| 摘要 |
Provided is a maraging steel with which maraging steel that has been subjected to nitriding treatment has excellent fatigue strength and stable high strength. Maraging steel that has been subjected to nitriding treatment to a thickness of 0.5 mm or less and comprises, by mass%, 0.008% or less of C, 0.5% or less of Si, 0.5% or less of Mn, 0.5 to 1.5% of Cr, 16.0 to 22.0% of Ni, 3.0 to 7.0% of Co, and 3.0 to 7.0% of Mo is a maraging steel further comprising, by mass%, 0.6 to 1.3% of Al and Fe and impurities as the balance, wherein the impurities are maintained at 0.01% or less of Ti, 0.01% or less of Nb, 0.01% or less of Ta, and 0.01% or less of W, the ratio of Al and Ti is Al/Ti <u>></u> 250, and by Vickers hardness, the surface hardness of the maraging steel is 800 to 1,050 HV and internal hardness of the maraging steel is 570 HV or less. |
