Twins and twin-related domains in a grain boundary-engineered 304 stainless steel

Abstract

The grain boundary (GB) network of a GB-engineered 304 stainless steel was investigated in three dimensions. The GB-engineered sample had a high proportion of twin-related boundaries (∼70%). However, these boundaries were not distributed uniformly, but rather in large-sized twin-related domains (TRDs). All grains within a TRD can be connected by a tree-shaped twin-chain. Any two grains within a TRD have ∑3 n-type misorientation, where the n-value could be determined according to the twin-chain. These results show that the formation of large-sized TRDs is correlated with extensively progressed multiple-twinning processes. A quadruple-junction has three twin-boundaries at most. Furthermore, all observed quadruple-junctions within TRDs have at least one twin-boundary. The common spatial morphologies of twin-boundaries are plane-shape, tunnel-shape and semi-closed tunnel-shape. This paper is part of a thematic issue on Nuclear Materials.

Nuclear Materials

“…The article by Peng et al [6] is particularly relevant to the primary piping in a fission power plant, and indeed to stainless steel overlays that are deposited on to the internal surfaces of steel pressure vessels, since work hardening in austenitic stainless steels is dramatic. Finally, the article by Liu et al [7] touches on the field of grain boundary engineering, which serves an important role in mitigating the corrosion of nuclear components.…”