Riff Raff:
Thanks for your interesting posting.
I agree with your general comments on differences on carburizing vs nitriding.
Actually, as you pointed out, we are speculating, because we do not know the actual process applied on the subject gear .
Anyway, on my similar personal experiences, I have seen that on vital parts:
- the "white layer" is removed, with one of the methods you listed
- copper plating is used to mask areas not to be hardened
As far as the weld is concerned, I imagine that in any case the two mating areas of the two "half shfts" are machined to provide a correct match and a good clean diameters and planar surface before welding, tolerances at this stage are usually too tight to leave them as they are.
Last edited by dascanio; 3rd Dec 2012 at 11:35.