The influence of build direction on the mechanical properties of SS316L produced by selective laser melting was investigated. The tensile tests were performed at room temperature for vertical and horizontal specimens. Large crater‐like voids were found, which are believed to be responsible for the reduced strength and premature failure of the vertical specimens, whereas the nano‐sized dimples were detected on the fracture surface of the horizontal specimens. Creep tests were also conducted at 650°C in the applied stress range of 149 to 226 MPa in vertical and horizontal directions. The vertical direction specimen showed better creep resistance. The micro‐cracks were delayed compared with the horizontal case. Optical micrographs of the tip of the creep rupture specimens along the cross‐sectional area were observed. The micro‐cracks located at grain boundaries. The grain shapes orientated in the applied stress direction for the vertical specimens, and perpendicular to the applied stress direction for the horizontal specimens.

中文翻译：

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构造方向对选择性激光熔炼316L不锈钢拉伸和蠕变性能的影响

研究了构建方向对选择性激光熔融生产的SS316L力学性能的影响。拉伸试验是在室温下对垂直和水平样品进行的。发现了较大的陨石坑状空隙，这被认为是造成垂直试样强度降低和过早破坏的原因，而在水平试样的断裂面上则检测到了纳米级的凹痕。还在650°C下在垂直和水平方向上施加的149至226 MPa应力范围内进行了蠕变测试。垂直方向的样品显示出更好的抗蠕变性。与水平情况相比，微裂纹被延迟了。沿横截面观察了蠕变断裂试样尖端的光学显微照片。微裂纹位于晶界。晶粒形状沿垂直试样的施加应力方向取向，垂直于水平试样的施加应力方向取向。