Q: I’m trying to determine the corrosion resistance of Hastelloy bolts compared to Duplex bolts. Can I use PREN to calculate the corrosion resistance between the two materials?
A: Unfortunately, PREN is a calculation that is only applicable to stainless steels. It cannot be used on nickel alloys like Hastelloy or Inconel. Though you cannot use PREN to give you a numerical comparison of these materials’ corrosion capabilities, I can say that overall nickel alloys will provide a higher level of corrosion protection than stainless steels like Duplex. This is due to the nickel content. Nickel is one of the most corrosion resistant elements. Since Hastelloy bolts contain a high level of nickel they will provide greater resistance compared to Duplex bolts.