Thaum A572 Gr.50 thiab Gr.60 tau siv dav, rau W-shape H-beams hauv kev tsim kho hauv North America, ASTM A992 tau dhau los ua tus qauv de facto txij li thaum nws pib thaum xyoo 1990s. Kev nkag siab txog qhov sib txawv yog qhov tseem ceeb rau cov khoom tsim nyog.
Core sib piv:
| Feature | ASTM A572 Qib 50 | ASTM A992 (Fy{1}} KSI) | Engineering Implication |
|---|---|---|---|
| Scope | Dav: daim hlau, tag nrho cov duab (W, S, HP, C, L). | Nqaim: Rolled structural shapes (W-shapes) nkaus xwb. | A992 yog qhov ua tau zoo -raws li spec optimized rau ib yam khoom. |
| Yield zog (Fy) | 50 hli (min). | 50 hli (min). | Zoo tib yam tsim lub zog. |
| Tensile zog (Fu) | 65 hli (min). | 65 hli (min). | Zoo ib yam. |
| Yield-rau-Tensile Ratio (Fy/Fu) | Tsis Qhia. Nws tuaj yeem siab li 0.95, muab cov yas cia me me. | Qhov siab tshaj plaws ntawm 0.85. Guarantees Fu/Fy Ntau dua lossis sib npaug rau ~ 1.18. | A992 lub ntsiab kom zoo dua. Ua kom lub siab ruaj khov yas, qhov tseem ceeb rau kev ua haujlwm ntawm cov seismic ductile thiab qhov system redundancy. |
| Tshuaj muaj pes tsawg leeg | Kev txwv dav dav rau C, Mn, P, S, Si + Cb/V. | Tighter, kev txwv ntau dua. Tsawg max carbon (0.23% vs A572's 0.26% rau Gr.60 comp), qis S & P. | Txhim kho weldability, toughness, thiab sib xws. Tsim los rau kev ua haujlwm zoo hauv tsev. |
| Ntws Toughness | Tsis xav tau (tshwj tsis yog S5 teev). | Yuav tsum tau. Yam tsawg kawg Charpy V-Notch ntawm 20 ft-lbs ntawm 70℃F. | A992 lav lub hauv paus toughness rau tag nrho W-puab, txhim kho kev ruaj ntseg tawg. |
| Daim ntawv thov tseem ceeb | Cov choj, kev lag luam, daim hlau, tsis yog -cov duab tsim. | Tsev thav duab (kem, kab teeb). | A992 yog lub hom phiaj- tsim rau lub khw no. |
Vim li cas A992 Predominates rau Tsev H-Beams:
Guaranteed Ductility (Lub Fy / Fu Ratio): Qhov no yog qhov laj thawj tseem ceeb tshaj plaws. Hauv cov xwm txheej seismic, cov tswv cuab ntawm cov qauv tsim los ua kom muaj txiaj ntsig hauv qhov chaw tswj hwm (cov pob yas yas). Qhov siab Fy / Fu piv txhais tau hais tias cov hlau yields tab sis muaj tsawg heev strain hardening ua ntej ncav lub zog tensile, ua rau ib tug luv luv yas plateau thiab muaj peev xwm rau localized straining thiab puas. A992's 0.85 max ratio ua kom lub siab ntev, ruaj khov yas, tso cai rau qhov tseem ceeb inelastic deformation thiab lub zog dissipation- lub hauv paus ntawm kev tsim seismic niaj hnub ntawm AISC 341.
Yuav Tsum Toughness: Qhov yuav tsum tau 20 ft -lb CVN ntawm 70℃F muab ib qho kev txheeb xyuas qib ntawm kev puas tsuaj, muaj txiaj ntsig zoo rau txhua qhov qauv, tshwj xeeb tshaj yog nyob rau hauv huab cua txias lossis rau cov tswv cuab nruj.
Optimized Chemistry: Cov muaj pes tsawg leeg zoo txhim kho weldability thiab ua kom zoo ib yam khoom siv thoob plaws cov cua sov thiab cov mills sib txawv.
Kev lag luam Standardization: AISC tau txais A992 raws li cov ntaub ntawv nyiam nyob rau hauvKev Siv Hluav Taws Xob Hlau. Cov lej hauv tsev thiab qhov project specifications niaj hnub hu rau A992 rau W-cov duab. Qhov kev tsim qauv no yooj yim rau kev yuav khoom thiab ua kom cov khoom zoo sib xws - khoom zoo.
Thaum Yuav Siv A572 H-Beams Hloov:
Thaum Qib 60 Lub Zog Xav Tau: A992 tsuas yog Qib 50 xwb. Rau txhua kab lossis girders qhov twg lub zog siab dua ntawm A572 Gr.60 yog xav tau rau kev txuag hnyav, A572 tau teev tseg.
For Shapes Other than W-shapes: A992 tsis npog S-beams, HP pawg, channels, or angles. Cov no tau muab los ua A572 (lossis A36).
Rau Cov Phaj: Ua- nce girders, shear daim hlau, thiab cov khoom sib txuas ua los ntawm phaj yuav siv A572 Gr.50 phaj.
Hauv Cov Txuas Txuas lossis Tsis yog- Cov Qauv Tsim: Thaum A992 qee zaum siv, cov lus qhia tshwj xeeb feem ntau hu rau A572 lossis nws qhov sib npaug ncaj nraim, AASHTO M270 Qib 50.
Hauv cov ntsiab lus, A992 sawv cev rau kev hloov pauv thiab tshwj xeeb ntawm A572 lub tswv yim. Nws yuav siv qhov pov thawj siab -lub zog qis- alloy thev naus laus zis thiab ntxiv cov ntsiab lus tshwj xeeb, yuav tsum tau ua rau ductility thiab toughness uas yog qhov tseem ceeb rau kev ua haujlwm ntawm lub tsev thav duab hauv qab hnyav hnyav. Rau cov engineers tsim cov qauv tsim, A992 W- cov duab yog lub neej ntawd, kev xaiv zoo dua, thaum A572 tseem muaj ntau yam, dav dav -lub hom phiaj HSLA steel rau ntau yam khoom thiab kev siv.