Novel maraging steel | 0.08%C-18%Ni-3%Al-4%Mo-0.8%Nb | Martensite + high density Ni(Al, Fe) coherent nano-precipitates | Solution treatment + aging | UTS = 2200 MPa, EL = 8% | High Ni content and high alloy cost | [38] |
Ultra-high strength steel with composite nano-precipitates | C 0.1%，Ni 10%, Cr 10%, Co 10% | Martensite + composite nano-precipitates (NiAl, Laves phase, MC carbide, Cu particles) | Solution treatment + aging | UTS 1800 MPa, EL 8% | Precipitate composition and sequence sensitive to chemical composition | [41,46] |
| Ultra-high strength steel with multiphase composite microstructure | C 0.25%-0.6%，Mn 5%, Cr 5% | Martensite (+ bainite) + retained austenite + small carbide | Quenching + partitioning (+ tempering) | UTS = 2000 MPa, EL = 10% | Poor weldability, microstructure sensitive to composition | [51,52] |
Nanostructured bainitic steel | C 0.3%，Ni 10%, Si 10%, Mn 10% | Bainitic ferrite lath (20-40 nm) + retained austenite (volume fraction 20%) | Bainite isothermal transformation + tempering/partitioning/cryogenic treatment | UTS = 2500 MPa, EL 8% | Long isothermal transformation period, poor weldability | [53] |
| Ultra-high strength steel subjected to severe plastic deformation and partitioning induced by high dislocation density | 0.47%C-10%Mn-2%Al-0.7%V | High density dislocation martensite + metastable austenite | Cold rolling + low temperature tempering | YS 2200 MPa, EL 16% | Complex processing, deformation parameters and heat treatment need stir control | [50] |