学科分类
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6 个结果
  • 简介:采用金相组织观察、力学性能测试和统计分析等手段,研究了成品退火工艺对Φ5mmTP2内螺纹铜管微观组织和力学性能影响规律。结果表明:Φ5mmTP2内螺纹铜管退火温度为470~480℃时,铜管组织细小、均匀,同时能获得较高塑性和较高强度;490~500℃时,铜管晶粒尺寸、力学性能波动大;510~520℃时,铜管组织易粗大。Φ5mmTP2内螺纹铜管在470℃退火时,晶粒尺寸随退火时间的规律变化为d=0.0008t3-0.062t^2+1.7t-1.3,保温21min时,铜管再结晶基本完成,保温时间为28~31min时,铜管组织状态和综合力学性能最佳。

  • 标签: 内螺纹铜管 成品退火 组织 延伸率 抗拉强度
  • 简介:利用水平连铸生产设备进行了稀土镧微合金化TP2铜管工业化试验,采用电感耦合等离子体发射光谱法仪、金相显微镜、扫描电镜和能谱仪等手段,研究了样品成分、组织、缺陷及稀土镧的收得率等。结果表明:稀土镧微合金化TP2铜水平连铸管坯含镧24~30ppm,杂质元素硫被有效地去除,组织明显改善,表现为晶粒细化、靠近铸坯内壁分布的微裂纹产生几率降低;镧实际收得率为10%~15%,镧大多被氧化成浮渣聚集在铸造炉后膛;稀土镧微合金化TP2铜管坯外表面裂纹沿着轴向不连续分布,而且裂纹较大、较长、较多,裂纹径向最大深度为490μm。

  • 标签: 稀土 微合金化 TP2铜 水平连铸 工业化试验
  • 简介:针对WH-800离心机出现的不推料故障,进行了系统分析、判断,经过检修,使离心机恢复了正常作业.

  • 标签: 故障 分析 判断 检修
  • 简介:Praseodymium(Pr)wasimpregnatedtoCeO2-ZrO2solidsolutionbyanimpregnationmethod.Theas-obtainedPrmodifiedCeO2-ZrO2wasimpregnatedwith1wt.%Pdtopreparethecatalysts.ThestructureandreducibilityofthefreshandhydrothermallyagedcatalystswerecharacterizedbyX-raydiffraction(XRD),Raman,X-rayphotoelectronspectroscopy(XPS),COchemisorptionandH2temperature-programmedreduction(H2-TPR).Theoxygenstoragecapacity(OSC)wasevaluatedwithCOservingasprobegas.EffectsofimpregnatedPronthestructureandoxygenstoragecapacityofcatalystswereinvestigated.TheresultsshowedthattheagedPr-impregnatedsampleshadmuchhigherOSCandbetterreducibilitythantheunmodifiedones.TheschemeofstructuralevolutionsofthecatalystswithandwithoutPrwasalsoestablished.PartialoftheimpregnatedPrdiffusedintothebulkofCeO2-ZrO2duringageing,whichinhibitedthesintering,andincreasedtheamountofoxygenvacanciesinCeO2-ZrO2support.Furthermore,thoseimpregnatedPrspecieswhichcoveredonthesurfaceofthesupportobstructedthestrongmetal-supportinteractionbetweenPdandCesoastoreducetheencapsulationofPdaswellasthebackspill-overoftheoxygenduringthecatalyticprocess.

  • 标签: 催化剂结构 储氧能力 浸渍法 氧化镨 氧化锆固溶体 X-射线光电子能谱
  • 简介:TwonovelwashcoatsCe0.8Zr0.15La0.05OδandCe0.8Zr0.2O2waspreparedbyanimpregnationmethod,whichactedasahostfortheactivePdcomponenttopreparePd/Ce0.8Zr0.15La0.05Oδ/substrateandPd/Ce0.8Zr0.2O2/substratemonolithiccatalystsfortoluenecombustion.ThewashcoatswascharacterizedbyX-raydiffraction(XRD),Ramanspectroscopy,Brunauner-Emmett-Teller(BET),andH2-temperature-programmedreduction(H2-TPR).Theresultindicatedthatboththewashcoatshadstrongvibration-shockresistanceaccordingtoultrasonictest.DopingLa3+intoCeO2-ZrO2solidsolutioncouldgeneratemoreoxygenvacancies,andcouldinhibitthesinterofCeO2-ZrO2solidsolutionwhencalcinedathightemperatures(800,900and1000°C).ThewashcoatCe0.8Zr0.15La0.05Oδhadmuchbetterredoxproperties.ThereductivetemperatureofCe4+speciesshiftedtolowtemperatureby60°Cwhenthewashcoatscalcinedathightemperatures(800,900and1000°C).ThePd/Ce0.8Zr0.15La0.05Oδ/substratemonolithiccatalystcalcinationat500°Chadthebestcatalyticactivityandthe95%tolueneconversionatatemperatureaslowas190°C.Whencalcinedatlowtemperature(500and700°C),thecatalyticactivityhaslittleimprovement,however,whencalcinedathightemperature,thecatalyticactivityofPd/Ce0.8Zr0.15La0.05Oδ/substratemonolithiccatalystshadsignificantimprovement.Ascatalystwashcoat,theCe0.8Zr0.15La0.05OδhadbetterthermalstabilitythanthewashcoatCe0.8Zr0.2O2,thedevelopedPd/Ce0.8Zr0.15La0.05Oδ/substratemonolithiccatalystinthisworkwaspromisingforeliminatingVolatileorganiccompounds.

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