ASTM A387 Qib 11 Chav Kawm 2 vs ASTM A387 Qib 22 Hlau
ASTM A387 Qib 11 Chav Kawm 2 yog 1.25% chromium, 0.5% molybdenum alloy steel phaj muab nyob rau hauv qhov normalized thiab tempered mob. Nws muaj qhov zoo siab - kub lub zog thiab oxidation tsis kam mus txog li 540℃(1000℃F), ua rau nws tsim nyog rau cov kev pab cuam loj me me hauv cov roj av refinery nkoj, fais fab boilers, thiab cov khoom raug hydrogen. Nws qhov txiaj ntsig tseem ceeb yog qhov muaj txiaj ntsig zoo ntawm kev ua tau zoo thiab tus nqi uas qhov kev tshaj tawm tag nrho -weld kev kho cua sov ntawm lub nkoj zaum kawg yog qhov ua tsis tau.
ASTM A387 Qib 22 Chav Kawm 2yog ib tug 2.25% chromium, 1% molybdenum alloy steel phaj kuj muab normalized thiab tempered. Nrog cov ntsiab lus chromium thiab molybdenum ntau dua, nws muab cov khoom zoo tshaj - qhov kub thiab txias zog, nkag siab, thiab tiv thaiv hydrogen nres ntawm qhov kub siab tshaj 540℃(1000℃F). Nws yog cov khoom ntawm kev xaiv rau cov kev pabcuam hnyav tshaj plaws hauv hydrocrackers, siab -siab reactors, thiab cov khoom siv fais fab tseem ceeb uas Qib 11 muaj peev xwm tshaj.
1. Chemical Composition: Qhov txawv ntawm Core
| Element | A387 Qib 11 (Class 2) | A387 Qib 22 (Class 2) |
|---|---|---|
| Chromium (Cr) | 1.00 – 1.50% | 2.00 – 2.50% |
| Molybdenum (hli) | 0.45 – 0.65% | 0.90 – 1.10% |
| Lub Npe | 1.25Cr-0.5Mo | 2.25Cr-1Mo |
Key Takeaway:Qib 22 muaj ntau dua Chromium thiab ze li ob npaug ntawm Molybdenum. Qhov no txhais ncaj qha mus rau qhov siab tshaj -kub kev ua haujlwm.
2. Cov khoom siv & kev ua haujlwm sib piv
| Khoom | A387 Qib 11 (Class 2) | A387 Qib 22 (Class 2) | Kev cuam tshuam |
|---|---|---|---|
| Siab -Tsev Muaj Zog | Zoo | Superior | Qib 22 muaj qhov tso cai siab dua qhov ntsuas kub siab tshaj ~ 450℃(840℃F) ib tus lej ASME. |
| Creep Resistance | Zoo | Zoo heev | Cov ntsiab lus Mo siab dua nyob rau qib 22 muab qhov zoo dua ntev dua -lub sij hawm tiv thaiv kev deformation nyob rau hauv kev ntxhov siab ntawm qhov kub siab. |
| Oxidation Resistance | Zoo (rau ~ 540℃/ 1000℃F) | Zoo dua (rau ~ 600℃/ 1110℃F) | Higher Cr tsim ib qho kev tiv thaiv ntau dua, tso cai rau kev siv ntawm cov hlau ntau dua. |
| Hydrogen Attack Resistance | Zoo rau kev pabcuam nruab nrab | Superior | Qib 22 yog tus qauv rau kev ua haujlwm siab -siab hydrogen kev pabcuam (xws li hydrocrackers). Nws siab dua Cr / Mo zoo dua tiv thaiv decarburization thiab methane blistering. |
| Toughness & Ductility | Zoo | Zoo (tab sis yuav tsum tau ceev faj ntxiv PWHT tswj) | Ob leeg yog tawv thaum tshav kub zoo- kho. Qib 22 yog qhov ua rau muaj kev kub ntxhov ntau dua yog tias txias maj mam mus txog 375-575℃ntau. |
| Weldability | Zoo, nrog tus qauv preheat / PWHT | Xav tau ntau dua | Qib 22 yuav tsum nruj tswj hwm ntawm preheat (feem ntau 200-250 degree), interpass kub, thiab PWHT vim muaj hardenability ntau dua. |
3. Kev kho cua sov (Class 2 rau ob qho tib si)
Ob leeg tau muab nkag rau hauv qhov Normalized thiab Tempered. Txawm li cas los xij, lawv cov kev kho cua sov tshwj xeeb txawv vim cov ntsiab lus alloy:
Qib 11:Hom tempering ntau ~ 650-720℃(1200-1325℃F).
Qib 22:Hom tempering ntau ~ 690-750℃(1275-1380℃F). Cov ntsiab lus alloy siab dua yuav tsum muaj qhov kub thiab txias dua kom ua tiav qhov zoo tshaj plaws ductility thiab toughness.
4. Daim Ntawv Thov: Qhov twg Txhua qhov tshwj xeeb
| A387 Qib 11 Chav Kawm 2 | A387 Qib 22 Chav Kawm 2 |
|---|---|
| • Nruab nrab-kub reactors (piv txwv li, catalytic hloov kho, qee yam hydrotreaters). • Fais fab nroj tsuag boilers (steam nruas, headers) rau subcritical units. • Thaum tshav kub kub exchangers thiab cov hlab ntsha nyob rau hauv tsawg dua hydrogen kev pab cuam. • Cov ntawv thov uas tus nqi -kev ua tau zoo yog qhov tseem ceeb thiab cov kev pab cuam nyob rau hauv nws cov kev txwv. |
• hnyav-cov kev pabcuam reactors (piv txwv li, siab-siab hydrocrackers, hydrodesulfurization units). • Siab-kub/siab- ntu siab ntawm cov tshuab hluav taws xob siab siab thiab cov tshuab ua kom sov. • Cov hlab ntsha tseem ceeb uas qhov siab tshaj plaws tiv thaiv hydrogen nres thiab nkag yog yuav tsum tau (ib API 941 "Nelson Curve"). • Petrochemical reactors nrog chemistry txhoj puab heev. |
5. Nqi & Fabrication xav txog
Tus nqi: Qib 22 kim dua vim nws cov ntsiab lus alloy siab dua.
Fabrication: Qib 22 yuav tsum muaj cov txheej txheem vuam nruj dua (WPS/PQR), ntau dua preheat, thiab feem ntau ntev dua PWHT lub sij hawm. Qhov kev pheej hmoo ntawm kev tawg yog ntau dua yog tias cov txheej txheem tsis ua raws li kev ua kom zoo.
1. Cov xwm txheej "Class 2" cuam tshuam li cas rau cov txheej txheem vuam rau A387 Qib 11?
Lo lus nug no tshawb txog qhov ua tau zoo ntawm kev siv cov khoom siv pre-tempered Class 2, tsom rau cov kev hloov kho tshwj xeeb uas xav tau rau preheat, interpass kub, thiab Post-Weld Heat Treatment (PWHT) piv rau Chav Kawm 1.
2. Dab tsi yog qhov tsis zoo ntawm kev qhia A387 Qib 11 Chav Kawm 2 dhau Chav Kawm 1?
Cov lus nug no tshawb xyuas qhov muaj peev xwm ua lag luam tawm -tawm, xws li tus nqi siab dua, tsis yooj yim rau kev tsim kub tom qab, lossis kev pheej hmoo ntawm cov khoom puas tsuaj yog tias tsis raug PWHT raug siv rau cov cua sov uas twb muaj lawm - cov phaj kho.
3. Nyob rau hauv daim ntawv thov tshwj xeeb twg yog A387 Qib 11 Chav Kawm 2 qhov yuav tsum tau ua lossis kev xaiv?
Lo lus nug no nrhiav kev txheeb xyuas cov xwm txheej engineering uas qhov siab dua li - xa lub zog thiab ua ntej - kho microstructure ntawm Chav Kawm 2 muab qhov txiaj ntsig tseem ceeb, xws li hauv kev kho cov phiaj xwm lossis rau cov khoom siv uas lub nkoj puv PWHT ua tsis tau.
4. Yuav tsum tswj hwm dab tsi thaum lub sij hawm PWHT ntawm cov khoom siv hauv chav kawm 2 los tiv thaiv kev kub ntxhov?
Lo lus nug no hais txog qhov kev pheej hmoo tseem ceeb: ua kom ntseeg tau tias qhov yuav tsum tau tshaj tawm -weld stress relief tsis txo qis cov txiaj ntsig thiab tensile lub zog ntawm lub hauv paus hlau hauv qab qhov tsawg kawg nkaus qhov tseem ceeb rau Chav Kawm 2.
5. Qhov cuam tshuam rau qhov hnyav ntawm Chav Kawm 2 piv rau Chav Kawm 1 li cas tom qab tsim kom raug?
Cov lus nug no sib piv cov kev pabcuam zaum kawg ntawm ob chav kawm, tshuaj xyuas seb cov kev tsim khoom sib txawv ua rau muaj qhov sib txawv tseem ceeb hauv kev puas tsuaj ntawm kev ua haujlwm kub.
Tag nrho cov specification thiab cov ntsiab lus muaj nyob rau ntawm kev thov. Cov ntaub ntawv saum toj no yog muab rau kev taw qhia nkaus xwb. Rau kev tsim tshwj xeeb thov hu rau peb cov neeg ua haujlwm muag khoom.
