ASTM A252 yog dab tsi?
ASTM A252 yog tus qauv los ntawm ASTM International uas npogseamless thiab welded steel yeeb nkab pawg. Cov kav dej no yog tsim los tsav mus rau hauv av los muab kev txhawb nqa rau cov qauv xws li cov tsev, txuas hniav, thiab cov phab ntsa tuav.
Ntsiab Lus:Cov kav dej ua rau tus qauv no yog npaj tshwj xeeb rau kev siv, tsis yog rau kev thauj cov dej hauv qab siab. Lawv muaj nuj nqis rau lawv lub zog siab thiab muaj peev xwm tiv taus lub zog loj heev thaum lub sij hawm pawg - tsav tsheb.
Vim li cas thiaj siv Steel Pipe Piles?
Siab Load-Bearing Capacity:Lawv tuaj yeem txhawb nqa hnyav ntsug (axial) loads.
Kev nkag mus los ntawm Hard Strata:Lawv lub zog tso cai rau lawv tsav los ntawm cov av ntom ntom thiab cov pob zeb tsis muaj zog kom ncav cuag cov khoom ruaj khov -cov txheej txheem.
Combined zog:Lawv tuaj yeem ua tiav nrog pob zeb (tsim ib qho "pob zeb-pile yeeb nkab") kom muaj zog dua compressive thiab buckling tsis kam.
Versatility:Muaj nyob rau hauv ntau yam diameters thiab phab ntsa thicknesses kom haum rau ntau yam kev xav tau.
Sib npaug Lightweight:Yooj yim rau lis thiab thauj piv rau lwm cov txheej txheem sib sib zog nqus.
ASTM A252 Qib
Tus qauv txhais tau peb qib raws li qhov muaj zog tawm los. Qib siab dua, cov hlau muaj zog dua.
| Qib | Yield zog (min.) | Tensile zog (min.) |
|---|---|---|
| Qib 1 | 30,000 psi (205 MPa) | 50,000 psi (345 MPa) |
| Qib 2 | 35,000 psi (240 MPa) | 60,000 psi (415 MPa) |
| Qib 3 | 45,000 psi (310 MPa) | 66,000 psi (455 MPa) |
Xaiv ib qib:
Qib 1:Siv rau cov khoom sib zog los yog qhov chaw tsav tsheb tsis xav tau.
Qib 2:Qib feem ntau tau teev tseg rau cov ntawv thov piling.
Qib 3:Siv rau tej yaam num uas xav tau lub zog siab tshaj plaws - rau - qhov hnyav piv, xws li cov qauv kev lag luam hnyav, qhov ntev tsis txhawb nqa, lossis cov haujlwm uas muaj kev tsav tsheb nyuaj heev.
Key Mechanical & Chemical Properties
1. Mechanical Properties (raws li cov lus saum toj no)
Yield zog:Qhov kev ntxhov siab uas cov khoom pib deform plastically. Qhov no yog qhov tseem ceeb rau kev tsim qauv.
Tensile zog:Qhov siab tshaj plaws ntawm cov khoom siv tuaj yeem tiv taus thaum ncab lossis rub ua ntej tawg.
2. Tshuaj muaj pes tsawg leeg
Tsis zoo li ntau lwm cov yeeb nkab steel specifications (xws li API 5L),ASTM A252 tsis qhia meej txog cov tshuaj muaj pes tsawg leeg. Cov cuab yeej yog ua tiav los ntawm kev ntsuas tshuab. Cov hlau feem ntau yog carbon steel, thiab cov chaw tsim khoom tswj cov chemistry kom ua tau raws li qhov xav tau ntawm cov khoom siv tshuab.
Kev tsim khoom
ASTM A252 yeeb nkab pawg tuaj yeem tsim tau raws li:
Seamless (SMLS):Tsim los ntawm piercing ib tug khoom billet ntawm steel. Tsis muaj weld seam. Feem ntau yog siv rau cov phab ntsa tuab lossis cov kab me me.
Welded:Ua los ntawm steel phaj los yog coil thiab ces welded raws seam. Feem ntau hom yog:
Electric Resistance Welded (ERW):Lub seam yog tsim los ntawm kev siv hluav taws xob tam sim no thiab siab.
Kev kuaj thiab tshuaj xyuas
Yuav kom ua tau zoo, cov kav dej yuav raug rau ntau qhov kev sim:
Flattening Test:Lub nplhaib ntawm cov yeeb nkab yog flattened mus rau ib qho kev ncua deb los xyuas qhov ductility thiab soundness, tshwj xeeb tshaj yog cov weld hauv ERW kav.
Khoov Test:Rau ERW cov kav dej, ib qho piv txwv hla lub vuam yog khoov los ua kom pom qhov vuam qhov ncaj ncees thiab ductility.
Hydrostatic Test (Yeem):Thaum tsis xav tau los ntawm tus qauv, nws feem ntau teev los ntawm tus neeg yuav khoom kom paub meej tias cov yeeb nkab xau -dawb thiab suab. Qhov no tsis yog rau kev ntsuas kev pabcuam siab tab sis rau kev ruaj ntseg zoo.
Dimensional soj ntsuam:Xyuas rau sab nraud txoj kab uas hla, phab ntsa thickness, thiab ncaj.
Kev tshuaj xyuas qhov muag:Cov yeeb nkab yog tshuaj xyuas qhov tsis xws luag.
Common Dimensions (NPS - Nominal Pipe Size)
ASTM A252 cov kav dej muaj nyob rau hauv ntau qhov ntau thiab tsawg. Feem ntau sab nraud diameters li ntawm txog10 nti (254 mm) txog 36 nti (914 mm). Phab ntsa tuab yog teev los ntawm tus neeg yuav khoom thiab feem ntau raug xa mus rau lub sijhawm (piv txwv li, Teem sijhawm 40, 80) lossis cov phab ntsa ncaj nraim hauv nti lossis millimeters.
Daim ntawv thov
Lub Hauv Paus Tsev:Rau skyscrapers, tsev kho mob, thiab cov tsev lag luam loj.
Choj Abutments thiab Piers:Txhawm rau txhawb nqa lub nra hnyav ntawm cov choj.
Marine Structures:Docks, wharves, thiab offshore platforms.
Retaining Phab ntsa:Raws li cov tub rog pawg hauv shoring systems.
Slope Stabilization:Txhawm rau tiv thaiv av.
Sib piv nrog Lwm Cov Qauv
Nws yog ib qho tseem ceeb kom tsis txhob cuam tshuam ASTM A252 nrog rau lwm cov qauv yeeb nkab:
| Txuj | Kev siv thawj zaug | Qhov txawv tseem ceeb |
|---|---|---|
| ASTM A252, ASTM A252 | Cov Txheej Txheem Txheej Txheem | Tsim los rau kev tsav tsheb thiab axial load bearing. |
| API 5L | Kev Thauj Mus Los | Tsim los nqa roj, roj, lossis dej nyob rau hauv siab. Cov tshuaj muaj zog nruj. |
| ASTM A500 1 | Tubing (kab, kab teeb) | Tsim los rau cov tswv cuab ntawm cov qauv tsim hauv cov tsev. Nws muaj qhov sib txawv ntawm qhov sib txawv. |
| ASTM A53 | General Purpose Pipe | Yuav siv tau rau cov kab ke ua ke lossis qis - cov kav dej siab. Tsis yog tsim los rau pawg tsav tsheb. |
Cov ntsiab lus
ASTM A252 carbon steel yeeb nkab pawgyog ib qho muaj zog, siab -lub hauv paus kev daws teeb meem. Nws specification yog nyob rau hauvmechanical kev ua tau zoo(yield thiab tensile lub zog) es tsis yog tshuaj lom neeg muaj pes tsawg leeg, ua rau nws muaj ntau yam thiab txhim khu kev qha xaiv rau kev sib sib zog nqus foundation project thoob ntiaj teb. Thaum qhia meej, engineers xaiv qhov tsim nyogQib (1, 2, lossis 3)thiab qhov ntev raws li cov av tej yam kev mob thiab structural loads ntawm qhov project.
