PREN
PREN
(OP)
Colleagues:
Can PRE numbers be applied to predict resistance to MIC (Microbiologically Induced Corrosion)? After all, Mo improves the passive layer. Is there a published relationship between PREN Vs resistance to MIC?
Thanks,
Corgas
Can PRE numbers be applied to predict resistance to MIC (Microbiologically Induced Corrosion)? After all, Mo improves the passive layer. Is there a published relationship between PREN Vs resistance to MIC?
Thanks,
Corgas





RE: PREN
RE: PREN
RE: PREN
Cladded vessel (separator) has shown extensive pitting due to MIC (sample already taken to id type of bacteria). Material is 304L and damage is confined to below water level (between 4 and 8 position).
What material would you recommend to repair existing cladding with weld overlay? Logic tells me that I should aim for a higher PREN material. Also, a biocide treatment is going to be put in place but it needs to be repaired.
RE: PREN
I would recommend using either 308L or 316L filler metal to weld repair the 304L cladding. Using a higher PREN filler metal is not going to help against MIC. Using a biocide treatment will be effective.
RE: PREN
If you select an alloy that is suitable for seawater service (6%Mo superaustenitic, superferritic, super duplex) then you will have MIC resistance. At any level less than that all bets are off.
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Plymouth Tube
RE: PREN
Agreed. The only publication that I've seen that shows some correlation is B.J.Little, P.A. Wagner and R.I. Ray, "An Experimental Evaluation of Titanium's Resistance to Microbiologically Influenced Corrosion", paper presented at NACE Corrosion/92, Preprint No 173, 1992 . They tested AL6XN in various MIC environments.
Reference was given by A.John Sedriks
Thanks,
Corgas