Ferrite content test on Duplex SS welds for Structural applications

[vellingiri]

Hi All,

My understanding about Duplex S.S is mostly used in pressure vessels. Ferrite content testing is important quality test for its welding because mostly it has to perform in corrosive environment with high thermal stresses.

But,we are using Duplex SS in rolling stock underframe where the environment is not highly corrosive and stresses are present due to static/ dynamic loading only.

Can anybody suggest what is the relevance of ferrite tests done on Duplex SS welds for application in structures.

 

[Ron]

I would suggest you post this in the metal and metallurgy engineering forum. Then red flag this post and it will be removed.

 

[dig1]

When you do re-post, please indicate what grade of duplex you are using. i am assuming you will use 2101 or 2202 but many people may think 2205 and that may impact comments received.

However, a short answer is that limiting ferrite is important because (for one thing) it is brittle. I would suggest that your ferrite range be limited to 30% to 60% as measured by either an image analysis or point count. This would apply to both the deposited weld metal and the heat affected zone.

ASTM A923 Method B could be used as a guideline but this is specifically for 2205 so this may not be directly applicable.

However, please re-post as Ron suggested to obtain a greater range of feedback.

Thanks,

Patrick