A387 Qib 12 Chav Kawm 2 yog dab tsi?
ASTM A387 Qib 12 Chav Kawm 2yog ib tug normalized thiab tempered chromium-molybdenum (1.25Cr-}0.5Mo) alloy steel phaj tsim los rau high-temperature kev pab cuam nyob rau hauv welded siab hlab ntsha thiab boilers, muab siab zog dua Class 1 los ntawm nws cov kev kho cua sov.
Direct sib npaug:SA-387 Qib 12 Chav Kawm 2 hauv ASME Boiler thiab Pressure Vessel Code (BPVC). Nws Tus Txheej Txheem Kev Sau Npe (UNS) tus lej yog K11762.
Hauv qab no yog ib lub rooj ntawm feem ntau hais txog thoob ntiaj teb thiab kev lag luam sib npaug. Lus Cim Tseem Ceeb: Cov no yog cov qhab nia zoo sib xws lossis zoo sib xws; lawv tsis yog ib txwm tshuaj zoo ib yam thiab muaj cov cuab yeej cuab tam sib txawv. Tag nrho qhov sib npaug rau ib daim ntawv thov tshwj xeeb yuav tsum tau txheeb xyuas los ntawm tus kws tshaj lij.
| Standard / cheeb tsam | Kev Cai Sib Tw | Sau ntawv |
|---|---|---|
| ASME(USA) | SA-387 Gr.12 Cl.2 | Qhov sib npaug ncaj qha hauv BPVC, Tshooj II, Ntu A. Qhov no yog qhov tseem ceeb tshaj plaws rau kev tsim cov hlab ntsha hauv North America. |
| UNS(USA) | K11762 | Cov khoom siv tus lej. |
| EN / DIN(Tebchaws Europe) | 13CrMo4-5 (1.7335) | Ib qho sib npaug European heev, dav siv rau tib daim ntawv thov. Cov muaj pes tsawg leeg thiab cov khoom yog ze heev. |
| JIS(Nyiv) | SWV 420 | Japanese siab lub nkoj steel qib. Cov kev qhia tshwj xeeb yog zoo sib xws. |
| GB(Tuam Tshoj) | 15 CrMoR | Thawj Suav sib npaug siab lub nkoj phaj steel. "R" stands rau " φ " (container / nkoj). |
| Hom Lub Npe / Alloy Group | 1¼Cr-½ Molos yog1.25Cr-0.5Mo | Qhov no yog lub npe luv luv ntawm kev lag luam raws li nws cov nominal chromium thiab molybdenum cov ntsiab lus. |
Cov kev sib txawv tseem ceeb rau kev sib npaug:
Chav Kawm 2 vs. Chav Kawm 1: Thaum nrhiav qhov sib npaug, koj yuav tsum qhia Hoob 2. Chav Kawm 1 yog annealed thiab muaj zog qis dua. Feem ntau qhov sib npaug thoob ntiaj teb (xws li 13CrMo4-5) tau ua raws li qhov qub thiab tempered mob ntawm Chav Kawm 2.
Qhov xwm txheej yog qhov tseem ceeb: Cov khoom sib npaug tiag tiag yuav tsum tau muab rau hauv cov xwm txheej zoo li qub thiab tempered (N&T) kom phim cov khoom siv kho tshuab ntawm A387 Gr.12 Cl.2.
Daim ntawv thov Standard: Rau kev tsim lub coded siab hlab ntsha (xws li, rau ASME BPVC), koj yuav tsum siv cov ntaub ntawv uas yog tsim nyog ASME SA-387 ntawv pov thawj thiab cim, tsis hais txawv teb chaws xaiv.
Hauv cov ntsiab lus: Rau kev lag luam thoob ntiaj teb thiab kev yuav khoom, qhov sib npaug ncaj qha thiab tseem ceeb tshaj plaws yog SA-387 Gr.12 Cl.2 (ASME), 13CrMo4-5 (EN), thiab 15CrMoR (GB).
1. Dab tsi yog qhov kev tshaj tawm -weld heat treatment (PWHT) kub thiab tuav lub sij hawm rau A387 Gr.12 Cl.2?
Rau A387 Qib 12 Chav Kawm 2, qhov raug pom zoo Post-Weld Heat Treatment (PWHT lossis kev ntxhov siab) qhov kub thiab txias yog 1100℃F txog 1250℃F (595℃txog 675℃). Lub sij hawm tuav feem ntau yog tsawg kawg yog 1 teev ib nti (25 hli) ntawm tuab, nrog rau qhov tsawg kawg nkaus ntawm 1 teev tag nrho. Cov txheej txheem no yog ib qho tseem ceeb los txo cov kev ntxhov siab ntawm vuam, ua kom sov sov- thaj tsam cuam tshuam (HAZ), thiab rov ua kom muaj zog corrosion, ua kom muaj kev ncaj ncees ntawm cov khoom siv hluav taws xob siab.
2. Vim li cas qhov preheating yuav tsum tau ua ntej vuam A387 Gr.12 Cl.2 steel?
Preheating, feem ntau nyob rau hauv thaj tsam ntawm 300℃F mus rau 450℃F (150℃rau 230 degree), yog yuav tsum tau rau vuam A387 Qib 12 hoob 2 los tiv thaiv hydrogen -induced cracking (HIC), kuj hu ua txias cracking. Qhov no alloy lub hardenability yuav ua rau ib tug nkig microstructure nyob rau hauv lub weld cheeb tsam thaum txias ceev. Preheating slows tus nqi cua txias, tso cai rau hydrogen diffuse tawm thiab txo txoj kev pheej hmoo ntawm kev sib tsoo - martensite susceptible martensite, yog li ua kom lub suab, tsis xws luag - weld dawb.
3. Dab tsi yog qhov siab tshaj qhov kev pabcuam kub rau A387 Gr.12 Cl.2 daim hlau?
Qhov siab tshaj plaws tau pom zoo ua haujlwm kub kub rau ASTM A387 Qib 12 Chav Kawm 2 daim hlau feem ntaumus txog 1000℃F (540 degree). Ntawm qhov ntsuas kub siab no, cov ntsiab lus chromium muab kev tiv thaiv zoo rau oxidation (scaling) thiab corrosion, thaum molybdenum txhim kho lub zog thiab txo qis. Rau kev pabcuam saum toj no qhov kub thiab txias, qib nrog cov ntsiab lus chromium siab dua (zoo li Qib 11 lossis 22) feem ntau suav hais tias.
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.
