共查询到18条相似文献,搜索用时 125 毫秒
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对首钢第二炼钢厂板坯铸机提高拉速的工艺进行了研究,为适应1.2~1.3m/min拉速条件下稳定正常的生产,对结晶器冷却水量、浸入式水口参数、二冷比水量、振动参数、保护渣性能指标进行了调整。通过采取以上措施,板坯月产量达到了9.5万t的水平,达到了双流铸机的产量水平。 相似文献
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根据攀钢2号板坯连铸的工艺特点,在分析了高速连铸对保护渣性能要求的基础上,研究开发出了适应高拉速浇注的连铸保护渣,工业试验结果表明,研究开发的XIZ-DT高拉速用连铸保护渣,在拉速≥1.75m/min时,结晶器内熔化状况良好,保护渣消耗量0.38-0.42kg/t,所浇铸坯表面质量良好,铸坯表面无清理率98.70%,能够满足攀钢2号板坯高速浇注的需求。 相似文献
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拉速变化对IF钢铸坯非金属夹杂物含量的影响 总被引:2,自引:0,他引:2
采用原位统计分布分析仪(OPA)对IF钢连铸过程拉速变动对铸坯表层试样非金属夹杂物含量的影响进行了研究,发现在由较高拉速(1.4m/min)向低拉速(0.6m/min)变动时,对结晶器保护渣卷入的影响主要发生在降速初期,而随后的降速和低拉速下停止降速对铸坯表层试样夹杂物含量影响不大。当由较低拉速(0.6m/min)向高拉速(1.4m/min)变动时,对保护渣卷渣的影响主要发生在提升到高拉速后停止升速阶段,而低拉速时启动升速和随后均匀升速对铸坯夹杂物含量的影响不大。研究中还发现在较高拉速下(1.4m/min)即使较少量地变速,也会造成铸坯表层夹杂物含量的显著增加,因此在较高拉速时应避免对拉速进行变动或尽量采用低的拉速改变速率。采用数值模拟方法对拉速变化影响进行的研究结果同样表明,在较高拉速下发生的拉速变化,对结晶器内钢水流动有更显著的影响。 相似文献
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美国动力钢公司的薄板连铸机为双流 ,A流于 1995年11月 10日投产 ,B流于 1998年 5月 18日投产。 1998年 1月 ,单流月产量达到 9.6万 t,平均注速为 4.95 m/ min。为了使平均注速提高到 5 .5 m/ min,且不影响铸坯质量或不增加拉漏率 ,该公司进行了大量的研究。研究发现在提高注速时 ,为保证铸坯质量必须选择合适的结晶器保护渣。该公司研究的四种典型的结晶器保护渣的性能见附表。通过对注速、热传导以及结晶器保护渣消耗的研究得出 ,结晶器保护渣 A、B适于低、中碳钢的生产。 附表四种典型的结晶器保护渣的性能项目 结晶器保护渣 A结晶… 相似文献
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H.S.Liu T.Fest D.Letzel J.Schoenbeck A.Zajber 《上海宝钢工程设计》2001,15(4):43-51
台湾烨联钢公司的现有小方坯连铸机改造成可生产小方坯和窄板坯的兼用连铸机。经改造后,该小方坯连铸机设有谐振式结晶器和组合式结晶器搅拌器。板坯铸流采用四偏心轮振动系统。板坯铸流至小方坯铸流的间距为1650mm。同时也可以1100mm间距按一机两流方式在板坯铸流上浇铸小方坯。板坯铸速0.8—1.2m/min。小方坯铸速1.1-2.2m/min。在设计方案中考虑了通过更换极少量部件和通过快速更换铸流导辊,形成板坯铸流浇铸方式,使调整时间大大缩短,与单一功能连铸机相似。除了可生产小方坯,该新的高度灵活兼用连铸机还可生产最大宽度1300mm的板坯,藉此钢厂可将板坯产量提高到150000t/a左右。 相似文献
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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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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
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针对薄板坯连铸中碳钢边角部出现的角横裂纹缺陷,通过典型中碳钢(50CrV4)缺陷试样的金相分析、热塑性分析和铸坯二冷模拟仿真计算等方法,确定了原工艺条件下典型中碳钢铸坯边角部在铸机弯曲和矫直处的温度为850 ℃、处于第Ⅲ脆性区(650~945 ℃)是造成铸坯边角部裂纹的主要原因。结合武钢CSP铸机工艺特点,提出了连铸高拉速4.0~4.2 m/min,二冷前段强冷、后段和边部弱冷以及提高铸机设备精度等控制措施。各项措施实施后,中高碳钢铸坯边角部温度显著提升,热轧板表面横裂纹基本消失,各项性能满足客户要求。 相似文献
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《钢铁冶炼》2013,40(2):112-118
AbstractIt is very important to obtain reliable lubrication from casting powder both at the meniscus and in the gap between strand and mould as it affects slab surface quality and caster productivity. With knowledge of mould friction, a quantitative insight into the behaviour of powder during caster operation is possible. In the present research, the friction was studied based on a slab continuous caster equipped with hydraulic oscillators. The effects of mould oscillation and the abrupt change of casting speed on mould friction force were evaluated, and the characteristics of lubrication behaviour in a casting sequence were investigated. In particular, a comparison between the mould friction force between sinusoidal oscillation mode and non-sinusoidal oscillation mode was made. Finally, the characteristics of friction before a breakout are discussed. The experimental and analytical results may contribute to the development of mould friction online measurement and more clearly learn the lubrication behaviour in different conditions. 相似文献
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外加液态保护渣可以提高铸坯质量和可浇性。在某厂板坯连铸机上,分别采用液态保护渣和固态保护渣进行多钢种浇注试验,对比液态保护渣和固态保护渣消耗量、结晶器温度分布、拉坯摩擦力及铸坯质量,并对液态保护渣的应用前景进行展望。结果显示,液态保护渣比固态保护渣消耗量增加60%左右,结晶器温度分布更均匀,连铸拉坯摩擦力降低约15%,铸坯质量有所提高。这说明在连铸过程中,液态保护渣使结晶器和铸坯间传热更均匀;液态保护渣润滑效果更好,可以提高铸坯质量。同时,有望不添加F-、Na+等有害离子,改善环保问题。 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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《钢铁冶炼》2013,40(3):206-215
AbstractAt the thin slab caster of Tata Steel, IJmuiden, mild cooling mould powders were introduced with the aim to control the mould heat transfer during casting. These mild cooling mould powders are characterised by specific values of basicity, solidification point and chemical composition. Application of these mould powders resulted in a redistribution of mould heat transfer during casting, i.e. a reduced and more stable mould heat transfer in the critical upper part of the mould and an increased mould heat transfer in the lower part of the mould. The average mould heat transfer and hence the shell thickness at mould exit are comparable to the standard powder. The application of mild cooling mould powders also resulted in improved solidification behaviour of the steel shell. A thinner chill zone with smaller thickness variations was observed. Furthermore, it was found that the mould taper required optimisation to match the changes in shrinkage behaviour to ensure uniform solidification. The use of mild cooling powders was observed to give an increase in mould friction. Mould thermal monitoring indicated that the solid slag films fractured (sheeting) in the upper part of the mould. However, no operational problems were reported, which indicate that the first 200 mm under the steel meniscus is essential for initial solidification and for the formation of a homogeneous steel shell. All these findings can be understood by considering the crystallisation properties of the mould slag, which include the cooling rate. Mild cooling has been shown to provide uniform heat transfer and adequate lubrication for high speed thin slab casting. 相似文献