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真空感应熔炼过程炉衬材料向钢液供氧现象的研究 总被引:1,自引:0,他引:1
通过50kg镁砂坩埚和25kg氧化钙砂坩埚真空感应炉进行了真空熔炼过程炉衬耐火材料向钢液供氧试验,以研究炉衬耐火材料向钢液供氧的基本规律和影响炉衬向钢液供氧的主要因素。试验结果表明,在超低氧范围内对钢液进行深度脱氧时,避免炉衬分解对钢液供氧是进一步脱氧的关键;在0.5~10Pa的真空下,随真空度和熔池钢水温度升高,炉衬分解向熔池供氧增加,并且钢中最终氧含量随钢液碳烧损量的增加而增加;镁砂炉衬向钢液的供氧量大于氧化钙炉衬向钢液的供氧量。 相似文献
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用氧化钙坩埚真空感应熔炼超低氧钢的脱氧动力学 总被引:7,自引:2,他引:5
为了获得氧化物夹杂含量极低的超低氧钢铁材料,研究了在真空感应炉中用氧化钙坩埚冶炼钢液时在超低氧含量范围内的深脱氧动力学因素。指出,在超低氧范围内(ωTO<5×10-6)精炼钢液时,避免炉衬分解对钢液供氧是关键。炉衬材质一定时,炉衬是否向钢液供氧决定于精炼时的真空度和钢液温度。对氧化钙质炉衬而言,欲避免炉衬向钢液供氧,合理的真空度应控制在10~50Pa。为了提高在超低氧范围内碳脱氧速度,应选择浅平的熔池,并加强熔池搅拌,提高钢液中氧的表观传质系数。 相似文献
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采用MgO坩埚真空感应熔炼08Cr9CoMo钢,纯铁经除锈与其他合金烘烤后按照0.06%C、1.3%Co、9.0%Cr、1.5%Mo、0.02%La-Ce,余量为铁配料,真空度≤10 Pa通电,熔化期控制真空度25~30 Pa,精炼期控制温度1600 ℃和真空度10 Pa,精炼20 min,出钢前添加0.02%稀土,最终分析结果为0.022%C,0.002 8%O。通过热力学计算了真空下碳脱氧能力,随着真空度的降低碳脱氧能力显著增强,热力学计算分析了MgO坩埚供氧与真空度的关系,真空度低于25 Pa后坩埚分解供氧更显著,当MgO坩埚分解供氧速率等于碳脱氧速率时钢液达到最低氧含量。 相似文献
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摘要:通过取样检测并结合热力学和动力学计算研究了氧化镁质(MgO)、镁铝尖晶石质(MgO·Al2O3)和氧化钙质(CaO)3种坩埚和2种真空压力(50~100Pa和5~10Pa)对AerMet100超高强度钢脱氮的影响。实验结果表明:随着精炼时间增加,3种坩埚在2种真空压力下的钢液中N质量分数都逐渐减少。相比之下,CaO坩埚脱氮效果最佳,2种真空压力下30min时N质量分数均减少到0.0005%。动力学计算结果表明:MgO和MgO·Al2O3坩埚在2种真空压力下的钢液中O和S活度较高,脱氮反应均服从2级,即钢液脱氮受界面化学反应控制;而CaO坩埚在2种真空压力下的钢液中O和S活度较低,脱氮反应均服从1~5级,即钢液脱氮由液相边界层传质和界面化学反应共同控制。此外,减小真空压力,脱氮速率加快,有利于钢液脱氮。 相似文献
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Fe-Mn-Al-C系低密度高强钢是前景广阔的先进钢材之一,其中添加有高含量Mn、Al等合金元素,在熔炼过程中与耐火材料反应,会造成材料蚀损及影响钢液洁净度。因此,针对钢包用铝镁质浇注料,采用坩埚法开展其抗高锰高铝钢侵蚀实验,探讨不同反应条件下钢液对浇注料的侵蚀行为和钢中夹杂的变化规律。结果表明:主要是钢中Mn对耐火材料扩散渗入较严重,与材料反应变质破坏结构,而随Al添加量增加会呈现对侵蚀的先抑制再逐步促进作用;随着反应时间延长,钢液对耐火材料侵蚀逐渐加剧,冶炼90 min后的钢中总O含量及非金属夹杂物略有增加。但总体上,钢液对铝镁质浇注料的最大侵蚀率仅7.07%,且对钢液质量的预期影响也相对有限,能适应高锰高铝钢的冶炼。 相似文献
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In the present work, the influence of sulfur addition to the high basicity slag on the Al‐killed molten steel with high sulfur content was investigated by using a vacuum induction furnace at 1873 K in MgO crucibles. CaO–SiO2–Al2O3–MgO–CaS slags were used to study the effect of high basicity slags with different CaS contents on sulfur loss, aluminum loss, and total oxygen content in the molten steel. It is shown that the sulfur content in the molten steel decreased with the time, and the addition of CaS into the slag can reduce the sulfur loss in the molten steel. Moreover, there was a decreasing tendency of the aluminum content in the molten steel with the time, and the addition of CaS into the slag can reduce the aluminum loss in the molten steel. Total oxygen content in the molten steel first increased and then decreased with the time when no CaS was added into the slag. However, it decreased monotonically with the time when the addition of CaS was made into the slag. 相似文献
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采用真空感应熔炼工艺冶炼航空轴承钢M50,对比分析了Ce处理、Mg处理和Ce–Mg复合处理对氧、硫含量和夹杂物分布特征的影响,结合热力学计算,阐明了加入Ce、Mg元素对钢液洁净度的影响机理。研究发现,Ce具有很强的脱氧、脱硫能力,加入Ce会优先生成Ce2O2S夹杂物,随着钢液中氧含量的降低,Ce还会与As等有害杂质元素结合,起到净化钢液的效果。过量的Ce会加剧其与镁铝尖晶石材质耐火材料的反应,导致钢中夹杂物数量的增加,Ce的质量分数为0.018%时,钢中夹杂物的尺寸和数量最小;添加Mg不仅可以脱氧、脱硫,还可以抑制Ce与镁铝尖晶石耐材的反应,Ce–Mg复合处理可以显著降低钢中的夹杂物的尺寸和数量,将钢中的氧的质量分数降低至0.00075%。 相似文献
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为了减少RH真空冶炼过程中钢水锰元素偏差和提高最终产品性能的稳定性,采用直读光谱仪对不同条件下RH真空冶炼镇静钢与非镇静钢锰损情况开展研究。结果表明,RH真空冶炼过程中锰损存在4种形式,与钢水中自由氧反应烧损、钢渣界面反应、合金粉末抽吸、真空锰挥发;随着钢水中锰含量增加、真空时间延长,钢水温度和氧化性提高,RH真空锰损逐渐增加;真空度小于1 000 Pa时,RH真空锰损随真空度的降低而降低,而当真空度大于1 000 Pa时,继续降低真空度,RH真空锰损几乎不变。通过降低RH真空度、进站锰含量和温度、减少RH真空处理时间等措施,RH结束目标锰的质量分数±0.01%命中率接近100%。 相似文献
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Voicu Brabie 《国际钢铁研究》1997,68(2):54-60
The conditions of formation of inclusions in steel during ladle refining in MgO-C lined ladles have been investigated in laboratory experiments at 1873 K in MgO-C crucibles with 50 g iron. From both the experimental results as well those of a thermodynamic study conducted in parallel, the following conclusions can be made about the reaction mechanism between the MgO-C refractory and aluminium deoxidised molten steel: At steelmaking temperature an internal oxidation-reduction occurs in the MgO-C refractory. The formation of a thin oxide layer at the interface is due to the reaction between magnesium vapour and aluminium dissolved into the molten steel and the CO(g) generated by the reaction between MgO and C in the crucible walls. The oxide inclusions formed in the steel have been shown mainly to consist of MgO, Al2O3 or mixture of them. Some of the finest inclusions are considered to be formed as secondary inclusions during cooling and solidification of the steel and they are connected only with the diffusion of magnesium from the crucible to the molten steel. The thermodynamic calculations indicate that during vacuum refining, as the pressure decreases, the chemical compatibility of carbon-bonded magnesia for ladle lining decreases. 相似文献
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摘要:钢中添加适量铝元素可以提高其韧性与耐腐蚀性,但在冶炼过程中会影响炉渣中Al2O3含量而改变其与现行铝镁质浇注料的界面反应,制约钢种冶炼及品质提升。因此,采用静态坩埚法开展铝镁质浇注料的抗CaO-Al2O3-SiO2渣蚀实验,并结合热力学模拟计算探究Al2O3含量(w(CaO)∶w(Al2O3),C/A)变化对耐火材料渣蚀的影响规律,得到以下结论:随着熔渣中Al2O3含量的增加,铝镁质浇注料与熔渣反应界面越易形成更厚的高熔点隔离层,将耐火材料组分向熔渣中的直接溶解转变为间接溶解,有利于提升铝镁质浇注料的抗侵蚀性;当渣中的Al2O3质量分数在32%左右时,熔渣的侵蚀性总体较弱,但当渣中的Al2O3质量分数不小于36%时,熔渣对铝镁质浇注料产生了严重的渗透性,也易造成材料变质剥落。这为面向含铝钢冶炼用耐火材料的优化设计提供参考。 相似文献
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The toughness and erosion resistance of steel can be improved by adding an appropriate amount of aluminum. However it will increase the content of Al2O3 in slag and react with the existing alumina magnesia castable, and affect smelting and quality of steel. Therefore, static crucible method was applied, corrosion experiments of the CaO-Al2O3-SiO2 slags on the alumina magnesia castable were carried out, and the influence of Al2O3 content (w(CaO)∶w(Al2O3), C/A ratio) on slag corrosion resistance was investigated by combining thermodynamic simulation. The following conclusions were obtained: with the increase of Al2O3 content in the slags, the thicker isolation layer with high melting point is easier to form at the reaction interface between alumina magnesia castable and the slags. The direct dissolution of the refractory components into the slags can be changed to indirect dissolution, which is conducive to improving the corrosion resistance of alumina magnesia castable. Nevertheless, when the content of Al2O3 in the slag is about 32 wt.%, the slag corrosion is generally weak, when the content of Al2O3 in the slag is more than 36 wt.%, the slag has serious permeability to the alumina magnesia castable, which is easy to cause the deterioration and spalling of the material. It provides guidance on the optimization and design of the refractories for Al containing steel smelting. 相似文献
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为了开发更优质的耐火材料以提高切割丝用钢的洁净度,试验采用MoSi2炉研究了MgO、MgO-CaO两种耐火材料对95Cr切割丝用钢中夹杂物的影响。结果表明,MgO、MgO-CaO两种坩埚冶炼均能使钢成分控制在目标范围内,夹杂物成分落点控制在目标低熔点区内。但与MgO坩埚相比,MgO-CaO坩埚净化钢液的效果更好,主要表现为两个方面。一方面,钢中P、S、Als、T[O]含量均更低。特别是w([S])可降低至0.000 6%,w([Al]s)降低到0.000 3%,w(T[O]) 降低到0.000 5%。另一方面,钢中夹杂物数量更少、尺寸更小、复合夹杂物中Al2O3的含量更低。具体表现为,经MgO-CaO坩埚冶炼后,钢中等效直径小于2 μm的夹杂物所占比例为91%,而经MgO坩埚冶炼的钢,此项值仅为78%;经MgO-CaO坩埚冶炼后,钢中复合夹杂物中w([Al2O3])几乎都低于10.0%。这主要是因为MgO-CaO耐火材料中的MgO、CaO均能脱磷,同时CaO还有间接脱硫、去除钢中Al2O3夹杂物的作用。 相似文献