Zas hlau: zog, cim thiab uas

Hlau - ib qho nyuaj, corrosion-resistant, tab sis lub cev tsis kho hlau-cov hlau nrog ib tug carbon cov ntsiab lus ntawm C nyob rau hauv ntau ntawm 2,14 mus 6,67%. Txawm tias lub hav zoov ntawm ib lub teeb meem, nws muaj ib tug ntau yam ntawm hom, zog, daim ntaub ntawv. Lug siv yog zas cam khwb cia hlau.

zaj dabneeg

Qhov no cov ntaub ntawv uas tau paub txij li thaum lub IV xyoo pua BC. e. Nws Suav keeb kwm yog nyob rau hauv lub VI. BC. e. Nyob rau hauv Teb chaws Europe, cov thawj mention ntawm lub industrial zus tau tej cov hlau yog sau hnub tim XIV, thiab nyob rau hauv Russia - XVI caug xyoo. Tab sis zas hlau ntau lawm technology yog patented nyob rau hauv Russia nyob rau hauv lub XIX caug xyoo. Tom qab txoj kev loj hlob ntawm AD Annosovym.

Txij li thaum lub grey irons yog tas nyob rau hauv kev siv vim tsis muaj txhua yam khoom, thiab steel - yeej kim heev thiab muaj ib tug tsis tshua muaj hardness thiab durability, cov lus nug sawv ntawm hlau tsim ib txhim khu kev qha, check, khoom, thaum muaj zog lub dag lub zog thiab ib tug tej yam yooj.

Wrought hlau tsis yog, txawm li cas los, vim rau yas yam ntxwv, nws lends nws tus kheej mus rau tej yam kev yas ua hauj lwm (e.g., forging).

ntau lawm

Lub ntsiab txoj kev - smelting nyob rau hauv lub moj tej tawg furnaces.

Cov pib ntaub ntawv rau lub moj tej tawg ua:

• Charge - hlau ore muaj hlau oxide nyob rau hauv daim ntawv Ferum.
• Roj - coke thiab cov nkev.
• Pa - yog txhaj los ntawm tshwj xeeb ntau.
• Fluxes - tshuaj tsim rau lub hauv paus ntawm manganese thiab (los yog) silicon.

Cov qib moj tej tawg cub tawg:

1. Rov qab los ntawm ntshiab hlau los ntawm tshuaj cov tshuaj tiv thaiv ntawm hlau ore nrog rau oxygen nkag los ntawm tuyeres.
2. Combustion ntawm coke tsim thiab cov pa roj carbon oxides.
3. Carburizing nyob hauv cov ntshiab hlau tshua nrog CO thiab CO _2.
4. Kev tsuas xyaus ntawm Fe ₃ C nrog manganese thiab silicon nyob rau hauv lub xav tau thaj chaw ntawm cov qhov tso zis.
5. Txhuav hauv lub tiav lawm hlau mus rau hauv pwm los ntawm lub taphole; txhuav slag los ntawm ib tug slag kais qhov.

Thaum kawm tiav ntawm lub moj tej tawg cub tawg khiav hauj lwm mus los tau hlau, slag thiab flue roj cua.

Hlau khoom raug sau

Nyob rau hauv lub txias npaum li cas, lub microstructure ntawm cov pa roj carbon saturation thiab additives yuav tau txais ob peb yam kev hlau:

1. Npua (dawb) carbon nyob rau hauv ib tug bound daim ntawv no, cov thawj xis mas. Siv raws li raw khoom rau lub smelting ntawm lwm yam hlau-carbon alloys ua. Mus txog 80% ntawm cov ua hlau sau.
2. Foundry (grey) carbon nyob rau hauv daim ntawv ntawm tag los yog tej free graphite, namely nws daim hlau. Malootvetstvennyh siv rau zus tau tej cov lub cev qhov chaw. Mus txog 19% los ntawm lub moj tej tawg cub tawg casting.
3. Tshwj xeeb: nplua nuj ferroalloys. 1-2% hom xam tau tias yog lawm.

Zas hlau twb npaj los ntawm tshav kub kev kho mob ntawm npua.

Lub hom phiaj ntawm hlau-lug

Carbon nrog Ferum yuav tsim ob peb ntau hom ntawm alloys rau tus siv lead ua ntxaij ntoo hom raws li qhia nyob rau hauv lub embodiment ntawm lub microstructure.

1. Allergic nyob rau hauv cov khoom tov α-hlau - ferrite.
2. Allergic nyob rau hauv cov khoom tov γ-hlau - austenite.
3. Cov tshuaj tsim ntawm Fe ₃ C (ua txhua yam lub xeev) - cementite. Lub hom yog tsim los ntawm ceev ceev txias ntawm lub molten kua. Secondary - ib tug qeeb kub txo los ntawm austenite. Tertiary - lub tsheb txhob sibtsoo cua txias ntawm lub ferrite.
4. Neeg kho tshuab sib tov ntawm ferrite thiab cementite nplej - perlite.
5. Neeg kho tshuab sib tov ntawm austenite nplej thiab pearlite los yog cementite - Ledebur.

Rau cov cam khwb cia hlau yog yus muaj los ntawm ib tug tshwj xeeb microstructure. Lub graphite yuav ua tau nyob rau hauv daim ntawv thiab khi hauv daim ntawv ntawm cov saum toj no qauv, thiab tej zaum yuav nyob rau hauv lub dawb lub xeev nyob rau hauv daim ntawv ntawm cov ntau yam impurities. Nyob rau cov khoom cuam tshuam ob leeg yooj yim nplej, thiab cov formations. Graphite fractions yog cov hlau paib, plaub ya ri los yog spheres.

Cov nplooj zoo yog raug rau gray hlau-carbon alloys. Nws ua rau lawv fragility thiab unreliability.

Inclusions yog ntxuav zas hlau tshaj ib tug zoo ntxim rau lawv cov neeg kho tshuab kev kawm.

Lub kheej kheej graphite qauv ntxiv pab txoj kev zoo ntawm cov hlau, rau qhov kev nce rau hauv hardness, durability, endurance tseem ceeb loads. Tej yam ntxwv muaj siab zog cam khwb cia hlau. Zas hlau zog nws ua ferrite los yog pearlite tsim ntawm lub xub ntiag ntawm flake graphite inclusions.

Kev npaj ntawm ferritic zas hlau

Nws yog ua los ntawm ib tug dawb npua proeutectoid tsawg-carbon hlau ingots los ntawm annealing nrog carbon ntsiab lus 2.4-2.8% thiab cov coj muaj cov additives (Mn, Si, S, P). Lub phab ntsa thickness annealed qhov chaw yuav tsum tsis ntau tshaj 5 cm. Castings loj thickness graphite yog nyob rau hauv daim ntawv ntawm cov phiaj thiab yam khoom no tsis tiav.

Yog xav tau kev cam khwb cia hlau nrog ferritic puag hlau yog muab tso rau hauv tshwj xeeb thawv thiab ncuav cov xuab zeb. Nruj nreem thawv ntim tau muab tso rau hauv ib lub cua sov cua sov. Nqa tawm raws li nram no cov kauj ruam thaum lub sij hawm annealing:

1. Siv yog rhuab nyob rau hauv furnaces rau kub 1000? C thiab tso cai rau sawv ntsug nyob rau ib qhov tshav kub rau 10 mus rau 24 teev. Raws li ib tug tshwm sim ntawm tsob thiab thawj cementite Ledebur.
2. Cov hlau yog txias mus rau 720? C nyob rau hauv lub cub tawg.
3. Thaum ib tug kub ntawm 720? C mas ntev los ntawm 15 mus rau 30 teev. Qhov no kub kom lub disintegration ntawm ob cementite.
4. Thaum cov kauj ruam kawg twb dua txias nrog cov ua hauj lwm qhov cub rau 500? C, thiab ces rho rau saum huab cua.

Qhov no annealing no yog hu ua graphitizing.

Tom qab ua hauj lwm microstructure yog ferrite nrog nplej ntawm graphite flake. Qhov no hom yog hu ua "chernoserdechnym" txij thaum ib tug so yog dub.

Kev npaj ntawm pearlitic malleable cam khwb cia hlau

Qhov no zoo ntawm cov hlau-cov hlau, uas kuj originates los ntawm proeutectoid dawb, tab sis cov pa roj carbon cov ntsiab lus los ntawm yog nce: 3-3.6%. Rau castings nrog pearlitic hauv paus, lawv muab tso rau hauv thawv thiab ncuav lub crushed hmoov hlau ore los yog zeb scale. Annealing txoj kev nws tus kheej yog yooj yim to taub.

1. Hlau kub twb tsa mus rau 1000? C, khaws cia 60-100 teev.
2. Tsim txias nrog lub cub tawg.

Vim hais tias daj nyob rau hauv qhov kev txiav txim ntawm tshav kub nyob rau hauv ib tug nws yog xim hlau puag ncig diffuses: releasable nyob rau hauv lub cementite decomposition graphite nplooj cov annealed nto txheej qhov chaw, hauv rau ore los yog slag nto. Npaj softer, tawv thiab zas topsheet "beloserdechnogo" zas hlau nrog ib tug khoom nruab nrab.

Qhov no annealing yog hu ua tsis tiav. Nws muab cov disintegration ntawm cementite thiab pearlite ledeburite rau lub phaj nrog rau qhov tsim nyog graphite. Yog hais tias tsim nyog granular pearlitic zas cam khwb cia hlau nrog ntau dua toughness thiab plasticity, siv ntxiv cov ntaub ntawv uas rhuab mus 720? C. Yog li no tsim nplej ntawm perlite nrog flake graphite inclusions.

Khoom, labeling thiab daim ntawv thov ntawm ferritic zas hlau

Ntev lub sij hawm "luas saib tsw taug" hlau hauv lub cub tawg tau nyob rau hauv ib tug tag nrho disintegration ntawm ledeburite thiab cementite nyob rau hauv ferrite. Vim hauj intricacies, lub alloy nrog ib tug high school cov carbon cov ntsiab lus - ferritic qauv yam ntxwv ntawm tsawg-carbon hlau. Tab sis carbon los ntawm nws tus kheej yog tsis mus deb - nws mus los ntawm cov kab xeev ntawm hlau nyob rau hauv free. Kub nyhuv hloov qhov zoo ntawm graphite inclusions rau flake.

Ferrite qauv ua rau ib tug txo nyob rau hauv hardness, ua rau kom lub zog tseem ceeb, lub xub ntiag ntawm xws ntxwv raws li toughness thiab ductility.

Npav wrought hlau ferrite chav kawm ntawv: KCH30-6, KCH33-8, KCH35-10, KCH37-12 qhov twg:

CN - hom kev qhia kom paub - malleable;

30, 33, 35, 37: σ _{ib tug,} 300, 330, 350, 370 N / hli ² - tshaj plaws load hais tias nws muaj peev xwm mas tsis rhuav;

6, 8, 10, 12 - elongation, δ,% - plasticity index (ntau dua qhov nqi, tus raug cov hlau siab kev kho mob).

Hardness - txog 100-160 HB.

Qhov no cov ntaub ntawv uas uas nws ua tau zoo yog intermediate ntawm xws li hlau thiab hlau-cov hlau yog grey. Zas hlau nrog ferritic pearlitic hauv paus ua tsis tau zoo nyob rau hauv cov nqe lus ntawm coj kuj, corrosion kuj thiab qaug zog lub zog, tab sis ntau cov neeg kho tshuab endurance, ductility, casting yam ntxwv. Nrog nws cov uas tsis muaj nqi yog dav siv nyob rau hauv kev lag luam rau qhov siv thiab ua qhov chaw khiav hauj lwm rau cov uas tsis muaj thiab medium loads: zog, housings, rear axles, kav dej.

Khoom, labeling thiab daim ntawv thov ntawm pearlitic malleable cam khwb cia hlau

Vim tsis tiav annealing thawj, nrab thiab cementite Ledebur lub sij hawm rau tag nrho yaj nyob rau hauv austenite, uas nyob rau ib tug kub ntawm 720? C yog hloov mus rau hauv perlite. Cov yav tas yog ib tug txhua yam sib tov ntawm ferrite thiab cementite nplej tertiary. Ua tau, ib feem ntawm cov pa roj carbon nyob rau hauv bound daim ntawv no, ua rau ib tug qauv, ib feem - "tso tawm" nyob rau hauv lub flake graphite. Thaum no perlite yuav ua tau ib tug phaj los yog grainy. Yog li tsim pearlitic malleable cam khwb cia hlau. Nws cov khoom yog vim nyeem nyuab me ntsis thiab tsawg pliable qauv.

Cov no, thaum piv nrog ferritic muaj dua xeb, hnav-resistant zog, lawv durability yog considerably ntau dua, tab sis tsawg dua ductility thiab castability yam ntxwv. Nyhav rau cov neeg kho tshuab kev nyuaj siab ntau zog nto thaum cov lus hardness thiab toughness ntawm cov tub ntxhais cov khoom.

Npav wrought hlau pearlitic: KCH45-7, KCH50-5, KCH56-4, KCH60-3, KCH65-3, KCH70-2, KCH80-1,5.

Thawj tug lej - los lub dag lub zog: 450, 500, 560, 600, 650, 700 thiab 800 N / hli ^2, ntsig txog.

Ob - ductility cim elongation δ,% - 7, 5, 4, 3, 3, 2 thiab 1.5.

Pearlite zas hlau daim ntaub ntawv nyob rau hauv mechanical engineering thiab kev ntsuas rau designs uas khiav lag luam nyob rau high school loads - ob qho tag nrho zoo li qub thiab dynamic: camshafts, crankshafts, clutch qhov chaw, pistons, txuas rods.

Thaum tshav kub kub kev kho mob

Cov khoom tau vim lub tshav kub kev kho mob, uas yog, tus annealing tej zaum yuav raug mus rau rov kub influences txoj kev. Lawv lub ntsiab lub hom phiaj - txawm ntau dua lub zog, durability, ua hauj corrosion thiab rau cov laus.

1. Tempering yog siv rau lug tau siab hardness thiab toughness; ua los ntawm cua kub los 900? C, qhov chaw uas txias nyob rau ntawm ib nqi nruab nrab ntawm txog 100? C / sec siv lub cav roj. Tom qab nws yuav tsum tau ib tug siab so nrog cua kub rau 650˚S thiab cua txias.
2. Normalization yog siv rau medium-qhov loj qhov yooj yim qhov chaw nyob rau hauv ib tug cub tawg yog cua sov rau 900? C, sab laug sawv ntawm no kub rau ib lub sij hawm ntawm 1 mus rau 1.5 sij hawm thiab tom ntej txias nyob rau hauv cov huab cua. Troostite muab granular perlite, nws firmness thiab kev cia siab ntawm lub tsis sib haum xeeb thiab hnav. Nws yog siv rau anti-kev sib txhuam malleable cam khwb cia hlau nrog ib tug pearlitic hauv paus.
3. Annealing yog ua dua nyob rau hauv qhov siv thiab ua antifriction: cua kub - mus 900? C, tuav ntawm no ntev lub sij hawm thaum tshav kub kub, cua txias nrog lub cub tawg. Muab ferritic los yog ferritic-pearlitic qauv antifriction zas hlau.

Cua sov lub cam khwb cia hlau cov khoom muaj peev xwm yuav nqa tawm zos los complex. Rau cov tshuaj pleev applied high-zaus currents los yog acetylene nplaim taws (tuav quenching). Rau txoj - cua kub cua sov. Thaum lub zos cua kub ntawm tsuas yog tus sab sauv txheej yog hardened, nws tsub kom nws hardness thiab lub dag lub zog, tab sis khaws cia ductility thiab viscosity indices ntawm cov tub ntxhais.

Nws yog ib qho tseem ceeb rau taw tes kom paub tias hlau forging tsis yooj yim sua, tsis tsuas vim hais tias ntawm tsis txaus cov neeg kho tshuab cov yam ntxwv, tab sis kuj vim hais tias ntawm nws cov high rhiab heev rau cia li kub hloov, uas yog kev tsis pom nrias thaum quenching nrog dej txias.

Anti-txhuam malleable cam khwb cia hlau

Qhov no ntau yam kuj siv rau malleable, thiab doped, lawv yog grey (asf), forging (APC) thiab siab zog (ACHV). APC yog siv rau zus tau tej zas cam khwb cia hlau, uas yog raug rau annealing los yog normalization. Cov dab yog nqa tawm nyob rau hauv thiaj li yuav txhim kho nws cov neeg kho tshuab zog thiab cov tsim ntawm yam ntxwv tshiab - hnav kuj nyob rau hauv lub tsis sib haum xeeb nrog lwm qhov chaw.

Sau tias: 1-APC, APC-2. Siv rau zus tau tej cov crankshafts, zog, bearings.

Nyhuv ntawm additives rau cov khoom

Sib nrug los ntawm cov hlau-graphite puag thiab lawv muaj nyob rau hauv lawv cov muaj pes tsawg leeg, thiab lwm yam, uas tseem ua rau lub thaj chaw ntawm cam khwb cia hlau: manganese, pob zeb ntais, phosphorus, sulfur, ib co alloying ntsiab.

Mangan pab flowability ntawm molten hlau, xeb kuj thiab hnav kuj. Nws muaj txhawb rau hardness thiab lub zog ntawm thwj toob ntawm carbon nrog hlau nyob rau hauv lub tshuaj mis Fe ₃ C, tus tsim ntawm granular perlite.

Silicon kuj muaj ib tug zoo ntxim rau cov fluidity ntawm lub molten hlau, nws muaj txhawb mus rau lub disintegration ntawm cementite thiab graphite inclusions faib.

Sulfur - tsis zoo, tiam sis ib tug inevitable tivthaiv. Nws thiaj li tus neeg kho tshuab thiab tshuaj zog, nkoos tsim ntawm tej kab nrib pleb. Txawm li cas los, muaj kuab kev sib raug zoo nrog nws cov ntsiab lus ntawm lwm yam hais (e.g., manganese) corrects microstructural dab. Yog li, thaum tus piv Mn-S 0,8-1,2 perlite yog muab cia rau hauv tej kub influences sij hawm poob. Los ua tus piv mus rau 3 yog nws ua tau kom tau tej yam qauv nyob rau preset tsis.

Phosphorus yog hloov rau lub zoo dua fluidity muaj feem xyuam rau lub dag lub zog, lowers tus toughness thiab ductility, tej yam nyob rau hauv lub caij ntawm graphitization.

Chromium thiab molybdenum es tsim ntawm graphite plaub ya ri, nyob rau hauv ib co txheem txhawb lub tsim ntawm granular perlite.

Tungsten tsub kom cov kuj hnav thaum kev khiav hauj lwm nyob rau hauv qhov chaw ntawm kev kub muaj peevxwm.

Txhuas, npib tsib xee thiab tooj liab ua rau kom graphitization.

By kho tus nqi ntawm cov tshuaj hais tias ua li tus hlau-cov hlau, raws li zoo raws li lawv cov ratio, nws yuav ua rau qhov kawg thaj chaw ntawm cam khwb cia hlau.

Zoo thiab tsis zoo

Zas chugun- khoom muaj coob leej ntau tus siv nyob rau hauv cov kos duab. Nws lub ntsiab zoo yog:

• theem ntawm hardness, hnav kuj, lub dag lub zog, nrog rau cov fluidity;
• qub yam ntxwv ntawm toughness thiab ductility;
• processability los ntawm siab kev kho mob, nyob rau hauv sib piv rau lub grey cam khwb cia hlau;
• thaj chaw ntawm ntau yam embodiments kho yam khoom nyob rau hauv tej yam txoj kev thermal thiab tshuaj-thermal kho mob;
• uas tsis muaj nqi.

Qhov tsis zoo yog tus neeg yam ntxwv:

• fragility;
• lub xub ntiag ntawm inclusions ntawm graphite;
• cov neeg pluag kev ua tau zoo nyob rau hauv tej;
• tseem ceeb hnyav castings.

Txawm tias tam sim no shortcomings, zas hlau yuav siv sij hawm xwb nyob rau hauv metallurgy thiab mechanical engineering. Los ntawm nws ua xws ib qho tseem ceeb kom paub meej li crankshafts, nres los qhov chaw, zog, pistons, txuas rods. Muaj ib tug me me ntau yam ntawm hom, ib tug neeg me me nyob rau hauv lub lag luam occupies ib tug zas hlau. Nws daim ntawv thov yog raug rau lub load rau hauv uas ntawm kev siv ntawm lwm yam ntaub ntawv yog tsis zoo li.