激光粉末床熔融制备奥氏体不锈钢的晶界特征分布与性能

doi:10.13251/j.issn.0254-6051.2025.04.022

摘要/Abstract

摘要： 采用激光粉末床熔融(LPBF)工艺,利用高能量密度和层间停留打印策略制备了316L奥氏体不锈钢,并对其进行了1300 ℃固溶处理,研究了不锈钢的显微组织、力学性能及耐腐蚀性能。结果表明,LPBF打印316L不锈钢具有近等轴的组织形貌,且晶内产生大量退火孪晶,Σ3ⁿ(n=1, 2, 3)晶界比例高达47.3%,表明LPBF过程中的热循环诱发了316L不锈钢动态再结晶行为。与后续固溶处理引发静态再结晶的试样相比,LPBF试样具有更高强度的同时仍具有优异的耐腐蚀性能。分析认为,动态再结晶后的均匀细小等轴晶组织和高比例的特殊晶界是LPBF试样分别可以提升强度和耐腐蚀性能的重要原因。

关键词: 激光粉末床熔融, 动态再结晶, 退火孪晶, 奥氏体不锈钢

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

中图分类号:

TG142

曹李策, 申发磊, 潘来涛, 李晨晨, 杜文祥, 方晓英. 激光粉末床熔融制备奥氏体不锈钢的晶界特征分布与性能[J]. 金属热处理, 2025, 50(4): 156-161.

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.

参考文献

[1] Astafurov S, Astafurova E. Phase composition of austenitic stainless steels in additive manufacturing: A review[J]. Metals, 2021, 11(7): 1052.
[2] Yim S, Sun J, Minowa K, et al. In-situ observation of powder spreading in powder bed fusion metal additive manufacturing process using particle image velocimetry[J]. Additive Manufacturing, 2023, 78: 103823.
[3] Liu Z, Zhao D, Wang P, et al. Additive manufacturing of metals: Microstructure evolution and multistage control[J]. Journal of Materials Science and Technology, 2022, 100: 224-36.
[4] Nadammal N, Mishurova T, Fritsch T, et al. Critical role of scan strategies on the development of microstructure, texture, and residual stresses during laser powder bed fusion additive manufacturing[J]. Additive Manufacturing, 2021, 38: 101792.
[5] Bakhtiarian M, Omidvar H, Mashhuriazar A, et al. The effects of SLM process parameters on the relative density and hardness of austenitic stainless steel 316L[J]. Journal of Materials Research and Technology, 2024, 29: 1616-1629.
[6] Laleh M, Hughes A E, Tan M Y, et al. Grain boundary character distribution in an additively manufactured austenitic stainless steel[J]. Scripta Materialia, 2021, 192: 115-119.
[7] 温飞娟, 谭春梅, 温奇飞, 等. 增材制造金属结构件残余应力的研究进展[J]. 中国材料进展, 2024, 43(1): 66-78.
Wen Feijuan, Tan Chunmei, Wen Qifei, et al. Research progress on residual stress of metal structure by additive manufacturing[J]. Materials China, 2024, 43(1): 66-78.
[8] Li J, Qu H, Bai J. Grain boundary engineering during the laser powder bed fusion of TiC/316L stainless steel composites: New mechanism for forming TiC-induced special grain boundaries[J]. Acta Materialia, 2022, 226: 117605.
[9] Wang C, Lin X, Wang L, et al. Cryogenic mechanical properties of 316L stainless steel fabricated by selective laser melting[J]. Materials Science and Engineering A, 2021, 815: 141317.
[10] Bian P, Wang C, Xu K, et al. Coupling analysis on microstructure and residual stress in selective laser melting (SLM) with varying key process parameters[J]. Materials, 2022, 15(5): 1658.
[11] Zhou C, Wang J, Hu S, et al. Enhanced corrosion resistance of additively manufactured 316L stainless steel after heat treatment[J]. Journal of the Electrochemical Society, 2020, 167(14): 141504.
[12] Fonda R W, Rowenhorst D J, Feng C R, et al. The effects of post-processing in additively manufactured 316L stainless steels[J]. Metallurgical and Materials Transactions A, 2020, 51(12): 6560-6573.
[13] Krakhmalev P, Fredriksson G, Svensson K, et al. Microstructure, solidification texture, and thermal stability of 316L stainless steel manufactured by laser powder bed fusion[J]. Metals, 2018, 8(8): 643.
[14] 曹永青, 程欢欢, 李智, 等. 扫描间距对选区激光熔化316L不锈钢组织及硬度的影响[J]. 热加工工艺, 2024, 53(19): 22-28.
Cao Yongqing, Cheng Huanhuan, Li Zhi, et al. Effect of scanning distance on microstructure and hardness of selective laser melted 316L stainless steel[J]. Hot Working Technology, 2024, 53(19): 22-28.
[15] Voisin T, Forien J B, Perron A, et al. New insights on cellular structures strengthening mechanisms and thermal stability of an austenitic stainless steel fabricated by laser powder-bed-fusion[J]. Acta Materialia, 2021, 203: 116476.
[16] 张楠, 张海武, 王淼辉. 微米级选区激光熔化316L不锈钢的拉伸力学性能[J]. 金属学报, 2024, 60(2): 211-219.
Zhang Nan, Zhang Haiwu, Wang Miaohui. Tensile mechanical properties of micro-selective laser melted 316L stainless steel[J]. Acta Metallurgica Sinica, 2024, 60(2): 211-219.
[17] Li W, Meng L, Wang S, et al. Plastic deformation behavior and strengthening mechanism of SLM 316L reinforced by micro-TiC particles[J]. Materials Science and Engineering A, 2023, 884: 145557.
[18] Tao H, Lv S, Zhou C, et al. Microstructure evolution and corrosion behavior of deformed austenitic stainless steel manufactured by selective laser melting[J]. Journal of Materials Engineering and Performance, 2021, 30(3): 1652-1664.
[19] Gao S, Hu Z, Duchamp M, et al. Recrystallization-based grain boundary engineering of 316L stainless steel produced via selective laser melting[J]. Acta Materialia, 2020, 200: 366-377.
[20] Wood P, Libura T, Kowalewski Z L, et al. Influences of horizontal and vertical build orientations and post-fabrication processes on the fatigue behavior of stainless steel 316L produced by selective laser melting[J]. Materials, 2019, 12(24): 4203.
[21] Ni X Q, Kong D C, Wen Y, et al. Anisotropy in mechanical properties and corrosion resistance of 316L stainless steel fabricated by selective laser melting[J]. International Journal of Minerals, Metallurgy, and Materials, 2019, 26(3): 319-328.
[22] Wang Y M, Voisin T, Mckeown J T, et al. Additively manufactured hierarchical stainless steels with high strength and ductility[J]. Nature Materials, 2018, 17(1): 63-71.
[23] Zhang Y Q, Quan G Z, Zhao J, et al. A review on controlling grain boundary character distribution during twinning-related grain boundary engineering of face-centered cubic materials[J]. Materials, 2023, 16(13): 4562.