Txheej txheem cej luam
SA-213 T91yog ib qho chromium-molybdenum alloy steel, tshwj xeeb tsim los rau siab -kev pabcuam kub. Nws yog ib qho ntawm cov qib siv dav tshaj plaws hauv kev tsim kho cov niaj hnub, siab -kev siv hluav taws xob zoo. Lub npe "T" txhais tau tias nws yog aseamless raj.
Nws qhov txiaj ntsig tseem ceeb yog nws qhov tshwj xeebcreep zog(tsis kam mus rau deformation nyob rau hauv ntev - lub sij hawm raug rau siab thiab kub) piv rau cov qib ua ntej xws li T22 (2.25Cr-1Mo).
Cov yam ntxwv tseem ceeb & qhov zoo
Siab -Tsub Muaj Zog:tuaj yeem ua haujlwm tsis tu ncua ntawm cov hlau kub txog li 625℃(1157℃F). Qhov no tso cai rau lub zog siab dua thiab qhov kub thiab txias, ua rau muaj zog cog kev ua haujlwm ntau dua.
Zoo heev Creep thiab Repture Strength:Nws lub microstructure ruaj khov los tiv thaiv deformation thiab tsis ua haujlwm ntev (100,{1}} teev) thaum muaj kev ntxhov siab thiab kub.
Zoo Oxidation & Corrosion Resistance:Cov ntsiab lus ntawm 9% Chromium muab kev tiv thaiv zoo dua rau chav oxidation thiab kub corrosion (sulfidation) dua li qis- alloy steels xws li T11, T12, thiab T22.
Zoo Thermal Fatigue Resistance:Nws tuaj yeem tiv taus cov kev ntxhov siab uas tshwm sim los ntawm cua sov thiab cua txias.
Weldability:Nws yog weldable, tab sis yuav tsum tau tswj nruj ntawm cov txheej txheem thiab tom qab-weld heat treatment (PWHT).
Tshuaj muaj pes tsawg leeg (ASTM A213 / A213M Txuj)
Kev sib xyaw ua ke tseem ceeb heev kom ua tiav cov khoom xav tau.
| Lub ntsiab | Kev sib xyaw (%) |
|---|---|
| Cov pa roj carbon (C) | 0.08 - 0.12 |
| Manganese (Mn) | 0.30 - 0.60 |
| Phosphorus (P) | 0.020 max |
| Sulfur (S) | 0.010 max |
| Silicon (Si) | 0.20 - 0.50 |
| Chromium (Cr) | 8.00 - 9.50 |
| Molybdenum (hli) | 0.85 - 1.05 |
| Vanadium (V) | 0.18 - 0.25 |
| Niobium (Nb) | 0.06 - 0.10 |
| Nickel (Ni) | 0.40 max |
| Aluminium (Al) | 0.02 max |
| Nitrogen (N) | 0.030 - 0.070 |
Vim li cas cov ntsiab lus no?
Cr & Mo:Muab cov tshuaj tiv thaiv kom muaj zog thiab tiv thaiv corrosion.
V & Nb (Cb):Ua kom zoo, ruaj khov carbides thiab carbonitrides uas muab cov yuam sijnag lossis daus reinforcingthiab inhibit dislocation txav ntawm qhov kub thiab txias.
N:Ua haujlwm nrog V thiab Nb los ua kom muaj zog carbonitrides thiab pab txhim kho microstructure.
Mechanical Properties (ASTM A213 / A213M Txuj)
| Khoom | Kev xav tau |
|---|---|
| Tensile zog | Ntau dua lossis sib npaug rau 585 MPa (85,000 psi) |
| Yield zog | Ntau dua lossis sib npaug rau 415 MPa (60,000 psi) |
| Elongation | Ntau dua lossis sib npaug li 20% (hauv 2 nti lossis 50mm) |
| Hardness | Tsawg dua lossis sib npaug li 250 HBW (Brinell) lossis 265 HV (Vickers) |
Metallurgy & Kev kho cua sov
Cov khoom zoo tshaj ntawm T91 yog qhov tshwm sim ncaj qha ntawm cov txheej txheem kho cua sov tshwj xeeb:
Normalizing:Rhaub rau qhov kub siab (kwv yees . 1040-1080}℃/ 1900-1975℃F) los tsim cov qauv austenite homogeneous thiab yaj cov ntsiab lus alloying.
Tempering:Txias sai sai (cua quenched) thiab tom qab ntawd rov ua kom qis dua (kwv yees . 730-780℃/ 1350-1435℃F). Qhov no tempers lub martensite thiab precipitates qhov zoo, ntxiv dag zog rau carbides thiab carbonitrides ntawm V, Nb, thiab Cr.
Qhov tshwm sim microstructure yogtempered martensite, uas yog tshwj xeeb muaj zog thiab ruaj khov ntawm qhov kub thiab txias.
Cov ntawv thov siv
SA-213 T91 kav yog siv nyob rau hauv lubcua sov seemntawm boilers thiab superheaters qhov kub thiab txias yog qhov hnyav tshaj plaws.
Superheater Tubes
Reheater Tubes
Phab ntsa Panels(hauv siab -cov dej num ntawm cov boilers siab heev)
Siab -Tub kub taub hau thiab kav dej(Txawm hais tias cov no feem ntau yog tsim los ntawm cov kav dej sib npaug,SA-335 P91)
Fabrication thiab Welding Considerations
Ua haujlwm nrog T91 yuav tsum tau saib xyuas tshwj xeeb:
Preheating:Yuav tsum tau tiv thaiv kom txhob txias tawg. Hom preheat yog 200-250℃(400-480℃F).
Welding Consumables:Yuav tsum siv cov khoom siv hluav taws xob sib xyaw ua ke (xws li ER90S-B9 rau TIG, E9015-B9 rau SMAW).
Tshaj tawm -Weld Heat Treatment (PWHT): Tseem ceeb heev.Yuav tsum tau ua nyob rau hauv ib tug tshwj xeeb kub ntau yam (feem ntau 730-760℃/ 1350-1400℃F) rau ib tug txaus lub sij hawm los kho cov microstructure thiab toughness nyob rau hauv lub tshav kub-cuam tshuam cheeb tsam (HAZ). Kev ua tsis tiav tuaj yeem ua rau ua tsis tiav ntxov.
Tswj Cooling:Tom qab vuam, cov khoom yuav tsum tau tso cai kom txias maj mam mus rau qhov kub thiab txias ua ntej PWHT.
Sib piv nrog Lwm Qib
vs. T22 (2.25Cr-1Mo):T91 muaj zog heev. Qhov no tso cai rau cov phab ntsa nyias nyias, txhim kho cov cua sov thiab txo cov thermal kev nyuab siab thiab qhov hnyav.
T92 / T911 vs.Cov no yog cov qib siab tshaj 9% Cr steels nrog qhov sib ntxiv ntawm Tungsten (W) thiab Boron (B), muab kev nkag siab ntau dua rau cov nroj tsuag siab tshaj plaws ultra-supercritical (USC). T91 yog qhov ua ntej ntawm cov qib no.
Lus Cim Tseem Ceeb ntawm "Carbon Steel" Classification
Thaum nws yog ib qho kev xa mus rau T91 ua "boiler steel," hu nws a"Carbon hlau"yog technically ib misnomer. Nws yog ibqis- hlau alloynrog rau qhov tseem ceeb ntawm cov ntsiab lus alloying (tag nrho tshaj 10%). Muaj tseeb carbon steels rau boilers (xws li SA-210 A1 / C) muaj cov ntsiab lus tsawg tsawg thiab siv rau qhov kub qis dua li cov phab ntsa dej thiab cov khoom siv nyiaj txiag.
Cov ntsiab lus
SA-213 T91 yog cov khoom siv hauv paus rau kev ua haujlwm siab - thermal zog tsim. Nws cov chemistry optimized thiab tswj kev kho cua sov muab ib qho kev sib xyaw ua ke ntawm qhov kub thiab txias, tsis muaj zog, thiab corrosion tsis kam rau nws cov chav kawm, ua rau nws lub workhorse alloy rau qhov tseem ceeb superheater thiab reheater tubing.
