Txheej txheem cej luam: Dab tsi yog SA-213 T24?
SA-213 T24yog tus qauv specification los ntawm American Society for Testing and Materials (ASTM) rauseamless ferritic thiab austenitic steel boiler, superheater, thiab tshav kub -exchanger tubes.
Lub npe "T24" yog hais txog ib qho tshuaj muaj pes tsawg leeg uas tsim tau ib qhochromium-molybdenum-vanadium hlaunrog kev txhim kho weldability thiab siab - qhov kub thiab txias piv rau nws cov neeg ua ntej xws li T22.
Nws thawj daim ntawv thov yog nyob rau hauvsiab-siab, siab- qhov kub thiab txiasntawm niaj hnub fais fab nroj tsuag, xws li:
Superheaters
Reheaters
phab ntsa dej(hauv advanced designs)
Cov yam ntxwv tseem ceeb & Vim li cas T24 siv
Zoo heev -Temperature Strength (Creep Resistance):T24 yog tsim los tiv thaiv lub siab loj thiab kub (txog ~ 600℃/ 1112℃F) hauv niaj hnub, siab - boilers efficiency tsis deforming lub sij hawm (ib qho tshwm sim hu ua "creep").
Txhim kho Weldability:Qhov no yog qhov txiaj ntsig tseem ceeb tshaj T22. T24 muaj cov ntsiab lus qis dua thiab ntxiv cov ntsiab lus xws li Vanadium (V) thiab Titanium (Ti). Qhov kev sib xyaw ua ke no txo qhov kev pheej hmoo ntawmtxias tawgnyob rau hauv lub tshav kub-Qhov cuam tshuam (HAZ) tom qab vuam, feem ntau tshem tawm qhov xav tau ua ntej- cua sov hauv ntau qhov xwm txheej (txawm tias tom qab-weld kev kho cua sov tseem yuav tsum tau ua).
Zoo Oxidation & Corrosion Resistance:Lub ~ 2.25% Chromium cov ntsiab lus muab kev tiv thaiv txaus rau oxidation (scaling) thiab qee hom kev xeb hauv ib puag ncig boiler.
Cov Khoom Siv Tshuaj (ASTM A213 / A213M)
Cov ntsiab lus alloying tshwj xeeb yog qhov tseem ceeb rau T24 cov khoom.
| Lub ntsiab | Kev sib xyaw (%) |
|---|---|
| Cov pa roj carbon (C) | 0.05 - 0.10 |
| Manganese (Mn) | 0.30 - 0.70 |
| Phosphorus (P) | 0.020 max |
| Sulfur (S) | 0.010 max |
| Silicon (Si) | 0.15 - 0.45 |
| Chromium (Cr) | 2.20 - 2.60 |
| Molybdenum (hli) | 0.90 - 1.10 |
| Vanadium (V) | 0.20 - 0.30 |
| Titanium (Ti) | 0.05 - 0.10 |
| Boron (B) | 0.0015 - 0.0070 |
| Aluminium (Al) | 0.020 max |
Vim li cas qhov kev sib xyaw no tseem ceeb:
Tsawg C + Ti:Txhim kho weldability los ntawm stabilizing cov pa roj carbon monoxide, tiv thaiv kev tsim ntawm tawv, tawg -sensitive martensite.
Cr & Mo:Muab lub zog thiab ruaj khov ntawm qhov kub thiab txias.
V, B, Ti:Cov no yog cov muaj zog ntxiv dag zog uas txhim kho creep tsis kam los ntawm kev ua kom zoo, ruaj khov carbides thiab nitrides hauv cov hlau microstructure.
Mechanical Properties (raws li ASTM A213 / A213M)
| Khoom | Kev xav tau |
|---|---|
| Tensile zog | 415 MPa (60 ksi) min |
| Yield zog | 205 MPa (30 ksi) min |
| Elongation | 20% min (hauv 50 mm) |
Kev tsim khoom
SA-213 T24 cov kav dej yog tsim los uaseamless. Qhov no yog ib qho tseem ceeb heev rau kev siv siab - siab vim nws tshem tawm txoj hlua txuas ntev, uas tuaj yeem yog qhov ua tsis tiav. Cov txheej txheem sib xws yog:
Kub Extrusion:Ib lub pob zeb yog rhuab thiab pierced los ua ib lub plhaub hollow.
Pilgering lossis Cold Drawing:Lub plhaub tau ua tiav ntxiv kom ua tiav qhov kawg qhov ntev, phab ntsa thickness, thiab nto tiav.
Qhov txawv tseem ceeb: T24 vs. T22
Qhov no yog ib qho kev sib piv, raws li T22 yog tus neeg ua haujlwm yav dhau los.
| Feature | SA-213 T22 (2.25Cr-1Mo) | SA-213 T24 (2.25Cr-1Mo-V-Ti-B) |
|---|---|---|
| Cov pa roj carbon | 0.05 - 0.15 | 0.05 - 0.10 |
| Alloying | Cr, Mo | Cr, Mo, V, Ti, B |
| Weldability | Zoo, tab sis yuav tsum nruj ua ntej- cua sov | Zoo heev, qis dua ua ntej - cua sov xav tau |
| Lub zog | Zoo siab - qhov kub thiab txias | Superiorsiab -kub (ceeb) lub zog |
| Daim ntawv thov | Laus boilers, superheaters | Niaj hnub nimno, siab -effinency boilers, phab ntsa dej |
Vuam ntawm T24
Vuam yog txheej txheem tseem ceeb rau T24. Thaum nws cov weldability tau txhim kho, nws yuav tsum tau ceev faj cov txheej txheem thiab cov kws txawj welding.
Filler Hlau:Feem ntau, ib qho kev sib xyaw ua ke muab cov hlau zoo liAWS A5.28 ER90S{2}}B9yog siv rau TIG vuam.
Ua ntej- Kub:Feem ntau tsis tas yuav tsum tau rau cov phab ntsa nyias vim muaj cov ntsiab lus ntawm cov pa roj carbon tsawg, tab sis yuav tsum tau txiav txim siab los ntawm cov txheej txheem vuam tsim nyog (WPS).
Tshaj tawm -Weld Heat Treatment (PWHT): Yuav tsum tau. Tus qauv yuav tsum tau ua kom sov lub welment rau725℃(± 15 degree) / 1337℃Frau ib lub sij hawm tshwj xeeb (feem ntau tsawg kawg yog 1 teev ib nti ntawm tuab) kom txo tau cov kev ntxhov siab seem thiab kub siab rau microstructure hauv HAZ.
Kev txiav txim siab tseem ceeb & Cov teeb meem muaj peev xwm
Hardness Control:Txawm hais tias nws zoo weldability, cov khoom siv hluav taws xob ntau dhau tuaj yeem ua rau muaj kev nyuaj siab hauv thaj tsam weld. Kev tsim nyog PWHT yog qhov tseem ceeb los coj cov tawv tawv mus rau qib tau txais.
Cracking thaum PWHT:Ib qho tshwm sim tshwj xeeb hu ua "reheat cracking" tuaj yeem tshwm sim hauv qis- alloy steels zoo li T24 thaum lub sij hawm PWHT lossis hauv kev pabcuam. Lub voj voog PWHT raug yog qhov tseem ceeb los txo qhov kev pheej hmoo no.
Strict Quality Control:Vim nws daim ntawv thov tseem ceeb, T24 yeeb nkab yuav raug kuaj nruj, suav nrog hydrostatic lossis tsis yog- kuaj kev puas tsuaj (eddy tam sim no, ultrasonic), kev ntsuam xyuas flattening, thiab tshuaj lom neeg thiab tshuaj ntsuam xyuas ntawm txhua qhov kub.
Cov ntsiab lus
SA-213 T24yog ib qho kev txawj ntse, siab -kev ua tau zoo steel raj qhov tseem ceeb rau kev ua tau zoo thiab kev nyab xeeb ntawm cov thee niaj hnub- raug rho tawm haujlwm thiab biomass fais fab nroj tsuag. Nws cov chemistry optimized muab kev sib xyaw ua ke zoo tshaj plaws ntawm siab - kub lub zog thiab weldability, ua rau nws cov khoom ntawm kev xaiv rau qhov xav tau tshaj plaws qhov siab qhov kev ntseeg tau ntau xyoo dhau los yog qhov tseem ceeb.
