Campag NR rear hub near dead

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09-23-19, 06:43 AM

#26

rootboy

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Originally Posted by Mad Honk

How do you harden a surface after the polishing process to get the hardness different than the base metal?

How about case hardening?

https://en.wikipedia.org/wiki/Case-hardening

09-23-19, 08:03 AM

#27

gfk_velo

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Quote:

Originally Posted by Mad Honk

I may be whistling in the graveyard here, But how do you think those cones got polished in the first place? How do you harden a surface after the polishing process to get the hardness different than the base metal? I spent more than a few years in the steel industry and have yet to see any post production hardening of the surfaces. I get that hard anodizing of aluminum will increase it's tensile strength, but have no knowledge of anything like that for steel. What the steel is, is what it is. High carbon, chrome, or vanadium will help it out but won't change the structure of the base material. Smiles, MH

If I understood correctly from a long discourse I had at the Campag factory (sadly in Italian - and I am not that fluent), they used to cut the radius, polish, case-harden and then polish again. Case hardening extends a fair way into the material (in comparative terms) so if the pits are very minor, I'd think that you can polish out without losing all of the hardened layer ...