Kuponya chitsulondi gulu la iron-carbon alloys yokhala ndi mpweya woposa 2%.Phindu lake limachokera ku kutentha kwake kochepa kosungunuka.Ma alloy amakhudza mtundu wake akasweka: chitsulo choyera chimakhala ndi zonyansa za carbide zomwe zimalola kuti ming'alu idutse molunjika, chitsulo chotuwa chimakhala ndi ma graphite flakes omwe amapatutsa mng'alu wodutsa ndikuyambitsa ming'alu yambirimbiri pamene zinthu zikusweka, ndipo chitsulo chopangidwa ndi ductile chimakhala chozungulira. graphite "nodules" omwe amalepheretsa mng'aluyo kuti isapitirire patsogolo.

Mpweya (C) kuyambira 1.8 mpaka 4 wt%, ndi silicon (Si) 1-3 wt%, ndizinthu zazikulu zophatikizira chitsulo chonyezimira.Ma iron alloys okhala ndi mpweya wocheperako amadziwika kuti chitsulo.

Chitsulo chachitsulo chimakhala chophwanyika, kupatulapo zitsulo zosungunuka.Ndi malo ake otsika osungunuka, madzi abwino, kutayika, machinability kwambiri, kukana kupunduka ndi kukana kuvala, zitsulo zotayidwa zakhala zida zaumisiri zomwe zimagwiritsidwa ntchito mosiyanasiyana ndipo zimagwiritsidwa ntchito popanga mapaipi, makina ndi zigawo zamagalimoto zamagalimoto, monga silinda. mitu, midadada silinda ndi ma gearbox.Imagonjetsedwa ndi kuwonongeka ndi okosijeni.

Zakale zakale kwambiri za chitsulo chopangidwa ndi chitsulo ndi za m'zaka za m'ma 500 BC, ndipo zinapezedwa ndi akatswiri ofukula zinthu zakale m'dera lomwe tsopano limatchedwa Jiangsu ku China.Chitsulo chachitsulo chinkagwiritsidwa ntchito ku China wakale pankhondo, ulimi, ndi zomangamanga.M'zaka za m'ma 1500, zitsulo zotayira zidayamba kugwiritsidwa ntchito ngati mizinga ku Burgundy, France, komanso ku England panthawi ya Reformation.Mlatho woyamba wachitsulo wopangidwa ndi Abraham Darby III unamangidwa m'zaka za m'ma 1770, ndipo umadziwika kuti Iron Bridge ku Shropshire, England.Chitsulo chachitsulo chinagwiritsidwanso ntchito pomanga nyumba.

Alloying zinthu

Makhalidwe a cast iron amasinthidwa ndikuwonjezera ma alloying osiyanasiyana, kapena ma alloyants.Pafupi ndi kaboni, silicon ndiye alloyant wofunikira kwambiri chifukwa amakakamiza kaboni kuchoka munjira.Chigawo chochepa cha silicon chimalola mpweya kukhalabe mu njira yopangira chitsulo carbide ndi kupanga chitsulo choyera.Kuchuluka kwa silicon kumapangitsa kuti mpweya utuluke mu njira yopangira graphite ndikupanga chitsulo chotuwa.Ma alloying ena, manganese, chromium, molybdenum, titaniyamu ndi vanadium amatsutsana ndi silicon, amalimbikitsa kusungidwa kwa kaboni, ndikupanga ma carbides.Nickel ndi mkuwa kuwonjezera mphamvu, ndi machinability, koma musasinthe kuchuluka kwa graphite anapanga.Mpweya wa carbon mu mawonekedwe a graphite umapangitsa chitsulo chofewa, kumachepetsa kuchepa, kumachepetsa mphamvu, komanso kumachepetsa kachulukidwe.Sulfure, makamaka zonyansa zikapezeka, zimapanga iron sulfide, zomwe zimalepheretsa kupanga graphite ndikuwonjezera kuuma.Vuto la sulfure ndiloti limapanga chitsulo chosungunuka chosungunuka, chomwe chimayambitsa zilema.Pofuna kuthana ndi zotsatira za sulfure, manganese amawonjezeredwa chifukwa awiriwa amapanga manganese sulfide m'malo mwa iron sulfide.Manganese sulfide ndi wopepuka kuposa kusungunula, choncho amakonda kuyandama kuchoka mu sungunuka ndi kulowa mu slag.Kuchuluka kwa manganese ofunikira kuti achepetse sulfure ndi 1.7 × sulfure + 0.3%.Ngati manganese ochulukirapo awonjezeredwa, ndiye kuti manganese carbide amapanga, omwe amawonjezera kuuma ndi kuzizira, kupatula muchitsulo chotuwira, komwe mpaka 1% ya manganese imawonjezera mphamvu ndi kachulukidwe.

Nickel ndi imodzi mwazinthu zomwe zimagwiritsidwa ntchito popanga ma alloying chifukwa imayenga ma pearlite ndi ma graphite, imapangitsa kulimba, komanso kusiyanitsa kuuma pakati pa makulidwe agawo.Chromium imawonjezeredwa pang'ono kuti muchepetse graphite yaulere, kutulutsa kuzizira, komanso chifukwa ndi mphamvu yamphamvu ya carbide;nickel nthawi zambiri amawonjezeredwa pamodzi.Tini yocheperako imatha kuwonjezeredwa m'malo mwa 0.5% chromium.Mkuwa umawonjezeredwa mu ladle kapena mu ng'anjo, pa dongosolo la 0.5-2.5%, kuchepetsa kuzizira, kuyeretsa graphite, ndi kuonjezera madzi.Molybdenum amawonjezedwa pa dongosolo la 0.3-1% kuti awonjezere kuzizira ndi kuyeretsa mawonekedwe a graphite ndi pearlite;nthawi zambiri amawonjezeredwa pamodzi ndi nickel, mkuwa, ndi chromium kupanga zitsulo zolimba kwambiri.Titaniyamu imawonjezedwa ngati degasser ndi deoxidizer, koma imawonjezera madzimadzi.0.15-0.5% vanadium imawonjezedwa ku chitsulo choponyedwa kuti chikhazikitse simenti, kuwonjezera kuuma, ndikuwonjezera kukana kuvala ndi kutentha.0.1-0.3% zirconium imathandiza kupanga graphite, deoxidize, ndi kuonjezera madzi.

Muzitsulo zosungunuka, bismuth imawonjezeredwa, pamlingo wa 0.002-0.01%, kuonjezera kuchuluka kwa silicon komwe kungawonjezedwe.Muchitsulo choyera, boron amawonjezeredwa kuti athandize kupanga chitsulo chosungunuka;Komanso amachepetsa coarsening zotsatira za bismuth.

Gray cast iron

Gray cast iron imadziwika ndi mawonekedwe ake a graphic, omwe amachititsa kuti zinthuzo zikhale zotuwa.Ndizitsulo zomwe zimagwiritsidwa ntchito kwambiri komanso zimagwiritsidwa ntchito kwambiri potengera kulemera kwake.Zitsulo zambiri zotayidwa zimakhala ndi mankhwala a 2.5-4.0% carbon, 1-3% silicon, ndi chitsulo chotsalira.Chitsulo cha Gray cast chili ndi mphamvu zocheperako komanso kukana kugwedezeka kuposa chitsulo, koma mphamvu yake yophatikizika imafanana ndi chitsulo chotsika komanso chapakati cha carbon.Zinthu zamakinazi zimayendetsedwa ndi kukula ndi mawonekedwe a ma graphite flakes omwe amapezeka mu microstructure ndipo amatha kudziwika molingana ndi malangizo operekedwa ndi ASTM.

Chitsulo choyera

Chitsulo choyera chimasonyeza malo oyera ophwanyika chifukwa cha kukhalapo kwa chitsulo cha carbide chotchedwa cementite.Pokhala ndi silicon yotsika (yothandizira graphitizing) komanso kuzizira kofulumira, mpweya wachitsulo choyera umatuluka kuchokera kusungunuka ngati simenti yosungunuka, Fe.₃C, osati graphite.Simenti yomwe imatuluka kuchokera kusungunuka imapanga ngati tinthu tating'onoting'ono.Pamene iron carbide imatuluka, imatulutsa mpweya kuchokera kusungunuka koyambirira, ndikusunthira kusakaniza kufupi ndi eutectic, ndipo gawo lotsalira ndi chitsulo chotsika cha carbon austenite (chomwe chikazizira chikhoza kusintha kukhala martensite).Ma eutectic carbides awa ndi okulirapo kwambiri kuti atha kupereka phindu la zomwe zimatchedwa kuuma kwa mpweya (monga zitsulo zina, pomwe mpweya wocheperako wa simenti ungalepheretse [kupindika kwa pulasitiki] polepheretsa kuyenda kwa kusuntha kudzera muzitsulo zoyera za ferrite).M'malo mwake, amawonjezera kuuma kwachitsulo chosungunuka chifukwa cha kulimba kwawo kwakukulu komanso kagawo kakang'ono ka voliyumu, kotero kuti kuuma kochuluka kungathe kuyerekezedwa ndi lamulo la zosakaniza.Mulimonsemo, amapereka kuuma pamtengo wa kuuma.Popeza carbide imapanga gawo lalikulu la zinthu, chitsulo choyera chikhoza kutchulidwa ngati cermet.Chitsulo choyera ndi chosasunthika kwambiri kuti chigwiritsidwe ntchito pazinthu zambiri zamapangidwe, koma ndi kulimba kwabwino komanso kukana kwa ma abrasion komanso mtengo wotsika, chimagwiritsidwa ntchito ngati malo ovala (zotengera ndi volute) zamapampu amatope, zomangira zipolopolo ndi mipiringidzo yonyamulira mu mpira. mphero ndi mphero autogenous akupera, mipira ndi mphete mu pulverisers malasha, ndi mano a chidebe kukumba backhoe (ngakhale cast medium-carbon martensitic zitsulo ndizofala pa ntchito imeneyi).

Ndikovuta kuziziritsa zokhuthala mwachangu kuti zisungunuke ngati chitsulo choyera podutsa.Komabe, kuzizira kofulumira kungagwiritsidwe ntchito kulimbitsa chipolopolo chachitsulo choyera, kenako chotsaliracho chimazizira pang'onopang'ono kupanga pakati pa chitsulo chotuwa.Zotsatira zake, zomwe zimatchedwa akuponya kozizira, ili ndi ubwino wa malo olimba ndi mkati mwake molimba.

Zosakaniza zachitsulo zoyera za chromium zimalola kuti zinthu zazikulu (mwachitsanzo, 10-tonne impeller) zikhale mchenga, popeza chromium imachepetsa kuziziritsa komwe kumafunikira kuti apange ma carbides kudzera mu makulidwe ake azinthu.Chromium imapanganso ma carbides okhala ndi chidwi chokana abrasion.Ma aloyi a chromium apamwambawa amapangitsa kuuma kwawo kopambana chifukwa cha kukhalapo kwa chromium carbides.Mitundu yayikulu ya ma carbides awa ndi eutectic kapena primary M₇C₃carbides, pomwe "M" imayimira chitsulo kapena chromium ndipo imatha kusiyanasiyana kutengera kapangidwe ka aloyi.Ma eutectic carbides amapangidwa ngati mitolo ya ndodo zopanda pake ndipo amakula molunjika ku ndege ya hexagonal basal.Kuuma kwa ma carbides awa kuli mkati mwa 1500-1800HV.

Chitsulo chosungunuka

Chitsulo chosungunuka chimayamba ngati chitsulo choyera chomwe chimatenthedwa kwa tsiku limodzi kapena awiri pa 950 ° C (1,740 °F) kenako n'kuzizira tsiku limodzi kapena awiri.Zotsatira zake, mpweya mu iron carbide umasandulika kukhala graphite ndi ferrite kuphatikiza carbon (austenite).The pang'onopang'ono ndondomeko amalola pamwamba mavuto kupanga graphite mu spheroidal particles osati flakes.Chifukwa cha chiŵerengero chawo chapansi, ma spheroids ndi aafupi komanso akutali wina ndi mzake, ndipo ali ndi gawo lochepa la mtanda vis-a-vis mng'alu wofalitsa kapena phonon.Amakhalanso ndi malire osamveka, mosiyana ndi ma flakes, omwe amachepetsa mavuto omwe amapezeka mu chitsulo chotuwa.Nthawi zambiri, chitsulo chosungunuka chimakhala ngati chitsulo chofewa.Pali malire a kuchuluka kwa gawo lomwe lingaponyedwe muchitsulo chosungunuka, monga chopangidwa ndi chitsulo choyera.

Ductile cast iron