Any alloy you can get to stand up to this acid combination will have the same problem.
This material will attack any ceramic that I'm aware of.
Most plastics have be reinforced to carry any load and again the mixed acids will attack.
You might look around for Polyethylene coated steel rod if the service isn't too rough and the temperature too high.
Which alloy are you using? How long do you want them to last? With Ni over $10/lb and Mo back over $25/lb you are going to pay.
You might get by with a 6%Mo superaustenitic or a superferritic if it doesn't have to last forever (or won't kill anyone when it fails).
= = = = = = = = = = = = = = = = = = = =
Rust never sleeps
Neither should your protection
in this enviroment the inconel will last aprox 5 years. I do not know much about metals edstainless. i could get away with 2-3 years if the cost is right. are we talking 10 or 50 % savings. are there other names for the metals you spoke of or do you know a good supplier of bar and rod stock?
Thank you for your time
we are using inconel alloy 625. once again i have limited knowledge on metals. basically i know we use c-276, Ti, inconel, hastalloy? and ss316. again the chemistry is 10-20% HF with 5% nitric at 150F. is there a good book or online resource to help me learn more about exotic metals??
One problem is that if you are buying limited quantities of bar stock you are not paying the 'mill price'.
Where are you located?
6%Mo superaustenitic alloys include AL-6XN, 1925hMo, 25-6MO
Superduplex alloys include 2507, Zeron 100, 255
In your case, the ready availability of 625 may make it the best thing to stick with.
Another Ni alloy option would be a "G" type of alloy. They sould work well in this application.
= = = = = = = = = = = = = = = = = = = =
Rust never sleeps
Neither should your protection