| Abstract |
| A study on grain boundary serration in the Ni-based Alloy 690 was conducted by heat treatments and subsequent microscopic examinations. Carbon had a strong influence on the grain growth behavior of this alloy. The grain boundaries were serrated in a limited temperature range during a controlled cooling. As the average grain size with more carbon content increased and/or the cooling rate decreased, the degree of serration increased with a precipitation of coarse intergranular Cr carbides. Cr carbides in Alloy 690 were identified as Cr23C6, and they grew in a planar shape along the curved grain boundaries. The grain boundaries had a convex shape into the incoherent grain, from which it is believed that the grain boundary shape is closely correlated with the grain boundary migration in this alloy during serration. (Received December 17, 2013) |
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| Key Words |
| alloys, annealing, grain boundary, transmission electron microscopy, serration |
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