Ductile hlau yog ib qho khoom siv hlau uas muaj zog cam khwb cia hauv xyoo 1950s.Nws cov khoom siv dav dav yog ze rau cov hlau.Raws li nws cov khoom zoo heev, nws tau ua tiav siv rau qee qhov castings nrog kev ua haujlwm siab ntawm kev ntxhov siab, lub zog, toughness, thiab hnav tsis kam.Ductile hlau tau tsim sai heev rau hauv cov khoom siv hlau cam khwb cia uas tau siv dav tom qab grey cam khwb cia hlau.Lub npe hu ua "hloov hlau nrog hlau" feem ntau yog hais txog cov hlau hlau.

Nodular cam khwb cia hlau yog nodular graphite tau los ntawm nodularization thiab inoculation kev kho mob, uas zoo txhim kho cov neeg kho tshuab zog ntawm cam khwb cia hlau, tshwj xeeb tshaj yog txhim kho cov yas thiab toughness, yog li tau txais lub zog siab dua carbon steel.

Tuam Tshoj Ductile Iron Development History

Hlau tau unearthed los ntawm cov hlau smelting qhov chaw nyob rau hauv nruab nrab thiab lig Western Han Dynasty nyob rau hauv Tieshenggou, Gongxian County, Henan xeev, thiab niaj hnub nodular cam khwb cia hlau tsis tau ntse tsim txawv teb chaws mus txog rau thaum 1947. Cov cam khwb cia hlau nyob rau hauv ancient Tuam Tshoj muaj ib tug tsawg silicon ntsiab lus rau. lub sij hawm ntev.Qhov ntawd yog hais tias, nyob rau hauv Western Han Dynasty txog 2000 xyoo dhau los, lub kheej kheej graphite nyob rau hauv Suav ironware tau softened los ntawm tsawg-silicon npua hlau castings uas yog tau los ntawm annealing.Qhov no yog lub ancient Suav cam khwb cia hlau technology.Cov kev ua tiav loj ntawm kev kos duab kuj yog cov txuj ci tseem ceeb hauv keeb kwm ntawm metallurgy hauv ntiaj teb.

Xyoo 1981, Suav cov kws tshaj lij hlau hlau siv cov txheej txheem kev tshawb fawb niaj hnub los kawm txog 513 ancient Han thiab Wei hlau wares unearthed, thiab txiav txim siab los ntawm ntau cov ntaub ntawv uas nodular graphite cam khwb cia hlau tau tshwm sim hauv Suav teb hauv Han Dynasty.Cov ntaub ntawv cuam tshuam tau nyeem nyob rau ntawm 18 Lub Rooj Sib Tham Ntiaj Teb ntawm Keeb Kwm Kev Tshawb Fawb thiab Tshuab, uas sensationalized thoob ntiaj teb foundry thiab keeb kwm ntawm science thiab technology.International metallurgical cov kws paub txog keeb kwm tau txheeb xyuas qhov no hauv xyoo 1987: Tuam Tshoj Ancient Tuam Tshoj twb pom txoj cai ntawm kev siv cov hlau ductile los ua cov hlau cam nodular, uas yog qhov tseem ceeb heev rau kev rov faib cov keeb kwm ntawm lub ntiaj teb metallurgical.

Kev sib xyaw

Cam khwb cia hlau yog cov hlau-carbon alloy nrog cov ntsiab lus carbon ntau dua 2.11%.Nws yog tau los ntawm kev lag luam npua hlau, seem hlau thiab lwm yam hlau thiab nws cov ntaub ntawv alloy los ntawm high-temperature melting thiab casting molding.Ntxiv nrog rau Fe, cov pa roj carbon muaj nyob rau hauv lwm cov cam khwb cia hlau yog precipitated nyob rau hauv daim ntawv ntawm graphite.Yog hais tias cov precipitated graphite nyob rau hauv daim ntawv ntawm strips, cov cam khwb cia hlau yog hu ua grey cam khwb cia hlau los yog grey cam khwb cia hlau; cam khwb cia hlau nyob rau hauv daim ntawv ntawm worms yog hu ua vermicular graphite cam khwb cia hlau;cam khwb cia hlau nyob rau hauv daim ntawv ntawm floc yog hu ua dawb cam khwb cia hlau los yog vaj hlau, cam khwb cia hlau cam khwb cia hlau yog hu ua ductile hlau.

Cov tshuaj muaj pes tsawg leeg ntawm spheroidal graphite cam khwb cia hlau tshwj tsis yog hlau feem ntau yog: carbon cov ntsiab lus 3.0 ~ 4.0%, silicon cov ntsiab lus 1.8 ~ 3.2%, manganese, phosphorus, sulfur tag nrho tsis ntau tshaj 3.0% thiab cov nyiaj tsim nyog ntawm cov ntsiab lus nodular xws li tsis tshua muaj ntiaj teb thiab magnesium. .

Kev ua haujlwm tseem ceeb

Cov hlau nplaum hlau tau siv nyob rau hauv yuav luag txhua qhov kev lag luam loj, uas xav tau lub zog siab, plasticity, toughness, hnav tsis kam, thiab nruj tsis kam.

Heavy thermal thiab mechanical shock, siab kub los yog kub tsis kam, corrosion kuj thiab dimension stability.Txhawm rau ua kom tau raws li cov kev hloov pauv no hauv kev pabcuam, nodular cam khwb cia hlau muaj ntau qib, muab ntau yam khoom siv thiab lub cev.

Feem ntau ntawm cov ductile hlau castings raws li tau teev tseg los ntawm International Organization for Standardization ISO1083 yog tsim nyob rau hauv lub unalloyed lub xeev.Pom tseeb, qhov no suav nrog qib siab zog nrog lub zog tensile ntau dua 800 Newtons ib square millimeter thiab elongation ntawm 2%.Lwm qhov tsis zoo yog qib yas siab, uas muaj qhov elongation ntau dua 17% thiab muaj zog sib xws (tsawg kawg 370 N / mm2).Lub zog thiab elongation tsis yog tib lub hauv paus rau cov neeg tsim qauv xaiv cov khoom, thiab lwm yam khoom tseem ceeb muaj xws li cov khoom muaj zog, elastic modulus, hnav tsis kam thiab qaug zog, hardness thiab cuam tshuam kev ua haujlwm.Tsis tas li ntawd, kev tiv thaiv corrosion thiab oxidation tsis kam nrog rau cov khoom siv hluav taws xob kuj tseem ceeb rau cov neeg tsim qauv.Txhawm rau kom ua tau raws li cov kev siv tshwj xeeb no, ib pawg ntawm austenite ductile irons, feem ntau hu ua Ni-Resis ductile irons, tau tsim.Cov hlau austenitic no feem ntau yog alloyed nrog npib tsib xee, chromium thiab manganese, thiab tau teev nyob rau hauv cov qauv thoob ntiaj teb.