Masking against hydrogen embrittlrment

[israelkk]

I have an 4340 steel part heat treated to 160-180 ksi but locally on small area it has a hard case 60-65 RC (flame or induction hardening). I would like to zinc coat it except the hard case area. What is the common way to mask/protect the hard cased area from hydrogen penetration during the zinc coating. The part will be baked against hydrogen embrittlement after the coating.

 

[CoryPad]

I believe copper plating is the preferred method.

 

[rodneybennet]

You might want to check

http://www.composite-agency.com/case-stories.htm,

here you will find diffusion / hydrogen embrittlement assessment for several different materials.

Kind Regards,
Rodney