ASTM A671 EFW steel yeeb nkab

ASTM A671 - Txuj Specification rau Hluav Taws Xob Fusion Welded Steel Yeeb Nkab rau Atmospheric thiab Kub Kub
 

ASTM A671 yog tus qauv tsim los ntawm American Society for Testing and Materials (ASTM International). Cov txheej txheem no siv rau cov kav hlau steel uas tsim los ntawm covHluav taws xob fusion vuam (EFW)txheej txheem, tsuas yog siv nyob rau hauv lub siab hlab ntsha, piping systems thiab lwm yam tseem ceeb daim ntawv thov nyob rau hauv ib txwm kub thiab tsis kub ib puag ncig.

Scope ntawm kev siv:
Cov kav dej siab, lub tso tsheb hlau luam, thiab lwm yam. siv rau cov kev pabcuam kub qis lossis ib txwm siv, feem ntau siv hauv cov roj, roj, tshuaj thiab lwm yam lag luam.
Kev ua haujlwm kub yog feem ntau tsis tsawg dua -50℃F (-45 degree), nyob ntawm qib steel thiab cov kev xav tau ntawm kev ntsuas.

Cov qib sib txawv (xws li CL22) tau muab faib raws li cov txheej txheem tsim khoom, kev soj ntsuam xyuas thiab qib kev ntxhov siab, thiab muaj cov kev cai nruj ntawm kev vuam zoo, tsis yog - kuaj kev puas tsuaj, thiab lwm yam.

Specifications thiab cov ntaub ntawv:
Sab nraud txoj kab uas hla: Ntau dua los yog sib npaug rau 16 in.(406mm)
Phab ntsa thickness: Ntau dua los yog sib npaug rau 1/4 nyob rau hauv.(6.4mm)

Cov ntaub ntawv qib:
Cov txheej txheem suav nrog ntau cov pa roj carbon steel thiab qis alloy steel qib (xws li CL15, CL16, CL20, CL22, thiab lwm yam), thiab tus lej sawv cev rau qhov tsawg kawg nkaus yield zog (unit: ksi, piv txwv li txhiab phaus ib square inch).

Piv txwv li: CL20 txhais tau hais tias qhov tsawg kawg nkaus tawm lub zog yog 20 ksi (li 138 MPa).

A671 CC60 yog cov pa roj carbon ntau nrog cov ntsiab lus carbon, silicon thiab manganese. A671 CC65 thiab CC70 kuj yog cov pa roj carbon ntau, thaum A671 CD70 yog manganese silicon steel. Tus qauv A671 tseem suav nrog cov nickel steels, xws li A671 CF66 thiab CF71.

Tshuaj muaj pes tsawg leeg:

ASTM A671 steel yeeb nkab yog ua los ntawm cov hlab ntsha siab zoo steel phaj. Cov qib sib txawv muaj qhov sib txawv ntawm cov tshuaj muaj pes tsawg leeg, tab sis feem ntau suav nrog cov hauv qab no cov ntsiab lus tseem ceeb tswj:

Cov pa roj carbon (C): cuam tshuam rau lub zog thiab weldability, feem ntau tswj tau qis dua (xws li Tsawg dua lossis sib npaug li 0.23%).
Manganese (Mn): txhim kho lub zog thiab tawv, ntau yam 0.79-1.3%.
Silicon (Si): siv rau deoxidation, feem ntau 0.13-0.45%.
Sulfur (S) thiab phosphorus (P): nruj me ntsis (tsawg dua los yog sib npaug rau 0.035%) kom tsis txhob kub thiab txias brittleness.

Lwm cov ntsiab lus alloying (xws li Ni, Cr, Mo, V, thiab lwm yam): qee qib yuav raug ntxiv los txhim kho qhov kub thiab txias.

Mechanical zog:

Cov kav hlau hauv qab ASTM A671 tus qauv feem ntau yog ua los ntawm cov pa roj carbon -manganese- silicon steel cov ntaub ntawv nrog lub zog zoo thiab tawv. Rau cov khoom siv tshwj xeeb, xws li "GR.CC 60", "GR" sawv cev rau qib, "CC 60" qhia hom thiab qib zog ntawm cov khoom, thiab "60" tuaj yeem sawv cev lub zog ntawm cov khoom, uas yog kwv yees li 415 MPa.

Cov khoom siv kho tshuab ntawm ASTM A671 steel kav nyob ntawm qib (xws li CC60, Gr.65) thiab qeb kho cua sov (xws li CL22, CL32), feem ntau suav nrog:

Yield Strength (YS): Yam tsawg kawg nkaus yuav tsum tau (xws li Ntau dua lossis sib npaug li 220 MPa lossis siab dua).
Tensile Strength (TS): Feem ntau 415-555 MPa (xws li CC60).
Elongation: Ntau dua lossis sib npaug li 21% ( ntsuas qhov ductility ntawm cov khoom).
Impact toughness (qee qib yuav tsum tau ua kom tau raws li qhov qis- ntsuas qhov ntsuas kub, xws li Charpy V- ntsuas ntsuas ntawm -45℃).

Kev tsim khoom:
Cov hlau phaj yog tsim rau hauv ib puag ncig raj los ntawm J (Joggle)-C (Crimp)-O (Qhib)-E (Expand) multi- kauj ruam ua.
Cov yeeb nkab steel yog welded los ntawm cov txheej txheem hluav taws xob fusion vuam (EFW), thiab cov welds raug rau 100% kev kuaj hluav taws xob (RT) lossis lwm yam tsis yog -kev kuaj kev puas tsuaj (NDT) kom ntseeg tau tias qhov zoo.
Cov txheej txheem vuam yuav tsum nruj tswj tam sim no, qhov hluav taws xob, thiab vuam ceev kom ntseeg tau qhov zoo ntawm vuam.

Cov kev cai xeem:
Hydrostatic test: Txhua cov yeeb nkab steel yog raug rau kev ntsuas hydraulic.
Tsis yog -kev kuaj kev puas tsuaj (NDT): Cov welds raug kuaj los ntawm hluav taws xob lossis ultrasonic.
Impact test (optional): Nyob ntawm qhov yuav tsum tau muaj qhov kub thiab txias, yuav tsum tau muaj Charpy V-notch impact test.

Qhov txawv ntawm lwm cov qauv:
Cov qauv zoo sib xws xws li ASTM A672 (rau siab -siab thiab siab-kub hluav taws xob fusion welded kav), thaum ASTM A671 tsom ntau dua rau kev siv qis- kub.
Tsis zoo li cov qauv seamless yeeb nkab (xws li ASTM A106), A671 yog cov yeeb nkab welded, tab sis nws raug soj ntsuam nruj me ntsis kom ntseeg tau tias muaj zog.

Kev siv ntau:
Cryogenic liquefied gas (LNG) kav
Petroleum refining khoom
Cryogenic siab hlab ntsha hauv kev lag luam tshuaj