Ultrathin sheet steels used in the global packaging industry for lightweight packaging applications have been achieved by an extra cold processing (double reduction) to increase yield stress, but usually at a severe loss of uniform elongation and formability. From an industrial point of view, achieving the synergy of strength and uniform tensile ductility in ultrathin sheets is difficult, owing to the stringent industry demands for low alloying and simple processing routes that are often neglected on a laboratory scale. In this work, we demonstrate that high strength and large uniform elongation of ultrathin sheet steels can be simultaneously achieved at low costs by simply using the standard industrial procedures. An optimized double reduction process, which exploits the beneficiary effects of dislocation density control and bake hardening, was designed. This optimized process leads to an ultrathin sheet steel that shows a significantly improved uniform elongation without sacrificing yield stress, thus offering an efficient way to improve the formability of ultrathin sheets with high yield stress. This enhanced uniform elongation is due to the initially unsaturated dislocation density that allows for the further multiplication of dislocations during plastic straining. The results highlight the important role of precisely controlling dislocations in producing the low-cost ultrathin sheet steels with high strength and high uniform tensile ductility, which are highly demanded for large-scale industrial production.

全球包装行业中用于轻质包装应用的超薄钢板已通过额外的冷加工（双压下）来增加屈服应力，但通常会严重损失均匀伸长率和成型性。从工业角度来看，由于工业对低合金化和简单加工路线的严格要求，在实验室规模上常常被忽视，因此很难在超薄板材中实现强度和均匀拉伸延展性的协同作用。在这项工作中，我们证明了通过简单地使用标准工业程序，可以以低成本同时实现超薄钢板的高强度和大均匀伸长率。优化的双重还原工艺，利用位错密度控制和烘烤硬化的有益效果，被设计。这种优化的工艺使超薄钢板在不牺牲屈服应力的情况下显着提高了均匀伸长率，从而为提高高屈服应力超薄钢板的成型性提供了一种有效的方法。这种增强的均匀伸长率是由于最初的不饱和位错密度允许在塑性应变过程中位错进一步增加。结果突出了精确控制位错在生产具有高强度和高均匀拉伸延展性的低成本超薄钢板中的重要作用，这是大规模工业生产的高要求。从而为提高具有高屈服应力的超薄板的成型性提供了一种有效的方法。这种增强的均匀伸长率是由于最初的不饱和位错密度允许在塑性应变过程中位错进一步增加。结果突出了精确控制位错在生产具有高强度和高均匀拉伸延展性的低成本超薄钢板中的重要作用，这是大规模工业生产的高要求。从而为提高具有高屈服应力的超薄板的成型性提供了一种有效的方法。这种增强的均匀伸长率是由于最初的不饱和位错密度允许在塑性应变过程中位错进一步增加。结果突出了精确控制位错在生产具有高强度和高均匀拉伸延展性的低成本超薄钢板中的重要作用，这是大规模工业生产的高要求。