Selective laser melting (SLM) process allows greater geometry flexibility; therefore, it has become more widespread in its deployment in the industry for fabricating metal alloys. However, a material characterization study is needed in order to understand better the correlation between the process, microstructure, and performance. In the current study, the raw SLM fabricated AISI stainless steel 304 L was fabricated with different processing parameters and build orientations (horizontal, inclined, and vertical). The tensile behavior was evaluated under different strain rates (0.0001/s, 0.001/s, 0.01/s, and 0.1/s) and then compared to commercial cold-rolled and annealed counterparts. Grain structures, tensile strength, elongation-to-failure, strain rate sensitivity, work hardening, and fractographic analysis were evaluated in terms of the effect of energy density, build orientation, and strain rate. The results indicate that the tensile strength increases with increasing strain rates. On the contrary, the elongation-to-failure shows a decreasing trend with strain rates. Tensile properties of specimens built in the horizontal and inclined orientations are more sensitive to strain rates due to the smaller dimension of grain structures. Tensile anisotropy depends on the energy input, where a high energy density could yield a strong build orientation-dependent anisotropy. The Hall-Petch relationship is validated to explain the mechanical anisotropy in different build orientations for SLM samples. The strain hardening exponent and work hardening rate are revealed to be positively correlated, and both of them increase with smaller grain sizes. The fine dimple features indicate the ductile fracture mode regardless of strain rates. The size of the ductile dimples seems to depend on the strain rates and build orientations.

选择性激光熔化 (SLM) 工艺允许更大的几何形状灵活性；因此，它在金属合金制造工业中的应用越来越广泛。然而，为了更好地理解工艺、微观结构和性能之间的相关性，需要进行材料表征研究。在目前的研究中，原始 SLM 制造的 AISI 不锈钢 304 L 采用不同的工艺参数和构建方向（水平、倾斜和垂直）制造。在不同的应变速率（0.0001/s、0.001/s、0.01/s 和 0.1/s）下评估拉伸行为，然后与商用冷轧和退火对应物进行比较。晶粒结构、抗拉强度、断裂伸长率、应变率敏感性、加工硬化、并根据能量密度、构建方向和应变率的影响对断口分析进行了评估。结果表明，抗拉强度随着应变速率的增加而增加。相反，断裂伸长率随应变率呈下降趋势。由于晶粒结构尺寸较小，水平和倾斜方向的试样的拉伸性能对应变率更敏感。拉伸各向异性取决于能量输入，其中高能量​​密度可以产生强的构建方向相关的各向异性。验证了 Hall-Petch 关系以解释 SLM 样品在不同构建方向上的机械各向异性。应变硬化指数和加工硬化率呈正相关，并且它们都随着较小的晶粒尺寸而增加。无论应变率如何，精细的凹坑特征都表明了韧性断裂模式。韧性凹坑的大小似乎取决于应变率和构建方向。