Yes, I am familiar with 300M and it is on my short list of material options and thank you for the 9310 suggestion. Back to the origonal question. To justify the expense of the 300M on paper by showing an increase in strength over 4340. If the hardness call outs are the same according to this...
The part is a bearing surface and requires the surface to be hard. Not sure if 4340 through hardened to Rc50 would be hard enough surface for wear with out the Nitride? Also not sure what the upper limit of 4340 is with out becoming too brittle.
Yes swall, I have the microhardness profile measured through the case and core. I have modeled the cross section in Microsoft Excel using the varing hardness profile at each depth interval. To compare a part through hardened made of 4340 with a thinner Nitride case I would model acordingly. I...
Thank you for the feedback. Does this mean that regardless of the specific alloy of steel that the strength calculations are based on the heat treat hardness specifications. I guess I assumed that different alloys at the same hardness would have a different YS and perform differently. I was...
I am trying to calculate the strength of a heat treated part made from 8620. I have the hardness profile of the case and core measured from a lab. I have a hardness conversion table for steel to convert Rc to UTS. Is this correct or should I use a table specific to my material. I would...
Yes current design in protypes is an involute design and is not aligned by the major diameter. The tier one supplier does roll their splines. This shaft is farmed out to a tier 2. This specific spline size was choosen because tooling was available, fit in the physical dimensional...
Thanks again for the added information. As far as loading on the shaft the unit was measured on a dyno to 47hp and 36ftlbs. This does not account for impulse or shock loads. The grease is synthetic Mobile 1. There were no nicks on the splines, but the "blue material" showed a lot of wear...
Yes, I must say your last reply smells very rude. I am not an ivory tower engineer. The production floor is somewhere in China. The testing was done in house in the USA. The evaluation of the broken parts was by myself and others. There is no question as to the root cause being axial forces...
Design does have boots as this application is off road and must be water proof. Tier 1 Supplier recommends this coating for friction reduction, but not able to speak to tier 2 supplier applying the coating. Is there a standard call out for thickness or for process of application of teflon on...
Thank you for the quick responces. Yes there is grease on the splines. There are physical limitations to increasing the size of the cages, but we are considering changing the material from 20CrMnTi to 8620 or 4340. Ball splines were considered initially, but this design was simplier and more...
Developing a CV axle with fixed end joints and a sliding spline in the center. Testing the prototypes found that the cages are breaking in the fixed joints because the splines are not slipping under heavy trottle. Current design is involute splines coated with blue antivibe material (Supplier...
Working on an application for a CV axle. Material called out for the cage in the supplier print in the CV joint is 20CrMnTi. This material was said to be equal to SAE 8620. I believe SAE 8620 is equal to 20CrNiMo. The part is to be carburized to HRC 58-62. This is an aftermarket application...
This would be more competition than high mileage. I believe that the two stage heat treat would give a tougher part and still have a hard surface to give good wear resistance. I also understand that the 300M is substantially tougher than 4340. The question for the experts is if the RHC values...
Looking for input on selection of material and heat treat for components in a Rzeppa style two fixed joints with plunging spline CV axle. The design is for an extreme ATV with high angle axles over 30 degrees and large aggressive mud tires. The goal is to design the “ultimate” ATV axle...
