Many traditional approaches for strengthening steels typically come at the expense of useful ductility, a dilemma known as strength–ductility trade-off. New metallurgical processing might offer the possibility of overcoming this. Here we report that austenitic 316L stainless steels additively manufactured via a laser powder-bed-fusion technique exhibit a combination of yield strength and tensile ductility that surpasses that of conventional 316L steels. High strength is attributed to solidification-enabled cellular structures, low-angle grain boundaries, and dislocations formed during manufacturing, while high uniform elongation correlates to a steady and progressive work-hardening mechanism regulated by a hierarchically heterogeneous microstructure, with length scales spanning nearly six orders of magnitude. In addition, solute segregation along cellular walls and low-angle grain boundaries can enhance dislocation pinning and promote twinning. This work demonstrates the potential of additive manufacturing to create alloys with unique microstructures and high performance for structural applications.

许多传统的钢加固方法通常是以牺牲有用的延展性为代价的，这是一个被称为强度-延展性折衷的难题。新的冶金工艺可能提供克服这一可能性的方法。在这里，我们报告说，通过激光粉末床熔合技术增材制造的奥氏体316L不锈钢具有超越常规316L钢的屈服强度和拉伸延展性的组合。高强度归因于固化过程中的蜂窝状结构，低角度晶界和制造过程中形成的位错，而高均匀伸长率则与由分级异质微结构调节的稳定且渐进的加工硬化机制有关，其长度范围跨越了近六个数量级。此外，沿细胞壁和低角度晶界的固溶偏析可以增强位错钉扎并促进孪晶。这项工作证明了增材制造技术的潜力，可以制造出具有独特的微观结构和高性能的合金，以用于结构应用。