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应用Anycasting软件,对Dmax油底壳压铸成形过程进行了模拟。通过观察铝液的填充过程,以及不同浇注方案铸件充型过程的分析和可能产生的铸造缺陷的预测,确定了铝液从铸件两侧同时填充的浇注系统设计方案,经实际生产验证获得了较好的效果。 相似文献
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铸造充型与凝固过程的变网格数值模拟研究 总被引:5,自引:0,他引:5
鉴于充型过程的模拟计算极为复杂,是铸造模拟过程中耗时最多的部分,为缩短充型过程计算时间,提高计算效率,提出了一种利用变网格进行模拟计算的新思路,即采用不同的空间步长分别模拟计算充型和凝固过程,在充型过程的模拟计算中采用比较大的网格,而在凝固过程的模拟计算中采用比较细的网格,并设计程序模块实现两种网格之间的转换和对应,使得充型过程结束时刻的大网格系统温度场能够精确完整地转换为凝固过程开始时刻的细网格系统的温度场。对这种变网格方法进行了验证,并对实际零件进行了模拟分析。结果表明,变网格方法是一种提高模拟计算效率的有效方法,这种方法能够克服充型和凝固过程采用统一的细网格进行模拟计算而产生的计算时间过长,效率低的缺点,使得铸造过程数值模拟的计算速度大大提高,而计算结果仍能满足工程实用的要求。 相似文献
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采用Procast软件中的Mile算法对Ag-28Cu合金连铸凝固过程中温度场的非稳态变化进行了模拟,研究了不同拉速、过热度和换热系数对温度场分布、凝固速率和凝固前沿温度梯度变化的影响。模拟结果表明:随拉速的增大,铸件中心区域的凝固速率加快,凝固前沿温度梯度变化范围减小。换热系数的改变在靠近铸件表面区域对凝固速率基本没有影响,但靠近铸件中心区域后,其凝固速率随换热系数开始大幅度增大。在整个凝固过程中,换热系数越大,凝固前沿温度梯度越大。随浇注温度的提高,其凝固速率呈振荡式增大,凝固前沿温度梯度呈振荡式减小。 相似文献
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本文通过实浇测温法,研究了缝隙式浇注系统对铝合金板状铸件凝固过程中铸件上温度分布、温度梯度分布和凝固次序的影响规律,可供铝镁合金铸件工艺设计时参考。 相似文献
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Numerical simulation of temperature field of copper and copper alloy in horizontal continuous casting 总被引:2,自引:0,他引:2
1IntroductionBecauseofthehighefficiencyandenergysavings,thecontinuouscastingtechnologyiswidelyapplied.Continuouscastingisdifferentfromordinarycastinginwhichthemetalliquidisnotcastintoasinglemold,butsteadilyintoamoldcooledbywater,andthesolidifiedme… 相似文献
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结晶器喂钢带连铸坯凝固过程的数学模拟 总被引:3,自引:0,他引:3
利用旅行薄片微元体能量守恒原理,引入喂钢带相对速度参量,发展了连铸凝固旅行薄片数学模型.采用有限体积法,用Visual Basic语言独立编制源码模拟程序,并对一典型喂钢带的连铸工艺进行模拟分析,得到了连铸坯温度分布和喂进钢带凝固状态的曲线.结果证明,喂进钢带改变了结晶器内温度场的分布和传统的由表及里凝固方式,钢带在结晶器内先凝固后熔化,降低了钢水过热度和铸坯断面温度梯度,使得温度分布更有利于等轴晶结晶过程的进行,有利于铸坯断面形核率的提高.同时该模型也给出了钢带尺寸、拉速和过热度等参数对连铸坯凝固过程的影响. 相似文献
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Most lost-foam casting processes involve non-equilibrium solidification dominated by kinetic factors, while construction of a common dynamic solidification curve is based on pure thermodynamics, not applicable for analyses and research of non-equilibrium macro-solidification processes, and the construction mode can not be applied to nonequilibrium solidification process. In this study, the construction of the dynamic solidification curve (DSC) for the nonequilibrium macro-solidification process included: a modified method to determine the start temperature of primary austenite precipitation (TAL) and the start temperature of eutectic solidification (TES); double curves method to determine the temperature of the dendrite coherency point of primary austenite (TAC) and the temperature of eutectic cells collision point (TEC); the "technical solidus" method to determine the end temperature of eutectic reaction (TEN). For this purpose,a comparative testing of the non-equilibrium solidification temperature fields in lost-foam casting and green sand mold casting hypoeutectic gray iron was carried out. The thermal analysis results were used to construct the DSCs of both these casting methods under non-equilibrium solidification conditions. The results show that the transformation rate of non-equilibrium solidification in hypoeutectic gray cast iron is greater than that of equilibrium solidification. The eutectic solidification region presents a typical mushy solidification mode. The results also indicate that the primary austenite precipitation zone of lost-foam casting is slightly larger than that of green sand casting. At the same time, the solid fraction (fs) of the dendrite coherency points in lost-foam casting is greater than that in the green sand casting.Therefore, from these two points, lost-foam casting is more preferable for reduction of shrinkage and mechanical burntin sand tendency of the hypoeutectic gray cast iron. Due to the fact that the solidification process (from the surface to center) at primary austenite growth area in the lost-foam cylinder sample lags behind that in the green sand casting,the mushy solidification tendency of lost-foam casting is greater and the solidification time is longer. 相似文献