GH4169合金真空感应熔炼过程中夹杂物演变规律研究

Research on the evolution law of inclusions in GH4169 alloy during the vacuum induction melting process

高温合金的夹杂物含量和存在形态影响合金的使用寿命及产品质量。文中系统研究了GH4169合金在真空感应熔炼过程中,O、N、Mg含量变化规律及夹杂物演变规律。结果表明,随着精炼时间的延长,GH4169合金中O含量逐渐降低,最终趋于平衡值,N含量逐渐降低;合金全熔时,夹杂物尺寸均小于1μm;精炼后,合金中氧化物含量明显减少;若在加入Al、Ti元素前未进行降温结膜操作,会加剧坩埚与熔体的反应,导致合金中Mg含量升高,夹杂物数量增多;加入Al、Ti、Mg等元素后,合金中夹杂物数量明显增加,夹杂物主要是以Mg-Ti-O为核心的Mg-Ti-Nb-O-N复合夹杂物。

The content and form of inclusions in superalloys have an important influence on the service life and reliability of the alloy.The changes of oxygen,nitrogen and magnesium content and the evolution law of inclusions of GH4169 alloy during the vacuum induction melting process were studied systematically.The results show that the oxygen content of the GH4169 alloy will not decrease all the time during the smelting process,but will tend toward an equilibrium value,and the nitrogen content will gradually decrease with the extension of refining time.The size of inclusions is generally less than 1μm when the alloy is fully melted.After refining,the amount of oxide in the alloy decreased obviously.If the liquid alloy is not cooled before adding Al and Ti,the reaction between the crucible and melt will be intensified,increasing the magnesium content and the number of inclusions.After the addition of Al,Ti and Mg,the number of inclusions in the alloy increases obviously,and the types of inclusions tend to be simple,mainly forming Mg-Ti-Nb-O-N complex inclusions with Mg-Ti-O as the core.