I. Cov Ntawv Thov Core: Kev Lag Luam Hlau (Tshaj 90% Qhia tawm)
Kev lag luam steel yog cov neeg siv khoom loj tshaj plaws ntawm ferrochromium alloys. Cov pa roj carbon sib txawv-cov ntsiab lus ferrochromium sib haum rau cov qib steel sib txawv, nrog rau nws cov haujlwm tseem ceeb yog los txhim kho cov khoom steel los ntawm "alloying."
1. Stainless Hlau Ntau Lawm (Pib Daim Ntawv Thov)
Cov cuab yeej tseem ceeb ntawm cov hlau tsis muaj steel - corrosion resistance- hauv paus yog nyob ntawm "passivation film" (Cr₂O₃) tsim los ntawm chromium ntawm cov hlau. Cov yeeb yaj kiab no cais cov pa oxygen thiab dej, tiv thaiv xeb. Ferrochromium alloys ua tus thawj chromium qhov hauv stainless hlau smelting, nrog cov ntsiab lus carbon ncaj qha txiav txim siab stainless hlau hom:
Siab -carbon chromium hlau (C> 4%): Siv rau smelt martensitic stainless hlau (xws li, 410, 420 steel). Hom no qhia txog qhov nyuaj thiab lub zog, dav siv hauv cutlery, li qub, cov khoom siv kho tshuab, thiab lwm yam.
Nruab nrab-carbon chromium hlau (0.5%-4%): Siv los tsim ferritic stainless hlau (xws li, 430 steel), feem ntau pom nyob rau hauv cov khoom vaj tse thiab cov ntaub ntawv zoo nkauj (muab zoo corrosion kuj tshaj martensitic steel ntawm tus nqi qis dua austenitic steel).
Tsawg-carbon/ultra- qis- carbon chromium hlau (C < 0.5%, ultra- qis C < 0.15%): Siv los tsim cov hlau tsis muaj austenitic (xws li 304, 316 steel) thiab ultra- qis- carbon stainless hlau (eg, 316L). Cov hlau tsis muaj steel muaj qhov tshwj xeeb tiv thaiv corrosion, yuav tsum tau tswj cov ntsiab lus ntawm cov pa roj carbon monoxide (carbon reacts nrog chromium los ua carbides, depleting chromium thiab cuam tshuam cov passivation txheej). Lawv tau siv dav hauv cov cuab yeej siv tshuaj, khoom siv kho mob, tshuab ua zaub mov, thiab qib siab -khoom noj khoom haus.
Piv txwv li: 304 stainless hlau muaj kwv yees li 18% chromium, nrog ze li tag nrho cov chromium tau los ntawm chromium hlau alloy; 316L (ultra-cov pa roj tsawg) yuav tsum siv micro-carbon chromium hlau los xyuas kom meej cov ntsiab lus carbon <0.03%.
2. Cov Cuab Yeej Hlau thiab Tuag Hlau: Txhim kho hardness thiab hnav tsis kam
Cov cuab yeej steel (piv txwv li, siab-cov hlau nrawm) thiab cov hlau tuag (txias / kub ua haujlwm tuag steels) tiv taus siab- kev sib txhuam thiab kev cuam tshuam. Ntxiv chromium hlau alloys txhim khu kev ua haujlwm tseem ceeb los ntawm "kev daws teeb meem" thiab "carbide ntxiv dag zog":
Siab -carbon chromium hlau: Siv rau txias- cov cuab yeej ua haujlwm hlau (xws li Cr12 steel) nrog kwv yees li 12% chromium cov ntsiab lus. Nws ua tau siab -hardness Cr₇C₃ carbides, ua kom cov pwm tuaj yeem tiv taus hnav los ntawm txias stamping thiab txias extrusion. Haum rau manufacturing stamping tuag, txiab, thiab lwm yam.
Nruab nrab-rau- qis carbon ferrochromium: Siv nyob rau hauv siab- steels ceev (xws li, W18Cr4V), qhov twg chromium txhim kho liab hardness (lub peev xwm los tuav hardness ntawm siab kub). Qhov no tiv thaiv softening thaum lub sij hawm siab - txiav ceev, ua rau nws haum rau lub tshuab cuab tam cutters, laum khoom, thiab cov ntawv zoo sib xws.
3. Bearing Steel: Extended Fatigue Life
Bearings ua siab ntev siab - zaus alternating loads thaum lub sij hawm ua hauj lwm, xav tau tshwj xeeb hnav tsis kam thiab qaug zog endurance. Chromium hlau alloys (feem ntau nruab nrab-carbon chromium hlau) yog ib qho tseem ceeb additives nyob rau hauv bearing steels zoo li GCr15:
Nrog kwv yees li ntawm 1.5% chromium cov ntsiab lus, nws ua tau zoo, sib xws Cr₂₃C₆ carbides nrog carbon. Cov carbides faib sib npaug thoob plaws hauv cov hlau matrix, txhim kho hardness (tiv thaiv hnav) thaum inhibiting tawg propagation (ntev lub neej qaug zog). Lawv tau siv dav hauv cov kabmob / kev sib tw rau tsheb, cov cuab yeej siv tshuab, thiab cov tshuab hluav taws xob.
4. High-Strungth Structural Steel: Txhim kho Toughness thiab Huab Cua Resistance
Cov haujlwm xws li kev tsim kho tshuab (excavators, ntauwd cranes), txuas hniav, thiab siab -cov tsev nce siab xav tau cov qauv hlau nrog "siab zog + siab toughness." Chromium hlau alloys (nruab nrab-cov pa roj carbon tsawg) ua ke nrog cov khoom xws li manganese thiab silicon:
Ua kom muaj zog tawm los (piv txwv li, Q690 siab- lub zog steel) thaum tiv thaiv kom txhob muaj zog ntxiv;
Cov ntsiab lus chromium tsawg (1% -3%) txhim kho huab cua tsis kam (atmospheric corrosion resistance) rau sab nraum zoov txuas hniav, ntim, thiab lwm yam. (lub npe hu ua "weathering steel").
5. Tshwj xeeb kev ua tau zoo Steels: niche daim ntaub ntawv rau tshav kub Resistance thiab corrosion kuj
Thaum tshav kub kub-cov hlau tsis muaj zog (piv txwv li, lub zog cog boiler raj, cov khoom siv dav hlau dav hlau): Chromium hlau alloys (nruab nrab- cov pa roj carbon tsawg) ua ke nrog npib tsib xee, tungsten, thiab lwm yam., tsim cov oxide zaj duab xis ruaj khov uas tiv thaiv oxidation ntawm qhov kub thiab txias thaum txhim kho siab - qhov kub thiab txias;
Acid-cov hlau tsis muaj zog (piv txwv li, chemical cia tanks, pickling tank): tso siab rau cov ntsiab lus chromium siab (17%-25%), xav tau cov pa roj carbon tsawg chromium hlau los xyuas kom muaj kev tiv thaiv corrosion hauv cov kua qaub uas muaj zog (xws li sulfuric acid, nitric acid).
II. Kev siv thib ob: Casting, Vuam, thiab lwm yam teb
1. Kev lag luam Casting: Kev tsim khoom hnav-Resistant Castings
Kev ua haujlwm casting yuav tsum muaj ntau qhov "siab-hardness, hnav-resistant" castings (xws li, sib tsoo pob, crusher liner, cement zeb yob lub tes tsho). Cov castings no feem ntau yog "siab-chromium cam khwb cia hlau," nrog chromium tag nrho los ntawm siab -carbon ferrochrome:
Sib tov siab -carbon chromium hlau (C> 6%) nrog molten hlau elevates chromium cov ntsiab lus nyob rau hauv castings mus rau 12% -30%, ua ntau Cr₇C₃ carbides (hardness mus txog HV1300, deb tshaj li qub cam khwb cia hlau). Lawv hnav tsis kam yog 5-10 npaug ntawm cov qauv cam khwb cia hlau, ua rau lawv siv dav hauv kev sib tsoo thiab crushing cov cuab yeej siv rau mining, cov khoom siv, thiab metallurgy industries.
2. Welding Materials: Ua kom muaj kev ua haujlwm zoo
Thaum welding stainless hlau los yog siab - lub zog steel, qhov muaj pes tsawg leeg thiab cov khoom ntawm cov vuam yuav tsum sib phim cov khoom siv los tiv thaiv corrosion los yog tawg. Chromium hlau alloys (feem ntau qis-carbon/micro-carbon) yog ib qho tseem ceeb additives hauv flux-coated electrodes thiab vuam hlau:
Piv txwv li: Vuam rods rau 304 stainless hlau yuav tsum tau micro-carbon chromium hlau nyob rau hauv lub flux txheej los xyuas kom meej weld chromium cov ntsiab lus ntau dua los yog sib npaug rau 18%, txuam cov khoom hauv paus thiab tiv thaiv corrosion vim chromium deficiency.
Vuam xov hlau rau siab - lub zog cov qauv hlau tau txais txiaj ntsig los ntawm nruab nrab - cov pa roj carbon chromium hlau ntxiv, txhim kho qhov vuam lub zog thiab tawv kom tiv thaiv kev sib koom ua ke.
3. Lwm yam: Deoxidation, Desulfurization, thiab tshwj xeeb Alloys
Deoxidizing/Desulfurizing Agent: Silicon-chromium alloy (muaj 40%-}45% silicon, 30%-35% chromium) tsis yog tsuas yog muab cov chromium xwb tab sis kuj ua haujlwm ua deoxidizer thiab desulfurizer hauv steelmaking - - Silicon nyiam ua ke nrog oxygen. SiO₂ (slag), thaum chromium pab desulfurization, txo cov impurities tsis zoo (oxygen thiab sulfur txo steel toughness) hauv steels. Qhov no yog siv los ua cov qib qis -oxygen, qis-sulfur high-end steel qib;
Cov Alloys Tshwj Xeeb: Cov khoom me me ntawm ferrochromium yog siv los ua npib tsib xee-raws li alloys thiab cobalt-raws li alloys (xws li aerospace siab- kub alloys), tab sis qhov kev faib ua feem tsawg heev thiab tsis yog ib qho tseem ceeb daim ntawv thov.
Cov ntsiab lus
Ferrochromium alloys ua "kev ua tau zoo" ntawm kev lag luam niaj hnub no, nrog rau lawv cov txiaj ntsig tseem ceeb hauv kev muab peb yam tseem ceeb rau cov ntaub ntawv los ntawm chromium: corrosion resistance, hnav tsis kam, thiab siab zog. Los ntawm niaj hnub stainless hlau chav ua noj rau cov khoom siv tshuaj lom neeg thiab kev tsim kho tshuab, thiab txuas mus rau siab -kawg daim ntawv thov xws li cov cuab yeej siv kho mob thiab cov khoom siv dav hlau dav hlau -txhua tus cia siab rau kev txhawb nqa ntawm ferrochromium alloys. Ntawm no, stainless hlau ntau lawm sawv cev rau nws daim ntawv thov tseem ceeb tshaj plaws, ncaj qha txiav txim siab lub ntiaj teb no muaj peev xwm thiab xav tau toj roob hauv pes rau ferrochromium alloys.
