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连铸中碳钢用CK—2保护渣的研制 总被引:3,自引:1,他引:3
中碳钢亦称裂纹敏感性钢,在加铸过程中容易产生铸坯表面纵裂纹等缺陷,使用性能合适的保护渣可以改善结晶器内初始坯壳的传热条件,控制表面裂纹的产生,介绍了研制武钢三炼钢厂中碳钢用保护渣的过程及裂纹控制效果,分析了保护渣使用过程的性能变化和渣膜微观结构。 相似文献
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连铸保护渣基料挥发率的测定 总被引:2,自引:2,他引:0
通过回归正交设计确定了连铸保护渣基料(CaF2-CaO-SiO2-Na2O)挥发率与碱度、Na2CO3、CaF2含量、温度及时间的二次函数关系式。分析结果表明,在碱度较低或时间较短时,Na2CO3、CaF2含量对挥发率影响不大;在上述5个因素中,温度对挥发率影响最大,而Na2CO3对挥发率的影响超过CaF2。 相似文献
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介绍并分析了济钢连铸所使用的保护渣的理化性能,结合生产实际对保护渣物理性能进行研究,优化了各项性能指标,选择与应用了高碱度、低熔点、低粘度、低凝固温度的预熔空心颗粒保护渣,使铸坯一次合格率达到98%以上,消除了由此造成的漏钢事故,保证了生产的顺利进行。 相似文献
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由于钢种特点,连铸马氏体不锈钢板坯容易产生裂纹缺陷,影响生产节奏和修磨效率;同时,由于采用通用型保护渣,也无法针对马氏体不锈钢板坯质量问题做出进一步改进。因此,尝试马氏体不锈钢板坯连铸保护渣的国产化研制和使用,通过保护渣碱度、CaF等的不同范围与保护渣结晶、黏度性能的关系研究,确定采用高碱度、低黏度、高结晶性的保护渣设计原则,并由此得出了适应马氏体不锈钢板坯连铸的保护渣设计方案。实际使用过程中,板坯纵裂率下降幅度达到30%,证明了马氏体不锈钢连铸板坯保护渣设计和研制的合理性和可行性。 相似文献
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结合唐山钢铁股份有限公司FTSC薄板坯连铸机生产实际情况,对导致薄板坯连铸结晶器液位波动的原因进行了分析.结果表明,液位检测系统的零点漂移、二次冷却效果和扇形段对中精度等因素均对结晶器液位稳定性有显著的影响. 相似文献
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以提高结晶器使用寿命和铸坯表面质量为目标,通过建立漏斗区自有锥度、结晶器总锥度和结晶器局部锥度的计算模型,研究了漏斗区的宽度和深度、窄边铜板偏移量以及磨损对结晶器锥度沿高度方向分布的影响,提出了漏斗区自有锥度和局部锥度沿高度方向分布应与铸坯的凝固收缩相匹配的设计理念,对薄板坯连铸结晶器宽面铜板内腔形状及窄边锥度调控工艺进行了优化设计,为结晶器操作工艺及管理制度的优化提供了理论依据。基于上述研究工作,研发了适合于FTSC工艺的新型结晶器,进行了大量的工业生产试验。结果表明:在浇注宽度为1 520mm的铸坯时,窄边附加偏移量可由12mm降低到7mm,窄边铜板的使用寿命得到了大幅度的提高,过钢量为2.25万t后,窄边铜板最大磨损量由5mm降低到2mm以下;新型结晶器有效控制了铸坯窄面凹陷和表面纵裂纹的发生。 相似文献
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武钢三炼钢连铸低碳钢用结晶器保护渣的研制 总被引:1,自引:0,他引:1
介绍用于武钢三炼钢厂板坯连铸低碳钢器保护渣的研制过程,包括实验室保护渣配方的确定,保护渣造粒,以及现场试验。叙述了保护渣使用情况,应用效果,分析了保护渣使用前后的性能变化。 相似文献
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Jeferson L. Klug Daniel R. Silva Suzana L. Freitas Márcia M. S. M. Pereira Nestor C. Heck Antônio C. F. Vilela Detlef Jung 《国际钢铁研究》2012,83(8):791-799
There is a clear trend in industry to eliminate fluorine from metallurgical slags. Regarding the continuous casting process, fluorine in mould powders is undesirable due to the following reasons: (i) evolves easily from slags producing health‐injurious gaseous substances like hydrofluoric acid, (ii) creates problems for storage and utilization of solid waste, and (iii) causes machinery corrosion. A collaboration among universities, mould powder supplier, and steel producer was established, aiming for the development of a new F‐free mould powder for billet casting. Firstly, technological parameters for a particular composition were determined: melting characteristics, viscosity, melting behavior, and crystallization tendency. Afterwards, industrial trials were performed in a Brazilian steelworks, doing some evaluations during the continuous casting process, such as ΔT between water cooling inlet and outlet, slag pool thickness, melting performance, powder consumption, Al2O3 pick‐up, and effect on SEN erosion. Comparable surface quality for the billets was obtained when using the F‐free mould powder, since the amount of scrap produced during the rolling process was not critical. 相似文献
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Flow instability in continuous thin slab casting moulds has been studied using a full scale water model with particle image visualization. The results show that jet impinging depth, circumfluence centre position and wave height are unsteady and periodical. The probabilities of jet impinging depth and circumfluence centre position seem to be Poisson distributions with the highest frequency near the average position. The flow pattern is asymmetrical for a short time and the phase difference of jet impinging depth, circumfluence centre position and wave height on the two sides of the mould centreline is half a period. The average jet impinging depth, average circumfluence centre position, average meniscus wave profile and the highest and lowest meniscus positions are generally symmetrical to the mould centreline. 相似文献
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针对唐钢超薄热带生产线中FTSC工艺的H2长漏斗型结晶器在使用过程出现的问题,开发设计了新的漏斗型结晶器.这种漏斗型结晶器将H2结晶器下部的漏斗区改为平面区,结晶器漏斗区高度由2100 mm缩短为900 mm,并通过模拟计算和优化设计,使结晶器内腔曲面形状各部分平滑过渡,使其具有生产铸坯承受变形应力小的优点.工业应用试验获得了成功,结果表明,使用新型结晶器较好地消除了开浇初期铸坯纵裂现象,提高了铸坯质量,新型结晶器对于钢种和铸坯断面具有良好的适应性,使用寿命达到了进口铜板的水平. 相似文献
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通过结晶器保护渣熔化过程的模拟实验以及对连铸生产过程中结晶器保护渣渣膜样的观察研究,深入分析结晶器保护渣的熔融凝固机理。由实验和观察结果可以看出,熔融凝固过程的微观分析有助于揭示保护渣在结晶器内的行为。 相似文献
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Mould powders impact the stability of the continuous casting process for steel at all casting speeds. The main functions of mould powder are to provide sufficient lubrication and to control the mould heat transfer between the solidifying steel shell and the copper mould. At higher casting speeds associated with thin slab casting, the role of the mould powder is even more important. Actual casting speeds for the thin slab caster at Corus IJmuiden are between 5.4 and 6 m/min; the production level is around 1.3 Mt/year (coils). It has been decided to increase the production of this caster to a level of 1.8 Mt/year (coils). In order to meet this demand, the steel in mould time has to be increased to approximately 85% and the maximum casting speed will be increased to 8 m/min. A collaborative project between Sumitomo Metal Industries (SMI) and Corus IJmuiden was initiated to develop mould powders which facilitate casting speeds up to 8 m/min at the thin slab caster. Main subjects of this project are: mould powder design, characterisation of mould powder and mould slag, trials at the pilot caster of Sumitomo and finally plant trials at the thin slab caster of Corus. A special point of attention is the condition to use mould powder as a granulated material at the thin slab caster. As a consequence, the characterisation work focussed on the choice of raw materials and on the corresponding phase relations at elevated temperatures. Typical of the developed mould powders are so‐called mild cooling properties which will result in a controlled mould heat transfer during casting. In this paper, several aspects of this joint project between Sumitomo and Corus will be described. 相似文献