Kev tswj cov purity ntawm molten hlau thaum lub sij hawm tsim Q890E-ib qho ultra- siab- zog, qis- kub toughness steel- yog qhov tseem ceeb tshaj plaws kev sib tw metallurgical. Cov impurities (S, P, O, N, H, thiab tsis yog-cov khoom siv hlau) yog cov yeeb ncuab tseem ceeb ntawm ob qho tib si toughness thiab weldability. Ua kom tau raws li qhov xav tau purity xav tau ntau yam -theem, nruj tswj cov txheej txheem ua kom zoo dua li cov txheej txheem steelmaking.
Ntawm no yog cov ncauj lus kom ntxaws txog kev tswj cov tswv yim ntawm txhua theem ntawm kev tsim khoom, feem ntau ua raws li txoj hauv kev: Hluav taws xob Arc Rauv (EAF) lossis Basic Oxygen Furnace (BOF) → Ladle Furnace (LF) Refining → Ruhrstahl-Heraeus (RH) lossis Nqus Oxygen Decarburization (VOD) tiv thaiv kev ntsuas.
1. Lub Hom Phiaj Tseem Ceeb ntawm Purity Control rau Q890E
Ultra-Low Sulfur (S) & Phosphorus (P): Tsawg dua lossis sib npaug li 0.005% (feem ntau Tsawg dua lossis sib npaug li 0.002%) kom ua kom tawv tawv thiab tiv thaiv kev kub ntxhov.
Ultra-Oxygen Tsawg (O) & Nitrogen (N): Feem ntau <20 ppm rau O, < 50 ppm rau N kom txo qis cov oxide / nitride suav nrog uas ua raws li cov neeg pib tawg.
Ultra-Low Hydrogen (H): < 1.5 ppm (feem ntau < 1 ppm) los tiv thaiv hydrogen-induced cracking (HIC) thiab flaking.
Kev Tswj Ntawm Kev Cuam Tshuam Cov Qauv: Hloov cov teeb meem, nkig inclusions (xws li, Al₂O₃ pawg) mus rau hauv me me, mos, thiab globular uas tsis tshua muaj kev puas tsuaj rau cov tawv nqaij.
2. Theem-los ntawm-Stage Control Strategy
Theem 1: Thawj Melting (EAF lossis BOF) - Pib Dephosphorization & Desulfurization
Tswj kom pom tseeb: Tshem tawm ntau P thiab S.
Txoj kev:
EAF: Siv ob -slag xyaum lossis eccentric hauv qab tapping (EBT) kom tshem tawm P- nplua nplua slag ntxov.
BOF: Optimize slag basicity (CaO/SiO₂ ratio) thiab oxygen blowing xyaum kom zoo P tshem tawm.
Kub Hlau Pretreatment: Rau BOF txoj kev, ua ntej-desulfurize thiab dephosphorize cov hlau kub ua ntej them.
Lub hom phiaj ntawm Kais: P <0.010%, S <0.010%.
Theem 2: Secondary Refining – The Heart of Purity Control
Qhov no yog qhov "ultra- huv" specification tiav.
Ladle Furnace (LF) Kev Kho Mob:
Muaj zog Desulfurization:
Tsim kom muaj - qhov yooj yim, txo cov slag (CaO-Al₂O₃ raws li CaF₂).
Siv argon nplawm hnyav kom ua kom cov slag-hloov sib cuag.
Txhaj tshuaj calcium hlau (Ca kev kho mob) kom ua tiav kev tswj cov kev tswj thiab ntxiv desulfurization. Calcium hloov kho nyuaj Al₂O₃ suav nrog rau hauv cov kua calcium aluminates (12CaO·7Al₂O₃), uas yog cov globular thiab tsis muaj teeb meem.
Deoxidation:
Siv kev sib xyaw ua ke ntawm txhuas (muaj zog deoxidizer) thiab lub tshuab nqus tsev degassing (cov kauj ruam tom ntej) kom ua tiav ultra- qib oxygen tsawg.
Kev tswj hwm ntawm Aluminium tua kom tswj tau qhov qis, zoo ib yam yaj Al cov ntsiab lus rau kev tswj cov qoob loo yam tsis muaj Al₂O₃ tsim.
Nqus Degassing (RH lossis VOD): Yuav tsum tau ua rau Q890E.
Degassing: Cov hlau yog ncig hauv qab lub tshuab nqus tsev siab (tsawg dua lossis sib npaug li 1 mbar). Qhov no tshem tawm:
Hydrogen (H): Rau <1.5ppm.
Nitrogen (N): mus rau qib qis (txawm tias N tshem tawm tsis muaj txiaj ntsig).
Oxygen (O): Ua kom cov pa roj carbon deoxidation ([C] + [O] → CO(g)), ntxiv cov pa oxygen kom tsis txhob muaj cov khoom sib xyaw.
Chemical Precision: Qhov kawg trim ntxiv ntawm microalloys (Nb, V, Ti, B) yog ua nyob rau hauv lub tshuab nqus tsev los tiv thaiv oxidation thiab ua kom muaj txiaj ntsig zoo.
Homogenization: Argon bubbling kom zoo meej uniformity ntawm kub thiab muaj pes tsawg leeg.
Kauj Ruam 3: Nruam Casting - Tiv Thaiv Qhov Ncauj
Lub hom phiaj yog los tiv thaiv reoxidation thiab slag entrapment.
Kev tiv thaiv huab cua: Siv argon shrouding los ntawm lub ladle mus rau tundish, thiab los ntawm tundish mus pwm, los tsim ib tug oxygen - txoj kev dawb.
Refractory Quality: Siv siab -zoo, yaig- cov ntaub ntawv tiv taus (xws li, magnesia lossis alumina-raws li) los tiv thaiv kev sib kis.
Tundish Metallurgy: Sib sib zog nqus tundish nrog ntws hloov pauv (weirs, dams) los txhawb kev suav nrog ntab thiab sib cais.
Pwm xyaum:
Electromagnetic Stirring (M-EMS): Txhim kho homogeneity thiab txo kev sib cais.
Pwm Flux: Siv qhov qis-viscosity, qis-reactivity flux optimized rau siab-Al steels kom nqus tau cov khoom seem uas tsis muaj kev cuam tshuam.
3. Cov txheej txheem tseem ceeb tswj kev yees & Sensors
Tiag -Tshem Tawm Sijhawm Txheej Txheem: Spark Optical Emission Spectrometry (OES) thiab Laser-Induced Breakdown Spectroscopy (LIBS) rau kev tawm tswv yim sai ntawm S, P, Al, thiab lwm yam.
Oxygen & Hydrogen Probes: Immersion- hom Celox lossis Hydrosteel sojntsuam ncaj qha, hauv -situ ntsuas ntawm yaj [O] thiab [H] hauv lub ladle.
Slag Detection Systems: EMAT (Electromagnetic Acoustic Transducer) lossis thermographic systems los tiv thaiv ladle slag nqa mus rau LF / RH.
Advanced Process Control (APC): Integrated computer model uas kwv yees thermodynamic equilibria, alloy ntxiv yields, thiab inclusion evolution, coj cov neeg txiav txim siab.
4. Inclusion Engineering
Rau Q890E, nws tsis yog tsuas yog cov pa oxygen xwb; Nws yog hais txog kev suav nrog morphology.
Calcium Treatment: Raws li tau hais, hloov pauv kev suav nrog. Lub hom phiaj yog Calcium-Aluminium piv uas ua kom cov kua dej sib xyaw ua ke ntawm qhov kub thiab txias.
Tsis txhob Macro-Inclusions: Kev tswj nruj ntawm slag nqa thiab refractory yaig yog qhov tseem ceeb. Ultrasonic Testing (UT) ntawm cov khoom kawg saib xyuas kev suav nrog bands.
Summary Table: Impurity Control rau Q890E
| impurity | Hom phiaj | Txoj Kev Tswj Thawj Coj | Secondary / Thaub qab txoj kev |
|---|---|---|---|
| Sulfur (S) | Tsawg dua lossis sib npaug li 0.002% | LF: Siab -basicity slag + Ar stirring + Ca kho. | Kub hlau pretreatment. |
| Phosphorus (P) | Tsawg dua lossis sib npaug li 0.005% | BOF / EAF: Slag tswj, ob chav slag. | Kub hlau dephosphorization. |
| Cov pa oxygen (O) | < 20 ppm | RH / VOD: Nqus carbon deoxidation. LF: Al tua nrog Ca hloov kho. | Kev tiv thaiv casting shrouding. |
| Hydrogen (H) | < 1.5 ppm | RH/VOD: Nqus degassing. | Khaws cov khoom raw kom qhuav. |
| Nitrogen (N) | < 50 ppm | Tiv thaiv huab cua ingress; Yog shielding. | Nqus degassing (cov nyhuv txwv). |
| suav nrog | Me me, globular, sparse | Ca kho rau morphology tswj. | Tundish flow tswj rau flotation. |
Xaus
Tswj lub purity ntawm Q890E molten steel yog ib tug symphony ntawm advanced theem nrab metallurgy. Nws nyob ntawm:
Sequential Refining: Ib qho LF + RH / VOD ua ke tsis yog -kev sib tham.
Active Chemistry Management: Siv slag chemistry, calcium txhaj, thiab lub tshuab nqus tsev aggressively tshem tawm thiab hloov impurities.
Tsis suav nrog: Tiv thaiv rov- kev sib kis thaum lub sij hawm casting nrog inert gas shrouding thiab huv si.
Tiag - Sijhawm Saib Xyuas: Sophisticated sensors thiab qauv rau kaw - voj tswj.
Qhov kev tswj hwm qib no yog qhov sib txawv ntawm cov txheej txheem steel ntau lawm los ntawm cov khoom tshwj xeeb steelmaking xav tau rau ultra-siab- zog, siab- qib toughness zoo li Q890E. Tus nqi thiab qhov nyuaj yog qhov ncaj ncees los ntawm kev ua tau zoo hauv cov ntawv thov tseem ceeb xws li offshore platforms, cov khoom siv mining hnyav, thiab cov tsheb tub rog siab heev.