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Hydrogen embrittlement suspicion
Hard Chrome |
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Piston rod of 1045 steel d=18 mm, l=30 cm should follow the sequences as below:
1-first grinding
2-surface induction hardening depth=1mm
3-cracks detection
4-tempering microhardness at this stage 450 HV (300 gr load)at o.6-1.0 mm depth area.
5-grinding
6- hard chromium micro cracked type 25 micron.
7-last buffing 5 micron
THE QUESTION IS : SHOULD WE EXPECT HYDROGEN EMBRITTLEMENT AND NEED FOR BAKING? The expert assistance will be appreciated.
Hadi Khosravi- Tehran, Iran
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Hadi, if it were my part, I would bake it. 150C, for 4 hours, within 4 hours of plating.
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Lee Gearhart |
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Dear Lee,
Thank u for respond. I received different answers, the most interesting was by Mr. Guffie through his book : Handbook of Hard Chromium Plating.in page 84 as follows: above 35 rockwell baking required for deposit thicker than0.001 inch. In our line I exactly sticking the boarder line 0.001 or 25 micron .That is why I need more experienced answer hoping get rid of baking facility for 3000 shaft per day.
Sorry for late respond,
Hadi Khosravi- Tehran, Iran