Availability of Improved PM Steels by Secondary Operations According to Different Requirements for Each Application

In order to improve fatigue strength of PM components, a suitable alloying system was selected and secondary operations like a heat treatment and a shot peening were optimized. Resultant stress from residual stress and stress profile from loading was used to estimate the optimized secondary operations. At last 670MPa of fatigue strength has been achieved.

Then the possibility to apply PM components for an actual gear in a car transmission was investigated by using simulation, fatigue limit diagram and a frequency for each gear to estimate it under a certain condition. A stress profile of a sprocket is also investigated as another type of component that requires completely different performance.