錳硅鐵合金爐外精煉的基礎(chǔ)研究
發(fā)布時間：2018-11-22 10:32
【摘要】：我國現(xiàn)有的錳硅鐵合金產(chǎn)品存在磷、鋁、鈦和氧雜質(zhì)含量偏高等質(zhì)量問題,已不能滿足部分品種鋼和新鋼種開發(fā)的技術(shù)要求。通過還原脫磷、吹氮脫鋁脫鈦等工藝對錳硅鐵合金進行爐外精煉,可降低其磷、鋁和鈦等雜質(zhì)含量。本課題主要針對錳硅鐵合金爐外精煉過程中遇到的基礎(chǔ)問題進行研究。首先,系統(tǒng)整理了錳基熔體熱力學(xué)數(shù)據(jù),將標(biāo)準(zhǔn)相互作用系數(shù)模型(UIPM)應(yīng)用于Mn-Fe-Si-C-Ca-P熔體。模型能夠計算錳基熔體中錳、硅、鐵、碳、鈣和磷的活度,碳和鈣的溶解度,以及鈣和磷的平衡等,還有助于理解錳鐵合金和錳硅鐵合金的生產(chǎn)過程。測定了Mn-Si-Fe三元熔體中氧的溶解度。用小樣電解提取夾雜物的檢測結(jié)果表明,高硅錳硅鐵合金的夾雜物多為石英,普硅錳硅鐵合金中的夾雜物多為石英和錳鐵硅酸鹽。根據(jù)理論分析,錳硅鐵合金產(chǎn)品中的氧幾乎全部以氧化物夾雜的形式存在,其總量可占錳硅鐵合金質(zhì)量的0.075-0.253%,主要來源于外來夾雜物。通過適當(dāng)延長鐵水包內(nèi)鎮(zhèn)靜時間和向熔體內(nèi)部吹氬等手段降低氧化夾雜物含量,理論上可將錳硅鐵合金中的氧降低至50ppm以下。采用氣體—金屬熔體平衡法,測定了氮在Mn-Si-Fe-(C飽和)熔體中的溶解度和熔體中氮化鋁和氮化鈦的濃度積。氮的溶解度與氮分壓的關(guān)系符合西華特定律,且其值大小隨溫度的降低和硅含量的增加而降低；在Mn60Si30Fe熔體中,氮化硅是飽和的。濃度積[%AI][%N]和[%Ti][%oN]值,以及三相平衡點處(熔體與氮氣和氮化鋁或氮化鈦三相平衡)的鋁或鈦含量,均隨溫度的降低和硅含量的升高而降低。采用吹氮脫鋁脫鈦工藝,理論上可將Mn60Si30FeC飽和熔體中的鋁和鈦分別降低至0.002%和0.011%,基本能夠滿足90級硬線鋼的生產(chǎn)工藝要求。無論是氬氣還是空氣氣氛下,均可用CaO-CaF2渣對錳硅鐵合金熔體進行界面還原脫磷,由合金熔體中的硅控制渣金界面處的氧勢,可以滿足還原脫磷的要求。還原脫磷率隨合金中硅含量的增加和溫度的降低而增加,CaO-CaF2渣對硅含量大于20%的錳硅鐵合金才有明顯脫磷效果。錳硅鐵合金的還原脫磷有回磷現(xiàn)象產(chǎn)生,在生產(chǎn)實踐中,選擇合適的除渣時間是還原脫磷工藝的關(guān)鍵。渣中含Al_2O_3和Na2O組分不利于錳硅鐵合金熔體的還原脫磷,石墨坩堝不宜用于還原脫磷。采用旋轉(zhuǎn)柱體法測量了含SiC和Si_3N_4顆粒的CaO-MgO-Al_2O_3-SiO_2熔體的粘度。無論是否含SiC或Si_3N_4顆粒,熔體粘度與溫度的關(guān)系總是符合Arrhenius定律。固-液兩相混合體系的粘度活化能取決于液相,而相對粘度幾乎不受溫度的影響。粘度和相對粘度隨轉(zhuǎn)速的降低和SiC(或S毛N4)體積分?jǐn)?shù)的升高而升高。固體顆粒的體積分?jǐn)?shù)相同時,熔體相對粘度受液態(tài)渣組分的影響。當(dāng)液態(tài)渣CaO與SiO_2含量的比值或MgO與Al_2O_3含量的比值較大時,相對粘度較低。
[Abstract]:The existing Mn-Si-Fe alloy products in China have high quality problems such as high content of phosphorus, aluminum, titanium and oxygen impurity, which can not meet the technical requirements of some kinds of steels and new steels. By reducing and dephosphorizing, blowing nitrogen to dealuminate and detitanium, and so on, Mn-Si-Fe alloy can be refined out of furnace, and the impurity contents such as phosphorus, aluminum and titanium can be reduced. In this paper, the basic problems in the refining process of mn-Si-Fe alloy are studied. Firstly, the thermodynamic data of manganese based melts are systematically processed, and the standard interaction coefficient model (UIPM) is applied to Mn-Fe-Si-C-Ca-P melts. The model can calculate the activities of manganese, silicon, iron, carbon, calcium and phosphorus, the solubility of carbon and calcium, and the balance of calcium and phosphorus in manganese based melts. It is also helpful to understand the production process of ferromanganese and ferromanganese alloys. The oxygen solubility in Mn-Si-Fe ternary melt was determined. The results showed that the inclusions of high silicomanganese ferrosilicon alloy were mostly quartz, and the inclusions in common silicomanganese ferrosilicon alloy were mostly quartz and ferromanganese silicate. According to the theoretical analysis, the oxygen in Mn-Si-Fe alloy almost exists in the form of oxide inclusions, the total amount of which can account for 0.075-0.253% of the Mn-Si-Fe alloy mass, which mainly comes from the foreign inclusions. By properly prolonging the calming time in the ladle and blowing argon into the melt to reduce the content of oxidized inclusions, the oxygen content in the Mn-Si-Fe alloy can be reduced to below 50ppm in theory. The solubility of nitrogen in Mn-Si-Fe- (C saturated) melt and the concentration product of aluminum nitride and titanium nitride in melt were determined by gas-metal melt equilibrium method. The relationship between the solubility of nitrogen and the partial pressure of nitrogen obeys the law of Sivalt, and its value decreases with the decrease of temperature and the increase of silicon content. In the melt of Mn60Si30Fe, silicon nitride is saturated. The concentration product [% AI] [% N] and [% Ti] [% oN], as well as the Al or Ti contents at the three-phase equilibrium point (melt equilibrium with nitrogen and aluminum nitride or titanium nitride) decreased with the decrease of temperature and the increase of silicon content. The aluminum and titanium in the saturated melt of Mn60Si30FeC can be reduced to 0.002% and 0.011% respectively by the technology of denitrification by blowing nitrogen, which can basically meet the requirements of the production process of the 90 grade hard wire steel. CaO-CaF2 slag can be used to dephosphorize Mn-Si-Fe alloy melt interfacial dephosphorization in argon or air atmosphere. The oxygen potential at the interface of slag and gold can be controlled by silicon in alloy melt, which can meet the requirement of reductive dephosphorization. The reduction and dephosphorization rate increased with the increase of silicon content and the decrease of temperature. The dephosphorization effect of CaO-CaF2 slag was obvious only when the silicon content was more than 20%. The dephosphorization of Mn-Si-Fe alloy has the phenomenon of phosphorus recovery. In the production practice, the key to dephosphorization is to select the proper time of slag removal. The composition of Al_2O_3 and Na2O in slag is unfavorable to the reduction and dephosphorization of Mn-Si-Fe alloy melt, and the graphite crucible is not suitable for reductive dephosphorization. The viscosity of CaO-MgO-Al_2O_3-SiO_2 melt containing SiC and Si_3N_4 particles was measured by rotating cylinder method. The relationship between melt viscosity and temperature is always in accordance with Arrhenius's law whether or not it contains SiC or Si_3N_4 particles. The viscosity activation energy of solid-liquid two-phase mixing system depends on the liquid phase, but the relative viscosity is almost unaffected by temperature. The viscosity and relative viscosity increase with the decrease of rotational speed and the increase of volume fraction of SiC (or S wool N _ 4). When the volume fraction of solid particles is the same, the relative viscosity of melt is affected by the composition of liquid slag. When the ratio of CaO to SiO_2 or MgO to Al_2O_3 is high, the relative viscosity is lower.
【學(xué)位授予單位】：北京科技大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2017
【分類號】：TF64
本文編號：2349052
[Abstract]:The existing Mn-Si-Fe alloy products in China have high quality problems such as high content of phosphorus, aluminum, titanium and oxygen impurity, which can not meet the technical requirements of some kinds of steels and new steels. By reducing and dephosphorizing, blowing nitrogen to dealuminate and detitanium, and so on, Mn-Si-Fe alloy can be refined out of furnace, and the impurity contents such as phosphorus, aluminum and titanium can be reduced. In this paper, the basic problems in the refining process of mn-Si-Fe alloy are studied. Firstly, the thermodynamic data of manganese based melts are systematically processed, and the standard interaction coefficient model (UIPM) is applied to Mn-Fe-Si-C-Ca-P melts. The model can calculate the activities of manganese, silicon, iron, carbon, calcium and phosphorus, the solubility of carbon and calcium, and the balance of calcium and phosphorus in manganese based melts. It is also helpful to understand the production process of ferromanganese and ferromanganese alloys. The oxygen solubility in Mn-Si-Fe ternary melt was determined. The results showed that the inclusions of high silicomanganese ferrosilicon alloy were mostly quartz, and the inclusions in common silicomanganese ferrosilicon alloy were mostly quartz and ferromanganese silicate. According to the theoretical analysis, the oxygen in Mn-Si-Fe alloy almost exists in the form of oxide inclusions, the total amount of which can account for 0.075-0.253% of the Mn-Si-Fe alloy mass, which mainly comes from the foreign inclusions. By properly prolonging the calming time in the ladle and blowing argon into the melt to reduce the content of oxidized inclusions, the oxygen content in the Mn-Si-Fe alloy can be reduced to below 50ppm in theory. The solubility of nitrogen in Mn-Si-Fe- (C saturated) melt and the concentration product of aluminum nitride and titanium nitride in melt were determined by gas-metal melt equilibrium method. The relationship between the solubility of nitrogen and the partial pressure of nitrogen obeys the law of Sivalt, and its value decreases with the decrease of temperature and the increase of silicon content. In the melt of Mn60Si30Fe, silicon nitride is saturated. The concentration product [% AI] [% N] and [% Ti] [% oN], as well as the Al or Ti contents at the three-phase equilibrium point (melt equilibrium with nitrogen and aluminum nitride or titanium nitride) decreased with the decrease of temperature and the increase of silicon content. The aluminum and titanium in the saturated melt of Mn60Si30FeC can be reduced to 0.002% and 0.011% respectively by the technology of denitrification by blowing nitrogen, which can basically meet the requirements of the production process of the 90 grade hard wire steel. CaO-CaF2 slag can be used to dephosphorize Mn-Si-Fe alloy melt interfacial dephosphorization in argon or air atmosphere. The oxygen potential at the interface of slag and gold can be controlled by silicon in alloy melt, which can meet the requirement of reductive dephosphorization. The reduction and dephosphorization rate increased with the increase of silicon content and the decrease of temperature. The dephosphorization effect of CaO-CaF2 slag was obvious only when the silicon content was more than 20%. The dephosphorization of Mn-Si-Fe alloy has the phenomenon of phosphorus recovery. In the production practice, the key to dephosphorization is to select the proper time of slag removal. The composition of Al_2O_3 and Na2O in slag is unfavorable to the reduction and dephosphorization of Mn-Si-Fe alloy melt, and the graphite crucible is not suitable for reductive dephosphorization. The viscosity of CaO-MgO-Al_2O_3-SiO_2 melt containing SiC and Si_3N_4 particles was measured by rotating cylinder method. The relationship between melt viscosity and temperature is always in accordance with Arrhenius's law whether or not it contains SiC or Si_3N_4 particles. The viscosity activation energy of solid-liquid two-phase mixing system depends on the liquid phase, but the relative viscosity is almost unaffected by temperature. The viscosity and relative viscosity increase with the decrease of rotational speed and the increase of volume fraction of SiC (or S wool N _ 4). When the volume fraction of solid particles is the same, the relative viscosity of melt is affected by the composition of liquid slag. When the ratio of CaO to SiO_2 or MgO to Al_2O_3 is high, the relative viscosity is lower.
【學(xué)位授予單位】：北京科技大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2017
【分類號】：TF64
【相似文獻】
相關(guān)期刊論文 前10條
1 馬玉香;黃會芹;張利軍;;高氯酸氧化-亞鐵滴定法快速測定硅鐵合金中鉻[J];山東冶金;2006年05期
2 ;中國硅鐵合金價格下降到1 450美元/噸的低水平[J];鐵合金;2011年01期
3 尹振晏,李燕蕓;硅鐵合金中硅的間接測定[J];光譜實驗室;1999年01期
4 盧文琪;劉紅英;;火焰原子吸收光譜法測定稀土鈣鎂硅鐵合金中的鈣和鎂[J];光譜儀器與分析;2005年02期
5 鮑希波;石毓霞;趙靖;韓斌;盧女平;;熔融制樣-X射線熒光光譜法測定硅鐵合金中主次元素[J];冶金分析;2010年05期
6 楊素卿;杜治坤;;全差示吸光光度法測定硅鐵合金中的硅[J];湖南冶金;1986年05期
7 趙貴芬;劉偉;;硅鐵合金中硅測定方法的改進[J];冶金標(biāo)準(zhǔn)化與質(zhì)量;2006年02期
8 胡素萍;在Triton Χ-100存在下利用火焰原子吸收法測定硅鐵合金中的鎳[J];寬厚板;1999年01期
9 宋煥臣;鈰硅鐵合金的研制[J];稀土;1984年01期
10 楊保祥;鈦硅鐵合金生產(chǎn)中金屬元素與渣氧化物的反應(yīng)和平衡[J];鋼鐵釩鈦;1995年02期
相關(guān)重要報紙文章 前1條
1 通訊員陳詠梅;伊河礦冶以技改促升級轉(zhuǎn)型[N];伊犁日報(漢);2010年
相關(guān)博士學(xué)位論文 前1條
1 韓培偉;錳硅鐵合金爐外精煉的基礎(chǔ)研究[D];北京科技大學(xué);2017年
，本文編號：2349052
本文鏈接：http://sikaile.net/shoufeilunwen/gckjbs/2349052.html
最近更新
教材專著
