共查询到18条相似文献,搜索用时 453 毫秒
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根据立式双辊铸轧机设备实际条件,设计出一套镁合金铸轧布流系统,利用Anycasting?软件对布流系统内的流动状态和温度分布进行了数值模拟;同时根据相似理论制作出一套与实际系统比例为1∶1的有机玻璃模型,用以进行物理模拟。结果表明,多级以及中间带有挡坝的布流系统不但可降低流股对熔池液面的冲击,还可以获得均匀的流场,挡坝的最优化高度为10mm,并优化了挡坝位置,确定了布流系统出口处的宽度。当宽度为1mm时可获得稳定且温度分布均匀的熔池。 相似文献
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利用改进的数学模型,通过数值模拟方法研究一种基于水平单带连铸的单冲击布流系统。采用中试铸机完成物理实验,从而对数值模拟结果进行验证。结果表明,弯月面处的湍流行为并非来自中间包,也不是来自熔体与冷却传送带的冲击。弯月面的高湍流能量来自传送带的移动,并且这个高湍流动能区可以搅动弯月面附近熔体。所研究的布流系统可与传送带共同构成一个缓冲区域,该区域的存在可避免工艺参数波动,尤其是中间包内熔池深度的变化。铸带底部的温度变化率比铸带表面的快大约4倍。 相似文献
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针对双辊薄带连铸过程,使用了耦合湍流流动和凝固传热的三维数学模型,模拟计算了使用楔型布流系统浇注时,连铸熔池内钢水的流动形态和凝固情况。结果表明,楔型布流系统可使钢水在熔池内合理分布,有利于均匀凝固。 相似文献
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结晶器内钢液流动状态会直接影响铸坯的质量,不合理的流场会导致液面流速过大,弯月面波动过大,造成卷渣。采用几何相似1:1水模型和Fluent流体力学软件研究了220 mm×260 mm方坯结晶器直通型水口浇注下,不同浸入深度对结晶器液面波动、表面流速、流场分布、冲击深度、保护渣覆盖的影响。结果表明:直通型水口流股集中,冲击深度较大,液面波动均匀,波动受浸入深度和拉速的影响较小。保护渣渣层覆盖良好,渣层均匀,出现卷渣的可能性较小。综合考虑冲击深度,保护渣活跃程度,结晶器电磁搅拌的影响,现场合适的浸入深度为80~100 mm。 相似文献
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SIMULATION OF THE TWIN ROLL STAINLESS STRIP CASTING PROCESS 总被引:3,自引:0,他引:3
1. IntroductionTwin roll stainless strip casting' process which can directly cast a thin strip with thickness less than 10mm from a molten metal pool is being researched by industrious workersall over the world. Compared with the conventional continuous casting, this process caneliminate the expansive and complex hot-rolling facilities, and can reduce both the capitalinvestmellt and the cost of production. Among various processes under development, thetwin-roll strip casting is revealed as the… 相似文献
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Cao LiuSun FeiChen TaoTeng ZihaoTang YulongLiao Dunming 《金属学报》2017,(11):1521-1531
Misrun and cold shut are common defects in casting productions, which could make surface accuracy of castings poorer, even leading to cracking and casting scraps in them. The formation process of misrun and cold shut is hard to be observed directly only by experiment measures, since casting filling process is in a state of high temperature flow inside mold. The key to predict the defects accurately is the way to handle the effect of liquid-solid conversion on flow behavior. On the basis of existing methods for treating liquid-solid conversion, a calculation model of mushy region flow behavior through measurement of solid-fraction is developed, which can effectively investigate the flow behavior of mushy region in different stages. Generally, the critical solid-fraction method is adopted for mushy region with high solid-fraction, in consideration of that only the speed of high solid-fraction region is supposed to be zero during casting filling process. The variable viscosity method is applied for mushy region with low solid-fraction, due to casting filling process being unlikely to form toothpaste-like flow. However, the porous medium drag-based model is used for mushy region with middle solid-fraction, because only the middle solid-fraction region can be equivalent to porous medium. Combining the above three methods, a flow-field calculation program considering the effect of liquid-solid conversion on flow behavior during casting filling process is developed, in which finite volume method (FVM) is included for discretization equations; the pressure implicit with splitting of operator (PISO) algorithm is added for coupling pressure and velocity; the volume of fluid (VOF) algorithm is also combined for interface tracking. An numerical simulation of water-filled S-shaped channel is performed in the case of taking no account of liquid-solid conversion, and the simulated results coincide better with the experimental results, which certifies for its accuracy as an adopted model. Since the bottom filling casting craft is commonly used in single-shape casting, a comparison between the calculated results obtained using other single models and those using this model at different control parameters, is needed. The better agreement between them indicates that this new model is appropriate for calculating the flow behavior in mushy region. 相似文献
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连铸中间包内夹杂物去除机理的水模型研究 总被引:2,自引:0,他引:2
通过选择乳状液滴模拟夹杂物和连铸中间包水模型实验,考察了控流装置、浇铸速度及夹杂物粒径对中间包内夹杂物去除行为的影响规律.结果表明:挡墙-挡坝组合控流去除夹杂物效果最佳,中间包内强湍流区夹杂物的碰撞、聚合以及向上和表面流速的增加是主因;中间包注流区加入冲击槽,虽然其流体流动特征发生改变,但对夹杂物去除率的影响并不显著;浇铸速度较高时,仅靠控流装置的优化已不能很好地改善夹杂物的去除效果. 相似文献