Nkag siab lub zog ntawm SA387 Qib 11 Chav Kawm 1 Steel Phaj
SA387 Qib 11 Chav Kawm 1 yog ASME / ASTM chromium-molybdenum alloy steel phaj, teev rau siab -kub siab cov hlab ntsha thiab boilers, muab cov corrosion zoo / oxidation tsis kam vim nws ~ 1% Chromium thiab ~ 0.5% Molybdenum cov ntsiab lus, nrog rau Chav Kawm 1 qhia txog qib qis tensile, roj siv thiab qib 2. Kev lag luam rau cov tso tsheb hlau luam thiab cov kav dej uas xav tau lub zog ntawm qhov kub thiab txias (H2S) ib puag ncig, muab kev txhim kho tensile zog, kub tsis kam, thiab tiv thaiv{10}} xeb.
Qhov "lub zog" ntawm SA387 Qib 11 Chav Kawm 1 yog ib lub tswv yim nuanced uas yuav tsum tau nkag siab nyob rau hauv cov ntsiab lus ntawm nws cov kev kho cua sov, txheej txheem fabrication, thiab lub xeev kev pab zaum kawg. Nws tsis yog ib qho khoom muaj nqis siab tshaj - tus nqi, tab sis qhov sib npaug tsim rau kev tsim khoom thiab hauv - kev ua haujlwm.
1. Raws li -Delivered (Annealed) Lub zog
Nyob rau hauv nws muab chav kawm 1 (Annealed), cov hlau yog nyob rau hauv nws softest, feem ntau ductile xeev.
Yield zog (Rp0.2): Ntau dua lossis sib npaug rau 205 MPa (30 ksi)
Tensile zog (Rm): 415 - 585 MPa (60 - 85 ksi)
Cov ntsiab lus tseem ceeb: Cov no yog qhov tsawg kawg nkaus qhov tseem ceeb. Lub zog tiag tiag yog txhob txwm ua rau qis kawg ntawm lub peev xwm alloy. Qhov no yog los ntawm kev tsim.
Vim li cas nws "tsis muaj zog" thaum xa khoom?
Annealing involves slow cooling from a high temperature, which produces a soft microstructure of ferrite and pearlite. This maximizes ductility (>22% elongation) thiab toughness ntawm tus nqi ntawm raw lub zog. Cov mob no yog xaiv rau formability.
2. Lub "Design Strength" - Lub luag hauj lwm ntawm Post-Weld Heat Treatment (PWHT)
Qhov no yog lub tswv yim tseem ceeb tshaj plaws. Raws li - xa lub zog tsis yog lub zog tsim.
Lub nkoj siab uas tsim los ntawm SA387 Gr.11 Cl.1 yuav tsum tau txais qhov kawg PWHT (Stress Relieving) tom qab tag nrho cov vuam thiab sib sau ua tiav.
Qhov no PWHT, feem ntau ua ntawm 620-690℃(1150-1275℃F), ua raws li lub voj voog tempering.
Cov txiaj ntsig: Cov khoom hloov pauv. Lub zog kawg ntawm cov khoom siv hauv kev pabcuam yuav siab dua li - xa cov txiaj ntsig annealed, nce mus txog (tab sis tsis ncav cuag) qib ntawm cov khoom qub thiab tempered (Class 2). Qhov tseeb kawg khoom nyob ntawm seb PWHT tsis.
3. Kev Sib Piv Zog: Chav Kawm 1 vs. Chav Kawm 2
Lub zog sib txawv ntawm cov chav kawm qhia qhov kev xaiv tsim:
| Khoom | SA387 Gr.11 Chav Kawm 1 (Annealed) | SA387 Gr.11 Chav Kawm 2 (N&T) |
|---|---|---|
| Yield zog (min) | 205 MPa (30 ksi) | 275 MPa (40 ksi) |
| Tensile zog | 415-585 MPa (60-85 ksi) | 485-620 MPa (70-90 ksi) |
| Tsim Lub Hom Phiaj | Optimized rau Formability | Optimized rau Raws li -Suplied Strength |
Chav Kawm 2 yog ~ 35% muaj zog nyob rau hauv lub zog tawm los raws li - muab. Chav Kawm 1 muab lub zog thawj zaug no rau kev yooj yim ntawm kev tsim.
4. Siab -Tub (Ceep) Strength
Rau siab - qhov kev pab kub (txog ~ 595℃/ 1100℃F), "lub zog" yog ntsuas raws li Creep Strength lossis Stress Rupture Strength.
Qhov 1.25% Chromium thiab 0.5% Molybdenum alloying yog qhov tseem ceeb ntawm no. Molybdenum tshwj xeeb tshaj yog txhim kho cov hlau lub zog ntawm qhov kub thiab txias los ntawm kev txo qis kev txav mus los.
Tseem ceeb: Qhov siab - qhov kub thiab txias zog yog zoo ib yam rau Chav Kawm 1 thiab Chav Kawm 2 tom qab ob leeg tau txais lawv cov kev kho cua sov uas tsim nyog. ASME Boiler thiab Pressure Vessel Code (Tshooj II, Ntu D) muab cov txiaj ntsig siab tshaj plaws uas tso cai rau ob chav kawm ntawm txhua qhov kub. Qhov no yog vim qhov kawg microstructure tom qab tsim nyog PWHT zoo ib yam.
Summary : Lub Hwj Chim Lub Zog ntawm Chav Kawm 1
Lub zog profile ntawm SA387 Qib 11 Chav Kawm 1 yog ob -theem txheej txheem:
Kauj Ruam 1 (Kev Tsim Khoom): Nws yog muab los ntawm kev txhob txwm "tsis muaj zog," ntau lub xeev kom tiv taus qhov mob khaub thuas hnyav heev (xws li, lub taub hau ntxuav, lub plhaub dov) tsis tawg. Nws lub zog ntawm no yog lub zog formability.
Theem 2 (Nyob rau hauv-Kev Pabcuam): Tom qab kev tsim khoom thiab qhov yuav tsum tau ua PWHT, cov khoom siv lub zog tau txhim kho. Nws qhov kawg tsim lub zog-tshwj xeeb tshaj yog nws qhov tseem ceeb siab -kub creep zog- tau paub meej thiab yog code- pom zoo rau kev tsim lub nkoj siab.
Yog li ntawd, kev nkag siab nws lub zog yuav tsum tau ua kom pom tseeb los ntawm daim ntawv pov thawj zeb qhov tseem ceeb mus rau qhov kawg, cua sov- kho mob ntawm cov khoom ua tiav lub nkoj. Nws qhov tseeb "lub zog" nyob rau hauv qhov sib xyaw ua ke ntawm cov ntaub ntawv zoo heev thiab txhim khu kev qha nce siab - qhov kub thiab txias tom qab kev kho cua sov.
1. Cov tshuaj muaj pes tsawg leeg ntawm A387 Qib 5 txawv li qib 11 lossis qib 12 li cas?
A387 Qib 5 yog ntau dua -chromium alloy steel, feem ntau muaj nyob ib ncig ntawm 5% chromium thiab 0.5% molybdenum. Qhov no tso nws nyob nruab nrab ntawm Qib 11 ntau dua (~ 1.25% Cr) thiab Qib 22 (~ 2.25% Cr), muab nws qhov zoo sib xws ntawm oxidation tsis kam thiab nce siab -qhov kub thiab txias piv rau qis dua- qib alloy, thaum muaj peev xwm ua tau tus nqi ntau dua -{3} kev pab cuam ntau dua li steel.
2. Dab tsi yog Qhov Kev Pab Cuam Tshaj Plaws Hauv Tsev Kawm Ntawv Qib Siab 2?
Lub hom phiaj tseem ceeb ntawm A387 Qib 5 Chav Kawm 2 yog nyob rau hauv nws qhov kev tiv thaiv oxidation zoo dua thiab muaj zog tuav ntau dua ntawm qhov kub thiab txias feem ntau yog li ntawm 540℃mus rau 600℃(1000℃F txog 1112℃F), tshaj qhov muaj peev xwm ntawm Qib 11 lossis 12. Qhov no ua rau nws tsim nyog rau cov khoom siv hauv catalytic furnacetro lwm qhov kev pabcuam hnyav, kev hloov pauv ntawm cov khoom siv hluav taws xob, scaling thiab creep yog kev txhawj xeeb tseem ceeb.
3. Dab tsi yog qhov tseem ceeb ntawm Vuam thiab Fabrication Considerations rau A387 Gr.5 Cl.2?
Vuam A387 Qib 5 Chav Kawm 2 yuav tsum muaj cov txheej txheem nruj vim nws cov ntsiab lus alloy siab dua. Nws xav tau qhov yuav tsum tau ua kom sov (feem ntau yog 175-250℃/ 350-480℃F) thiab nruj tswj qhov kub thiab txias los tiv thaiv qhov nyuaj, tawg-sensitive microstructures. Tsis tas li ntawd, qhov yuav tsum tau ua tom qab Weld Heat Treatment (PWHT) nyob rau hauv thaj tsam ntawm 675-730℃(1250-1350℃F) yog qhov tseem ceeb kom npau taws rau thaj tsam weld, txo kev ntxhov siab, thiab rov ua kom corrosion.
4. Dab tsi yog Tus Txheej Txheem Kev Kho Hniav Kub Rau A387 Qib 5 Chav Kawm 2 Phaj?
A387 Qib 5 Chav Kawm 2 daim hlau tau muab rau hauv cov xwm txheej zoo li qub thiab Tempered. Normalizing muaj cua sov saum toj no qhov kev hloov pauv thiab cua txias kom ua kom zoo dua cov qauv nplej, ua raws li tempering ntawm sub- kub tseem ceeb kom ua tiav qhov kev pom zoo ua ke ntawm lub zog thiab cov khoom siv tau teev tseg hauv tus qauv (feem ntau yog qhov tsawg kawg nkaus lub zog ntawm 310 MPa / 45 ksi).
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.
