Pitting Index for Alloy 825? 1

[bmoorthy]

I know that Pitting ndex or PREN are applied to Duplex and Super Duplex Grades. Is this formaula also applicable to Alloy 825 material?

Is it necessary to modify the PREN formula(As defined in NACE) to suit 825 material since "N" is not part of 825 material.

 

[metengr]

Yes it is. The web site below is from Special Metals that contains Technical Information and papers on the use of Ni-base alloys. The paper on

“High-Performance Age-Hardenable Nickel Alloys Solve Problems in Sour Oil and Gas Service” rates the corrosion resistance using CPT and PREN

http://www.specialmetals.com/products/incoloyalloy825.htm

 

[EdStainless]

Please resist using PRE numbers to compare alloys of different classes. There are some offsets that do not make the calcualted values for a duplex mean the same thing that they do for an austenitic.
Look up CPT (CCCT) values. It is best if your source has copared a few different alloys, that way you can see if the data line up with other sources.

= = = = = = = = = = = = = = = = = = = =
Corrosion, every where, all the time.
Manage it or it will manage you.

http://www.trent-tube.com/contact/Tech_Assist.cfm

 

[SJones]

Which begs the question: what is going on behind the original posting? Why is PREN such an issue?

Steve Jones
Materials & Corrosion Engineer

http://www.pdo.co.om/pdo/