共查询到19条相似文献,搜索用时 171 毫秒
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长城特钢一厂采用空心保护渣浇铸含TI不锈钢,经试验成渣性能良好.铸坯表面质量提高,修磨铸坯金属损耗下降了1.3%,试验结果表明国内研制的空心保护渣其性能优于进口粉状渣. 相似文献
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保护渣中Al2O3质量分数变化是渣钢交互作用的结果,包括吸附钢液中Al2O3夹杂和渣金反应产物。氧化铝对保护渣成分与性能稳定性影响突出,进而影响铸坯质量。分析指出,影响保护渣吸附Al2O3夹杂的因素包括接触角、润湿速率和界面张力、熔渣成分和性能等。熔渣与夹杂物的交互作用行为决定了其对上浮夹杂的去除率。高铝钢连铸过程渣金反应尤为突出,保护渣的工作性能将发生明显改变。基于近年关于Al2O3夹杂的吸附溶解试验研究,以及高铝钢浇铸渣金反应及其保护渣性能变化的研究结果,探讨了通过合理设计保护渣成分或更换渣系等措施来实现该类钢种保护渣工作性能的相对稳定性。 相似文献
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针对生产16Mnq,A36等稀土处理钢使用普通保护渣存在的问题,分析了 稀土钢专用保护渣性能要求,阐述了其设计过程与试验,并开发了稀土钢专用保护渣,满足了板坯铸机生产稀土钢的要求。 相似文献
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在连铸过程中,保护渣起着提高产品表面质量、提供适宜的润滑和绝热保温等作用,因此,保护渣的正确选择对单个钢种是至关重要的。为了获得良好的表面质量,选择合适的保护渣目前仍然是一个难题。广泛采用的办法是使用供应商推荐的在其他工厂试验成功的保护渣以及在工业试验中获得成功的保护渣。这些新型保护渣的工业试验不仅导致极大的操作费用,而且带来了连铸机损坏的隐患(漏钢、结晶器磨损和停机)。此外,对于已选择的保护渣,即使在正常的成分范围内,其表现的性能也是不同的。新钢种需求的增长和当前经济的不平衡,导致塔塔钢铁公司欧洲工厂通过保护渣试验,寻找其替代品。为了研究与钢水成分、不同的浇注参数和产品表面质量相关的保护渣的行为,蒂塞德技术中心(TTC)启动了一项保护渣评估试验工作。在塔塔钢铁公司欧洲工厂进行了几次在线和离线的监测,收集了多个钢水试样、原始保护渣、渣膜和渣圈试样,并分析了不同浇次的有关保护渣、熔融层厚度、振痕和表面质量的数据。保护渣特性分析技术,如粘度测量、STA热分析、金相学、化学分析已经被应用于这个评估试验。试验观察到顶渣中氧化铝含量增加的同时,伴随有不同化合物的吸收和减少现象。试验证明:氧化铝、氧化钙、氧化硅和氧化锆化合物的增加和减少会影响保护渣的性能。 相似文献
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稀土处理钢连铸结晶器保护渣的研制 总被引:8,自引:0,他引:8
研究了稀土氧化物(RE_xO_y)对连铸保护渣理化性能的影响,分析了RE_xO_y在液体保护渣中的扩散熔解过程,确定了稀土处理钢连铸保护渣的化学成分。应用新型的稀土处理钢用保护渣没有发生拉漏事故,并提高了铸坯表面质量。 相似文献
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薄板坯连铸结晶器铜板温度及热流密度分布 总被引:5,自引:1,他引:4
薄板坯连铸结晶器的传热过程直接影响到铜板的寿命,有必要研究薄板坯连铸结晶器的传热特征。为了研究薄板坯结晶器的热流密度,通过开发的结晶器温度监测软件检测了珠钢结晶器铜板的温度。根据在线实测的铜板温度以及薄板坯连铸机冷却参数,建立了薄板坯结晶器铜板传热模型,计算并验证了结晶器热流密度的分布函数,同时通过二次回归得出了结晶器热流密度与结晶器高度的关系式。结果表明,在宽度方向上铜板温度和热流密度的分布具有相似的规律性,距离弯月面越近,热流密度和温度的波动越大。弯月面处热流密度值大于4.2MW/m^2,是造成结晶器铜板被侵蚀的主要原因。 相似文献
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In this paper, the high temperature rupture strengths of some solid mould flux slag films in Swedish continuous casting processes are presented. The apparatus, designed and constructed in the present laboratory is based on the principle that the solidified film of the mould flux slag is subjected to elongation stress at temperatures below the solidus points of the fluxes. The rupture strength tests were conducted in air. The results indicate that the rupture strength is dependent on the extent of polymerization of the silicate network. The results of Raman spectra studies of the mould flux slags used in the present work were corroborated by estimations of the NBO/T ratios of the slags. It was found that lower NBO/T ratios in the slag led to higher rupture strengths. Earlier measurements of the viscosities, thermal diffusivities as well as stress relaxation results for the same slags followed a similar trend indicating the dependency of these properties on the slag structure and a clear link between thermophysical and mechanical properties of slags. The results are expected to provide some basic guidelines to develop the next‐generation mould flux and modelling of the continuous casting process. 相似文献
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《钢铁冶炼》2013,40(1):37-54
AbstractWith the drive to cast higher quality, many minimills are adopting mould powder as a lubricant for the continous casting of steel billets. Over the past three decades considerable experience has been accumulated on the relationship between mould behaviour and billet quality for oil lubrication, but comparatively few studies have been conducted for mould powder lubrication. This study, conducted at a Canadian minimill, involved instrumenting four faces of a copper mould with thermocouples and monitoring mould temperatures during casting of 208 × 208 mm billets with mould flux lubrication. Billet samples were also taken to coincide with periods of measurements. Mould temperatures were monitored for two different mould powder compositions, for different mould oscillation frequencies, two mould cooling water velocities, and a range of steel compositions. An inverse heat conduction model was developed to calculate mould heat transfer from the measured temperatures. In this paper, which is the first part of a two part series, details of the inverse heat conduction model and mould heat transfer data are presented. The results obtained for mould flux lubrication have been compared with those for mould heat transfer for oil lubrication. For peritectic steels, with carbon content in the range 0·12–0·14%, it was found that lubricant type has little influence on the measured mould heat flux distribution at the centreline of a face. The peak mould heat flux was found to be approximately 2500 kW m-2 . In contrast, for medium carbon steels, mould heat transfer with mould powder was significantly lower than when oil was employed as a lubricant. For instance, at the meniscus, the peak heat flux with mould powder was approximately 2500 kW m-2 , which was half that recorded with oil as a lubricant. The influence of oscillation frequency, mould cooling water velocity, and mould powder type on mould heat flux has also been presented. 相似文献
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A full-scale finite-element model of a slab and its mould was developed to reveal the complex thermal behaviour of special steel in a vertical caster during slab continuous casting. An inverse algorithm was applied to calculate the heat flux and combined with the temperatures measured using thermocouples that were buried in different positions of the mould. The model was validated by comparing the calculated temperature with the measured ones. The temperature distribution of the slab is not symmetric, reflecting the non-uniform nature of heat transfer and hence the necessity of formulating a full-scale model. It will provide a helpful tool for further improving the casting parameters and operations for special steel. 相似文献
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结合某厂连铸生产数据,采用带有附加动量项的改进BP算法,建立了连铸板坯中心偏析的BP人工神经网络预测模型。应用结果表明,其预测准确率为90%,可满足连铸生产中对铸坯中心偏析预报精度的要求。分析导致预报偏差的主要原因是,网络模型隐含层节点较多、网络结构复杂、中心偏析等级为1.0的样本学习次数较多和噪音样本剔除不彻底等。 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