Q355NH thiab Q420NH weathering steel muaj zoo tib yam atmospheric corrosion kuj.-lawv core corrosion-resistant alloy element ranges (Cu, Cr, P) yog tag nrho raws li GB / T 4171 tus qauv, thiab qhov sib txawv ntawm ob qib yog cov khoom siv zog (yield / tensile), uas tsis cuam tshuam rau lawv lub peev xwm los tsim kev ruaj khov patina los yog tiv thaiv atmospheric corrosion.
Cov ntsiab lus tseem ceeb lees paub qhov sib npaug Corrosion Resistance
Zoo tib yam Corrosion-Resistant Alloy Formulation
Ob qib sib piv qhov yuav tsum tau ua tib yam rau cov ntsiab lus alloy uas ua rau kev ua haujlwm huab cua (GB / T 4171):
Tooj liab (Cu): 0.20-0.50% (initiates thiab densifies lub tiv thaiv patina)
Chromium (Cr): 0.30-1.20% (txhim kho patina tshuaj stability)
Phosphorus (P): 0.07-0.15% (txhim kho patina adhesion thiab uniformity)
Lwm cov ntsiab lus alloy (Si, Mn) sib txawv tsuas yog kho cov khoom siv dag zog, tsis yog corrosion kuj.
Tib Patina Tsim & Kev Tiv Thaiv Kev Ua Haujlwm
When exposed to outdoor atmospheres (urban, industrial, rural), both Q355NH and Q420NH form a dense, adherent reddish-brown patina (main component: -FeOOH) within 6–12 months. Cov patina no ua haujlwm zoo ib yam li lub cev / tshuaj tiv thaiv tiv thaiv dej, oxygen, thiab corrosive ions, ua rautib yam tsawg corrosion(≈0.01–0.03 hli / xyoo nyob rau hauv industrial cua, 6-10 npaug qis dua li cov pa roj carbon zoo tib yam).
Tsis Qib -Raws li kev tiv thaiv corrosion
GB / T 4171 faib cov huab cua steel los ntawmcorrosion kuj qib (piv txwv li, Qib C rau cov atmospheric corrosion)thiabqib zog (355/420=yam tsawg kawg nkaus yield zog hauv MPa)-ob qib poob rau hauv tib chav kawm tiv thaiv corrosion, nrog lub zog tsuas yog qhov sib txawv.
Vim li cas lub zog tsis cuam tshuam rau Corrosion Resistance
Lub zog sib txawv (Q355NH: Ntau dua lossis sib npaug rau 355 MPa yield zog; Q420NH: Ntau dua lossis sib npaug rau 420 MPa) yog ua tiav los ntawm kev khomanganese (Mn)thiabsilicon (Si)cov ntsiab lus (Q420NH muaj me ntsis siab dua Mn/Si rau cov khoom siv ntxiv dag zog), tsis yog los ntawm kev hloov cov corrosion-resistant Cu/Cr/P core. Cov zog no - txhim kho cov ntsiab lus tsis cuam tshuam nrog kev tsim patina lossis kev tiv thaiv kev ua haujlwm.
