Significant enhancement of strength in a lamellar-type nanostructured maraging steel subjected to equal-channel angular pressing for 12 passes

An overall lamellar-type nanostructure was successfully obtained in maraging steel via equal-channel angular pressing (ECAP) for 12 passes at room temperature. After subsequent ageing treatment (440–500 °C), the nano-thick martensite lamellae still survived, while the high density nano-precipitates emerged within them uniformly. By ECAP and subsequent aging treatment, very high tensile strength (2400–2700 MPa) was achieved in comparison with the general strength of 1985 MPa. The influences of ECAP and aging treatment on the microstructures and tensile strength were discussed qualitatively.