwhichcanaccuratelydeterminethecompositionofmaceral(exinite,vitrinite,inertinite).Sincetheseimprovementswerecompleted,thesystemhasachievedhigherautomation,speedandaccuracy,collectedmoreinformationandperformedmoreaccuratemaceralanalysisforcokeproduction.Meanwhile,theimprovedsystemhasprovidedareliableanalyticalbasisforthefurtherstudyontherelationshipbetweencokequalityandcoalblending.
简介:在M-2000型摩擦磨损实验机上,以GH4169合金环为配副,对以粗糙层/光滑层/树脂炭(RL/SL/RC)为基体炭的C/C复合材料和拟用作航空发动机轴间密封环的高强石墨的滑动摩擦磨损性能进行对比研究。结果表明,随着时间延长,C/C复合材料的摩擦表面逐渐形成完整、致密的摩擦膜,因而摩擦因数逐渐降低,趋于平稳,在60~180N载荷下,摩擦因数仅为0.11~0.18;而石墨材料摩擦因数在试验开始后迅速上升,达到动态平衡后保持小幅度的增长趋势,在60~180N载荷下其摩擦因数为0.23~0.28。与高强石墨相比,C/C复合材料还具有更小的体积磨损,更适用于发动机轴间密封环材料。