hydrogen embrittlement of flame hardened part 1

[stralkin]

I have a large part made of 1060 steel that has been flame hardened on one surface to Rc>60. We need to electroplate the part for corrosion and wear purposes (0.2 to 0.3 mills dense Chrome), but are concerned about warpage if we bake. most of the material is Rc ~ 25. do i need to worry about Hydrogen Embrittlement without the bake?

 

[TVP]

Yes.

 

[strider6]

http://www.me.wpi.edu/MTE/Research/PDF/Hydrogen.pdf

s

Corrosion Prevention & Corrosion Control

 

[stralkin]

Thanks for the link to the paper on H2 Embrittlement - it makes clear that electroplating on relatively high hardness material is a concern, but it is not quite the same situation as i have, where most of the material that is to be electroplated is relatively soft (<25 Rc) with flame hardening on one of the surfaces resulting in a thin layer with high hardness - would you expect a crack to run through the softer material?

 

[CoryPad]

It is possible

 

[redpicker]

Yes, cracking is possilbe and you should bake. The flame hardening process will impart a high level of residual stress in the part. Add a hydrogen source to this and you have everything you need to see delayed cracking.

I am not sure I understand the concern on warpage. At the low temperatures used for baking, the only warpage I can see would be from the relaxation of these residual stresses, which will occur naturally, to some extent, with use. It seems to me it would be better to for this to happen piror to putting into service rather than after.

rp