Alloy 2205 1

[usadaytrader]

I am a newbie engineer and do not have any experience in corrosion engineering. I was assigned to try to determine if Alloy 2205 is suitable for SS316 replacement. We have an RDT unit at a regional seweage treatment plant experiencing surface corrosion. I addition to that, we have other items (I don't know which so I am unable to specify) made of SS316 and are also experiencing the same corrosion problems. I know compared to the many other posts here it is very vague. but what advantages can 2205 give me over 316. Basically I am looking for experiences and a cliffnotes version of 2205 as to not get confused. Thanks

 

[CoryPad]

2205 is lower cost than 316.

 

[SJones]

http://www.nickelinstitute.org/inde...=15786&la_id=1&method=1&search_keyword=duplex

Steve Jones
Materials & Corrosion Engineer

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

 

[strider6]

2205 has generally (water, atmospheric exposure) higher corrosion resistance than 316, higher mechanical properties (approx double than 316) and for what i know the cost is slightly higher than 316. welding of 2205 need some particualar care but is not a problem.

http://www.spiusa.com/Ref001/1008EN-GB4_Duplex.pdf

S

Corrosion Prevention & Corrosion Control

 

[davefitz]

2205 duplex is not susceptible to chloride stress corrosion cracking and less susceptible to general corrosion than 316, but is yet vulnerable to crevice corrosion.

Welding to a lower alloy. or less noble material will require "overmatching" using an incolnel weld filler, and no preheat used unless very thin sections are welded together.

Crevice corrsoion addressed by flake glass or gasket sealer at flanges and zones which trap liquids.

Alos, bulk purchases of 2205 to be tested to ensure proper mix of austenite/ferrite , other QC issues are well addressed by vendores that market 2205==> use google .

 

[EdStainless]

With today's lower Ni prices and high Mo prices 2205 is not less than 316 on a $/lb basis.
But that said it is a much better alloy. It will handle significantly higher chloride levels without pitting. The higher strength allows you to use thinner material in many application and through this route save significant money.

= = = = = = = = = = = = = = = = = = = =
Plymouth Tube

 

[moltenmetal]

Finished article pricing for things like pipe, fittings and especially valves have never been cheaper in 2205 duplex than in 316 in my experience.

The superiority of the corrosion resistance for services where 316 is marginal, not the materials price savings, is the reason to use it. A cheaper vessel or piping system which is scrap due to corrosion in a few years has not saved anybody any money- unless of course the design life was only a few years!

 

[rmw]

Plymouth Tube sent me a Christmas Card today. In it was this link;

http://www.plymouth.com/_tmp/Janikowski Blessman FWH You have a Choice.pdf

I think you will find a lot of what you are looking for here even though the paper specifically relates to boiler feedwater and surface condenser tubing. The technology is applicable across a wide range of tubing. You may even spot a different grade you hadn't considered yet.

Enjoy.

rmw

 

[SJones]

2205 duplex is not susceptible to chloride stress corrosion cracking

Maybe take a look at the attached document.

Steve Jones
Materials & Corrosion Engineer

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

 

[davefitz]

touche', Sjones.

as per the IMOA "practical guidelines for the fabrication of duplex stainless steels" , 2205 may have better resistance than 316L to chloride stress corrosion cracking, it is not immune, and might not be reliably used for HX service in saltwater applicatons due to its vulnerability to crevice corrosion.

refer to these guielines at ....

<

http://www.nidi.org/index.cfm/ci_id/10683.htm>

 

[SJones]

That's a better statement

Steve Jones
Materials & Corrosion Engineer

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

 

[strider6]

In this page of Outokumpu webnsite there is a graph with resistance to SCC of duplex and SS 316.

http://www.sandvik.com/sandvik/0140/internet/se01598.nsf/cdatas/98A6DA5240941BAF41256618006F4439

S

Corrosion Prevention & Corrosion Control

 

[0707]

About this subject go to

http://www.sandvik.com/sandvik/0140/internet/se01598.nsf/cdatas/257EF36BEA44B38ECA2569ED0005A110

lm