1. Peb tiam ntawm Hnav-Cov ntaub ntawv uas tsis muaj zog
Hnav-cov khoom tiv taus - zeb liners, sib tsoo pob thiab crusher qhov chaw ua haujlwm thermal zog, cement, hlau-ore thiab alumina nroj tsuag - yog tsim los ntawm peb tsev neeg txuas ntxiv ntawm cov khoom siv hlau:
Siab -manganese austenitic steels(thawj tiam). Nyob rau hauv raws li -cast condition tus qauv yog austenite nrog carbide tes hauj lwm ntawm grain ciam teb. Ib qho dej-tuaj tawv (kev daws teeb meem) ntawm li 1050℃dissolves cov carbides thiab tsim ib qho -theem austenitic qauv uas ua hauj lwm- hardens sai nyob rau hauv kev cuam tshuam.
Tsawg- alloy hnav- cov hlau tsis muaj zog( tiam thib ob). Feem ntau Cr-Mo systems nrog me me ntxiv ntawm lwm cov ntsiab lus, muab raws li martensitic, bainitic, austenitic-bainitic duplex lossis martensitic-bainitic duplex qib.
Hnav-cov hlau cam khwb cia hlau tiv taus(peb tiam). Muab faib ua cov hlau dawb dawb, npib tsib xee-chromium (Ni-Hard type) irons thiab siab -chromium dawb irons; ob lub tom kawg yog siv dav tshaj plaws vim lawv cov carbide nyuaj hauv cov matrix tawv.
2. Yog vim li cas quenching nruab nrab teeb meem
Rau siab - alloy steels, nruab nrab - alloy steels thiab hnav - cam khwb cia hlau resistant, cov khoom ntau yam - los ntawm kev sib tsoo pob rau liner phaj - dictates qhov kev xaiv ntawm quenching nruab nrab. Ib qho nruab nrab uas txias dhau qeeb yuav tsis ncav cuag tag nrho hardness; ib qho uas txias heev ua rau thermal thiab transformation stresses uas tawg siab - carbon Cheebtsam. Qhov no yog vim li cas cov kev cai rau cov quenchant feem ntau tau teev tseg rau tus neeg muag khoom ntawm kev tshaj lij quenching thiab cua txias xov xwm.
3. Dej-Soluble Polymer Quenchants ua lwm txoj rau Roj
Kev loj hlob ntawm ib puag ncig kev paub thiab kev ua kom nruj cov kev cai tso tawm tau ua tiav kev hloov pauv cov roj quenchants nrog dej -soluble polymer media, tshwj xeeb tshaj yog rau hnav- cov ntaub ntawv tiv taus. Kev sim "Dej tsis siv roj" tau nthuav dav siv cov khoom siv polymer, txiav cov nqi tsim khoom thiab txaus siab rau kev ua raws li ib puag ncig.
Rau qhov yuav tsum tau quenching hnyav heev, tsuas yog inorganic -cov tshuaj ntsev muab lub zog txias txaus; Txawm li cas los xij, rau feem ntau cov ntawv thov kev tsim khoom, txawm li cas los xij, dej - cov khoom siv polymers yog siv. Lawv cov txheej txheem yog ncaj nraim: ntawm qhov kub ntawm qhov chaw ua haujlwm siab, cov polymer deposits los ntawm boiling tov thiab tsim ib zaj duab xis rau saum npoo. Cov yeeb yaj kiab no txo qis kev tshem tawm cov cua sov, txo qis qhov ua kom txias txias ntawm chav da dej thiab txo qhov kev pheej hmoo ntawm quench cracking.
Dej-soluble polymers poob rau hauv peb pawg: natural polymers (guar gum, xanthan gum), semi-synthetic polymers (carboxymethyl cellulose, hydroxyethyl cellulose) thiab hluavtaws polymers xws li poly (ethylene oxide) (PEO), sodium polyacrylate (ACR) thiab polyalkylene (PAG). Txij li thaum nruab nrab - xyoo pua 20th yuav luag txhua txhua qhov yooj yim uas muaj dej-soluble polymer tau raug tshuaj xyuas hauv cov ntaub ntawv, tseem tsuas yog peb tsev neeg tau tsim kev lag luam niaj hnub no: PAG, ACR (polyacrylate) thiab PVP.
4. PAG Quenchants
PAG yog copolymer ntawm ethylene oxide (EO) thiab propylene oxide (PO); ib qho kev sib xyaw aqueous muaj li ntawm 75% EO thiab 25% PO thiab nthuav tawm ib qho kev rov qab solubility (huab point) saum toj li 75℃. Tshaj li qhov kub ntawm hydrogen kev sib txuas ntawm PO ntu thiab dej yog cuam tshuam, cov polymer precipitates rau ntawm qhov chaw ua haujlwm kub, thiab cov yeeb yaj kiab ua rau kom txias.
Vim hais tias cov saw tseem ceeb ntawm polyether yog linear thiab tsis muaj sab ceg, nws cov thermal thiab tshuaj stability yog siab tshaj ntawm polyacrylamide - hom polymers. Polyethers kuj yog tsim los ntawm anionic polymerization, uas yields ib tug nqaim molecular - nyhav tis tshaj dawb -radical polymerization. Hauv kev pabcuam, PAG tau khaws cia kom raug da dej - nrog kev tswj hwm kev tswj hwm thiab kev ncig kom tiv thaiv kab mob loj hlob - tuaj yeem kav ntev dua 10 xyoo, piv rau quenching roj. Qhov no yog vim li cas PAG yog cov dej siv dav tshaj plaws -soluble quenchant.
PAG muaj kev txwv rau kev hnav- cov ntaub ntawv tiv taus, txawm li cas los xij: nws qhov hnyav molecular yog tswj tau tsuas yog nyob rau hauv qhov nqaim, thiab ultra- siab- molecular- hnyav PAG tseem tsis tau tsim tawm hauv kev lag luam. Raws li qhov tshwm sim, qhov qis- qhov kub thiab txias ntawm PAG da dej tseem sib piv nrawm rau kev tawg -sensitive siab- cov khoom siv carbon chromium. Txhim kho PAG concentration txo qis qhov cua txias ntawm 300℃los ntawm kwv yees li 95℃/ s mus rau 40℃/ s, tab sis kev txo qis ntxiv yog qhov nyuaj, thiab cov concentrations siab heev impairing txias uniformity.
5. ACR (Sodium Polyacrylate) Quenchants
Tsis zoo li kev lag luam PAG, nws qhov hnyav molecular raug txwv rau kaum tawm txhiab, kev lag luam sodium polyacrylate (ACR) tau nkag mus txog qhov hnyav ntawm ntau lab lossis kaum lab lab. Ib qho qis -concentration ACR tov yog li ntawd muaj viscosity siab heev thiab txo qhov nro ntawm qhov chaw. Qhov qis ntawm qhov nro txo qis qhov tseem ceeb ntawm cov cua sov ntawm cov kev daws teeb meem thiab stabilizes cov yeeb yaj kiab vapor, ncua zaj duab xis vau thiab softening thawj qhov cua txias poob siab.
Txias- cov ntaub ntawv nkhaus qhia tau tias qhov kev ua haujlwm txias ntawm ACR thoob plaws hauv qhov siab - qhov kub thiab txias (500-800℃) ze ze ze ntawm huab cua- huab cua txias. Qhov no maj mam siab -kub tus cwj pwm zoo heev txo cov thermal- kev ntxhov siab tawg ntawm siab -carbon chromium cam khwb cia- hlau Cheebtsam nyob ib ncig ntawm 700℃thaum lub sij hawm quenching - qhov kub ntau qhov twg transformation thiab thermal stresses ncov.
6. Xaiv Txoj Cai Nruab Nrab
Siab -manganese steels:dej toughening yog ib qho kev daws teeb meem, tsis yog lub zog quench - tag nrho cov dej quenching yog siv los tuav cov qauv austenitic.
Tsawg- alloy martensitic hnav steels:PAG los yog roj ceev; concentration yog tuned rau seem thickness kom tsis txhob mos me ntsis thaum limiting distortion.
High-carbon / siab- chromium cam khwb cia hlau:siab -molecular- nyhav ACR (los yog PVP qhov kev ruaj ntseg ntawm zaj duab xis yog qhov tseem ceeb) kom soften lub 500-800℃theem thiab txo qhov tawg ntawm 700℃.
Cov kab loj loj thiab tuab ntu:sab laj tus neeg muag khoom quenchant nrog rau feem geometry, hardenability thiab lub hom phiaj hardness; txheeb xyuas los ntawm kev ua kom txias -kev ntsuas nkhaus rau ISO 9950 ua ntej tsim khoom.
Txias-kev ntsuas nkhaus ntawm quenchants ua raws ISO 9950 (thiab cov txheej txheem ASTM D6482 / D6200), uas qhia txog tus cwj pwm cua txias ntawm kev lag luam quenching xov xwm raws li kev sojntsuam cov qauv.
7. Cov lus xaus
Kev kho cua sov ntawm siab -cov pa roj carbon hnav- cov ntaub ntawv tiv taus yog txiav txim siab ntau npaum li qhov nruab nrab quenching raws li lub voj voog ntawm lub cub tawg. Dej-soluble polymer quenchants - PAG rau kev lag luam thiab kev ruaj ntseg, ACR rau tawg -sensitive siab-carbon chromium irons, PVP qhov twg zaj duab xis stability yog qhov tseem ceeb - tam sim no tso cai rau "dej es tsis txhob roj" hloov yam tsis muaj kev txi hardness los yog pheej hmoo tawg. Rau ib qho khoom hnav-cov khoom tiv thaiv, los ntawm cov khoom sib tsoo mus rau cov khoom siv zeb, qhov nruab nrab quenching yuav tsum tau xaiv nrog cov khoom siv hardenability, seem loj thiab tawg kev pheej hmoo nyob rau hauv lub siab, thiab validated los ntawm standardized txias- nkhaus kuaj.
