| 摘要 |
<p>Provided is a steel material having excellent contact pressure fatigue strength, which is formed from a steel for machine structural use and is used as a component for power transmission such as a gear or a shaft that is used in an automobile or an industrial machine. This steel material contains, in mass%, 0.15-0.35% of C, 0.30-0.95% of Si, 0.10-1.00% of Mn, 0-0.030% of P, 0-0.030% of S, 0.80-2.30% of Cr, 0-0.30% of Cu, 0.008-0.500% of Al, 0-0.0030% of O, 0.0020-0.0300% of N, 0-3.00% of Ni, 0-0.29% of Mo, 0-0.200% of Ti, 0-0.20% of Nb and 0-0.0050% of B, with the balance made up of Fe and unavoidable impurities. This steel material has a parameter represented by Si + Cr - 2Mn in mass% of 1.05 or more and a parameter represented by 0.7Si + 2.5Mn + 2.0Cr + 2.5Ni + 4.0Mo in mass% of 6.30 or less.</p> |
