Tsawg- qhov kub thiab txias (-20℃, -40 degree) ua rau muaj kev sib tw tseem ceeb rau Q235NH Corten Steel: raws li qhov kub thiab txias, cov khoom siv ductility txo qis, ua rau muaj kev pheej hmoo ntawm nkig puas thaum muaj kev cuam tshuam lossis kev thauj khoom. Rau cov dej num hauv cheeb tsam txias, qhia meej Q235NH qhov ntsuas kub qis yog qhov tseem ceeb rau kev nyab xeeb ntawm cov qauv. Puas yog Q235NH haum rau kev pabcuam ntawm -20℃lossis -40 degree? Raws li GB / T 4171 tus qauv, cov ntaub ntawv xeem cuam tshuam, thiab kev xyaum ua haujlwm, cov ntsiab lus tseem ceeb yog qhov tseeb:Q235NH yog marginally haum rau -20℃nrog kev tswj nruj, tab sis kiag li tsis haum rau -40℃; nws qhov kub-kub toughness yog tsis txaus los tiv thaiv brittle puas ntawm ultra-tsawg kub. Hauv qab no yog ib qho yooj yim, kev txiav txim siab tawg.
Cov ntsiab lus tseem ceeb: Tsawg-Tsuas Cwj Pwm Txhaum Cai
Steel lub toughness (muaj peev xwm nqus tau tej lub zog) poob sharply raws li qhov kub thiab txias poob qis dua qhov tseem ceeb. Rau Q235NH, qhov no yog tsav los ntawm cov qauv nplej thiab tshuaj muaj pes tsawg leeg:
Thaum qhov kub thiab txias, cov hlau lub atomic txav tau txo qis, ua rau nws tsis tuaj yeem deform plastically nyob rau hauv kev ntxhov siab- ua rau tam sim ntawd, tsis pom qhov tawg tawg es tsis txhob ductile dabtsi yog khoov.
Q235NH cov ntsiab lus qis carbon tsawg thiab yooj yim los tiv thaiv- cov ntsiab lus corrosion (Cu, Cr, P) tsis txhim kho qis- qhov kub thiab txias, tsis zoo li siab dua - qib steels nrog npib tsib xee (Ni) lossis ua kom zoo dua TMCP.
Q235NH Kev ua tau zoo ntawm Cov Cuab Yeej Tseem Ceeb
Q235NH qhov tsim nyog sib txawv ntawm -20℃thiab -40 degree, raws li Charpy V-notch cuam tshuam lub zog xav tau (GB/T 4171):
1. Ntawm -20 degree: Marginal Suitability nrog nruj tswj
Impact Zog Performance: Q235NH's minimum Charpy V-notch impact energy at -20℃ is 27J (per GB/T 4171), just meeting the threshold for non-brittle fracture. However, this value drops to 20-25J in thick plates (>25mm) vim grain coarsening.
Tej yam uas siv tau: Tsuas yog haum rau tsis yog -load-cov kabmob lossis qis- dynamic- thauj khoom (piv txwv li, hniav cladding, lub teeb guardrails) nyob rau hauv cheeb tsam nrog luv luv -lub sij hawm -20℃raug (tsis ntev ultra-txias spells).
Tsim nyog tswj: Siv cov ntawv nyias nyias (tsawg dua lossis sib npaug li 20mm), txais yuav qis - hydrogen vuam, thiab tsis txhob muaj kev ntxhov siab (xws li cov ces kaum ntse) kom txo tau kev puas tsuaj.
2. Thaum -40 degree: Tsis haum rau txhua qhov kev pabcuam
Impact Energy Deficit: Ntawm -40 degree, Q235NH qhov cuam tshuam lub zog poob rau<15J-far below the 27J threshold. This guarantees brittle fracture under even minor impact or static load.
Kev piav qhia Risk: Ntev ntev -40℃exacerbates grain coarsening thiab residual stress, ua rau cov hlau tsis tshua muaj nkig. Tsis muaj kev ua haujlwm lossis kev tswj hwm kev ntsuas tuaj yeem ua rau nws qhov hnyav mus rau qib kev nyab xeeb.
Txoj Kev Xav Tau: Rau -40℃kev pabcuam, hloov mus rau qib siab Corten Steels (piv txwv li, S355K2W, Q355NH) nrog -40℃cuam tshuam lub zog Ntau dua lossis sib npaug rau 27J.
Daim Ntawv Qhia Txog Kev Siv Tau Zoo rau Thaj Chaw Txias
Txhawm rau zam qhov qis - qhov kub tsis ua haujlwm thaum siv Q235NH, ua raws li cov cai no:
Temperature Ciam teb: Txwv Q235NH rau ib puag ncig nrog qhov kub thiab txias tsawg tshaj li lossis sib npaug rau -15℃. Rau -15℃txog -20 degree, tsuas yog siv cov ntawv nyias nyias (tsawg dua lossis sib npaug li 20mm) thiab ua qhov kev ntsuas cuam tshuam ntxiv.
Kev txwv kev txwv: Tsis txhob siv Q235NH rau kev thauj khoom -cov kabmob (piv txwv li, choj girders, kev txhawb nqa thav duab) nyob rau hauv qhov kub thiab txias tsawg dua lossis sib npaug rau -20℃-brittle fracture tuaj yeem ua rau cov qauv tawg.
Vuam & Kev Ua Haujlwm: Preheat plates >16mm rau 80-120℃ua ntej vuam; tsis txhob txias dabtsi yog khoov ntawm qhov kub tsawg dua lossis sib npaug li 0℃los tiv thaiv microcracks.
Kev sib piv nrog qis-Tub kub Resistant Corten Steels
Rau tej yaam num uas yuav tsum tau qis - qhov kub thiab txias kev pab cuam, Q235NH yog outperformed los ntawm cov qib optimized rau toughness:
S355K2W: Haum rau -40 degree, nrog rau qhov cuam tshuam tsawg kawg nkaus Lub zog Ntau dua lossis sib npaug rau 27J; zoo tagnrho rau txias - cheeb tsam load-bearing qauv tab sis 20-30% kim dua.
qw 355n: Suav sib npaug rau S355K2W, haum rau -20℃rau -40 degree, nrog ntau zog yield zog (355MPa) thiab toughness tshaj Q235NH.
Hauv cov ntsiab lus, Q235NH Corten Steel tsis yog qhov kev xaiv txhim khu kev qha rau qis - qhov kev pabcuam kub. Nws tuaj yeem siv tau marginally ntawm -20℃rau tsis yog- tseem ceeb nyias- phaj Cheebtsam nrog kev tswj nruj, tab sis nws tsis tsim nyog rau -40℃. Rau cov dej txias-cov haujlwm hauv cheeb tsam, ua qhov tseem ceeb rau qib siab Corten Steels nrog cov pov thawj qis-kub toughness los xyuas kom muaj kev nyab xeeb ntawm cov qauv.
