| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a flat member provided with a gear part of a surface hardness of Hv400-500 at the gear part, a low manufacturing cost, and a high tooth form precision at the gear part, after hardening. SOLUTION: To a flat member of steel comprising C by 0.10-0.18 wt.%, Si by 0.03 wt.% or lower, Mn by 0.60-1.50 wt.%, P by 0.020 wt.% or lower, S by 0.013 wt.% or lower, B by 0.001-0.004 wt.%, and balance comprising Fe and unavoidable impurities, press work is applied to from a driven gear 10 provided with a gear part 10b of a prescribed form. High-frequency hardening is then applied only to the gear part 10b, thereby the surface hardness of the gear part 10b after hardening is set to Hv400-500.</p> |
