2205 /1803 duplex in seawater: corrosion tabels available? 1

[demser]

Hi community

my first time in eng-tips.

I am looking for reliable tables on corrosion of duplex in seawater (if there are any).
Can anybody help me?

Thank you

 

[SJones]

What data do you wish the tables to contain? Is it critical pitting temperature by alloy grade? Mass loss according to flow rate? Etc etc. Duplex stainless steels are usually selected to be resistant to marine corrosion and, therefore, tables don't really apply - it becomes a case of go - no go with respect to temperature limits for example.

http://tools.outokumpu.com/spt/pub/upload/acom_10292653.pdf

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[demser]

SJones, thank you for your advice.

I was looking for 22Cr duplex to be applied at 10°C.
General corrosion seems not to be an issue at this temp., whereas CPT is about 30°C and CCT less than 20°C. So, 22Cr should be applicable.

Regards!

 

[SJones]

For a raw seawater containing system, or a seawater immersed system with or without CP?

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[demser]

for a valve of a seawater piping system. Seawater is applied for cooling.

 

[SJones]

So - chlorinated seawater then? Are you sure about 10 deg C? If you were to use ISO 21457 it would tell you super duplex up to an operating temperature of 20 deg C.

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[SJones]

Just to be clear - UNS S31803 is NOT a super duplex.

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[demser]

Yes, that is the is exactly the problem.
An UNS S31803 device has been ordered though super duplex should be applied - I fully agree to you.
"Troubleshooting: install 1803 and replace by superduplex when available"
At 10°C, CCT is not far...