浸炭試料を用いた平歯車の押出し成形

抄録

We previously proposed a two-step cold extrusion method that requires a relatively low punch pressure to form completely teethed gears. The method was found to be capable of forming gears with better quality than gear formed by the conventional method. In this paper we report on our study of the application of this forming method to the S15C low-carbon steel material that has been pretreated by carburization only, and as such has a high carbon content in its surface layer. The specifications of the spur gear examined were as follows: module m=1.25 and number of teeth Z=18. We found that this method is capable of forming gears with a high carbon content in their surface layer with a low punch pressure applied to a material that is of high deformation resistance and pretreated by carburization only. By using this method, the carburization process after gear forming can be replaced with induction hardening, which takes less time.