氧氮氢碳硫在镍基高温合金锭中分布的研究

探讨杂质元素分布对避免缺陷产生和扩展意义重大,通过解剖整个镍基高温合金锭,探索氧、氮、氢、碳和硫在镍基合金锭中的分布。解剖方式为横向切片取样为主,沿锭边纵向抽取4mm×4mm细条为辅。横向切5个圆饼,每片制出约56个单样;纵向2根棒,每根棒切出80个单样。数据采集使用基于红外和热导检测原理的氧、氮、氢、碳、硫分析仪器,准确性有保障。实验结果显示:氧、氮、氢、碳沿锭纵向分布较均匀,仅锭芯部例外。其横向分布偏析严重,越靠近中心部位,氧、氮、氢、碳偏析越严重,氧和氢甚至可超出一个数量级范围以上。碳也不例外,在合金锭中心孔洞区域,通过金相显微镜可以观察到微小碳化物颗粒沿缩孔边缘处聚集析出。氮偏析不太严重,硫的横向、纵向分布均匀,未见偏析。

Study on distribution of oxygen,nitrogen, hydrogen,carbon and sulfur in nickel-based high temperature alloy ingot

It is of great significance to discuss the distribution of impurity elements to avoid defect generation and expansion. The distribution of oxygen, nitrogen, hydrogen, carbon and sulfur in nickel-based alloy ingot was explored by dissecting the entire nickel-based high temperature alloy ingot. The anatomical method was mainly transverse section sampling, with longitudinal sampling of 4mm×4mm thin strips along the ingot side as a supplement. Five pieces of round cakes were cut transversely, and about total 56 single samples were prepared for each piece. Two rods were cut longitudinally, and 80 single samples were prepared for each rod. The oxygen, nitrogen, hydrogen, carbon and sulfur analyzers based on infrared and thermal conductivity detection principle were adopted for data acquisition to guarantee the measurement accuracy. The experimental results showed that oxygen, nitrogen, hydrogen and carbon were evenly distributed in longitudinal direction along the ingot with the exception of the ingot core. The segregation of transverse distribution was serious. The closer to the core was, the more serious the segregation of oxygen, nitrogen, hydrogen and carbon. For oxygen and hydrogen, the segregation range even exceed an order of magnitude. Carbon was no exception, and the aggregation and precipitation of tiny carbide particles along the edge of shrinkage cavity could be observed by metallographic microscope in the central pore area of the alloy ingot. The segregation of nitrogen was not serious. The transverse and longitudinal distribution of sulfur was uniform without segregation.