I am designing 2 circular mating part for a motor assembly. Material for 1st part is 316 SS (Mod of elasticity: 2.79e7 psi and yield limit of 20,000psi. Material for 2nd part is 17-4 PH steel (Mod of elasticity: 2.85e7 psi and yield limit of 160,000psi. From FEA, i found out that at the mating surface between the two parts, i am getting stresses of abt 93 ksi in 17-4 part and stresses of about 60 ksi in the 316 part. Please let me know if this result seems alright. Should the 316 SS (Lower yield limit) part show more stresses when compared to 17-4 ph (Higher yield limit) If yes , why is it so?? If not , why not??

To satisfy equilibrium, the stress distribution in the contact region needs to be equal for both bodies. For simple geometry without additional loads, the stresses should become uniform proportional to the cross sectional area (stress = force/area), but stress concentration factors may affect this. Can you show a picture?