casting alloy for nitriding
casting alloy for nitriding
(OP)
We are looking to change our existing alloys for investment casting from 431 stainless steel to 4130 or 17-4 ph. We then saltbath nitride the parts. We want to reach a Rc of around 30-34 Rc to prevent the parts to become too brittle but keep a good wear characteristic.
Which alloy would be the best choice and why?
thanks
p
Which alloy would be the best choice and why?
thanks
p





RE: casting alloy for nitriding
SBN or salt bath carbo-nitriding of 17/4 will give you one of the best easily wear surfaces there is. If you use a process like QPQ (Quench Polish Quench) it will enhance most of the properties of either over just QP (Quench Polish).
I would go with the 17/4 as it has been my work horse as far as wearing and galling. I have a sleeve and barrel made from 17/4 and Nitronic 60 that have run over thirty year in split case horizontal injection pump for a waste injection well. I haven't used much SBN 4130. We used a lot of 4130/4140 parts that are gas nitrided in some very severe services with good results.
A word of caution 17/4 doesn't gas nitride very well.
If you could describe your application it will help someone give you a better answer.
It would be nice to know what you are running against.
Here is a pretty good paper on the SBN process.
http://www.burlingtoneng.com/wear_resistance.html
RE: casting alloy for nitriding
RE: casting alloy for nitriding
RE: casting alloy for nitriding
If you sue the 17-4 you need to integrate the SBN and the aging treatment. You don't want to use 17-4 that has not been properly heat treated and aged.
= = = = = = = = = = = = = = = = = = = =
Plymouth Tube