According to nickel content, maraging steel is divided into 25% Ni, 20% Ni, 18% Ni and 12% Ni. The 18% Ni type is widely used. It is an ultra-low carbon iron-nickel (18%)-diamond (8.5%) alloy containing molybdenum, titanium and other strengthening elements, including 3 grades: 18%Ni (200), 18% Ni (250), and 18% Ni (300) (200, 250, 300 are tensile strength grades, the unit is Ksi).
This high-strength steel is strengthened by the precipitation of intermetallic compounds. High plasticity is achieved by the carbon-free martensite matrix, and finally high strength plastic fit is achieved. This kind of steel has good formability, welding performance and dimensional stability, and the heat treatment process is relatively simple. It is used for aviation and spacecraft components and cold extrusion and cold stamping molds.