High-performance lightweight materials are urgently needed, given the pressing quest for weight reduction and the associated energy savings and emission reduction. Here, by incorporating the multi–principal element feature of compositionally complex alloys, we develop the concept of lightweight steels further and propose a new class of compositionally complex steels (CCSs). This approach allows us to use the high solid solution strengthening and shift the alloys’ compositions into previously unattainable phase regions where both nanosized shearable κ-carbides and non-shearable B2 particles are simultaneously formed. The achievement of dual-nanoprecipitation in our CCSs leads to materials with ultrahigh specific tensile strength (up to 260 MPa·cm³ g⁻¹) and excellent tensile elongation (13 to 38%), a combination outperforming all other high-strength high-entropy alloys and advanced lightweight steels. Our concept of CCSs is thus useful for guiding the design of ultrastrong lightweight metallic materials.

迫切需要减轻重量和相关的节能减排，迫切需要高性能的轻质材料。在这里，通过结合成分复杂的合金的多主要元素特征，我们进一步发展了轻质钢的概念，并提出了一类新的成分复杂的钢（CCS）。这种方法使我们能够使用高固溶强化，并将合金成分转移到以前无法获得的相区域，在该相区域中同时形成了纳米级可剪切κ碳化物和不可剪切B2颗粒。在我们的CCS中实现双纳米沉淀导致材料具有超高的比抗张强度（高达260 MPa·cm ³ g ^-1）和出色的拉伸伸长率（13％至38％），其性能优于所有其他高强度高熵合金和先进的轻质钢。因此，我们的CCS概念对于指导超强轻质金属材料的设计很有用。