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为了进一步提高真空熔铸高温合金铸件的的质量,本文系统研究了在K417高温合金真空熔铸过程中施加由工频交流电磁场和恒稳直流电磁场组成的复合磁场对高温合金铸件凝固组织的影响。实验结果表明:在浇注完毕后同时施加60A旋转电磁场和290 A恒稳直流电磁场的工艺条件下,由于恒稳直流电磁场在金属液面处产生的电磁制动效应可以抑制施加旋转电磁场所引起的金属液面的波动,因此既可以避免因金属液液面波动太大而使铸件缩孔恶化的情况出现,又可以大幅提高旋转电磁场在金属液凝固过程中的作用范围和效果,最终得到细小等轴晶比例达到99%、缩孔明显改善的优质高温合金铸件。
In order to further improve the quality of vacuum casting superalloy castings, this article systematically studied the impact of the composite magnetic field consisting of commercial alternating current electromagnetic field and constant DC electromagnetic field on the solidification microstructure of superalloy castings during the vacuum casting of K417 superalloy. The experimental results show that under the conditions of simultaneous application of 60A rotating electromagnetic field and 290 A constant DC electromagnetic field after casting, the electromagnetic braking effect caused by the steady DC electromagnetic field at the metal surface can restrain the metal caused by the application of rotating electromagnetic field Liquid level fluctuations, it can avoid the metal liquid due to excessive fluctuations in liquid casting shrinkage hole to make the case worse, but also can significantly improve the rotating electromagnetic field in the liquid metal solidification process of the scope and effectiveness of the final fine equiaxed Crystal ratio of 99%, shrinkage significantly improved high-quality high-temperature alloy castings.