| 摘要 |
PURPOSE:To facilitate the working and to enhance the strength by working softened carbon steel into a pinion, annealing the pinion at a prescribed temp., and heating it again to carry out hardening. CONSTITUTION:Softened carbon steel is cut to form a pinion. The tooth part 11 of the pinion is preheated to a temp. above the A3 or Acm point, e.g. to 800- 1,000 deg.C by high frequency heating, and the preheated tooth part 11 is cooled to a temp. below the A3 or Acm point. It is then heated again in a short time and suddenly cooled to form a hardened part 12 by hardening. Thus, a high strength pinion easy to work and having a well hardened structure at the tooth bottom part as well as that at the tooth part is obtd. |
