ASTM A572 H beam steel yog dab tsi thiab nws haum rau hauv toj roob hauv pes ntawm cov qauv hlau li cas?

A ASTM A572 yog ib qho tseem ceeb ntawm American technical standard, hu ua "Standard Specification for High-Strength Low-Alloy Columbium-}Vanadium Structural Steel," zoo meej curated los ntawm ASTM International. Nws qhov tseem ceeb yog nyob rau hauv kev muab cov tsev neeg ntawm cov qib steel uas muaj lub zog ntau dua li cov pa roj carbon me me (xws li A36), thaum tuav cov weldability zoo dua thiab tsim tau zoo dua piv rau siab heev - lub zog alloys. Qhov no yog ua tiav los ntawm cov microalloying meej, feem ntau nrogColumbium (Niobium, Cb) thiab/los yog Vanadium (V), tsis yog cia siab rau cov ntsiab lus carbon siab lossis kim alloying ntsiab xws li chromium lossis npib tsib xee. Cov ntsiab lus microalloying no pab txhawb cov nplej ua kom zoo dua qub thiab nag lossis daus ntxiv dag zog thaum lub sij hawm thermomechanical tswj dov txheej txheem, yielding ib tug nplua -grained microstructure uas muab ib tug zoo heev tshuav nyiaj li cas ntawm lub zog thiab toughness. Cov kev qhia tshwj xeeb npog cov phaj, dov cov duab (xws li H- kab teeb, I- kab teeb, thiab cov kab), thiab cov ntawv piling. Cov qhab nia raug xaiv los ntawm lawv qhov tsawg kawg nkaus yield zog nyob rau hauv kilopounds ib square inch (ksi), nrog rau feem ntau yog Qib 42, 50, 55, 60, thiab 65. Ntawm cov no, A572 Qib 50 (yield zog ntau dua los yog sib npaug rau 50 ksi / 345 Gradee sib npaug rau 60 yoj yoj) ksi / 415 MPa) yog cov neeg ua haujlwm rau kev ua haujlwm niaj hnub. Lawv ua hauj lwm raws li ib qho kev sib tw hauv nruab nrab, muab qhov hnyav hnyav -txuag kom zoo dua thiab nce load-cov kabmob muaj peev xwm tshaj A36 (36 ksi yield) yam tsis muaj venturing rau hauv cov khoom kim heev thiab vuam complex txuam nrog quenched thiab tempered steels zoo li A514. Lawv txoj kev loj hlob tau tsav los ntawm nruab nrab- xyoo pua 20th xav kom muaj txiaj ntsig zoo dua, sib dua, thiab siab dua cov qauv hauv skyscrapers, ntev- ncua txuas hniav, thiab cov chaw tsim khoom, ua rau cov kws tsim khoom tsim cov tswv cuab nrog txo cov ntu ntu ntu, yog li txuag cov khoom siv, nthuav qhov chaw siv tau, thiab ua kom yooj yim rau kev thauj mus los thiab txhim kho.