The 316L stainless steel meets all health, strength, and quality standards and is an irreplaceable material in the manufacture of medical equipment. The study focused on the 316L austenitic stainless steel, manufactured with the conventional technique in accordance with ASTM A276/A276M–17 Condition A (samples rolled and annealed at 1050°C with water cooling) and with the selective laser melting (SLM) technique (as-printed starting samples). Unlike conventional manufacturing techniques, SLM offers significantly greater design freedom. An AxioMat 200M optical microscope was employed to analyze the microstructure in different lighting modes, and Kalling’s and Marble’s reagents were used to reveal the structure. The 316L steel produced conventionally mainly consisted of austenite (microhardness of 239 kg/mm²), and substantial cross- sectional grain heterogeneity was established in the test sample. Twins and an atypical multidirectionally oriented dense acicular structure in the area of individual grains (microhardness of 260‒286 kg/mm²) and a unidirectional loose structure (microhardness of 317‒328 kg/mm²) were observed. The microstructure of the 316L steel produced with the SLM technique mainly consisted of austenite (microhardness of 268 kg/mm²). The boundaries of the primary austenite grains were revealed with Marble’s reagent, and arc-shaped structures of the melt bath were established. Kalling’s reagent revealed an atypical multidirectionally oriented intragranular substructure, located primarily between the tops of next-layer tracks in areas where previous-layer tracks overlapped (longitudinal microhardness of 239–251 kg/mm² and cross-sectional microhardness of 286–317 kg/mm²). Elongated columnar grains were found using differential interference contrast microscopy. The average ultimate strength of the steel samples produced with the conventional technique was higher than that of the samples produced with SLM by 4.63%, yield strength by 1.53%, relative elongation by 8.27%, and relative contraction by 18.36%. The lower level of properties and greater spread of their values for the SLM steel were due to the presence of elongated grains and anisotropy relative to the buildup direction. The actual level of properties shown by the SLM steel in the starting state meets the regulatory requirements.

316L不锈钢符合所有健康、强度和质量标准，是医疗设备制造中不可替代的材料。该研究重点关注 316L 奥氏体不锈钢，该不锈钢采用符合 ASTM A276/A276M–17 条件 A 的传统技术（样品在 1050°C 下轧制并水冷退火）和选择性激光熔化 (SLM) 技术制造。打印的起始样品）。与传统制造技术不同，SLM 提供了更大的设计自由度。采用 AxioMat 200M 光学显微镜分析不同照明模式下的微观结构，并使用 Kalling's 和 Marble's 试剂揭示结构。传统生产的316L钢主要由奥氏体组成（显微硬度为239 kg/mm ²），并且在测试样品中建立了显着的横截面晶粒不均匀性。在单个晶粒区域观察到孪晶和非典型的多向致密针状结构（显微硬度为260-286 kg/mm ²）和单向松散结构（显微硬度为317-328 kg/mm ² ）。采用SLM技术生产的316L钢的显微组织主要由奥氏体组成（显微硬度为268 kg/mm ²）。用Marble试剂显露了初生奥氏体晶粒的边界，并建立了熔池的弧形结构。 Kalling 试剂揭示了一种非典型的多向定向晶内亚结构，主要位于前一层轨道重叠区域的下一层轨道顶部之间（纵向显微硬度为 239–251 kg/mm ²，横截面显微硬度为 286–317 kg/毫米²）。使用微分干涉对比显微镜发现细长的柱状晶粒。常规工艺生产的钢样比SLM生产的钢样平均极限强度高4.63%，屈服强度高1.53%，相对伸长率高8.27%，相对收缩率高18.36%。 SLM 钢的较低性能水平和较大的值分布是由于存在细长晶粒和相对于堆积方向的各向异性。 SLM钢在起始状态下表现出的实际性能水平符合法规要求。