Solution annealing 17-4, how much vacuum?
Solution annealing 17-4, how much vacuum?
(OP)
I want to solution anneal 17-4 in a vacuum. We have a spare tube furnace (6” tubes) that is used for semi conductor production. Our problem is that it is an atmosphere furnace. How much vacuum do I need to pull and maintain to avoid surface oxidation? Thanks!





RE: Solution annealing 17-4, how much vacuum?
I ended up heat treating PH alloy before machining and machine all dimensionS in the heat treated condition.
If someone else has another experience I will be glad to hear about it.
RE: Solution annealing 17-4, how much vacuum?
We have has parts vacuum hear treated, but there always is a little surface oxidation so a light pickle was required.
The slight oxidation from the aging isn't enough to cause problem.
= = = = = = = = = = = = = = = = = = = =
Corrosion never sleeps, but it can be managed.
http://www.trenttube.com/Trent/tech_form.htm
RE: Solution annealing 17-4, how much vacuum?
RE: Solution annealing 17-4, how much vacuum?
EdStainless: What do you mean exactly by "both bright and oxide anneal"? What is the difference and how can you be sure of getting a bright anneal? Also, can you give me a precise definition of "a light pickel". I don't think I can get that from Heinz.
We now return you to our regularly scheduled programing.
RE: Solution annealing 17-4, how much vacuum?
RE: Solution annealing 17-4, how much vacuum?
Secondly, vacuum furnaces are different. We have diffusion pumps on ours, and they get to 10^-3 or 10^-4 Torr readily. We don't have any problem with discoloration. Our LA facility has vacuum furnaces with only mechanical pumps, and theirs gets down to 10^-1 Torr. It's not surprising they see more discoloration than we do.
Oh, and to put in a shameless plug, AMS 2769 is a specification on vacuum heat treatment, so it's a useful reference document when dealing with supplier-purchaser issues. But what's best about it is the charts of metal vapor pressures in the back. They make it easy to explain to folks why we have chromium deposits on the cooler regions of our furnace interior.
RE: Solution annealing 17-4, how much vacuum?
Maui
RE: Solution annealing 17-4, how much vacuum?
Can you give some brands or specs for the paint for the book?
Michael McGuire
http://stainlesssteelforengineers.blogspot.com/
RE: Solution annealing 17-4, how much vacuum?
http://www.heatbath.com/Products-link-page.htm
You can contact Heatbath directly at (313)-895-7215 for more specific information regarding this type of paint.
I thought that your book was already in print!
Maui
RE: Solution annealing 17-4, how much vacuum?
Michael McGuire
http://stainlesssteelforengineers.blogspot.com/