Hydrogen Embrittlement of 8620 Pickled
Hydrogen Embrittlement of 8620 Pickled
(OP)
If we acid pickle 8620 steel in the as cast condition and then machine and heat treat (carburize at 1700F) will the heat treating drive off any hydrogen or acid that is present in surface defects?
TIA
TIA





RE: Hydrogen Embrittlement of 8620 Pickled
http://www.welding-advisers.com/
RE: Hydrogen Embrittlement of 8620 Pickled
Are you pickling just to remove molding sand or something else?
Can you use mechanical claning?
What is you acid/acids for pickling?
RE: Hydrogen Embrittlement of 8620 Pickled
Regards,
Cory
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: Hydrogen Embrittlement of 8620 Pickled
RE: Hydrogen Embrittlement of 8620 Pickled
RE: Hydrogen Embrittlement of 8620 Pickled
I wanted to be general when I mentioned 'pickling'. Its actually a type of vibratory finishing process that polishes the small castings we use in our products. There have been some fatigue failures that we think are related to the shot blasted finish from the foundry....we wanted to smooth up the outside surfaces.
The reason I mentioned pickling is that yesterday I was informed that the vibratory finishing process uses an acidic base wash (the parts are actually black from the acid).
The parts were rinsed after the finishing process.
Machining consistes of some holes drilled and a skim cut at a couple of locations.....so most of the casting surface is not removed.
Sorry for the mis-communication.
TIA
RE: Hydrogen Embrittlement of 8620 Pickled
RE: Hydrogen Embrittlement of 8620 Pickled
This process is not a vibratory finish process that uses a soap based liquid medium.....but a speciality acid based medium. Supposedly it is supposed to polish the surfaces without very agressive ceramic media needed.....this way the corners do not get rounded off so much.
RE: Hydrogen Embrittlement of 8620 Pickled
If so thats a pretty mild acid they use, in fact I think its weaker than the citrisurf citric acid passivation solutions.
RE: Hydrogen Embrittlement of 8620 Pickled
It's a proprietay process developd by the chemist at a finishing hose here in eastern PA. I don't know much about the specifics but I think I need to give them a call to find out.