Structure of the continuously cast Ni-based superalloy GMR 235

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• 作者：F. Zupanič ; T. Bonč ; ina ; G. Lojen ; B. Markoli ; S. Spaić
• 关键词：Ni-based superalloy ; Solidification ; Microstructure ; Continuous casting ; Surface marks
• 刊名：Journal of Materials Processing Technology
• 出版年：2007
• 出版时间：7 May 2007
• 年：2007
• 卷：186
• 期：1-3
• 页码：200-206
• 全文大小：1661 K

文摘

In this work we characterized the structure of continuously cast small cross-section rods (Ø10 mm) of the Ni-based superalloy GMR 235. In the microstructure prevailed dendritic columnar γ-grains with γ′-precipitates. In the interdendritic regions MC-carbide and M₃B₂-boride were identified. The inverse macrosegregation was very faint, except at the secondary witness marks and natural corrugations. It was found that the alternating drawing mode had much greater influence on microstructure than other casting parameters. Special attention was given to explanation of processes leading to formation of surface marks (primary and secondary witness marks and natural corrugations). Formation of hot tears and appearance of inverse segregation is also discussed.