greyironpresentation灰鐵的冶金講解課件

BasicMetallurgyGreyIron.

灰鐵的冶金學(xué)基本理論27.07.2023Developingpeople-creatingvalue2Greyironistheoldest(i.e.hasexistedlongest)ofthecastironsandthuscastironisoftensynonymuswithgreycastiron.Unfortunatelymostpeopleknowgreyirontobebrittleandthusbelieveallcastironstobebrittle.灰鐵是最古老的鑄鐵之一，灰鐵通常也稱之為灰口鑄鐵。不幸的事，大多數(shù)都知道灰鐵是易脆的，因此人們認(rèn)為所有的鑄鐵都是易脆的。Greyironiscalledgreybecauseofthecolourofitsfracturesurface.Thecarbonispresentasmoreorlesscontinuousflakesofgraphitewithinamatrixofnormallymostlypearlitebutitcanalsocontainsomeferrite.Greyironhasagoodfluidityandincombinationwiththeexpansionofthegraphiteduringsolidificationmakesitidealforcastingofshrinkagefreecomplexpartslikeengineblocks.灰鐵之所以被稱之為灰鐵，是因?yàn)槠鋽嗫诔苫疑４蠖鄶?shù)碳在灰鐵是以連續(xù)狀的片狀石墨存在于絕大多數(shù)為珠光體基體中，同時基體中也會存在少量的鐵素體?；诣F具有很好的流動性結(jié)合在凝固過程中的石墨化膨脹使得灰鐵是鑄造無縮松的發(fā)動機(jī)缸體的理想材料。Theflakesingreyironareimportantforthemechanicalproperties.Thegraphiteflakesinducesstressintheironmatrixandpossiblecrackswillrapidlypropagatealongtheflakes.Thisisthecauseoftheverysmallplasticelongationbeforerupture.Thegraphiteflakesmakestheironeasytomachine,actingaslubricant.灰鐵中的片狀石墨對其機(jī)械性能有著十分重要的影響。片狀石墨可以引導(dǎo)基體中的應(yīng)力和裂紋沿著片狀石墨快速傳播。這導(dǎo)致了灰鐵在失效時只具有很小的塑性。片狀石墨在機(jī)加工時起到了潤滑作用，使得灰鐵很容易被加工。IntroductiontoGreyCastIron

灰口鑄鐵的介紹SomeexamplesofcastingsinGreyIron

一些灰鐵的應(yīng)用案例27.07.2023Developingpeople-creatingvalue3WhyGreyIron?為什么選擇灰鐵lowrawmaterialcosts原材料成本低lowproductioncosts生產(chǎn)成本低

highcastingyield成品率較高goodcastingqualities好的鑄造質(zhì)量lowgaspick-up吸氣較少goodas-castproperties較好的毛胚件質(zhì)量easymachinable易加工gooddampingquality較好的減震性能goodcorrosionresistance較好的防腐蝕性能easilyalloyed易合金化temperaturestability耐熱性能27.07.2023Developingpeople-creatingvalue4GreyIron-FlakeGraphite

灰鐵—片狀石墨27.07.2023Developingpeople-creatingvalue5NormalCompositionRange:通常的成分范圍：2.5-4.0%Carbon碳1.0-3.0%Silicon硅0.4-1.0%Manganese錳0.05-1.0%Phosphorous磷max0.2%Sulphur

硫Thecompositionhastobeselectedtosatisfy:成分選擇需要滿足以下要求：requiredgraphiteshapeanddistribution必要的石墨形態(tài)和分布carbide-freestructure金相結(jié)構(gòu)中無碳化物requiredmatrix必要基體組織?ElkemMechanicalProperties機(jī)械性能TensileStrength: 100-450MPaElongation: <1%Themechanicalpropertiesandthemicrostructureofgreyirondependson:機(jī)械性能和金相結(jié)構(gòu)取決于以下：Sectionsize壁厚ChemicalComposition化學(xué)成分CoolingRate冷去速率NucleationPotential形核潛力?ElkemSectionSize壁厚Microstructure金相結(jié)構(gòu)Properties性能SectionSize壁厚+=fIncreasingSectionSize DecreasingCoolingRategraphitecoarsening石墨粗化increasinggrainsize晶粒尺寸增大pearlitecoarsening珠光體變粗糙?ElkemSectionSize壁厚Asthesectionsizeincreasesthestrengthofgreycastironsfalls.隨著壁厚的增加灰鑄鐵的強(qiáng)度是在降低的。*TypicalMicrostructuresofCastMetals-IBF?ElkemFe-C–Phasediagram鐵碳相圖**ASMSpecialtyHandbookFe-C–Phasediagram鐵碳相圖27.07.2023Developingpeople-creatingvalue10Consistsofastableandametastablesystem由穩(wěn)定和亞穩(wěn)定系統(tǒng)組成Stable穩(wěn)定物Metastable亞穩(wěn)定物Carbonasgraphite碳以石墨形式存在Eutecticpoint:4.3wt%CTeutectic=1153°CTeutectoid=738°CCarbonasFe3C碳以滲碳體形式存在Eutecticpoint:4.26wt%CTeutectic=1147°CTeutectoid=723°CEffectofCarboninGreyIron

碳在灰鐵中的作用27.07.2023Developingpeople-creatingvalue11reducesmeltingtemperature降低熔點(diǎn)improvescastability改善鑄造性能improvesmachinability改善機(jī)加工性能improvesdampingcapacity提高減震性reducesneedforfeeding降低縮水increasesthermalconductivity提高熱傳導(dǎo)性能decreaseschillingtendency減少白口傾向reducesmechanicalstrength降低機(jī)械強(qiáng)度coarsergraphitestructure粗化石墨結(jié)構(gòu)?ElkemSilicon硅improvesgraphitisation促進(jìn)石墨化reduceschillformation減少白口的形成promotesferrite促進(jìn)鐵素體promotesstablesolidification促進(jìn)穩(wěn)定凝固increasingcontentleadstocoarserpearlite提高粗糙珠光體的含量

?ElkemPhosphorous磷foundinallgreyirons所有灰鐵中都含有increasesfluidity提高流動性formslow-meltingphosphideingreyiron;steadite,Fe3P在灰鐵中形成低熔點(diǎn)的磷化物

；穩(wěn)定的化合物Fe3Ppromotesshrinkageporosityathighlevels含量較高時促進(jìn)疏松的產(chǎn)生promotesmeltpenetrationintomouldatverylowlevels

較低的含量下可以促進(jìn)鐵水向鑄型滲透wearresistanceincreaseswithincreasingP-content提高磷的含量可以提高耐磨性能CarbonEquivalent碳當(dāng)量27.07.2023Developingpeople-creatingvalue14Carbonequivalentformula:碳當(dāng)量的公式EffectofCarbonEquivalentinGreyIron

碳當(dāng)量在灰鐵中的作用27.07.2023Developingpeople-creatingvalue15Strengthofgreyironwill,ingeneral,decreasewithincreasingcarbonequivalent.Whileamountofgraphiteinthestructureincreases.通?；诣F的強(qiáng)度將會隨著碳當(dāng)量的提高而降低；同時金相結(jié)構(gòu)中的石墨也會增多。?ElkemManganese錳tiesupSandO束縛硫和氧reduceschillformation減少白口的形成promotesaustenite促進(jìn)奧氏體strongpearlitepromoter強(qiáng)烈的珠光體促進(jìn)劑weakcarbidepromoter弱的碳化物促進(jìn)劑TotieupS: %Mn=1.7[%S]+0.3Togivepearliticstructure: %Mn=3[%S]+0.35Manganese錳27.07.2023Developingpeople-creatingvalue17?ElkemSulphur硫foundinallgreyirons所有灰鐵中都有pearlitepromoterformslow-meltingsulphideingreyiron,FeSbalancedoutbyMntoMnS,whichactsasnucleationpointspromotessmallereutecticcellshardnessincreasewithincreasingS-levelUTSvsSulphurContent

抗拉強(qiáng)度與硫含量的關(guān)系27.07.2023Developingpeople-creatingvalue19?ElkemSulphur硫wt%SHighchillingtendencyLargeGrainsD-graphite過冷度大，晶粒較大，D型石墨HighchillingtendencyFineGrainsD-graphite過冷度大，晶粒細(xì)小，D型石墨LowchillingtendencyMediumSizeGrainsA-graphite過冷度較小，晶粒尺寸適中，A型石墨EffectofManganeseandSulphur

錳和硫的作用27.07.2023Developingpeople-creatingvalue21EquilibriumreactionMnS:Mn+S?MnS反應(yīng)平衡式EquilibriumreactionFeS:Fe+S?FeS反應(yīng)平衡式Stoichiometricbalance:[%Mn]=1.7[%S]ToensureonlyMnS:[%Mn]=1.7[%S]+0.30%ToachievemaximumstrengthprecipitationofMnShastosuppressedtoaslowtemperatureaspossiblepriortoonsetofsolidification.為了獲得最大的強(qiáng)度，

要確保MnS的在凝固后期較低的溫度下析出TooearlyMnSprecipitation=40–80MPalowerstrengthMnS過早析出=抗拉強(qiáng)度有40–80MPa的降低

Manganese&SulphurasfunctionofCE

錳和硫與碳當(dāng)量的關(guān)系27.07.2023Developingpeople-creatingvalue22?ElkemTypeofGraphiteFlakes

石墨片層的種類EInterdendriticSegregationPreferredorientatedDInterdendriticSegregationRandomorientatedBRosetteGroupingRandomorientatedAInoculatedIronsUniformdistributedRandomorientatedCSuperimposedFlakeSizeRandomorientatedUndercooling,TC.EC.E=4.26FlakeGraphiteStructures

片層石墨結(jié)構(gòu)27.07.2023Developingpeople-creatingvalue24GreyIronSolidification

灰鐵的凝固曲線27.07.2023Developingpeople-creatingvalue25FlakeGraphiteSize

石墨片大小27.07.2023Developingpeople-creatingvalue26Effectofdifferentelementsontensilestrength

一些合金元素的灰鐵抗拉強(qiáng)度的影響27.07.2023Developingpeople-creatingvalue27ChillDepthinGreyIron

灰鐵中白口深度27.07.2023Developingpeople-creatingvalue28Thefigureshowstherelativechillingpowerofdifferentelements圖形展示的是不同元素的促進(jìn)白口能力EffectofVanadium

釩的作用27.07.2023Developingpeople-creatingvalue29Promotesformationofeutecticironcarbidewhichcanberemovedbyheattreatment可以促進(jìn)合金碳化物的形成，這類碳化物可以通過熱處理消除。Inoculationcanhelpreduceformationofeutecticcarbides孕育作用有助于減少共晶碳化物的形成LowchillingtendencyinhighcarbonironsandincombinationwithCu高碳鑄鐵和合金銅的加入可以降低白口傾向Increasesnucleationingreyirongivingfinerandmoreuniformgraphitestructures提高灰鐵的形核率，從而可以細(xì)化石墨結(jié)構(gòu)提高石墨結(jié)構(gòu)的一致性SegregateswithPgivinghardparticleswithgoodslidingwearresistance與磷一起偏析形成硬點(diǎn)，從而形成耐磨層Increasesstrengthespeciallyinhighcarbongreyiron提高灰鐵的強(qiáng)度，尤其是高碳灰鐵MoreeffectivethanCrandMo比鉻和鉬的效率更高Factorsaffectingmachinability

影響機(jī)加工的因素27.07.2023Developingpeople-creatingvalue30Carboncontent碳含量Eutecticcellcount共晶團(tuán)數(shù)量VolumeofMnSparticlesMnS顆粒的數(shù)量Mnlevel錳的含量Snlevel錫的含量ControlofPropertiesinGreyIron

灰鐵性能的控制27.07.2023Developingpeople-creatingvalue31Fractureandcracksareinitiatedbytheflakegraphite.斷裂和裂紋是開始于石墨片。SizeandDistributionofthegraphiteinGreyIronarethusthemost

importanttooltocontrolthemechanicalproperties.灰鐵金相中的石墨的大小和分布是控制其鑄件機(jī)械性能最重要的因素。CalculatedUTS–developedbyBateset.al.

抗拉強(qiáng)度的計算—有貝茨等人發(fā)明27.07.2023Developingpeople-creatingvalue32UTS=FactorA*FactorBFactorA:101.1193*(%TC+%Si/4+%P/2)+4.3887/castbarradiusFactorB:1.00+0.1371Si–0.0021(Mn-1.7S)–0.3131S+0.3562Cr+0.0282Ni+0.1107Cu+0.6297Mo–5.2985Ti–0.2350SnThecoefficientsaredevelopedfromregressionanalysis.系數(shù)是由回歸分析法來計算獲得的References參考文獻(xiàn)27.07.2023Developingpeople-creatingvalue33Nucleationofgraphiteincastironmeltsdependingonmanganese,sulphurandoxygen.–A.Sommerfeld,B.TonnInternationaljournalofCatsMetalsResearch2008vol21no1-4?Tin-alloyedGreyIronCylinderBlocks–A.J.Tache,R.M.CageAmericanSocietyofAutomotiveEngineers14.January1964?Eutecticcellandnodulecountincastirons–E.Fras,M.Gorny,W.Kapturkiewicz,H.Lopez