Solution Anneal for duplex SS

[Spoonful]

Hi All,

I got an customer spec saying all duplex SS need to be solution annealed. (requirement from NORSOK M630)for both castings and forgings.

We are going to weld some forging onto the cast. the question is when should the solution anneal be performed? Should it be performed on individual items before they are welded together? Or it should be done after welding?

Thanks in advance for any comment.

Regards

Spoonful

 

[EdStainless]

It has to be done after welding, in order to meet the intent of the requirement.
You may want to anneal before with a long soak, and then just give a shorter anneal after welding (if the weld is in a thin portion). It will depend on the section thickness involved.

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Plymouth Tube

 

[metengr]

The solution anneal must be done after welding.

 

[bhollands]

I would solution anneal the parts before welding as well as after. If you have some sigma in your as cast structure it may cause problems during welding.

Bob

 

[Spoonful]

Thanks for all the comment,
I am buying A182 F51 to weld with A815 WP-S UNS S31803,
both part are solution annealed by code requirement. Is there a reason that solution anneal needs to be done again after welding?

Thanks

Spoonful

 

[metengr]

Spoonful;

Is there a reason that solution anneal needs to be done again after welding?

Yes, to restore maximum corrosion resistance after welding.

 

[cloa]

And that the weld is solidified metal and the metal next to the weld is heat affected and neither is in the solution annealled condition.

 

[EuroWeld]

Be aware that not every shape can be solution annealed at about 1050 degree celsius after assembling. F51 forgings according to ASTM A182 must be solution annealed and rapitly quenched afterwards to prevent intermetallic phases.

I do not have any expierence with solution annealing after welding, because in most of our situations this practicly can not be performed.

Sure, it is better for corrosion resistance but with proper welding this can also be achieved. But at the end the custumer or code decides.


Also I like to expand this issue with an additional question: Can somebody help me to find a CCT diagram of F51 (2205) duplex stainless steel? After solution annealing rapit quenching is needed to prevent the growth of intermetallic phases. I want to determine the needed cooling rate.

Thanks in advance,

 

[EuroWeld]

Be aware that not every shape can be solution annealed at about 1050 degree celsius after assembling. F51 forgings according to ASTM A182 must be solution annealed and rapidly quenched after forging to prevent intermetallic phases like, Nitrides, Sigma and Chi.

I do not have any expierence with solution annealing after welding, because in most of our situations this practicly can not be performed.

Sure, it is better for corrosion resistance but with proper welding meaning Controlled heat imput this can also be achieved. But at the end the customer or code decides. I believe that when you perform the heat treatment you only achieve a better corrosion resistance, do you need this?


Also I like to expand this issue with an additional question: Can somebody help me to find a CCT diagram of F51 (2205) duplex stainless steel? After solution annealing rapid quenching is needed to prevent the growth of intermetallic phases. I want to determine the needed cooling rate.

Thanks in advance,

 

[Hercules28]

You may also want to do some stress relieving before welding if you have distortion issues.