A387 qib 22 yog dab tsi?
A387 Qib 22 Khoom siv
ASTM A387 Qib 22 yog chromium-molybdenum alloy steel phaj tshwj xeeb tsim rau welded siab hlab ntsha ua haujlwm ntawm qhov kub siab. Nws kuj yog feem ntau paub los ntawm nws cov alloy muaj pes tsawg leeg: 2¼ Chromium - 1 Molybdenum (2.25Cr-1Mo). Cov ntsiab lus alloy siab dua no txawv ntawm qib 11 ntau dua (1.25Cr-0.5Mo), muab kev ua tau zoo dua qub hauv kev pabcuam hnyav.
Mechanical Properties
|
Qib |
Thickness |
Yield zog |
Tensile zog |
Elongation hauv 2 "1) |
Kev txo qis ntawm cheeb tsam 2) |
|---|---|---|---|---|---|
|
Qib 22 Chav Kawm 1 |
0.185 - 3.60 |
30 |
60 - 85 |
18 |
40 |
|
Qib 22 Chav Kawm 2 |
0.185 - 3.60 |
45 |
75 - 100 |
18 |
40 |
Cov yam ntxwv tseem ceeb:
1.Composition & Heat Treatment Classes:
Chemistry: Nominal 2.25% Chromium, 1% Molybdenum. Cov chromium txhim kho oxidation thiab corrosion kuj, thaum molybdenum nce siab - kub lub zog thiab creep kuj.
Ob Chav Kawm: Nws muaj nyob rau hauv ob lub tshav kub- kho mob:
Chav Kawm 1: Muab nyob rau hauv qhov zoo li qub lossis Kev Nyuaj Siab -Txoj kev kho mob. Lub hom phiaj rau fabrications qhov twg lub nkoj ua tiav yuav ua tiav Post-Weld Heat Treatment (PWHT).
Chav Kawm 2: Muab nyob rau hauv qhov Normalized thiab Tempered (los yog quenched & Tempered). Siv thaum kawg lub nkoj tsis tuaj yeem ua kom sov tag nrho- kho, raws li nws tuaj txog nrog siab dua, ua ntej- tempered zog.
2.Superior High -Tsub Khoom:
Higher Allowable Stress: It has higher design strength (allowable stress values per ASME codes) at temperatures above approximately 450℃(840℃F) compared to lower-grade alloys.
Zoo heev Creep Resistance: Ua tau zoo nyob rau hauv lub sij hawm ntev - kev ntxhov siab ntawm qhov kub thiab txias.
Resistance to Hydrogen Attack: Nws qhov txiaj ntsig tseem ceeb yog kev ua tau zoo tshaj hauv kev ua haujlwm siab -siab hydrogen kev pabcuam, raws li qhia los ntawm nws txoj haujlwm ntawm Nelson Curve (API RP 941). Nws tiv taus hydrogen embrittlement thiab decarburization zoo dua qis dua Cr-Mo steels.
3.Fabrication Considerations:
Yuav tsum tau ceev faj preheating (feem ntau 200-250℃/ 400-480℃F) ua ntej vuam vim nws cov hardenability siab.
Yuav Tsum Tshaj Tawm -Weld Heat Treatment (PWHT) yog qhov tseem ceeb los txo cov kev ntxhov siab, ua kom sov sov- thaj tsam cuam tshuam, thiab ua tiav qhov zoo tshaj plaws toughness thiab corrosion kuj. Qhov kub ntawm PWHT feem ntau yog 690-750℃(1275-1380℃F).
Cov ntawv thov tseem ceeb:
A387 Qib 22 yog cov khoom siv ua haujlwm rau qhov xav tau tshaj plaws - kub thiab siab - cov hlab ntsha hauv siab:
Petroleum Refining: Cov reactors tseem ceeb hauv hydrocracking, hydrotreating, thiab catalytic hloov kho units.
Lub Hwj Chim Muaj Peev Xwm: Siab- ntu siab ntawm cov boilers, chav nruas, thiab cov khoom siv hluav taws xob rov qab los (HRSGs).
Tshuaj/Petrochemical: Reactors ua hauj lwm hauv hydrogen hnyav thiab siab -kub ib puag ncig.
Cov ntsiab lus:
Hauv qhov tseem ceeb, A387 Qib 22 (2.25Cr-1Mo) yog qhov siab -kev ua tau zoo alloy steel xaiv thaum muaj kev pabcuam- xws li kub, kub siab, thiab raug hydrogen- dhau lub peev xwm ntawm tus qauv chromium-molybdenum steels zoo li Qib 11 thiab qhov kev xaiv kawg ntawm Chav Kawm 11. Kev kho cua sov ntawm lub nkoj yog ua tau.
1. Vim li cas ib tug engineer yuav qhia A387 Qib 22 Chav Kawm 1 es tsis yog Chav Kawm 2 rau lub nkoj siab?
Cov lus nug no tsom mus rau cov qauv tsim thiab kev tsim cov logic tom qab xaiv qhov softer, normalized condition of Class 1, feem ntau yog rau cov khoom uas yuav tsum tau welding dav thiab tom qab tag nrho cov kev kho cua sov.
2. Dab tsi yog qhov tseem ceeb tshaj plaws - cov kauj ruam tsim khoom tsim nyog rau A387 Qib 22 Chav Kawm 1 kom ua tiav nws cov khoom xav tau?
Cov lus nug no qhia txog lub luag haujlwm tseem ceeb ntawm qhov yuav tsum tau ua Post-Cov txheej txheem Weld Heat Treatment (PWHT) uas hloov cov khoom siv hauv chav kawm 1 rau hauv lub nkoj nrog lub zog thiab tawv.
3. PWHT kub npaum li cas rau A387 Qib 22 Qib 1 txawv ntawm Qib 11 li cas?
Cov lus nug no tshawb txog cov txheej txheem vuam qhov sib txawv, vim tias cov ntsiab lus alloy siab dua ntawm Qib 22 yuav tsum muaj PWHT qhov kub thiab txias ntau dua los ua kom zoo rau lub microstructure.
4. Dab tsi yog qhov txiaj ntsig tseem ceeb ntawm kev siv A387 Qib 22 Chav Kawm 1 hauv kev pabcuam hydrogen hnyav?
Cov lus nug no tsom rau cov khoom siv tseem ceeb ntawm daim ntawv thov tsav tsheb, txuas nws 2.25Cr-1Mo chemistry rau nws qhov kev tiv thaiv zoo tshaj plaws rau kev kub siab hydrogen nres piv rau qis alloys.
5. Puas muaj kev pheej hmoo yog dab tsi yog A387 Qib 22 Chav Kawm 1 tsis muab PWHT zoo tom qab vuam?
Cov lus nug no hais txog qhov tseem ceeb ntawm kev nyab xeeb thiab kev txhawj xeeb zoo, tsom mus rau qhov tshwm sim ntawm kev tawm hauv ib qho nyuaj, nkig microstructure nyob rau hauv qhov vuam cua sov- thaj tsam cuam tshuam.
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.
