钢包渣改质剂在LF上生产Q345C钢的应用

介绍了钢包渣改质剂在50t LF上生产含铝Q345C钢时的应用,结果表明应用试验钢包渣改质剂后提高了铝的收得率,加强了钢液的深脱硫和脱磷,并极大地降低了精炼渣中的T.Fe含量,改善了轧材的力学性能,降低了含铝钢的生产成本.     

钢包顶渣改质剂生产16MnR钢的应用研究

介绍了钢包顶渣改质剂在50 t LF炉精炼含铝16MnR钢时的应用,研究结果表明:应用试验钢包顶渣改质剂后,在钢成品中铝含量满足成分要求的基础上,加强了钢液的深脱硫和脱磷,并降低了精炼渣中的TFe含量.     

钢包顶渣改质剂在50t LF精炼炉上的应用

本文介绍了钢包顶渣改质剂在50t LF炉精炼含铝Q345C钢的应用,结果表明：应用试验钢包顶渣改质剂后提高了铝的收得率,加强了钢液的深脱硫和脱磷,极大地降低了精炼渣中的TFe含量,改善了轧材的机械性能,降低了含铝钢的生产成本。     

济钢钢包顶渣改质剂的开发与应用试验

为降低钢包顶渣的氧化性,通过分析钢包顶渣脱硫的动力学条件及炉渣的理化性能,结合生产实际,确定了顶渣改质剂的组成：Al 13％-17％,Al2O3 58％-62％,SiO2 8％-12％,MgO3％-7％,盐类〈8％,改质剂具有高效实用、成本低、环境友好的特点。试验中用改质剂代替原工艺中的精炼剂（Q235C钢种）,通过对改质剂不同加入量的冶金效果进行对比分析,确定的改质剂加入量为每炉80kg,试验表明,改质剂化渣快,能迅速降低顶渣的氧化性,与原工艺相比,钢中平均铝含量提高0.06％,脱硫率提高89．25％,渣中全铁降低0.6％,稳定了含铝钢的生产。     

低硅钢种LF精炼控硅脱硫技术进展

对前人开发的低硅钢种控硅脱硫技术的最新进展进行了总结。通过控硅热力学分析，明确了为达到目标Si含量，钢液中Al和Ca的控制目标含量。为防止脱硫过程中回硅，应重点控制转炉下渣量、脱硫LF精炼时间、LF进站铝含量，采用合适的渣系，还应控制钢液中钙含量。由于脱硫要求增加吹氩量以强化钢渣间界面反应，但控硅要求吹氩量不宜过大，所以存在最佳吹氩量。为提高脱硫率，应采用碱度为5.0～8.0的精炼渣，还应控制钢水温度高于1 565℃。     

浅议低碳低硅铝镇静钢精炼过程硅含量的有效控制

在进行对低碳低硅铝镇静钢的冶炼过程中对于硅含量的有效控制使其冶炼中极为重要的一项内容。由于LF精炼脱氧、脱硫还有强还原环境下很容易导致回硅的情况出现以至于造成钢材内部的硅含量出现超标。同时转炉终渣成分还有下渣量以及LF精炼渣成本与钢中酸溶铝含量等方面因素的存在对于硅含量的控制均会产生一定程度的影响,以至于使得其控制难度相对增加。     

ML08Al钢150mm×150mm连铸坯的生产实践

包钢采用83 t转炉,83 t钢包炉(LF),6机6流150 mm×150 mm方坯连铸机生产低碳低硅铝镇静钢ML08Al(%:≤0.08C,0.20~0.50Mn,≤0.06Si,0.02Al)。生产实践表明,转炉出钢时用43%Al、13%Mn、2%Ti的铝锰钛合金替代铝锭进行脱氧,可使钢中铝含量稳定在0.02%~0.09%;将钢中的硫含量降至0.01%以下时,可减少钢液中CaS的产生,基本消除中间包水口堵塞;转炉出钢过程减少下渣量,并加入400 kg石灰,调整LF精炼过程脱氧剂加入量和加入时间,以减少回硅量,使钢中硅含量≤0.06%。     

钢包顶渣改质在转炉冶炼汽车用钢中的应用

结合生产实际,通过对转炉出钢后的钢包顶渣加入一定量的改质剂进行改质处理试验,大大降低了钢包顶渣中的FeO含量,降低了钢包顶渣的氧化性,使铝的"回收率"稳定并提高。对减少和稳定钢中Al2O3夹杂起到了有效的控制作用。在冶炼汽车用DQ1J钢时进行该试验,效果良好,目前已纳入正常生产工艺,并在经RH路径进行精炼处理的所有钢种中均已采用钢包顶渣改质处理。     

低硅、低硫铝镇静钢冶炼技术研究

分析了低硅、低硫铝镇静钢精炼过程中回硅的原因,并提出了改善措施。认为精炼渣中SiO_2含量及其氧化性是增硅的主要原因。通过加强转炉终点钢水温度、顶渣成分和下渣量控制,并优化精炼渣成分和脱氧过程,控制碱度在8～12,w(CaO)为50%～60%、w(Al_2O_3)为20%～30%、w(SiO_2)为4%～8%、w(MgO)为5%～7%,同时脱氧时将钢砂铝改为粒度小的铝粒,控制其加入量和氩气流量,使铝粒浮在渣面,降低其氧化性等一系列技术措施,脱硫效果优于原工艺,钢中硅质量分数明显降低,平均为0.024%,且控制稳定。     

精炼过程硅和铝脱氧机理分析

从热力学和动力学两方面对精炼过程深脱氧机理进行理论分析,并通过工业生产数据进行验证,研究结果表明,Al脱氧钢会促进回硅反应,且随着时间的延长回硅量增大,控制渣中低SiO2活度,高Al2O3活度及钢液中低酸溶铝含量有利于控硅,而且温度也是Al脱氧钢应考虑的控硅因素。     

Effects of Quicklime and Iron Tailings as Modifier on Composition and Properties of Steel Slag

Steel slag had lower activity and much lower hydration rate than cement.Quicklime and iron tailings were designed as modification agent to adjust the composition and properties of high temperature steel slag.The results show that quicklime as modifier can greatly increase the content of cementitious minerals in modified steel slag and also promote the decomposition of RO phases and transformation of MgO in RO phase to f-MgO.After high temperature modification with compound modifier of quicklime and iron tailings,steel slag shows the main mineral phases of C3 S,C2F and MgFe2O4.The activity index of modified steel slag at 28 days reaches 95.5% when the steel slag is modified by 15% of the compound modifier with the ratio of quicklime to iron tailings equal to 2∶1at 1 350℃.Moreover,the sample with the modified steel slag exhibits the dense structure of hydration paste and the main hydration products of C-S-H gels and Ca(OH)2 crystals.     

高铝钢连铸保护渣结晶矿相的研究

 针对高铝钢浇铸过程中保护渣Al2O3含量大幅增加而导致保护渣玻璃形态恶化的问题,采用SEM和XRD分析方法对高铝钢浇铸前后保护渣的显微组织和结晶矿相进行分析,研究了不同组分对保护渣结晶性能的影响。结果表明：高铝钢连铸保护渣初始SiO2含量较高,保护渣玻璃形态较好。浇铸过程中随着保护渣Al2O3含量的增加和SiO2含量的减少,保护渣的结晶率增加,玻璃性能变差;渣中Li2O容易与F-生成LiF晶相;渣中CaF2含量较高时,容易析出CaF2晶体。     

高速铁路轨道用钢中铝含量控制研究

通过计算的方法研究了高速铁路轨道用钢中铝含量的控制措施,计算结果表明:在LF精炼工况下,重轨钢中的硅元素可以将渣中的Al2O3还原到钢中,从而引起钢中铝含量的增加。因此,通过控制炉渣低碱度、低Al2O3及把钢中硅含量控制在下限,可以将钢中铝含量控制在较低水平。     

Evaluation of Sulfur Addition to the High Basicity Slag on the Sulfur,Aluminum, and Cleanliness of High Sulfur Al‐Killed Molten Steel

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.     

GCr15轴承钢LF精炼过程脱硫能力的热力学评价

通过现场取样分析和热力学计算,评价了工业化生产GCr15轴承钢LF精炼工序的脱硫能力.分析了精炼温度、钢中酸溶铝含量、精炼渣的光学碱度对LF精炼过程硫分配比的影响.由于实际精炼过程中脱硫反应未达到平衡,实际测得的硫分配比低于理论计算值.得到了精炼温度为1 830～1 855 K,钢中酸溶铝的质量分数为0.020％～o.050％,精炼渣光学碱度在0.760～0.795范围内,精炼温度、钢中酸溶铝、渣的光学碱度及渣中Al2O3、SiO2含量对硫分配比影响的回归方程,该方程可作为实际生产条件下LF精炼工序脱硫能力的评价依据.根据回归方程,设计了改变精炼渣组成的3因素4水平正交实验,分析了精炼渣二元碱度R2及Al2O3和SiO2含量对硫分配比的影响,得出渣-钢间最优硫分配比的精炼渣组成(质量分数)为:CaO 55.11％,Al2O3 30％,SiO26.89％,MgO 8％,光学碱度为0.777.     

碳铝顶渣改质剂在低碳钢生产中的应用实践

钢包顶渣的改质是防止钢水二次氧化、钢液深度脱氧、优化钢液和夹杂物去除的重要工艺方法。120 t转炉+LF +板材生产线生产低碳铝镇静钢SPHC和330CL时,LF精炼采用碳铝改质剂(/%: ≥35Al₂O₃,15~30C,5~15Al, ≤5SiO₂,6 ~12CaF₂ )较无碳改质剂 (/%：40~ 60Al₂O₃, ≥20A1,2~ 10CaO,≤10SiO₂)钢水增氮量从0.000,5% ~0.0015% 降至≤0.001%,脱硫率从40%增至45%。     

Titanium Content Control for Bearing Steel

On the basis of the thermodynamic analysis and fundamental study in the laboratory, the equilibrium of the Ti A10 system was investigated. The results showed that the equilibrium titanium content in the steel increased with the increase in the soluble aluminum content in the steel and the TiO2 content in the slag. Although the slag basicity decreased and Al2O3 content in the slag increased, the titanium content increased. Based on these results, the BOF smelting process of low titanium bearing steel was put forward.     

帘线钢中酸溶铝含量的变化及其对夹杂物的影响

 研究了采用LD－RH－LF－CC工艺流程生产帘线钢时,钢中酸溶铝含量的变化情况。研究发现,精炼过程中酸溶铝含量略有下降,但连铸过程中酸溶铝含量急剧下降。夹杂物中Al2O3含量随着酸溶铝含量的上升而逐渐增大。SiO2含量降低时夹杂物熔点提高。采用低碱度、低Al2O3含量的顶渣精炼工艺,严格控制钢中w(［Als］)在0.0005%～0.001%范围内,促进夹杂物上浮,有利于钢中氧化物夹杂的数量减少、尺寸细小和塑性化。     

不锈钢AOD渣固化效果影响因素及其机理

 不锈钢氩氧脱碳（AOD）渣在冷却过程中易发生体积膨胀导致粉化扬尘,这不仅会对环境造成严重污染,给人体带来很大危害,还会造成资源的浪费,因此急需解决不锈钢渣的粉化扬尘问题,提高不锈钢渣的利用率。对不同改性剂对渣的粉化抑制效果进行研究,结果表明,随着B2O3和P2O5掺量的增加,对AOD渣有明显的固化效果,随着CuO的增加,AOD渣没有明显固化。分析原因表明,通过向不锈钢渣中添加半径比Si4+小的离子如B3+、P5+,可以使其在2CaO·SiO2的晶界或位错上富集,降低缺陷的自由能,降低[γ-2CaO·SiO2]成核的驱动力,抑制[γ-2CaO·SiO2]晶核的形成及长大,使2CaO·SiO2可以更好地稳定在[β]相,从而抑制了不锈钢渣的粉化扬尘。     

Inclusion Variations of Hot Working Die Steel H13 in Refining Process

 Inclusion variations of die steel H13, including changes of species, morphologies, compositions, amounts and sizes, in the production of EAF→LF→VD→ingot casting→electro-slag refining (ESR) procedure, were investigated by systematic sampling, and analyzed with scanning electron microscope (SEM), energy dispersive spectrum (EDS), and metallographic microscope. The variation mechanism was studied by comprehensive analysis of total oxygen, nitrogen, and acid soluble aluminum as well as chemical test of refining slag. Based on the investigations, technical measures for cleanness improvement were discussed. The results show that oxide inclusions in H13 steel change from irregular Al2O3→near globular CaO-MgO-Al2O3 and CaO-Al2O3-SiO2 complex inclusions→finer CaO-Al2O3-SiO2 inclusions with higher CaO content→CaO-Al2O3-SiO2 inclusions with higher Al2O3 content and irregular MgO-Al2O3 inclusions→fine irregular MgO-Al2O3-CaS inclusions in various steps of the production; the variations are related with changes of acid soluble aluminum content, reactions between slag and steel, re-oxidation of liquid steel during casting, and refining of ESR. It is also found that Al2O3 inclusions are modified by refining slag in LF and VD refining; and ESR plays a good role in inclusion removal, especially in controlling the large linear VC-CrC-MoC inclusions distributed in grain boundaries. It is suggested that casting protection should be improved, and the basicity of refining slag and acid soluble aluminum content in steel should be raised.