The cellular sub-grain was widely reported as the main contributor to the high yield strength of selective laser melted stainless steels, but its underlying strengthening mechanism was still unclear. In this study, the high yield strength of selective laser melted 316L stainless steel was studied by manipulating the cellular sub-grain through various heat treatments. Although the cellular sub-grain still existed in the heat-treated samples, the yield strength decreases significantly after heat treatment. This study firstly demonstrated that the high density of dislocations at the cellular boundary played a key role in the interfacial strengthening effect. Despite the small misorientation between the neighbouring cellular sub-grain, the cellular boundary acted as the high-angle grain boundary during deformation. The dislocation network consisted of the cellular boundaries provided a high density of interfaces that significantly inhibited the dislocation motion, resulting in higher yield strength.

蜂窝状亚晶粒被广泛报道为选择性激光熔融不锈钢的高屈服强度的主要贡献者，但其潜在的强化机制仍不清楚。在这项研究中，通过操纵各种热处理来处理蜂窝状亚晶粒，研究了选择性激光熔融316L不锈钢的高屈服强度。尽管热处理后的样品中仍存在蜂窝状亚晶，但热处理后的屈服强度明显降低。这项研究首先证明，在细胞边界处高位错密度在界面增强作用中起着关键作用。尽管相邻的蜂窝状子晶粒之间的取向差很小，但在变形过程中，蜂窝状边界却充当了高角度晶粒边界。