Well first off I'm not an engineer I'm just making them, so a lot of what you are asking is beyond what I know. From what I know this a prototype, and beyond that I'm not sure what its function is I'm just making it to the print they sent me. The material call out is pretty vague it just calls...
We are making bearing races for a customer and the outers get split and assembled over the inners. Target heat treat is 52 - 55 Hrc. My original plan was to split them after heat treat, but I had heard that one of the 4xxx materials gets pretty springy after heat treat I don't know or remember...