1. Cov ntsiab lus uas txhim kho qis - kub cuam tshuam todight
Npib tsib caug (ni): Qhov tseem ceeb tshaj plaws. Tsis pub dhau ntawm Q450NQR1 cov qauv txheej txheem (tsawg dua lossis sib npaug ntawm cov kab sib txuas me me, thiab cov roj qis - brittle transitt Kub "(DBTT). Cov ntsiab lus Ni siab dua (piv txwv li, 0.4-0.65%) tso cai rau tus qauv tswj hwm txawm tias brittle fracture thaum muaj kev cuam tshuam.
Manganese (mn): Hauv cov qauv txheem (1.00-1.60%), MN txhawb nqa cov hlau los ntawm kev tsim kom muaj kev nplua nuj, tawv ferrite nplej. Nws offsets tus brittleness tshwm sim los ntawm lwm cov ntsiab (piv txwv li, p) thiab ua kom pom tseeb cov khoom seem uas tsis tshua muaj kub.
2. Cov ntsiab lus uas txo qis - kub cuam tshuam tawv (xav tau kev tswj nruj (xav tau tswj nruj)
Phosphorus (p): Q450nqr1 yuav tsum P (0.07-0.15%) rau corrosion tsis kam, tab sis ntau dhau putegregates ntawm cov kab ke nplej (cov "kev sib txuas" tsis muaj zog "ntawm microstructure). Qhov kev cais tawm hardens fararies, txo qis dua lawv lub dbt {{5 thov ua cov steel nquag mus rau brittle backure ntawm tsawg kub. Yog li, p yuav tsum tau tswj hwm rau qis kawg ntawm nws cov qauv txheem (piv txwv li, 0.07-0.10%) kom sib npaug corrosion tsis kam thiab tawv.
Sulphur (s): Txwv rau tsawg dua lossis sib npaug rau 0.035% hauv Q450NQR1. S reacts nrog manganese los tsim cov mni mns suav, uas ua raws li "nrib pleb pib cov ntsiab lus" thaum muaj qhov cuam tshuam kub} kev cuam tshuam kub. Txawm tias cov nyiaj ntau me me ntawm s tuaj yeem delastically txo qis kev nruj los ntawm kev muab txoj hauv kev tawg kom sai.
3. Cov ntsiab lus uas tswj hwm microstructure
Silicon (si): Controlled at 0.15–0.50%. Si enhances oxidation resistance but can cause brittleness if overused (e.g., >0.50%). Ua kom SI hauv cov qauv txheej txheem kom nws tsis tsa lub DBTT, khaws cia qis- kub ductility.
Carbon (c): Txwv tsawg dua los yog sib npaug rau 0.18%. Cov ntsiab lus siab nce nce ntau npaum li cas ntawm cov partrigle loj heev hauv microstructure thiab txo cov ferrite (cov theem ductuc). Los ntawm kev tswj c rau qib qis, Q450NQQr1 tswj hwm ib qho nyuaj ferrite- Qhov tseem ceeb rau kev muaj kev cuam tshuam tsawg {}} kub cuam tshuam.
