Influence of Elevated Temperatures on the High-Strength X3NiCoMoTi 18-9-5 Maraging Steel Behavior

High-strength X3NiCoMoTi 18-9-5 maraging steel belongs to highly researched materials due to its wide application range. Thanks to its outstanding mechanical properties, it is usually used for high-loaded parts in the aircraft and aerospace industry. Hardness and ultimate tensile strength are strong-ly affected by heat treatment allowing to create Ni3X (X = Mo, Ti), Fe2Mo, and (Fe, Ni, Co)3(Ti, Mo) precipitate which almost doubles their properties. In the present study, microstructure and mechani-cal properties of the thermo-mechanically processed maraging steel were studied two modes of heat treatment. Microhardness values improved from 350 HV0.1 to 650 HV0.1, and ultimate tensile strength has increased from 1029 up to 2140 MPa. On the contrary, elongation has reduced from 11 to 4 %. After heat treatment, precipitates Ni3Mo has been formed in the material volume.