Cam khwb cia hlauyog ib pawg ntawm cov hlau-carbon alloys nrog cov ntsiab lus carbon ntau dua 2%.Nws cov txiaj ntsig tau muab los ntawm nws qhov kub tsis tshua muaj melting.Cov khoom siv sib xyaw ua ke cuam tshuam rau nws cov xim thaum tawg: dawb cam khwb cia hlau muaj carbide impurities uas tso cai rau cov kab nrib pleb kom dhau mus ncaj, grey cam khwb cia hlau muaj graphite flakes uas deflect ib qho kev tawg thiab pib suav tsis txheeb cov kab nrib pleb raws li cov khoom tawg, thiab cov hlau cam khwb cia hlau muaj kheej kheej. graphite "nodules" uas nres qhov tawg ntawm kev nce qib ntxiv.

Cov pa roj carbon (C) xws li 1.8 txog 4 wt%, thiab silicon (Si) 1-3 wt%, yog cov ntsiab lus tseem ceeb ntawm cov hlau cam khwb cia.Hlau alloys nrog qis carbon cov ntsiab lus yog hu ua steel.

Cov hlau cam khwb cia zoo li nkig, tshwj tsis yog cov cam khwb cia hlau.Nrog nws qhov qis melting point, zoo fluidity, castability, zoo heev machinability, tsis kam mus deformation thiab hnav tsis kam, cam khwb cia hlau tau dhau los ua ib yam khoom siv engineering nrog ntau yam kev siv thiab siv hauv cov kav dej, tshuab thiab kev lag luam tsheb, xws li lub tog raj kheej. taub hau, lub tog raj kheej blocks thiab gearbox rooj.Nws yog resistant rau kev puas tsuaj los ntawm oxidation.

Qhov ntxov tshaj plaws cam khwb cia hlau artefacts hnub mus rau lub xyoo pua 5 BC, thiab tau pom los ntawm archaeologists nyob rau hauv dab tsi tam sim no Jiangsu nyob rau hauv Suav teb.Cam khwb cia hlau tau siv nyob rau hauv Suav teb thaum ub rau kev ua tsov ua rog, kev ua liaj ua teb, thiab kev tsim vaj tsev.Thaum lub xyoo pua 15th, cam khwb cia hlau tau siv rau cov phom loj hauv Burgundy, Fabkis, thiab hauv tebchaws Askiv thaum lub sijhawm Reformation.Tus nqi ntawm cov cam khwb cia hlau siv rau cov phom loj yuav tsum tau ua cov khoom loj loj.Tus thawj cam khwb cia hlau tau tsim thaum xyoo 1770 los ntawm Abraham Darby III, thiab hu ua The Iron Choj hauv Shropshire, England.Cam khwb cia hlau kuj tau siv rau hauv kev tsim vaj tsev.

Alloying khoom

Cam khwb cia hlau cov khoom raug hloov los ntawm kev ntxiv ntau yam alloying ntsiab, los yog alloyants.Tom ntej no mus rau carbon, silicon yog qhov tseem ceeb tshaj plaws alloyant vim hais tias nws quab yuam carbon tawm ntawm cov kua.Tsawg feem pua ​​​​ntawm silicon tso cai rau cov pa roj carbon nyob twj ywm hauv kev daws cov hlau carbide thiab tsim cov hlau cam khwb cia dawb.Qhov feem pua ​​​​ntawm silicon yuam cov pa roj carbon monoxide tawm ntawm kev sib sau graphite thiab tsim cov hlau cam khwb cia grey.Lwm cov khoom siv alloying, manganese, chromium, molybdenum, titanium thiab vanadium counteracts silicon, txhawb nqa cov pa roj carbon monoxide, thiab tsim cov carbides.Nickel thiab tooj liab nce lub zog, thiab machinability, tab sis tsis hloov tus nqi ntawm graphite tsim.Cov pa roj carbon nyob rau hauv daim ntawv ntawm graphite ua rau cov hlau softer, txo shrinkage, txo lub zog, thiab txo qhov ceev.Sulfur, feem ntau yog cov kab mob paug thaum tam sim no, tsim cov hlau sulfide, uas tiv thaiv kev tsim ntawm graphite thiab nce hardness.Qhov teeb meem nrog sulfur yog tias nws ua rau molten cam khwb cia hlau nkig, uas ua rau muaj qhov tsis xws luag.Txhawm rau tiv thaiv cov teebmeem ntawm leej faj, manganese ntxiv vim tias ob daim ntawv rau hauv manganese sulfide tsis yog hlau sulfide.Cov manganese sulfide yog sib dua li yaj, yog li nws zoo li ntab tawm ntawm yaj thiab mus rau hauv slag.Tus nqi ntawm manganese yuav tsum ua kom tsis muaj leej faj yog 1.7 × sulfur ntsiab lus + 0.3%.Yog hais tias ntau tshaj li cov manganese ntxiv, ces manganese carbide cov ntaub ntawv, uas ua rau kom hardness thiab chilling, tshwj tsis yog nyob rau hauv grey hlau, qhov twg mus txog rau 1% ntawm manganese nce zog thiab ceev.

Nickel yog ib qho ntawm feem ntau alloying ntsiab vim nws refines lub pearlite thiab graphite qauv, txhim kho toughness, thiab evens tawm hardness sib txawv ntawm seem thicknesses.Chromium yog ntxiv rau me me kom txo tau cov graphite dawb, ua kom txias, thiab vim tias nws yog lub zog carbide stabilizer;nickel feem ntau ntxiv ua ke.Ib qho me me ntawm cov tin tuaj yeem ntxiv los hloov pauv 0.5% chromium.Copper yog ntxiv rau hauv lub ladle lossis hauv qhov cub, ntawm qhov kev txiav txim ntawm 0.5-2.5%, kom txo qis txias, ua kom zoo dua graphite, thiab nce fluidity.Molybdenum yog ntxiv rau qhov kev txiav txim ntawm 0.3-1% kom txias thiab ua kom cov graphite thiab pearlite qauv;nws feem ntau ntxiv ua ke nrog npib tsib xee, tooj liab, thiab chromium los tsim cov hlau muaj zog.Titanium yog ntxiv raws li ib tug degasser thiab deoxidizer, tab sis nws kuj ua rau kom fluidity.0.15-0.5% vanadium yog ntxiv rau cam khwb cia hlau kom ruaj khov cementite, nce hardness, thiab ua kom tsis kam hnav thiab kub.0.1-0.3% zirconium pab tsim graphite, deoxidize, thiab nce fluidity.

Nyob rau hauv malleable hlau melts, bismuth yog ntxiv, ntawm qhov ntsuas ntawm 0.002-0.01%, kom ntau npaum li cas silicon ntxiv.Nyob rau hauv cov hlau dawb, boron yog ntxiv los pab hauv kev tsim cov hlau malleable;nws kuj txo cov coarsening nyhuv ntawm bismuth.

Grey cam khwb cia hlau

Grey cam khwb cia hlau yog tus cwj pwm los ntawm nws cov graphitic microstructure, uas ua rau tawg ntawm cov khoom kom muaj qhov muag grey.Nws yog feem ntau siv cam khwb cia hlau thiab feem ntau siv cam khwb cia khoom raws li qhov hnyav.Feem ntau cov cam khwb cia hlau muaj cov tshuaj muaj pes tsawg leeg ntawm 2.5-4.0% carbon, 1-3% silicon, thiab cov hlau seem.Grey cam khwb cia hlau tsis muaj zog tensile thiab poob siab tsis kam tshaj hlau, tab sis nws lub zog compressive yog piv rau qis- thiab nruab nrab-carbon steel.Cov khoom siv tshuab no yog tswj los ntawm qhov loj thiab cov duab ntawm cov graphite flakes tam sim no hauv microstructure thiab tuaj yeem ua tus yam ntxwv raws li cov lus qhia los ntawm ASTM.

Dawb cam khwb cia hlau

Dawb cam khwb cia hlau qhia cov pob txha tawg dawb vim muaj cov hlau carbide precipitate hu ua cementite.Nrog rau cov ntsiab lus ntawm silicon qis (graphitizing tus neeg saib xyuas) thiab cov cua txias sai dua, cov pa roj carbon hauv cov hlau cam dawb precipitates tawm ntawm cov yaj raws li theem metastable cementite, Fe₃C, tsis yog graphite.Cov cementite uas precipitates los ntawm yaj cov ntaub ntawv raws li qhov loj hais.Raws li cov hlau carbide precipitates tawm, nws tshem tawm cov pa roj carbon monoxide los ntawm qhov qub yaj, txav cov sib tov mus rau ib qho uas ze rau eutectic, thiab cov theem ntxiv yog cov hlau qis-carbon austenite (uas ntawm qhov txias yuav hloov mus rau martensite).Cov eutectic carbides no loj heev los muab cov txiaj ntsig ntawm qhov hu ua nag lossis daus hardening (xws li hauv qee cov hlau, qhov ntau me me cementite precipitates yuav inhibit [yas deformation] los ntawm impeding lub zog ntawm dislocations los ntawm cov ntshiab hlau ferrite matrix).Es tsis txhob, lawv nce lub hardness ntawm cov cam khwb cia hlau yooj yim los ntawm kev tsim txiaj ntawm lawv tus kheej siab heev hardness thiab lawv cov khoom ntim loj, xws li cov hardness ntau tuaj yeem kwv yees los ntawm txoj cai ntawm kev sib tov.Nyob rau hauv txhua rooj plaub, lawv muab hardness ntawm tus nqi ntawm toughness.Txij li thaum carbide ua ib feem loj ntawm cov khoom siv, cov hlau cam dawb tuaj yeem raug cais raws li cermet.Cov hlau dawb yog nkig heev rau kev siv ntau yam khoom, tab sis nrog zoo hardness thiab abrasion tsis kam thiab kuj tsis tshua muaj nqi, nws pom siv nyob rau hauv xws li daim ntaub ntawv xws li hnav nto ( impeller thiab volute ) ntawm slurry twj, plhaub liners thiab lifter tuav hauv pob. mills thiab autogenous sib tsoo mills, pob thiab rings hauv thee pulverisers, thiab cov hniav ntawm lub backhoe lub thoob khawb (txawm hais tias cam khwb cia nruab nrab-carbon martensitic steel yog ntau dua rau daim ntawv thov no).

Nws yog ib qho nyuaj rau txias tuab castings sai txaus kom solidify lub yaj li dawb cam khwb cia hlau tag nrho txoj kev los ntawm.Txawm li cas los xij, kev ua kom txias sai sai tuaj yeem siv los ua kom muaj lub plhaub dawb ntawm cov hlau cam khwb cia, tom qab ntawd cov seem txias dua maj mam tsim cov tub ntxhais ntawm grey cam khwb cia hlau.Lub resulting casting, hu ua achilled casting, muaj cov txiaj ntsig ntawm qhov tawv tawv nrog ib qho me ntsis tougher sab hauv.

High-chromium dawb hlau alloys pub loj loj castings (piv txwv li, ib tug 10-tonne impeller) los ua xuab zeb cam khwb cia, raws li cov chromium txo cov cua txias yuav tsum tau tsim carbides los ntawm cov thicknesses ntau dua ntawm cov khoom.Chromium kuj tseem tsim cov carbides nrog kev ua kom puas ntsoog.Cov high-chromium alloys ntaus nqi lawv cov hardness superior rau muaj chromium carbides.Daim ntawv tseem ceeb ntawm cov carbide no yog eutectic lossis thawj M₇C₃carbides, qhov "M" sawv cev rau cov hlau los yog chromium thiab tuaj yeem sib txawv nyob ntawm seb cov alloy muaj pes tsawg leeg.Cov eutectic carbides tsim raws li pob khoom ntawm hollow hexagonal rods thiab loj hlob perpendicular mus rau lub hexagonal basal dav hlau.Lub hardness ntawm cov carbide yog nyob rau hauv thaj tsam ntawm 1500-1800HV.

Malleable cam khwb cia hlau

Malleable hlau pib raws li ib tug dawb hlau casting uas yog ces kub kho rau ib hnub los yog ob hnub ntawm 950 ° C (1,740 ° F) thiab ces txias tshaj ib hnub los yog ob hnub.Yog li ntawd, cov pa roj carbon nyob rau hauv hlau carbide hloov mus rau hauv graphite thiab ferrite ntxiv rau carbon (austenite).Cov txheej txheem qeeb tso cai rau qhov nro saum npoo los tsim cov graphite rau hauv spheroidal hais es tsis yog flakes.Vim lawv qhov piv txwv qis, cov spheroids luv luv thiab nyob deb ntawm ib leeg, thiab muaj ib qho qis dua vis-a-vis ib qho propagating tawg los yog phonon.Lawv kuj muaj cov ciam teb tsis meej, tsis zoo li cov flakes, uas txo cov teeb meem kev ntxhov siab pom nyob hauv grey cam khwb cia hlau.Feem ntau, cov khoom ntawm malleable cam khwb cia hlau zoo li cov hlau me me.Nws muaj kev txwv rau qhov loj npaum li cas tuaj yeem muab pov rau hauv cov hlau tsis muaj hlau, vim nws yog tsim los ntawm cov hlau cam khwb cia dawb.

Ductile cam khwb cia hlau