ASTM A335 P22 Yeeb Nkab yog dab tsi
ASTM A335 P22 yog seamless ferritic alloy steel yeeb nkab qib nrog nominal muaj pes tsawg leeg ntawm 2-1/4% chromium thiab 1% molybdenum. Nws yog tsim nyob rau hauv A335 specification rau seamless yeeb nkab rau siab - kub kev pab cuam thiab tau siv rau ntau xyoo nyob rau hauv boilers, chav chav thiab refinery txheej txheem piping, uas yog vim li cas nws yog feem ntau piav raws li lub workhorse ntawm chromium-molybdenum tsev neeg.
Cov ntsiab lus chromium muab kev tiv thaiv rau oxidation thiab sulphur- bearing flue gas, thaum cov ntsiab lus molybdenum muab lub zog creep xav tau rau cov khoom uas nqa cov dej los yog cov txheej txheem kub hauv qab kev ntxhov siab. Qhov sib npaug ntawm ob lub ntsiab lus muab cov qib dav dav, cov ntaub ntawv ua haujlwm zoo ntawm cov pa roj carbon steel thiab qib siab chromium qib 9%.
Chemical Composition thiab Mechanical Requirements
Cov lus hauv qab no qhia txog cov kev txwv ntsuas kub thiab cov kev xav tau tensile siv los ntawm ASTM A335 rau Qib P22.
| Yam khoom | Kev xav tau |
|---|---|
| Cov pa roj carbon | 0.05-0.15% |
| Manganese | 0.30-0.60% |
| Phosphorus, max | 0.025% |
| Sulphur, max | 0.025% |
| Silicon, max | 0.50% |
| Chromium | 1.90-2.60% |
| Molybdenum | 0.87-1.13% |
| Tensile zog, min | 415 MPa rau |
| Yield zog, min | 205 MPa |
| Yam khoom | Seamless, kub tiav |
| Kev sim | Tensile, khoov, flattening thiab hydrostatic xeem siv rau qib no |
Raws li nrog rau lwm qib hauv qhov kev qhia tshwj xeeb, qhov tseem ceeb hauv cov lus yog qhov tsawg kawg nkaus rau kev lees paub es tsis yog tsim kev tso cai. Cov kws tsim qauv tsim qauv siv cov kev ntxhov siab uas tso cai rau qib los ntawm cov cuab yeej siv siab uas tswj hwm qhov project, uas tabulates qhov tseem ceeb uas poob thaum cov hlau kub nce thiab uas yog raws li qhov ntev - lub sij hawm nkag thiab tawg cov ntaub ntawv es tsis yog nyob rau hauv chav tsev kub tensile xeem ib leeg.
Kev siv hluav taws xob tsim hluav taws xob thiab kev ua haujlwm
Superheater thiab reheater platens thiab pendants, qhov twg chav mus txog nws qhov kawg kub ua ntej nkag mus rau lub turbine.
Cov kab tseem ceeb, cov kab kub reheat thiab cov headers uas sau thiab rov faib cov chav hauv lub boiler kob.
Refinery txheej txheem piping, cub rhaub rhaub coils thiab hloov kab tuav kub hydrocarbons.
Hydroprocessing thiab hloov kho chav nyob, qhov twg hydrogen ib feem siab thiab kub ob qho tib si ua rau ntawm cov yeeb nkab phab ntsa.
Thaum tshav kub kub exchanger plhaub thiab cov hlab ntsha siab nyob rau hauv nruab nrab thiab siab -tej dej kub.
Retrofit thiab lub neej txuas ntxiv ua haujlwm ntawm cov nroj tsuag uas twb muaj lawm, qhov twg P22 twb yog cov khoom siv.
Nyob rau hauv cov khoom siv siab tsim cov lej cov qib tseem nyob rau hauv daim ntawv teev cov lus tso cai rau kev ntxhov siab txog li 650 ° C. Kev xaiv tswv yim txawm li cas los xij txiav txim siab los ntawm kev lag luam ntau npaum li cov ntaub ntawv: qhov twg kub nce siab tshaj li 565 ° C, creep lub zog poob thiab cov neeg tsim khoom nce mus rau qib 9% chromium kom cov phab ntsa thickness nyob rau hauv qhov tsim nyog txwv.
Fabrication, Vuam thiab Kev kho cua sov
Vuam yuav tsum muaj cov txheej txheem tsim nyog, sib txuam chromium-molybdenum muab tub lim hlau thiab tswj cov cua sov nkag; qis-kev xyaum hydrogen yog qhov yuav tsum tau ua.
Preheat ua ntej thawj zaug dhau thiab kev saib xyuas qhov tsawg kawg nkaus interpass kub kom tsis txhob nyuaj, tawg rhiab cua sov- cuam tshuam thaj chaw cov qauv.
Ncej -weld cua sov kev kho mob rov ua kom tawv nqaij thiab txo qis kev ntxhov siab; Qhov kub thiab txias, tuav lub sijhawm thiab cua sov thiab cua txias ua raws li txoj cai kev tsim kho.
Kub dabtsi yog khoov thiab kub sib sau ua nyob rau hauv lub qhov rais tswj qhov kub thiab txias, ua raws li normalizing thiab tempering los yog los ntawm ib tug tag nrho ncej- kev kho cua sov raws li xav tau.
Cov pob qij txha sib txawv ntawm P22 thiab qis alloy lossis austenitic Cheebtsam xav tau lawv tus kheej cov txheej txheem tsim nyog vim tias cov cua sov- cuam tshuam thaj chaw thiab cov hlau vuam sib txawv ntawm txhua sab.
Kev soj ntsuam thiab Ntev -Lub Sij Hawm Kev Ncaj Ncees
Txheeb xyuas qhov ntsuas kub thiab ntsuas ntsuas qhov ntsuas ntawm daim ntawv pov thawj zeb tawm tsam cov kev qhia tshwj xeeb ua ntej tso tawm rau kev tsim khoom.
Tshawb xyuas qhov ntev, phab ntsa thickness thiab ncaj, txij li phab ntsa thickness tswj lub siab ntsuas ntawm cov kab tiav.
Tshawb xyuas cov voj voog ncig thiab cov kab ntev nrog cov uas tsis yog -kev puas tsuaj uas xav tau los ntawm tus qauv tsim.
Rau hauv -cov khoom siv pabcuam, npaj kev tshuaj xyuas ib ntus ntawm welds thiab siab- qhov chaw muaj kev ntxhov siab, vim tias kev puas tsuaj nkag mus thiab hom IV tawg qeeb thiab raug kuaj pom los ntawm kev rov ua dua lossis cov txheej txheem ultrasonic siab dua es tsis yog los ntawm kev kuaj pom.
Sau cov lej xov tooj cua sov thiab daim ntawv qhia vuam kom cov kev kho yav tom ntej tuaj yeem taug qab mus rau cov ntaub ntawv tsim khoom qub.
FAQ
Q: ASTM A335 P22 yog dab tsi?
Nws yog seamless ferritic alloy steel yeeb nkab qib nrog kwv yees li 2-1/4% chromium thiab 1% molybdenum, muab raws li A335 specification rau high-temperature kev pab cuam.
Q: Vim li cas P22 tau piav qhia tias yog qib workhorse?
Vim nws lub zog creep, oxidation tsis kam, weldability thiab tus nqi tau khaws cia nws nyob rau hauv kev pab rau ntau xyoo dhau los ntawm boilers, chav chav thiab refinery units thoob ntiaj teb.
Q: P22 tuaj yeem siv tau li cas?
Cov qib yog tabulated nyob rau hauv cov khoom siv siab tsim cov cai txog li 650 degrees C, tab sis cov tswv yim xaiv ib txwm hloov mus rau 9% chromium qib siab tshaj li ntawm 565 degrees C rau creep zog vim li cas.
Q: Puas yog P22 yeeb nkab xav tau kev tshaj tawm -weld cua sov kho?
Yog lawm. Tom qab-weld heat treatment yog xav tau rau cov phab ntsa thicknesses thiab cov kev pab cuam them los ntawm kev tsim cov cai, thiab nws yog ib qho tseem ceeb rau kev kho cov cua sov- cuam tshuam cheeb tsam toughness.
Q: P22 piv nrog 9% chromium qib li cas?
P22 yog pheej yig dua, yooj yim rau welding thiab txaus mus txog nws qhov kev txwv tsis pub nkag; 9% chromium qib xws li P91 thiab P92 tso cai rau cov cua kub ntau dua thiab cov phab ntsa nyias, ntawm cov khoom siv ntau dua thiab cov nqi tsim khoom.
Q: Dab tsi yuav tsum tau kuaj xyuas thaum xa khoom?
Qib thiab cua sov tooj, ntsuas kub, ntsuas tensile, qhov ntev, phab ntsa thickness thiab hydrostatic thiab tsis yog -cov ntaub ntawv ntsuas kev puas tsuaj.
