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Thermal stability of the dislocation cellular structure and the precipitation behavior of chromium carbide (M₂₃C₆), silicide (Mo₃Si), and σ phase in austenitic 316L stainless steel (SS) fabricated by laser powder bed fusion (L-PBF) additive manufacturing (AM) were studied at 500–800 ℃. The dislocation cellular structure and hardness remained stable at 500 ℃ and 600 ℃ for up to 400 h. However, the regional coarsening of cellular structure resulted in a slight reduction of hardness after 100 h aging at 700 ℃. Short-time thermal exposure (less than 0.5 h) at 800 ℃ destructed the cellular structure. Discontinuous coarse M₂₃C₆ carbide and semi-continuous fine molybdenum silicide precipitated along high angle grain boundaries (HAGBs), but not on the dislocation cellular boundaries at 700 ℃. A moderate Cr depletion of ~12.7 wt% was observed along HAGB. At 800 ℃, the σ phase precipitated both along the HAGBs …