简介:Thermodynamiccalculation,SEM(scanningelectronmicroscopy),TEM(transmissionelectronmicroscopy),XRD(X-raydiffraction),phaseextraction,andchemicalanalysiswereemployedtostudythephasestabilityandphaseprecipitationinanewNi-Cr-Cobasesuperalloyheat-treatedat704and760℃foralongtime.Theresultsshowthattheprecipitatesofthisnewalloyheat-treatedatstandardannealingconditionandheat-treatedat704and760℃foratimeupto2000hareγ′,MC,M23C6,andM6C,andηphaseformsatgrainboundariesandinmatrixofsamplesheat-treatedat760℃aswell.Themassfractionsofγ′(+η),MC,M23C6,andM6Cinallsampleshavenolargechangeswithanincreaseinagingtime,butγ′precipitatesgrowobviously.Theγ′-to-ηtransformationinthesamplesheat-treatedat760℃tookplacewithincreasingagingtime.TheηprecipitatesformaWidmanstattenpattemandtheγ′phaseshaveremeltedpartlyinthesamplesheat-treatedat760℃.Thealloymaintainsabettermicrostructuralstabilityduringprolongedagingat704℃,butaworsemicrostructuralstabilityduringprolongedagingat760℃.
简介:Co,Ni,CrandVin25typicalsoilsofChinawerefractionatedintoexchangeable,carbonatebound(calcareoussoils),Mnoxidebound,organicallybound,amorphousFeoxidebound,crystallineFeoxideboundandresidualformsusingaseven-stepsequentialextractionprocedure,soastostudythedistributionofchemicalformsofthesemetalsaswellastheeffectsofsoilproipertiesonthedistribution.TheresultsshowedthatmostofsoilCo,Ni,CrandVwerepresentinresidualforms,andthedistributionratioaveraged48.2%forCo,53.0%forNi,81.5%forCrand68.7%forV.Thespeciationofheavymetalswasgreatlyinfluencedbysoilphysico-chemicalpropertiesandthechemistryofelements.Theresultsalsoindicatedthattherecoveryofmetalelementsbythesequentialextractionprocedurewassatisfactory,withtherelativedifferencebetweenthesumofsevenformsandthetotalcontentinsoilsaveraging9.5%forCo,12.8%forNi,6.6%forCrand7.2%forV.
简介:Twoseriesofmixedoxides,CoAlMandMgAlM(M=Cr,Mn,Fe,Co,Ni,Cu),werepreparedbycalciningtheircorrespondinghydrotalcite-likecompounds(HTLc).TheratioofMg:Al:M(orCo:Al:M)was3:1:1.ThecatalyticactivityofallsamplesforthereactionofNO+COwasinvestigated.TheresultsshowedthattheactivityofCoAlMwasmuchhigherthanthatofMgAlM.ThestructureandthepropertyofredoxwerecharacterizedbyXRDandH2-TPR.TheresultsindicatedthatonlyMgOphasewasobservedaftercalciningMgAlMhydrotalcites,andthetransitionmetalsbecamemorestable.Thespinel-likephaseappearedinallofCoAlMsamplesafterthecalcination,andthetransitionmetalswerechangedtobemoreactive,andeasilyreduced.TheactivitiesofthreeseriesofmixedoxidesCoAlCuobtainedfromdifferentpreparationmethods,differentratioofCo:Al:Cuandatdifferentcalcinationtemperatures,werestudiedindetailforproposingthemechanismofreaction.TheabilityofadsorptionofNOandCO
简介:PrecipitationstudywascarriedoutinNi-35at.pctCralloybymeasuringelectricalresistivityatdifferentageingtemperaturesandlongageingtimes.Duringageing,itwasobservedthatelectricalresistivityinitiallyrosewithageingtimeandthenfellafterverylongageingataconstanttemperature.TheinitialincreaseinresistivityduringageingmaybeattributedtotheformationofGPzones/Cr-richprecipitatesatearlystagesbynucleationprocessanddecreaseinresistivity,andafterattainingamaximum,isduetothegrowthofprecipitateparticlesandsubsequentlybycoarseningoftheseprecipitates.TheresultsofelectricalresistivitymeasurementsduringageingwereconfirmedbyX-raydiffractionanalysisindicatingtheformationofaCr-richphaseandaCr3Ni2phaseintheNimatrix.
简介:ThesecondaryhardeningreactionisaccompaniedwithprecipitationoffinecarbidesinhighCoNiultrahighstrengthsteel.Thecrystalstructureoftheprecipitatingcarbidesisunambiguouslydeterminedbymicrobeamdiffractionintransmissionelectronmicroscopy.Itisidentifiedthattheneedle-shapedcarbidesareM2Cwithahexagonalstructure.TheconcentrationofsubstitutionalalloyingelementsinthecarbidesquantifiedbyenergydispersiveX-rayspectroscopy(EDS)alsosupportstheresultabove.ThespatialstructureofM2CisidenticalwithL'3type.Metalatomsareinaclosepackedhexagonalstructure,thecarbonatomspartlydistributewithrandomintheoctahedralintersticesandthefillingprobabilityislessthan1/2.Particularattentionwaspaidtotherelationshipofneedle-shapedcarbides/ferritematrixatsecondaryhardeningpeaktemperedat482℃for5h.Observationbyhighresolutiontransmissionelectronmicroscopy(HRTEM)confirmsthatcarbideswithblack-whitecontrastarefullycoherentwithferriteandhaveindividualcrystalstructure,andthecoarsenedcarbideswithmoirefringearepartiallycoherentwithmatrix.TheorientationrelationshipbetweenM2CandferritematrixisdirectlyobservedandidentifiedwiththewellestablishedP-Srelationship[001]α//[111]c.
简介:针对23Co14Ni12Cr3Mo超高强度钢材料,研究喷丸强化对其表面性能的影响。采用扫描电镜、白光干涉仪等设备,分析喷丸强化对试样表面形貌、粗糙度、硬度、残余应力、元素含量等的影响。结果表明:喷丸强化后,试样表面留有大量弹坑,产生明显塑性变形;表面粗糙度增大,算术平均粗糙度为1.33μm;硬度显著增大,最表层硬度由喷丸前的HV476增加至HV497,硬化层深度约150μm;试样表层的残余压应力值由375MPa增加至475MPa,最大残余压应力值约518MPa,位于距表面50μm深度处,喷丸形成的残余压应力层深度约为134μm;喷丸后试样中C、Si、Cr等各元素的质量分数均略有增加。喷丸在一定程度上改善了23Co14Ni12Cr3Mo钢材料的表面性能,有利于提高其疲劳抗力和耐腐蚀性。
简介:Ni-Cr-Mo合金经冷压成型后于真空中以不同温度进行烧结.通过测定其相对密度、线收缩率、拉伸强度和硬度,研究烧结温度对合金性能的影响.研究结果表明:当烧结温度不超过1330℃时,合金的相对密度、收缩率、拉伸强度和硬度随烧结温度的上升而缓慢增加;当温度上升到1360℃时,合金的这些性能指标急剧增大;当温度上升到1390℃时,烧结后的合金试样外形发生严重变形.
简介:本文针对N4/1Cr18Ni9Ti与N4/0Cr25Ni20复合板的特殊焊接要求,根据NB/T47014—2011《承压设备焊接工艺评定》的要求,制备2块N4/1Cr18Ni9Ti试板,2块N4I/0Cr25Ni20试板,尺寸均为500mmX150mmX(4+14)mm。不锈钢基层采用GTAW打底,焊丝选用HOCr21Ni10,SMAW填充与盖面,焊条选用A302与A402。镍复层的焊接采用手工钨极氩弧焊,焊丝选用含Ti、AI等脱氧元素的ERNi-1焊丝,保护气体选择98%Ar+2%H2。试板焊接完成,外观检验合格后进行100%RT,检测结果符合JB厂r4730,2—2005I级合格,镍复层进行100%PT,检测结果符合JB/T4730.5—2005I级。两种焊接试板分别取样并做拉伸、弯曲力学性能分析,镍复层焊缝做化学成分分析。通过两块焊接试板试验对比,不锈钢基层焊接材料选择HOCr21Ni10焊丝与A302焊条。镍复层焊接采用ERNi-1焊丝,焊接保护气体为98%Ar+2%H2。通过焊接工艺评定试验研究,解决了N4/1Cr18Ni9Ti与N4I/0Cr25Ni20复合板焊接问题,提高了用户坩埚的返修质量与再次使用寿命,为使用单位节约了成本。
简介:Cr2O3-formingferriticstainlesssteelshavebeenwidelyexploredasintermediatetemperaturesolidoxidefuelcells(SOFCs)interconnects.However,theevaporationofchromiascalemightmigratetoandpoisonthecathode,leadingtodegradationofthecellperformance.Inthisstudy,Ni-Co-Fe-Pcoatingsweredepositedontheferriticstainlesssteelbymeansofacost-effectivetechniqueofelectrolessmethod.Theyareexpectedtobeconvertedinto(Ni,Co,Fe)3O4spinelwithahighelectricalconductivityandCTEmatchwithstainlesssteel,whichcanblocktheevaporationofchromiaformedonsteelsubstrateexposedtothecathodeenvironmentoftheSOFC.TheeffectsofpH,massratioofFeSO4/(FeSO4+NiSO4+CoSO4)andtemperatureofsolutiononthedepositionrate,compositions,surfacemorphologiesandstructuresoftheNi-Co-Fe-Pcoatingswereinvestigated.TheresultsindicatedthatthedepositionrateincreasedwithincreasingpHwhenpHwaslowerthan9andthenreducedwhenpHwashigherthan9.Thedepositionrateincreasedwithincreasingtemperaturewhentemperaturewaslowerthan80℃andthendecreasedwhentemperaturewashigherthan80℃.ThedepositionratedecreasedwiththeincreaseinmassratioofFeSO4/(NiSO4+CoSO4+FeSO4).ThecoatingsconsistedofNi,Co,FeandP.Thephasestructureofthecoatingwasamorphous.
简介:TheTm-Ni-Coalloyfilmshavebeenpreparedbythesweeppotentialdepositiontechnique.ThesurfaceappearanceofTm-Ni-Coalloyfilmswassilver,smoothandadhesive.ThesurfacesofTm-Ni-Coalloyfilmsobservedbyscanningelectronmicroscope(SEM)wereuniform,adhesiveandcompact.Thesizesofmetallicgrainswereabout80-100nm,100-200amorphousasprovenbytheX-raydiffraction(XRD).
简介:磁性的元素Fe,公司和Ni的线性热扩大(CLE)的系数用与MATLAB计算相结合的理论模型从试验性的信息被估计。模型参数能精确地被决定,并且估计的数据在对试验性的结果的好同意。便于评价,热扩大的理论被使用把CLE分开成它的无磁性、磁性的部件。对CLE的无磁性的贡献的计算基于MnBi/NdFeB混血儿的修改Grc性质结合的磁铁都逐渐地减少,当混合磁铁的密度几乎线性地改善时。在293-398的一个温度范围?K,混合磁铁的coercivity温度系数从0.59逐渐地改善?%比较。建模和频率与二低角落频率认为压力消除阀门是一个秒顺序系统是合理的试验性的结果表演。PID控制,死了的乐队赔偿控制和鷸?鷸??
简介:建立起HNO3-H2O2-HF体系微波消解前处理样品,利用电感耦合等离子体质谱(ICP—MS)同时测定土壤中的铬(Cr)、镍(Ni)、铜(Cu)、砷(As)、铊(Tl)、铅(Pb)6种重金属元素含量的方法。该方法的相关系数在0.9996~1.000,相对标准偏差在0.669%~3.02%,加标回收率为94.68%~115.5%,检出限为2.004~312.4ng/L,结果表明该方法满足重金属分析的要求。用建立起的方法测定了来自湖南、湖北、云南、贵州、河南、福建、辽宁7个省45个产区烟田土壤中的Cr、Ni、Cu、As、田和Pb6种重金属元素含量;与对应烟叶中的6种重金属含量相比,聚类分析结果表明不同省区间土壤中的重金属含量无明显差异,而烟叶中却差异明显。
简介:摘要本文简要介绍了镍基合金的特点、分类和其在AP1000核电中的应用。以SB168UNSN06690镍基合金为代表,分析了Ni-Cr-Fe合金的焊接性,从焊接工艺特点和焊接接头性能方面分析了其焊接特点,针对焊接难点,总结了各难点的解决措施。并结合SB168UNSN06690的焊接性和工艺试验,总结了几点关于今后现场施工中应注意的建议。