Heat treatment of SA 240 310S

[fakhfakh]

Dear All,

Ou client requires to perform heat treatment after the manufacturing of a pressure vessel to ASME VIII Div 1
Mtrl: SA 240 310S
Thick: 26 to 28mm
Welded

The Code do not require neither prohibit a PWHT

Normally such type of mterial needs a heat treatment to a temperature 1050-1100°C
Is it necessary to perform fast cooling after heating knowing that it is almoste impracticable?

Thank you

 

[EdStainless]

If this is low carbon 310 (as i presume from the S) then cooling rate is not as critical.
That said, you do want to get below 800F as rapidly as possible. Fan cooling is usually sufficient to prevent sensitization.

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P.E. Metallurgy, Plymouth Tube

 

[fakhfakh]

Thank you.

How can we apply fun cooling on that big vessel (16m long, 1.6m Dia) ?

I thought about but did not find some one having that facility on place

 

[metengr]

Air cooling for 310S stainless steel is acceptable.

 

[EdStainless]

On large equipment fans are often used to try to assure more even cooling by stirring the air in paces where natural convection is poorer.
You are not trying to force cool the entire unit.
By cooling more uniformly you minimize stresses and distortion.
Of course the first step is very good blocking and support for the anneal.
This requires a lot of attention to get correct.

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P.E. Metallurgy, Plymouth Tube

 

[Don56]

Ed is correct. If not supported correctly, your vessel afterwards may resemble a 3 month old banana.

 

[fakhfakh]

Dear All,

I don't find till now even at the well known suppliers someone who gives a positive reply to the solution annealing of the complete vessel. I know that every thing is possible but in my opinion if the cost of this required HT will be close to the cost of the item it self there should be some thing wrong in the design including the selection of such material.

I've asked the welding institute of France the reply is "avoid". The same reply from my AI

My problem is that the MDR of similar item already manufactured precise HT 1080-1100°C. The name plate includes HT stamped under the "U" designator!

How this can happen?

Some hing is wrong!