Q420B yog ib qho qis- alloy, siab - lub zog steel qauv txhais los ntawm Suav teb chaws tus qauv GB/T 1591-2018 (Tsawg- alloy siab - lub zog steels). Nws sawv cev rau qib siab zog hauv tib tsev neeg raws li feem ntau siv Q355B thiab Q390B.
Ntawm no yog ib qho kev nthuav dav ntawm nws cov yam ntxwv:
1. Core Material Identity
Txuj: GB / T 1591-2018.
Qib Qib Decoding:
Q: Sawv rau Yield Strength.
420: Qhia qhov tsawg kawg nkaus yield zog (ReH) nyob rau hauv MPa rau cov khoom thinnest daim ntawv (thickness Tsawg dua los yog sib npaug rau 16 hli). Yog li, Q420B muaj qhov tsawg kawg nkaus tawm lub zog ntawm Ntau dua lossis sib npaug rau 420 MPa.
B: Sawv cev rau qib zoo, lav qhov cuam tshuam tshwj xeeb ntawm +20℃(Charpy V-notch Ntau dua lossis sib npaug rau 34 J).
2. Cov cuab yeej cuab tam tseem ceeb (Thickness-nyob ntawm)
Yield zog (ReH):
Ntau dua los yog sib npaug rau 420 MPa (rau thickness t Tsawg dua los yog sib npaug li 16 hli)
Txo cov phaj tuab (piv txwv li, Ntau dua lossis sib npaug rau 400 MPa rau 16 < t Tsawg dua lossis sib npaug 40 mm, Ntau dua lossis sib npaug rau 390 MPa rau 40 < t Tsawg dua lossis sib npaug 63 mm, ib GB / T 1591 Table 2).
Tensile zog (Rm): 520 - 680 MPa
Elongation (A): Ntau dua lossis sib npaug li 18% (rau t Tsawg dua lossis sib npaug rau 40mm, cov qauv ntev)
Impact Toughness: Guaranteed Charpy V-notch impact zog Ntau dua los yog sib npaug rau 34 J ntawm +20℃.
3. Tshuaj muaj pes tsawg leeg & kev siv zog
Q420B ua tiav nws lub zog siab dua los ntawm kev tsim qauv microalloying, uas yog nws tus yam ntxwv txhais:
Cov pa roj carbon tsawg (C): Tsawg dua lossis sib npaug li 0.20% - Ua kom zoo weldability thiab toughness.
Tswj Manganese (Mn): Tsawg dua lossis sib npaug li 1.70% - Muab cov tshuaj tiv thaiv kom muaj zog.
Cov ntsiab lus tseem ceeb Microalloying: Vanadium (V), Niobium (Nb), Titanium (Ti) yog txhob txwm ntxiv. Cov ntaub ntawv zoo carbonitride precipitates thaum tswj dov thiab txias, muab cov nag lossis daus muaj zog thiab ua kom cov nplej zoo dua. Qhov no yog thawj txoj hauv kev kom ua tiav nws lub zog 420 MPa yield zoo.
Strict Impurity Control: Tsawg Phosphorus (P Tsawg dua lossis sib npaug li 0.030%) thiab Sulfur (S Tsawg dua lossis sib npaug li 0.030%) kom ntseeg tau zoo toughness thiab weldability.
Cov pa roj carbon sib npaug (Ceq): Feem ntau yog li ntawm ~ 0.45% txog 0.52%. Thaum siab dua Q355B, nws tau ua tib zoo tswj kom sib npaug zog thiab weldability.
4. Cov ntawv thov tseem ceeb
Q420B yog siv rau hauv hnyav-lub luag haujlwm, qhov hnyav-sensitive, lossis loj- ncua cov qauv uas qis dua- lub zog steels tsis txaus lossis tsis muaj nqis:
Loj -Span Choj: Cov girders loj, arches, thiab cov khoom tseem ceeb.
High-Rise & Super-High-Rise Buildings: Core kem thiab hloov cov qauv hauv cov plag tsev qis.
Heavy Industrial Plants: Txhawb cov qauv rau ultra- cranes hnyav (piv txwv li, hauv steel mills, fais fab nroj tsuag).
Mining & Hydraulic Machinery: Booms, thav duab, thiab siab -cov khoom muaj zog.
Transmission Towers: Rau ntxiv - cov kab hluav taws xob siab hauv qhov xav tau ib puag ncig.
Offshore & Marine Structures: Modules thiab topside Cheebtsam (tsis yog-xav cheeb tsam).
5. Kev sib piv nrog Cov Ntsiab Hlau Qib
| Qib | Min Yield Strength (t Tsawg dua lossis sib npaug li 16mm) | Qhov txawv tseem ceeb vs. Q420B |
|---|---|---|
| Q355B | 355 MPa rau | Tsawg zog, zoo weldability. Q420B yog nws qhov kev hloov kho siab - zog. |
| Q390B | 390 MPa ua | Qib qis tam sim ntawd. Q420B siv cov lus tshaj tawm microalloying rau qhov ntxiv 30 MPa yield zog. |
| Q420B | 420 MPa rau | Lub hauv paus rau qib siab - lub zog steel qauv. Yuav tsum tau ceev faj welding. |
| ASTM A572 Gr 1. | 415 MPa (60 ksi) | Asmeskas ze - sib npaug. Me ntsis qis nominal yield tab sis siv nyob rau hauv tib daim ntawv thov. |
| S420NL / S420ML | 420 MPa rau | European sib npaug nrog lav qis -kub toughness. |
6. Kev txiav txim siab Fabrication tseem ceeb
Vuam: Vim nws lub zog ntau dua thiab microalloyed muaj pes tsawg leeg, vuam yuav tsum tau ua raws li cov txheej txheem nruj.
Yuav tsum muaj tsawg -hydroden xyaum.
Preheating yuav luag txhua zaus los tiv thaiv hydrogen -induced txias cracking.
Thaum tshav kub kub input yuav tsum tau tswj kom khaws HAZ toughness.
Txiav & Kev Tsim: Kub txiav (plasma, nplaim taws) yog tus qauv, tab sis cov npoo ntawm daim hlau tuab yuav xav tau kev sib tsoo yog siv rau kev qaug zog- daim ntawv thov tseem ceeb. Cold forming yuav tsum muaj zog ntau dua rau Q355B.
7. Cov yam ntxwv tseem ceeb
Rau cov ntawv thov tshwj xeeb, lwm cov qib zoo ntawm Q420 muaj:
Q420C/D/E: Rau qis- kev pabcuam kub, nrog rau kev cuam tshuam toughness guaranteed ntawm 0 degree, -20 degree, thiab -40 degree, feem.
Q420GJ: Siab-kev ua tau zoo ntawm cov qauv hlau nrog cov kev xav tau nruj dua ntawm kev ua kom tawv, lub zog sib xws, thiab qis qis dua - rau - tensile piv, siv hauv cov qauv seismic tseem ceeb.
Cov ntsiab lus
Q420B yog tus qauv Suav siab -lub zog, microalloyed structural steel nrog qhov tsawg kawg nkaus tawm lub zog ntawm 420 MPa thiab lav chav- kub toughness. Nws yog engineered rau qhov tseem ceeb, hnyav loaded lug qhov twg cov khoom hnyav los yog txo qhov loj yog qhov tseem ceeb. Nws siv yuav tsum tau siv cov txheej txheem vuam siab heev thiab kev tswj kev tsim khoom kom paub meej nws lub zog muaj peev xwm thaum tswj kev ua haujlwm zoo. Nws sawv cev rau lub ntsiab lus nkag mus rau hauv lub npe ntawm qib siab siab - lub zog steels feem ntau siv nyob rau hauv niaj hnub mega - tej yaam num.