| 摘要 |
PURPOSE:To obtain timepiece parts with superior toughness by working a free cutting carbon steel with a specified C content to the required shapes, carburizing or nitriding it, and carrying out hardening and tempering to regulate the hardness of the peripheries and that of the cores. CONSTITUTION:A free cutting carbon steel contg. 0.35-0.55% C is worked to the required shapes of timepiece parts and subjected to a heat treatment such as carburizing or nitriding. Hardening and tempering are then carried out to regulate the peripheries and cores of the parts to different hardness values. Thus, timepiece parts with improved wear and impact resistances and superior toughness are obtd. inexpensively. |
