Calcium silicon alloysyog cov khoom sib xyaw ua ke ntawm silicon (Si) thiab calcium (Ca), feem ntau muaj 28% -35% Ca, 55% -65% Si, nrog rau qhov seem yog hlau thiab me me ntawm impurities.
Qhov kev sib xyaw ua ke ntawm ob lub ntsiab lus no tsis txhais tau tias yog kev sib tsoo, tab sis ua tib zoo tsim "golden pairing" los ntawm metallurgists:
| Cov ntsiab lus | Qhov tsis zoo ntawm kev siv nws ib leeg | Qhov zoo ntawm kev sib xyaw |
| Calcium (Ca) | Tsawg kub taw tes (1482 degree), muaj zog vaporization ntawm molten steel kub, tsis tshua muaj yield, nyuaj rau tswj. | Silicon, ua raws li "cov khoom thauj khoom," txo qis qhov vapor siab ntawm calcium, tso cai rau nws kom yaj ruaj khov hauv cov hlau molten. |
| Silicon (Si) | Nruab nrab deoxidation muaj peev xwm; tsis tuaj yeem ua tiav deoxidation sib sib zog nqus thaum siv ib leeg. | Ua haujlwm synergistically nrog calcium, nws thawj zaug tsim cov kev mob zoo rau calcium thaum pib deoxidation, nce deoxidation efficiency los ntawm 30% -40%. |
Cov ntsiab lus tseem ceeb:Lub xub ntiag ntawm silicon tso cai rau calcium kom yaj "tsim" nyob rau hauv molten steel, es tsis txhob instantly vaporizing thiab khiav. Qhov no yog lub hauv paus thev naus laus zis rau CaSi alloys los ua lub luag haujlwm dual.
Vim li cas ho xav txog qhov kev txiav txim ntawm deoxidation thiab desulfurization?
Hauv ladle refining txheej txheem, silicon calcium alloy (SiCa) yog hailed li "universal refining agent." Nws tuaj yeem ua tiav ib txhij ua deoxidation, desulfurization, thiab kev hloov pauv hauv kev suav nrog, ua rau nws yog ib qho tseem ceeb ntawm cov khoom siv rau kev tsim cov hlau purity siab. Ntxiv tsuas yog 0.2%-0.5% ib tuj ntawm steel yog txaus rau kev sib sib zog nqus refining, ua rau nws yog ib tug tseem ceeb auxiliary khoom nyob rau hauv zus tau tej cov mid- mus rau -high-end steel.
Txawm li cas los xij, cov lus nug tseem ceeb tau muaj teeb meem tsis tu ncua ntawm -cov kws tsim khoom thiab cov txheej txheem tsim: thaum calcium silicon alloy ntxiv rau cov hlau molten, puas deoxidation thiab desulfurization tshwm sim ib txhij, lossis ua ntu zus? Yog qhov kawg, qhov twg tshwm sim thawj zaug?
Cov lus teb rau lo lus nug no ncaj qha txiav txim siab:
Lub sijhawm ntxiv:Nws puas yuav tsum tau ntxiv rau hauv cov theem ntxov lossis lig ntawm kev kho kom zoo?
Txoj kev ntxiv:Nws puas yuav tsum tau ntxiv tag nrho ib zaug lossis hauv cov khoom siv?
Tus nqi -effectiveness:Yuav ua li cas kom siv calcium ntau tshaj plaws?
Leej twg cov tshuaj tiv thaiv yog "kho"?
1. Nyob rau hauv molten steel, calcium koom nyob rau hauv cov nram no tseem ceeb tshwm sim ib txhij:
Cov tshuaj tiv thaiv deoxidation
| Hom tshuaj tiv thaiv | Kev sib npaug tshuaj tiv thaiv | Kev piav qhia |
| Basic deoxidation ntawm silicon |
Si + 2FeO → SiO₂ + 2Fe |
Cov txheej txheem no tshwm sim spontaneously nyob rau hauv molten steel ntawm 1500-1600 degree. SiO₂ has a low density and easily floats to form slag. |
| Txhim kho deoxidation ntawm calcium |
2 Ca + O₂ → 2CaO |
Calcium muaj zog affinity rau oxygen dua silicon thiab txhuas, thiab tuaj yeem tshem tawm cov pa seem ntawm cov hlau molten. |
| Inclusion denaturation |
Ca + Al₂O₃ → CaO·Al₂O₃ |
Nws hloov nkig Al₂O₃ mus rau qis- melting-point kua calcium aluminate. |
Cov tshuaj tiv thaiv desulfurization
| Hom tshuaj tiv thaiv | Kev sib npaug tshuaj tiv thaiv | Kev piav qhia |
| Calcium{0}}dominated desulfurization |
CaS + FeS → CaS + Fe |
CaS muaj qhov melting point ntawm 2450℃thiab yuav luag insoluble nyob rau hauv molten hlau, ntab li khoom hais. |
| Silicon{0}} pab desulfurization |
Si + 2FeO → SiO₂ + 2Fe |
Nws txo cov pa oxygen cov ntsiab lus ntawm cov hlau molten, tsim kom muaj qhov chaw txo qis rau desulfurization thiab tiv thaiv kev tsim ntawm CaSO₄. |
2. Hauv metallurgical thermodynamics, qhov tsis zoo ntawm Gibbs dawb lub zog hloov pauv (ΔG) ntawm cov tshuaj tiv thaiv, qhov muaj zog dua qhov kev xav ntawm cov tshuaj tiv thaiv, thiab qhov "kho" ntau dua.
Calcium's Reaction affinity Order:
Calcium cov tshuaj tiv thaiv nrog oxygen: ΔG yog qhov tsis zoo; ntawm steelmaking kub (1600 degree), calcium muaj ib tug heev muaj zog affinity rau oxygen.
Calcium cov tshuaj tiv thaiv nrog sulfur: ΔG kuj tsis zoo, tab sis tsawg dua qhov tsis zoo ntawm calcium - cov tshuaj tiv thaiv oxygen.
Xaus:Los ntawm qhov kev xav ntawm thermodynamic nkaus xwb, calcium nyiam tshaj tawm nrog oxygen, thiab tom qab ntawd nrog leej faj.
3. Cov ntsiab lus tseem ceeb: Oxygen's "qhov tseem ceeb tshaj plaws"
Cov kev tshawb fawb pom tau hais tias desulfurization tsuas yog tshwm sim ntawm qhov loj me thaum cov pa oxygen hauv cov hlau molten txo mus rau qee theem:
Thaum cov pa oxygen pib tsawg dua lossis sib npaug li 50ppm, tus nqi desulfurization yog 25% siab dua thaum cov ntsiab lus oxygen yog 80-100ppm. Silicon lub luag haujlwm deoxidation yog qhov tseem ceeb hauv cov txheej txheem no, tsim kom muaj qhov tsim nyog txo qhov chaw rau cov tshuaj tiv thaiv calcium-sulfur.
Kev sib piv ntawm Deoxidation thiab Desulfurization teebmeem
1 Quantitative Data ntawm Deoxidation nyhuv
Raws li kev xyaum ua lag luam txheeb cais, cov nyhuv deoxidation ntawm siliconcalcium alloys yog ze rau cov qib steel thiab cov nyiaj ntxiv:
| Qib Steel | CaSi ntxiv | Cov ntsiab lus oxygen pib (ppm) | Oxygen ntsiab lus tom qab refining (ppm) | Deoxidation efficiency |
| Plain carbon hlau (Q235) |
0.2%-0.3% |
80-100 |
40-50 |
45%-60% |
| Tsawg Alloy Siab -Lub zog hlau (Q355) |
0.3%-0.4% |
90-110 |
35-45 |
55%-68% |
| Stainless hlau (304) |
0.4%-0.5% |
100-120 |
25-35 |
65%-79% |
| Alloy Steel Qauv (40Cr) |
0.3%-0.4% |
85-105 |
30-40 |
58%-71% |
2 Quantitative Data ntawm Desulfurization nyhuv
Cov teebmeem ntawm cov tshuaj tiv thaiv desulfurization tau ua ib txhij yog raws li hauv qab no:
| Qib Steel | CaSi ntxiv | Initial sulfur ntsiab lus (%) | Cov ntsiab lus sulfur tom qab refining (%) | Desulfurization efficiency | Core tus nqi |
| Plain carbon hlau (Q235) |
0.2%-0.3% |
0.03-0.05 |
0.015-0.025 |
30%-50% |
Tsis txhob kub brittleness |
| Tsawg Alloy High Strength Steel (Q355) |
0.3%-0.4% |
0.02-0.04 |
0.008-0.015 |
55%-70% |
Txhim kho weldability |
| Stainless hlau (304) |
0.4%-0.5% |
0.015-0.03 |
0.003-0.008 |
70%-85% |
Txhim kho corrosion kuj |
| Hnav-Resistant Steel (NM450) |
0.3%-0.4% |
0.02-0.04 |
0.006-0.012 |
65%-80% |
Txhim kho hnav tsis kam |
3 Deep Desulfurization Muaj peev xwm
Rau siab - qib steel, siliconcalcium alloys tuaj yeem ua tiav desulfurization tob:
| Txheej txheem Scenarios | CaSi ntxiv | Refining tej yam kev mob | Cov ntsiab lus sulfur tom qab desulfurization | Desulfurization efficiency |
| Cov niaj hnub Ntxiv |
0.1%-0.3% |
- |
<0.01% |
80%-90% |
| Siab -End Steel Refining |
0.3%-0.5% |
LF rauv refining |
<0.005% |
Ntau dua lossis sib npaug li 93% |
| Nruam Casting Protective Casting |
0.05%-0.1% |
Pub ceev 3-5m / s |
<0.003% |
Ultra- tus qauv qis sulfur steel |
Kev nkag siab tseem ceeb:Muab piv rau ob lub rooj qhia tias, ntawm tib qhov ntau npaum li cas, cov tshuaj tiv thaiv deoxidation tshwm sim ua ntej thiab sai dua, thiab cov deoxidation efficiency feem ntau nce mus txog qib siab ua ntej cov tshuaj tiv thaiv desulfurization pib. Qhov no lees paub qhov kev txiav txim ntawm qhov ntsuas kub ntawm deoxidation ua ntej tshaj desulfurization.
Cov lus teb tau tshwm sim: Qhov twg tshwm sim thawj zaug, deoxygenation lossis desulfurization?
Los ntawm cov tshuaj tiv thaiv, deoxygenation tshwm sim ua ntej desulfurization.
| Sib piv Dimensions | Cov tshuaj tiv thaiv deoxygenation | Cov tshuaj tiv thaiv desulfurization |
| Thermodynamic Tendency | Calcium muaj kev sib raug zoo rau cov pa oxygen, ua rau muaj qhov tsis zoo ΔG ntau dua | Secondary affinity |
| Sijhawm Sequence | Nws tshwm sim thoob plaws hauv tag nrho cov txheej txheem, tab sis yog qhov tseem ceeb hauv cov theem pib | Active nyob rau hauv nruab nrab theem, yuav tsum tau oxygen theem kom txo |
| Oxygen Content Dependence | Nws tseem tuaj yeem tshwm sim hauv cov mob hyperoxia | Yuav tsum muaj cov pa oxygen tsawg dua lossis sib npaug li 50ppm rau kev ua haujlwm tau zoo |
| Lub luag haujlwm ntawm Silicon | Core deoxygenation keeb | Auxiliary (tsim kom muaj ib puag ncig txo) |
Tus cwj pwm ntawm calcium hauv molten steel tuaj yeem xav txog yog "kev kho mob tseem ceeb" txheej txheem:
Thawj qhov tseem ceeb:Deoxidation-Tom qab nkag mus rau hauv cov hlau molten, calcium ua ntej "nrhiav" oxygen atoms los ua ke nrog, thaum silicon pib deoxidizes, tsim cov xwm txheej rau calcium.
Qhov tseem ceeb thib ob:Desulfurization-Thaum siv cov pa oxygen mus rau theem qis (tsawg dua lossis sib npaug li 50ppm), calcium pib ua ke nrog sulfur ntau.
Qhov tseem ceeb thib peb:Kev hloov kho-Thaum kawg, cov calcium uas tseem tshuav yog siv los hloov kho Al₂O₃ residual inclusions, ua kom tsawg- melting-point calcium aluminate, optimizing cov inclusion morphology.
Cov txheej txheem cuam tshuam
Lub hauv paus ntsiab lus tshawb fawb no qhia rau ntawm -site engineers:
Tsis txhob cia siab tias yuav ua kom tiav deoxidation thiab desulfurization ib txhij nrog ib qho ntxiv - qhov tseem ceeb ntawm calcium dictates tias nws yuav tsum tau ua nyob rau theem.
Kev tswj cov pa oxygen yog qhov yuav tsum tau ua ua ntej rau kev ua tau zoo desulfurization - yog tias deoxidation tsis tiav nyob rau theem pib, qhov ua tau zoo ntawm desulfurization nyob rau theem tom ntej yuav raug cuam tshuam.
Kev kho calcium nyob rau theem tom ntej ntawm kev ua kom zoo yog qhov tseem ceeb sib npaug - txawm tias tom qab deoxidation thiab desulfurization tiav lawm, cov calcium uas tsim nyog yog qhov tseem ceeb rau kev txhim kho kev ua haujlwm casting.
FAQ
Q1: Vim li cas kev kho calcium ua nyob rau theem tom qab ntawm kev ua kom zoo dua?
A: Vim tias calcium nyiam ua rau cov pa oxygen. Tsuas yog tom qab cov ntsiab lus oxygen tau txo qis mus rau theem qis tuaj yeem ua cov calcium zoo ua desulfurization thiab suav nrog kev hloov pauv.
Q2: Yuav ua li cas txhawm rau txhim kho calcium yield?
A: Siv txoj kev pub mis cored (15% -20% ntau dua li kev pub mis ncaj qha), tswj cov hlau kub ntawm 1500-1600 degree, thiab pib ntxiv calcium thaum 1/3 ntawm cov hlau tau tapping.
Q3: Dab tsi yog qhov tshwm sim ntawm kev ntxiv silicon ntau dhau -calcium alloy?
A: Excessive addition (>0.6%) yuav ua rau cov ntsiab lus calcium ntau dhau hauv cov hlau, tsim CaO suav nrog, thiab txo cov kev cuam tshuam toughness los ntawm 10% -15%.
Q4: Dab tsi yog silicon ua si hauv silicon-calcium alloy?
A: Silicon ua raws li cov khoom nqa khoom, txo cov vapor siab ntawm calcium, tso cai rau nws kom yaj ruaj khov hauv cov hlau molten; ib txhij, silicon ua ntej deoxidation, tsim cov xwm txheej rau calcium desulfurization.
