Stainless hlau yog luv luv rau stainless thiab acid{0}}resistant steel. Cov hlau tsis muaj zog corrosive media xws li huab cua, chav, thiab dej, lossis cov uas muaj xeb-cov khoom tiv taus, hu ua stainless hlau. Cov hlau uas tiv taus cov tshuaj corrosion (acids, alkalis, ntsev, thiab lwm yam) hu ua acid-resistant steel.
Vim qhov sib txawv ntawm cov tshuaj muaj pes tsawg leeg, stainless hlau tsis tas yuav tiv taus cov tshuaj corrosion, thaum stainless hlau feem ntau muaj xeb- cov khoom tiv taus. Lub corrosion kuj ntawm stainless hlau nyob ntawm cov alloying ntsiab nws muaj.
Nws yog feem ntau cais raws li nws cov qauv metallographic:
Feem ntau, raws li cov qauv metallographic, zoo tib yam stainless hlau tau muab faib ua peb pawg: austenitic stainless hlau, ferritic stainless hlau, thiab martensitic stainless hlau. Raws li peb qhov yooj yim metallographic qauv, duplex stainless hlau, nag lossis daus- hardening stainless hlau, thiab siab- alloy steel nrog cov ntsiab lus hlau tsawg dua 50% tau muab los rau cov kev xav tau tshwj xeeb thiab lub hom phiaj.
1. Austenitic Stainless hlau
Lub matrix yog tsim los ntawm austenitic qauv (CY theem) nrog lub ntsej muag -centered cubic crystal qauv. Nws tsis yog-sib nqus thiab feem ntau ntxiv dag zog los ntawm kev ua haujlwm txias (uas tuaj yeem ua rau qee qhov hlau nplaum). 1. **2. ** Ferritic Stainless Hlau: ** Stainless hlau nrog lub cev feem ntau -centered cubic ferrite ( -theem) matrix. Nws yog hlau nplaum thiab feem ntau tsis tuaj yeem hardened los ntawm kev kho cua sov, tab sis kev ua haujlwm txias tuaj yeem ntxiv dag zog rau nws. Lub koom haum American Hlau thiab Hlau (AISI) xaiv nws li 430 thiab 446.
3. **Martensitic Stainless Steel:** Stainless hlau nrog martensitic (lub cev -centered cubic los yog cubic) matrix. Nws yog hlau nplaum, thiab nws cov khoom siv kho tshuab tuaj yeem hloov kho los ntawm kev kho cua sov. Lub AISI xaiv nws li 410, 420, thiab 440. Martensite nthuav tawm cov qauv austenitic ntawm qhov kub thiab txias; Thaum txias rau chav sov ntawm tus nqi tsim nyog, cov qauv austenitic hloov mus rau hauv martensite (ie, hardening).
** 3. **Martensitic Stainless Steel:** Stainless hlau nrog martensitic (lub cev -centered cubic los yog cubic) matrix. Nws yog hlau nplaum, thiab nws cov khoom siv kho tshuab tuaj yeem hloov kho los ntawm kev kho cua sov. AISI xaiv nws li 410, 420, thiab 440. 4. Austenitic-Ferric (Duplex) Stainless Steel
Hom stainless hlau no muaj cov matrix uas muaj ob theem austenitic thiab ferritic, nrog rau cov matrix me me feem ntau suav nrog ntau dua 15%. Nws yog hlau nplaum thiab tuaj yeem ua kom muaj zog los ntawm kev ua haujlwm txias . 329 yog ib qho piv txwv ntawm duplex stainless hlau. Piv rau austenitic stainless hlau, duplex stainless hlau muaj lub zog ntau dua thiab txhim kho kev tiv thaiv intergranular corrosion, chloride stress corrosion, thiab pitting corrosion.
5. Cov nag lossis daus Hardening Stainless hlau
Hom stainless hlau no muaj austenitic lossis martensitic matrix thiab tuaj yeem ua kom tawv los ntawm kev kho nag lossis daus hardening. Lub koom haum American Hlau thiab Hlau tsim nws nrog cov lej hauv 600 series, xws li 630, uas yog 17-4PH.
Feem ntau hais lus, tshwj tsis yog rau cov alloys, austenitic stainless hlau muaj kev tiv thaiv corrosion zoo heev. Ferritic stainless hlau tuaj yeem siv rau hauv qhov chaw qis -corrosion. Nyob rau hauv ib puag ncig me me corrosive, yog tias xav tau lub zog siab lossis siab hardness, martensitic thiab nag lossis daus hardening stainless hlau tuaj yeem siv.
Thickness sib txawv
1. Thaum lub sij hawm dov txheej txheem nyob rau hauv steel mills, cov rolls undergo me ntsis deformation vim tshav kub, ua rau thickness deviations nyob rau hauv cov dov daim hlau, feem ntau thicker nyob rau hauv nruab nrab thiab nyias ntawm cov npoo. Cov kev cai hauv tebchaws tau hais tias lub thickness ntawm lub phaj yuav tsum tau ntsuas ntawm qhov nruab nrab ntawm cov ntug saum toj kawg nkaus.
2. Tolerances tshwm sim los ntawm kev ua lag luam thiab cov neeg xav tau, feem ntau categorized li loj los yog me me tolerances. Piv txwv li:
[Duab]
Dab tsi ntawm stainless hlau tsis tshua muaj xeb?
Muaj peb yam tseem ceeb cuam tshuam rau corrosion ntawm stainless hlau:
1. Cov ntsiab lus ntawm alloying ntsiab
Feem ntau hais lus, steel nrog cov ntsiab lus chromium ntawm 10.5% tsis tshua muaj xeb. Cov ntsiab lus chromium thiab nickel ntau dua ua rau muaj kev tiv thaiv corrosion zoo dua. Piv txwv li, 304 stainless hlau xav tau 8% ~ 10% nickel thiab 18% ~ 20% chromium; xws li stainless hlau feem ntau yuav tsis xeb.
2. Cov txheej txheem smelting ntawm cov tuam txhab tsim khoom kuj cuam tshuam rau corrosion kuj ntawm stainless hlau.
Loj stainless hlau mills nrog zoo smelting technology, cov cuab yeej siv siab heev, thiab cov txheej txheem siab heev tuaj yeem ua kom tswj tau cov ntsiab lus alloying, tshem tawm impurity, thiab billet txias kub. Yog li ntawd, lawv cov khoom yog ruaj khov thiab txhim khu kev qha zoo, nrog zoo sab hauv zoo thiab tsis nquag xeb. Hloov pauv, qee qhov me me steel mills muaj cov cuab yeej siv thiab cov txheej txheem dhau los, thiab cov impurities tsis tuaj yeem raug tshem tawm thaum lub sij hawm smelting, ua rau lawv cov khoom muaj feem yuav xeb.
3. Ib puag ncig sab nraud: Qhuav thiab zoo- qhov chaw nyob qhov cua tsis tshua muaj xeb.
Txawm li cas los xij, ib puag ncig nrog cov av noo siab, huab cua tsis tu ncua los nag, lossis siab acidity / alkalinity hauv huab cua yog qhov ua rau xeb. Txawm tias 304 stainless hlau yuav xeb yog tias ib puag ncig ib puag ncig tsis zoo.
Yuav ua li cas tiv thaiv xeb ntawm cov hlau stainless?
1. Cov txheej txheem tshuaj:
Siv cov tshuaj pleev xim los yog tshuaj tsuag los pab rov-passivate thaj chaw xeb, tsim cov chromium oxide zaj duab xis kom rov ua kom muaj zog corrosion. Tom qab pickling, nws yog ib qho tseem ceeb heev uas yuav tsum yaug kom zoo nrog dej huv kom tshem tawm tag nrho cov kab mob thiab acid residues. Tom qab tag nrho cov kev kho mob, repolish nrog polishing khoom thiab foob nrog polishing ciab. Rau cov me me, qhov chaw xeb hauv zos, 1: 1 sib xyaw ntawm cov roj av thiab cov roj cav siv tau los so lawv nrog ib daim ntaub huv.
2. Mechanical Methods
Txhaj tshuaj blasting, siv iav los yog ceramic microparticles rau txhaj blasting, burring, txhuam, thiab polishing. Cov txheej txheem siv tshuab tuaj yeem tshem tawm cov kab mob ntawm cov khoom siv yav dhau los tshem tawm, cov khoom polishing, lossis cov ntaub ntawv burring. Txhua yam kab mob, tshwj xeeb tshaj yog cov hlau txawv teb chaws, tuaj yeem ua qhov chaw ntawm corrosion, tshwj xeeb tshaj yog nyob rau hauv ib puag ncig ntub. Yog li ntawd, mechanically cleaned nto yuav tsum tau muab ntxuav kom zoo nyob rau hauv qhuav tej yam kev mob. Cov txheej txheem siv tshuab tsuas yog ntxuav qhov chaw thiab tsis txhob hloov cov khoom siv los ntawm corrosion kuj. Yog li ntawd, nws raug nquahu kom rov- polishing nrog cov khoom siv polishing thiab foob nrog polishing wax tom qab kev kho tshuab.
Hom Stainless Hlau Qib thiab Cov Khoom Siv rau Cov Khoom Siv
1. 304 Stainless hlau. Ib qho ntawm feem ntau siv austenitic stainless hlau, haum rau kev tsim cov khoom sib sib zog nqus- kos qhov chaw, cov kav dej kua qaub, cov thawv ntim khoom, cov khoom siv, ntau lub cev ntsuas, thiab lwm yam. Nws tuaj yeem siv los tsim cov khoom tsis yog- sib nqus, cov khoom siv cryogenic thiab cov khoom siv.
2. 304L Stainless Hlau. Txhawm rau hais txog qhov cuam tshuam loj heev ntawm kev sib tsoo ntawm 304 stainless hlau nyob rau hauv qee yam kev mob vim Cr23C6 nag lossis daus, ultra- carbon austenitic stainless hlau tsawg tau tsim. Nws tsis kam mus rau intergranular corrosion nyob rau hauv lub xeev sensitized yog ho superior rau ntawm 304 stainless hlau. Tsuas yog me ntsis qis zog, nws lwm yam khoom zoo ib yam li 321 stainless hlau. Nws yog tsuas yog siv rau corrosion{11}}cov cuab yeej tiv taus thiab cov khoom siv uas yuav tsum tau vuam tab sis tsis tuaj yeem raug kho, thiab tuaj yeem siv los tsim ntau lub cev ntsuas, thiab lwm yam.
3. 304H Stainless hlau. Ib ceg sab hauv ntawm 304 stainless hlau, nrog rau cov pa roj carbon ntau ntawm 0.04% - 0.10%, nws qhov siab - qhov kub thiab txias ua haujlwm zoo dua li ntawm 304 stainless hlau.
4. 316 Stainless hlau. Raws li 10Cr18Ni12 steel, molybdenum ntxiv, muab cov hlau zoo tiv thaiv kom tsis txhob muaj xov xwm thiab pitting corrosion. Nyob rau hauv dej hiav txwv thiab ntau lwm yam xov xwm, nws corrosion kuj yog superior rau ntawm 304 stainless hlau, thiab nws yog tsuas yog siv rau pitting corrosion resistant cov ntaub ntawv.
5. 316L Stainless Hlau. Ib qho ultra- cov pa roj carbon tsawg nrog kev ua haujlwm zoo rau sensitized intergranular corrosion, tsim nyog rau kev tsim cov khoom siv welded thiab cov khoom siv nrog tuab tuab - ntu, xws li corrosion- cov ntaub ntawv tiv taus hauv cov khoom siv petrochemical. 6. 316H Stainless Steel. Ib ceg sab hauv ntawm 316 stainless hlau, nrog cov ntsiab lus carbon ntawm 0.04% -0.10%. Nws qhov siab - qhov kub thiab txias ua haujlwm zoo dua rau 316 stainless hlau.
7. 317 Stainless hlau. Nws tsis kam rau pitting corrosion thiab creep yog superior rau 316L stainless hlau. Nws yog siv rau hauv kev tsim cov khoom siv petrochemical thiab cov cuab yeej tiv taus cov organic acid corrosion.
8. 321 Stainless hlau. titanium-stabilized austenitic stainless hlau. Qhov sib ntxiv ntawm titanium txhim kho nws qhov kev tiv thaiv rau intergranular corrosion thiab nws muaj qhov zoo siab -kub txhua yam khoom. Nws tuaj yeem hloov tau los ntawm ultra- qis carbon austenitic stainless hlau. Tsuas yog rau cov ntawv thov tshwj xeeb xws li siab - kub lossis hydrogen corrosion kuj, nws feem ntau tsis pom zoo siv.
9. 347 Stainless hlau. A niobium-stabilized austenitic stainless hlau. Qhov sib ntxiv ntawm niobium txhim kho nws cov kev tiv thaiv rau intergranular corrosion. Nws cov corrosion kuj nyob rau hauv cov kua qaub, alkali, thiab ntsev media zoo ib yam li 321 stainless hlau. Nws muaj qhov zoo weldability thiab tuaj yeem siv los ua ob qho tib si corrosion- cov khoom siv tiv taus thiab cov cua sov- cov hlau resistant. Nws yog tsuas yog siv nyob rau hauv thermal zog thiab petrochemical teb, xws li nyob rau hauv kev tsim cov thawv, kav, tshav kub exchangers, shafts, furnace tubes nyob rau hauv industrial furnaces, thiab rauv tube thermometers . 10. 904L Stainless hlau. Lub super austenitic stainless hlau tsim los ntawm Outokumpu, lub tuam txhab Finnish, nws muaj cov ntsiab lus nickel ntawm 24% ~ 26% thiab cov ntsiab lus carbon tsawg dua 0.02%. Nws muaj kev tiv thaiv corrosion zoo heev, uas qhia tau zoo tiv thaiv tsis yog -oxidizing acids xws li sulfuric acid, acetic acid, formic acid, thiab phosphoric acid. Nws kuj muaj qhov ua haujlwm zoo rau crevice corrosion thiab kev ntxhov siab corrosion. Nws yog haum rau siv nrog sulfuric acid ntawm ntau yam concentrations hauv qab no 70℃thiab qhia tau hais tias zoo corrosion kuj nyob rau hauv acetic acid thiab tov acids ntawm formic acid thiab acetic acid ntawm tej concentration thiab kub nyob rau hauv ib txwm siab. Tus qauv qub ASME SB-625 cais nws raws li cov nickel-raws li alloy, thaum tus qauv tshiab cais nws li stainless hlau. Hauv Suav teb, tsuas yog qib kwv yees 015Cr19Ni26Mo5Cu2 steel muaj. Ob peb lub tuam txhab European siv 904L stainless hlau ua cov khoom tseem ceeb; Piv txwv li, lub raj ntsuas ntawm E + H lub ntsuas dej loj yog ua los ntawm 904L stainless hlau, thiab Rolex saib cov rooj plaub kuj yog ua los ntawm 904L stainless hlau.
11. 440C Stainless Hlau. Martensitic stainless hlau, qhov nyuaj tshaj plaws ntawm hardenable stainless hlau, nrog ib tug hardness ntawm HRC57. Feem ntau yog siv los ua nozzles, bearings, valve cores, valve rooj, tes tsho, thiab valve stems.
12. 17-4PH Stainless hlau. Martensitic nag lossis daus hardening stainless hlau nrog hardness ntawm HRC44. Nws muaj lub zog siab, hardness, thiab corrosion kuj, tab sis tsis tuaj yeem siv ntawm qhov kub siab tshaj 300 degree. Nws muaj corrosion kuj zoo rau huab cua thiab diluted acids los yog ntsev, zoo ib yam li 304 thiab 430 stainless hlau. Siv nyob rau hauv kev tsim offshore platforms, turbine hniav, valve cores, valve rooj, tes tsho, thiab valve stems.
