Zigawo zachitsulo cha kaboni Chithunzi Chowonetsedwa

Zigawo zazitsulo za carbon

Kufotokozera Kwachidule:

Mawu akuti carbon steel angagwiritsidwenso ntchito ponena za zitsulo zomwe sizitsulo zosapanga dzimbiri;mu ntchito mpweya zitsulo angaphatikizepo zitsulo aloyi.Mpweya wa carbon zitsulo uli ndi ntchito zambiri zosiyanasiyana monga makina ophera, zida zodulira (monga tchizilo) ndi mawaya amphamvu kwambiri.

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Tsatanetsatane wa Zamalonda

Zolemba Zamalonda

Kulowetsedwa kwa zida za Carbon steel

Mpweya wa carbon ndi chitsulo chokhala ndi mpweya wochokera pa 0.05 mpaka 3.8 peresenti polemera.Tanthauzo la carbon steel kuchokera ku American Iron and Steel Institute (AISI) limati:
1. palibe zochepa zomwe zatchulidwa kapena zofunikira pa chromium, cobalt, molybdenum, faifi tambala, niobium, titaniyamu, tungsten, vanadium, zirconium, kapena chinthu china chilichonse kuti chiwonjezedwe kuti apeze mphamvu ya alloying;
2. chiwerengero chochepa chamkuwa sichidutsa 0,40 peresenti;
3. kapena kuchuluka kwa zinthu zomwe zafotokozedwa pa chilichonse mwa zinthu zotsatirazi sikudutsa maperesenti otchulidwa: manganese 1.65 peresenti;silicon 0,60 peresenti;mkuwa 0.60 peresenti.
Mawu akuti carbon steel angagwiritsidwenso ntchito ponena za zitsulo zomwe sizitsulo zosapanga dzimbiri;mu ntchito mpweya zitsulo angaphatikizepo zitsulo aloyi.Mpweya wa carbon zitsulo uli ndi ntchito zambiri zosiyanasiyana monga makina ophera, zida zodulira (monga tchizilo) ndi mawaya amphamvu kwambiri.Izi zimafuna microstructure yabwino kwambiri, yomwe imawonjezera kulimba.

Chithandizo cha kutentha kwa zida za Carbon steel

Pamene chiwerengero cha carbon chikukwera, zitsulo zimatha kukhala zolimba komanso zamphamvu kupyolera mu kutentha kutentha;komabe, zimakhala zochepa ductile.Mosasamala kanthu za chithandizo cha kutentha, kuchuluka kwa mpweya wa carbon kumachepetsa weldability.Muzitsulo za kaboni, kuchuluka kwa kaboni kumachepetsa kusungunuka.

Cholinga cha kutentha kuchitira mpweya zitsulo ndi kusintha mawotchi katundu zitsulo, kawirikawiri ductility, kuuma, mphamvu zokolola, kapena kukana zotsatira.Dziwani kuti magetsi ndi matenthedwe conductivity amangosinthidwa pang'ono.Monga momwe zilili ndi njira zambiri zolimbikitsira zitsulo, Young's modulus (elasticity) simakhudzidwa.Mankhwala onse a zitsulo zamalonda zamalonda kuti awonjezere mphamvu ndi mosemphanitsa.Chitsulo chimakhala ndi kusungunuka kwapamwamba kwa carbon mu gawo la austenite;Choncho mankhwala onse kutentha, kupatula spheroidizing ndi ndondomeko annealing, kuyamba ndi kutentha zitsulo kutentha kumene austenitic gawo angakhalepo.Chitsulocho chimazimitsidwa (kutentha kotulutsidwa) pang'onopang'ono mpaka pang'onopang'ono kulola mpweya kufalikira kuchokera ku austenite kupanga iron-carbide (cementite) ndikusiya ferrite, kapena pamlingo waukulu, kutseketsa mpweya mkati mwachitsulo ndikupanga martensite. .Mlingo umene chitsulocho umazirala chifukwa cha kutentha kwa eutectoid (pafupifupi 727 °C) kumakhudza mlingo umene mpweya umatuluka kuchokera ku austenite ndikupanga simenti.Nthawi zambiri, kuziziritsa mwachangu kumasiya chitsulo chachitsulo chomwazika bwino ndikupanga ngale yabwino kwambiri ndipo kuziziritsa pang'onopang'ono kumapereka pearlite yokulirapo.Kuziziritsa chitsulo cha hypoeutectoid (chosakwana 0.77 wt% C) kumabweretsa mapangidwe a lamellar-pearlitic azitsulo zachitsulo za carbide ndi α-ferrite (pafupifupi chitsulo choyera) pakati.Ngati ndi chitsulo cha hypereutectoid (kuposa 0,77 wt% C) ndiye kuti mapangidwewo ndi pearlite yodzaza ndi timbewu tating'ono (zazikulu kuposa pearlite lamella) za cementite zomwe zimapangidwa pamalire a tirigu.Chitsulo cha eutectoid (0.77% kaboni) chidzakhala ndi pearlite mumbewu zonse popanda simenti pamalire.Miyezo yofananira ya zigawo imapezeka pogwiritsa ntchito lamulo la lever.M'munsimu muli mndandanda wa mitundu ya mankhwala kutentha zotheka.

Zigawo zazitsulo za Carbon Versus Alloy zitsulo

Chitsulo cha aloyi ndi chitsulo chomwe chimapangidwa ndi zinthu zosiyanasiyana pamlingo wokwanira pakati pa 1.0% ndi 50% polemera kuti zithandizire kukonza makina ake.Zitsulo za alloy zimagawidwa m'magulu awiri: zitsulo zotsika ndi zitsulo zamtengo wapatali.Kusiyana pakati pa ziwirizi kumatsutsana.Smith ndi Hashemi amatanthauzira kusiyana kwa 4.0%, pamene Degarmo, et al., amatanthauzira pa 8.0%.Nthawi zambiri, mawu akuti "zitsulo zachitsulo" amatanthauza zitsulo zotsika.

Kunena zowona, chitsulo chilichonse ndi aloyi, koma sizitsulo zonse zomwe zimatchedwa "zitsulo za alloy".Zitsulo zosavuta kwambiri ndi chitsulo (Fe) chopangidwa ndi carbon (C) (pafupifupi 0.1% mpaka 1%, kutengera mtundu).Komabe, mawu oti "chitsulo cha alloy" ndi mawu omwe amagwiritsidwa ntchito ponena za zitsulo ndi zinthu zina zowonjezera zomwe zimawonjezeredwa mwadala kuwonjezera pa carbon.Ma alloyants wamba amaphatikizapo manganese (yomwe imadziwika kwambiri), faifi tambala, chromium, molybdenum, vanadium, silicon, ndi boron.Ma alloyants ocheperako amaphatikiza aluminium, cobalt, mkuwa, cerium, niobium, titaniyamu, tungsten, tini, zinki, lead, ndi zirconium.

Zotsatirazi ndi mndandanda wa zinthu zabwino muzitsulo za aloyi (poyerekeza ndi zitsulo za carbon): mphamvu, kuuma, kulimba, kukana kuvala, kukana kwa dzimbiri, kuuma, ndi kuuma kotentha.Kuti tikwaniritse zina mwazinthu zabwinozi, chitsulo chingafunike kutenthetsa.

Zina mwa izi zimapeza kugwiritsidwa ntchito kwachilendo komanso kofunikira kwambiri, monga ma turbine blades a injini za jet, ndi zida zanyukiliya.Chifukwa cha ferromagnetic katundu wa chitsulo, ma aloyi ena azitsulo amapeza ntchito zofunika pomwe mayankho awo ku maginito ndi ofunikira kwambiri, kuphatikiza ma mota amagetsi ndi ma transfoma.

Chithandizo cha kutentha pazigawo zazitsulo za Carbon

Spheroidizing
Spheroidite imapanga pamene chitsulo cha carbon chitenthedwa kufika pafupifupi 700 ° C kwa maola oposa 30.Spheroidite imatha kupanga pamatenthedwe otsika koma nthawi yofunikira imawonjezeka kwambiri, chifukwa iyi ndi njira yoyendetsedwa ndi kufalikira.Zotsatira zake ndi kapangidwe ka ndodo kapena magawo a simenti mkati mwa dongosolo loyambirira (ferrite kapena pearlite, kutengera mbali ya eutectoid yomwe mulipo).Cholinga chake ndi kufewetsa zitsulo zapamwamba za carbon ndi kulola kuti zikhale zowonjezereka.Ichi ndiye chitsulo chofewa kwambiri komanso chofewa kwambiri.

Kukonzekera kwathunthu
Chitsulo cha mpweya chimatenthedwa kufika pafupifupi 40 °C pamwamba pa Ac3 kapena Acm kwa ola limodzi;izi zimatsimikizira kuti ferrite yonse imasandulika kukhala austenite (ngakhale simenti ingakhalepobe ngati mpweya wa carbon ndi waukulu kuposa eutectoid).Chitsulocho chiyenera kuziziritsidwa pang'onopang'ono, m'malo a 20 °C (36 °F) pa ola.Kawirikawiri amangokhala ng'anjo yoziziritsidwa, kumene ng'anjo imazimitsidwa ndi chitsulo chikadali mkati.Izi zimapangitsa kuti pearlitic ikhale yolimba, zomwe zikutanthauza kuti "magulu" a pearlite ndi wandiweyani.Chitsulo chokwanira chokwanira chimakhala chofewa komanso chodumphira, chopanda kupsinjika kwamkati, chomwe nthawi zambiri chimakhala chofunikira pakupanga kopanda mtengo.Chitsulo chokhacho cha spheroidized ndi chofewa komanso chochulukira.

Process annealing
Njira yomwe imagwiritsidwa ntchito pofuna kuthetsa nkhawa muzitsulo zozizira zozizira za carbon ndi zosakwana 0.3% C. Chitsulocho chimatenthedwa mpaka 550-650 ° C kwa ola limodzi, koma nthawi zina kutentha mpaka 700 ° C.Chithunzi chakumanja[kumveka kofunikira] chikuwonetsa malo omwe kubwereza kumachitika.

Isothermal annealing
Ndi njira yomwe chitsulo cha hypoeutectoid chimatenthedwa pamwamba pa kutentha kwapamwamba kwambiri.Kutentha kumeneku kumasungidwa kwa kanthaŵi kenaka n’kuchepetsedwa kufika m’munsi mwa kutentha kofunikira kwambiri ndipo kumasungidwanso.Kenako amaziziritsidwa mpaka kutentha.Njirayi imachotsa kutentha kulikonse.

Normalizing
Chitsulo cha mpweya chimatenthedwa kufika pafupifupi 55 °C pamwamba pa Ac3 kapena Acm kwa ola limodzi;izi zimatsimikizira kuti chitsulo chimasintha kwathunthu kukhala austenite.Zitsulozo zimaziziritsidwa ndi mpweya, zomwe zimazizira pafupifupi 38 °C (100 °F) pamphindi.Izi zimabweretsa mawonekedwe abwino a pearlitic, komanso mawonekedwe ofananirako.Chitsulo chokhazikika chimakhala ndi mphamvu zambiri kuposa chitsulo chosungunuka;ali ndi mphamvu kwambiri ndi kuuma.

Kuzimitsa
Chitsulo cha kaboni chokhala ndi osachepera 0.4 wt% C chimatenthedwa kuti chizizizira bwino ndipo kenako chimazimitsidwa (kuzima) m'madzi, brine, kapena mafuta mpaka kutentha kwambiri.Kutentha kwakukulu kumadalira zomwe zili mu carbon, koma monga lamulo, zimakhala zochepa pamene mpweya wa carbon ukuwonjezeka.Izi zimabweretsa dongosolo la martensitic;mtundu wachitsulo womwe umakhala ndi mpweya wochuluka kwambiri wodzaza kwambiri ndi makristalo opindika am'kati mwa thupi (BCC), otchedwa body-centered tetragonal (BCT), wokhala ndi kupsinjika kwamkati.Choncho chitsulo chozimitsidwa chimakhala cholimba kwambiri koma chophwanyika, nthawi zambiri chimakhala cholimba kwambiri kuti chigwiritsidwe ntchito.Zovuta zamkati izi zitha kuyambitsa ming'alu yapakatikati.Chitsulo chozimitsidwa chimakhala cholimba kuwirikiza katatu (chinai chokhala ndi mpweya wambiri) kuposa chitsulo chokhazikika.

Kugulitsa (Martempering)
Martempering si njira yochepetsera, motero mawu akuti marquenching.Ndi mtundu wa chithandizo cha kutentha kwa isothermal chomwe chimagwiritsidwa ntchito pambuyo pozimitsa koyamba, nthawi zambiri mumsamba wosungunuka wamchere, pa kutentha pamwamba pa "kutentha koyambira kwa martensite".Pakutentha uku, kupsinjika kotsalira mkati mwazinthuzo kumamasulidwa ndipo bainite ina imatha kupangidwa kuchokera ku austenite yosungidwa yomwe inalibe nthawi yosintha kukhala china chilichonse.M'makampani, iyi ndi njira yomwe imagwiritsidwa ntchito poyang'anira ductility ndi kuuma kwa zinthu.Ndi marquenching nthawi yayitali, ductility imawonjezeka ndi kuchepa pang'ono kwa mphamvu;chitsulo chimagwiridwa mu yankho ili mpaka kutentha kwa mkati ndi kunja kwa gawolo kukhale kofanana.Kenako chitsulocho chimakhazikika pa liwiro lapakati kuti kutentha kusakhale kochepa.Sikuti izi zimangochepetsa kupsinjika kwamkati ndi kupsinjika kwapang'onopang'ono, komanso kumawonjezera kukana kwamphamvu.

Kutentha
Uwu ndiye chithandizo chodziwika bwino cha kutentha chomwe chimakumana nacho, chifukwa zinthu zomaliza zimatha kutsimikiziridwa ndi kutentha ndi nthawi yakutentha.Kutentha kumaphatikizapo kutenthetsanso chitsulo chozimitsidwa ku kutentha pansi pa kutentha kwa eutectoid kenako kuzizira.Kutentha kwapamwamba kumapangitsa kuti spheroidite ikhale yochepa kwambiri, yomwe imabwezeretsa ductility, koma imachepetsa kuuma.Kutentha kwenikweni ndi nthawi zimasankhidwa mosamala pazolemba zilizonse.

Kudziletsa
Njira ya austempering ndi yofanana ndi martempering, kupatula kuzimitsa kumasokonekera ndipo chitsulocho chimasungidwa mumadzi osambira amchere osungunuka pa kutentha kwapakati pa 205 °C ndi 540 ° C, ndiyeno atakhazikika pamlingo wocheperako.Chitsulo chotsatira, chotchedwa bainite, chimapanga acicular microstructure muzitsulo zomwe zimakhala ndi mphamvu zazikulu (koma zochepa kuposa martensite), ductility yaikulu, kutsutsa kwakukulu, ndi kusokoneza pang'ono kusiyana ndi zitsulo za martensite.Kuipa kwa austempering kungagwiritsidwe ntchito pazitsulo zochepa, ndipo kumafuna kusamba kwapadera kwa mchere.