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从分析高拉速包晶钢板坯连铸结晶器内凝固传热行为特征入手,首先阐明拉速对结晶器内的界面热阻、凝固坯壳的温度与应力分布的影响规律,研究发现拉速超过1.6 m·min?1时,界面热阻明显增加,拉速由1.4 m·min?1提升至1.6 m·min?1和1.8m·min?1时,出结晶器坯壳厚度相应减少约10%,其发生漏钢的危险不断增加;在此基础上,阐述了结晶器的内腔结构、保护渣、振动与液面控制等控制结晶器内坯壳凝固均匀性的相关技术。要实现高速连铸,首要应考虑结晶器内腔结构的优化设计,使其能更好地迎合凝固坯壳的生长,研制适合包晶钢等凝固特点的专用连铸保护渣至关重要,铸坯鼓肚控制也是保障高拉速液面稳定的关键。 相似文献
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20Mn23AlV高锰无磁钢的高铝含量导致连铸过程中钢水与连铸保护渣的剧烈反应,连铸坯产生大量裂纹缺陷,影响其连铸正常生产。为提高铸坯质量,保证20Mn23AlV高锰钢连铸生产顺行,本研究对现场生产20Mn23AlV的连铸工艺和采用的连铸保护渣进行了系统的研究和分析。通过实验室的感应加热炉进行渣-金反应试验,并结合化学分析和扫描电镜等方法研究开发出20Mn23AlV低反应性连铸保护渣,并采用工业试验证明采用低反应性连铸保护渣可以消除连铸坯表面裂纹缺陷,20Mn23AlV高锰钢铸坯修磨量可由8%降低至1%。 相似文献
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Sabri Ozturk Mustafa Merih Arikan Yilmaz Kacar 《Metallurgical and Materials Transactions B》2013,44(3):706-710
Star crack defects encountered during the continuous casting of slab are elucidated in the current article. Trials were carried out to obtain basic information on the behavior of the star cracks under same casting conditions for different grade materials. It is important that star cracks form in the mold, and increase later in the casting process during the straightening. Star crack defects are clearly seen when using copper-based molds. The influences of steel carbon content, material grades, and mold type have been discussed. It is believed that defects in continuously cast products are minimized while using a nickel-coated mold wall in casting. 相似文献
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钢的软接触电磁连铸技术的研究进展 总被引:1,自引:0,他引:1
钢的软接触电磁连铸技术(SoftContactElectromagneticContinuousCasting)是利用高频交变电磁场在结晶器内铸坯初始凝固区施加电磁压力来减少钢液与结晶器壁的接触压力,从而减小结晶器振动对铸坯表面质量的影响,降低拉坯阻力和减弱初始凝固点的传热来提高铸坯表面质量。分析了实现钢的软接触电磁连铸在结晶器结构、材质以及电磁场参数等方面需要解决的问题,并介绍了该技术的最新研究成果:高频调幅磁场及无结晶器振动的电磁连铸技术。 相似文献
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高拉速连铸过程传输行为特征及关键技术探析 总被引:1,自引:0,他引:1
高拉速连铸是实现直轧、铸轧的前提保障,是实现钢铁生产流程高效化、绿色化的具体体现,是发展新一代高效连铸的主题。高拉速连铸面临最大挑战是漏钢与裂纹频发,凝固坯壳均匀生长控制应是其实现的核心内涵,重点在于结晶器技术集成,包括结晶器流动控制、保护渣类型、结晶器润滑、结晶器内腔结构、结晶器冷却结构与制度等,关键在于结晶器液位的稳定控制。阐述了高拉速连铸过程传输行为特征及其实现的关键技术。 相似文献
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In high speed continuous casting of peritectic steel slabs, mold fluxes with high basicity are required for less surface defect product. However, the basicity of remaining liquid slag film tends to decrease in casting process because of the crystallization of 3CaO·2SiO2·CaF2. Thus, a way is put forward to improve mold fluxes′ properties by raising the original basicity. In order to confirm the possibility of this method, the effect of rising original basicity on the properties of mold fluxes is discussed. Properties of high fluorine based mold fluxes with different basicities and contents of CaF2, Na2O, and MgO were measured, respectively. Then, properties of higher basicity mold fluxes were discussed and compared with traditional ones. The results show that increasing the basicity index can improve the melting and flow property of mold fluxes. With the increasing basicity, crystallization rate of mold fluxes increases obviously and crystallization temperature tends to decrease when the basicity exceeds 1.35. The method presented before is proved as a potential way to resolve the contradiction between horizontal heat transfer controlling and solidified shell lubricating for peritectic steel slab casting. But further study on improving the flow property of liquid slag is needed. This work can be used to guide mold fluxes design for high speed continuous casting of peritectic steel slabs. 相似文献
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A. Badri T. T. Natarajan C. C. Snyder K. D. Powers F. J. Mannion A. W. Cramb 《Metallurgical and Materials Transactions B》2005,36(3):355-371
Surface defects, such as oscillation marks, ripples, and cracks that can be found on the surface of continuously cast steel,
originate in the continuous casting mold. Therefore, a detailed knowledge of initial solidification behavior of steel in a
continuous casting mold is necessary because it determines the surface quality of continuously cast slabs. In order to develop
an understanding of the initial solidification of continuous cast steels, a “mold simulator” was designed and constructed
to investigate heat-transfer phenomena during the initial phase of strand solidification. The mold simulator was used to obtain
solidified steel shells of different grades of steel under conditions similar to those found in industrial casting operations.
The resulting cast surface morphologies were compared with industrial slabs and were found to be in good agreement, indicating
that it is possible to simulate the continuous casting process by a laboratory scale simulator. 相似文献
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本文介绍了LB-352液位计在连铸结晶器钢水液位测量与自动控制中的应用。用根据连铸结晶器尺寸、预先制做的长形试块,模拟连续铸钢过程中,结晶器内钢水液位的波动等方法,对LB-352液位计进行初步的标定和调试。在连铸热调过程中,对其进行与拉坯实际情况逐步迫近的细调试,最终达到了LB-352液位计与PLC控制器、液压伺服系统联锁控制塞棒动作,调节由中间包流入结晶器钢水的流量,实现了结晶器内钢水液位在点达 相似文献
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高铝钢连铸保护渣性能的控制 总被引:5,自引:0,他引:5
高铝钢连铸过程中,钢渣反应将导致连铸保护渣成分和性能发生较大的变化。论文从热力学方面分析了高铝钢钢渣反应特性,计算结果表明为了减少渣中SiO2的还原,应控制渣中的SiO2含量,此外,在连铸保护渣中配加MnO能抑制渣中SiO2的大量还原;同时采用高碱性高玻璃化连铸保护渣理论保证熔渣在钢渣反应和吸收Al2O3夹杂后性能的稳定性。在此基础上,进行了工业性试验,结果表明:高铝钢连铸保护渣吸收夹杂物后熔点和粘度变化不大,铸坯表面和皮下质量良好,完全满足高铝钢浇铸要求。 相似文献
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本文运用数值模拟研究方法,研究高拉速厚板坯连铸非稳态结晶器流动特性,研究浸入式水口堵塞、水口不对中对结晶器流场、液面流速和对初生坯壳的影响。高拉速厚板坯连铸,铸坯质量下降,90%表面缺陷集中在铸坯边角区域,最严重的缺陷是铸坯中心和角部纵裂。非稳态工况对结晶器的流场影响因素更为显著,研究发现水口堵塞程度、水口出口流速、流量分配比是结晶器液面流速不对称、液面波动的主要影响因素,水口不对中是钢液流股对结晶器初生坯壳局部热冲击的主要因素,因此高拉速连铸应尽量避免非稳态工况操作,确保产品质量和效率的双赢。 相似文献
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薄板坯连铸结晶器三维流场和温度场的数值模拟 总被引:11,自引:0,他引:11
针对ISP型薄板坯连铸结晶器,利用数值模拟的方法,计算结晶器的内流体的三维流场和温度场,比较和分析水口结构形状,插入深度及拉坯速度对结晶器内流场和温度场的影响,为薄板坯连铸结晶器以及相适应的伸入式水口结构形状选型提供参考。 相似文献
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介绍了连铸坯表面纵裂纹的成因及特征,从钢水成分、连铸机拉速、保护渣液渣层厚度和结晶器液面波动、结晶器冷却效果和二次冷却方面,提出了防止连铸坯表面纵裂纹的具体措施。 相似文献
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Multiphase Flow and Thermo-Mechanical Behaviors of Solidifying Shell in Continuous Casting Mold 总被引:1,自引:0,他引:1
The metallurgical phenomena occurring in the continuous casting mold have a significant influence on the performance and the quality of steel product. The multiphase flow phenomena of molten steel, steel/slag interface and gas bubbles in the slab continuous casting mold were described by numerical simulation, and the effect of electromagnetic brake (EMBR) and argon gas blowing on the process were investigated. The relationship between wavy fluctuation height near meniscus and the level fluctuation index F, which reflects the situation of mold flux entrapment, was clarified. Moreover, based on a microsegregation model of solute elements in mushy zone with δ/γ transformation and a thermo-mechanical coupling finite element model of shell solidification, the thermal and mechanical behaviors of solidifying shell including the dynamic distribution laws of air gap and mold flux, temperature and stress of shell in slab continuous casting mold were described. 相似文献
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《Baosteel Technical Research》2015,(4):20-25
With the continuous improvement of product quality and function,the quality control of mold steel is becoming increasingly stricter. Argon protection is essential for ensuring casting quality during ingot casting. The development of argon protection in ingot casting and the production process of enclosed argon protection in 40 t line is discussed,w ith particular focus given the factors affecting the flow of oxygen in the argon protection cover are discussed. The influence of some related factors on the oxygen content is analyzed. On the basis of the online measurements of the oxygen content,the optimized operational approaches for improving the effect of argon protection are developed. This can decrease the liquid steel via secondary oxidation,and improve the quality of the ingots. 相似文献