Grain boundary character distribution and properties of austenitic stainless steel prepared by laser powder bed fusion

doi:10.13251/j.issn.0254-6051.2025.04.022

Abstract

Abstract: By using laser powder bed fusion (LPBF) process, 316L austenitic stainless steel was prepared with high energy density and inter-layer stay printing strategy, and then the solution treatment at 1300 ℃ was carried out. The microstructure, mechanical properties and corrosion resistance of the stainless steel were studied. The results show that the near-equiaxed grains with populated annealing twins was obtained in the 316L steel by LPBF, and the fraction of Σ3ⁿ(n=1, 2, 3) grain boundaries reaches 47.3%, indicating that dynamic recrystallization (DRX) occurs during the LPBF thermal cycles. Compared to the specimen treated by post solution treatment, the LPBF specimen has high strength and excellent corrosion resistance. It suggested that the fine and uniform equiaxed grain microstructure and the high fraction of special grain boundaries after dynamic recrystallization are responsible for the simultaneous improvement of strength and corrosion resistance of the LPBF specimen.

Key words: laser powder bed fusion, dynamic recrystallization, annealing twin, austenitic stainless steel

CLC Number:

TG142

Cao Lice, Shen Falei, Pan Laitao, Li Chenchen, Du Wenxiang, Fang Xiaoying. Grain boundary character distribution and properties of austenitic stainless steel prepared by laser powder bed fusion[J]. Heat Treatment of Metals, 2025, 50(4): 156-161.

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