| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a gear part having improved facial pressure strength resistance and to provide a method of producing thereof. <P>SOLUTION: The gear part according to the present invention has a quench hardened layer around the teeth surface thereof. The gear part is made of a steel containing carbon of 0.43 to 1.2 wt%, and a relationship between a DI value (inch) showing the hardenability of austenite phase in a gear pitch circle and a module M (mm) of the gear part satisfies an expression of DI≤0.12×M+0.2. An alloy element concentrates in cementite phase in a pretreated steel, thereby causing concentration of the alloy element in ferrite phase to decrease, and a rapid induction heating to A3 transformation temperature or Acm transformation temperature causes carbon of 0.3 to 0.8 wt.% to diffuse and dissolve in austenite phase, and the DI value is preferably determined by using a concentration of the alloy element and a concentration of the carbon. The alloy element is one or more elements selected from the group consisting of Mn, Cr, Mo, V and the like. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
