| 摘要 |
PROBLEM TO BE SOLVED: To provide a gear for an electric car motor, which exhibits more excellent seizure resistance in a power transmission system where a low-kinematic viscosity lubricating oil is used in a high-rotation and high-slide environment.SOLUTION: A gear for an electric car motor has a specified chemical composition and has a steel structure in which a carbide with an average circle-equivalent diameter of 0.05 to 1.0 μm is deposited in an amount of 1 to 5% by area ratio on tempered martensite and/or tempered bainite, and nitrogen concentration in the portion from the surface to a depth of 20 μm is 2.0 to 6.0%. |
