高温合金结构件逐渐向复杂化和薄壁化发展，在铸造过程中易出现欠铸及疏松等缺陷。 基于上述问题，通过ProCAST 模拟及实验验证的方法，研究了Mg微合金化对K492M高温合金铸造性能及热物性参数的影响，揭示了 Mg 元素对流动性和疏松缺陷的影响机理。 结果表明，添加Mg元素可有效提高K492M合金流动性，同时降低疏松缺 陷。 Mg含量为0.01%(质量分数)时，流动性明显提高，相较于母合金流动性提高了32.9%，且疏松缺陷从0.033%降至 0.005%。 其作用机理主要在于Mg元素使得K492M合金凝固温度区间减小，黏度降低，有利于提高液相流动性；同时， Mg元素的加入使得剩余液相量和碳化物尺寸增加以及黏度降低，从而降低了合金的疏松缺陷。

Superalloy components are constantly evolving toward more complex structures and thin-walled designs, and misrun and microporosity potentially result from the casting process. In response to the above issues, ProCAST simulations and experiments were used to investigate the castability of the Mg microalloyed K492M superalloy, and the influence mechanism of Mg on fluidity and microporosity defects was also revealed. The results show that the addition of Mg can efficiently improve the fluidity of the K492M superalloy and reduce microporosity. The longest fluidity is obtained when the content of Mg is 0.01 wt.%, which is approximately 32.9% greater than that of the master alloy, and the microporosity decreases from 0.033% to 0.005%. The mechanism is that the solidification temperature range and viscosity are reduced in the Mg microalloyed K492M superalloy, which is conducive to improving the melt fluidity. Moreover, the size of the carbides and remaining liquid phase quantity increase, and the viscosity decreases, which is beneficial for reducing the microporosity.