| 摘要 |
A maraging steel for metallic belts which has a composition capable of being reduced in the content of TiN, which serves as a starting point for fatigue failure in a high-cycle-rate region. The composition facilitates nitriding to heighten the surface hardness. The steel has a nitrided surface layer having increased compressive residual stress and hence improved flexural fatigue strength. In the steel, former austenite crystal grains have been reduced in size in order to secure higher strength and higher ductility. The maraging steel contains, in terms of mass%, up to 0.01% C, up to 0.1% Si, up to 0.1% Mn, up to 0.01% P, up to 0.005% S, 17.0-22.0% Ni, 0.1-4.0% Cr, 3.0-7.0% Mo, 7.0-20.0%, excluding 7.0%, Co, up to 0.1% Ti, up to 2.5% Al, up to 0.03% N, up to 0.005% O, and up to 0.01% B (excluding 0), provided that Co/3+Mo+4Al is 8.0-15.0%, with the remainder being Fe and incidental impurities.
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