Nickel-Based Casting Macrosegregation
Nickel-base cast microstructure macrosegregation refers to composition differences over macroscopic distances in castings. They arise from density differences and require diffusion annealing for homogenization.
Physical-Chemical Working Principle
Nickel-base casting macro-segregation refers to concentrated differences in composition over macroscopic distances in the casting. These inhomogeneities arise from density differences between alloy components in the melt, which lead to macroscopic structures during the cooling process.
Metallurgical Relevance & Risks in Welding
These macro-segregations can cause uneven stresses and cracks, especially if they are near weld seams. The different compositions affect the mechanical properties of the weld, such as strength and durability.
Workshop Practice & Instructions
To minimize macro-segregation, careful control of the casting process is required. This includes diffusion annealing to homogenize the casting. When welding, make sure the weld is in a homogenized zone to ensure consistent mechanical properties.