ASME Section II vs FFS-1 Material - State of Heat Treatment?

[InTheField]

Please this questions is cross posted in a couple of threads.

Hi all, I have an interesting query as I have not noticed this before. Hopefully someone here has some background.

OK, as an industrial boiler specialist I was putting together an in house data base which compares ASME allowable stress in ASME Section II, table 1a to FFS-1 calculated stresses. We sometimes get into FFS on boiler components within the boiler setting. Under the creep range is fairly straight forward (by the way there are some interesting differences with ASME Section II and FFS-1 MPC and WRC values).

Within the creep range, the MPC creep coefficients (Strain Rate Parameters and Omega parameters) have different values for SA213 T11/T22 depending heat treatment (N&T and annealed).
I thought, OK Section II must state the fabrication and heat treatment for tubing supply. After checking Section II Part A and Part D, I could find no specific requirement for as supplied condition.
I also double checked section I and there is also no reference to the heat treatment of supplied tubes.

Does anyone have any experience in this and know if there is a requirement under Section II to have a standard heat treatment for supply of boiler tubes? I am looking and SA213 T11/T22, but there are likely other materials which fall under this question.

I ended up looking at low and medium carbon steels (those applicable to boiler construction). Short of having to take a field sample/etching and check the grain size, I am hoping there is another solution. Note: this is not an immediate problem, I am just putting this together out of interest. The goal is to quickly evaluate which stress governs failure of a material at a given temperature based on FFS-1 compared to ASME.

Thanks for the help all!

 

[mfgenggear]

I am not boiler guy, it is out of my expertise.
However what is the final heat treated condition. Of the material.
Intermidiate heat treat is normally
For prefabrication. Bending, welding
Fabricating as not to induce working and cracking. And there may be several.
After completed then a final Post
Final heat treat is required.
The specification chosen must meet the final stress and hardness requirements.

 

[InTheField]

While true, there are different heat treatment methods which may result in the same MINIMUM strength and hardness requirements yet, have different creep coefficients. I guess my real question is which heat treatment does ASME section II part D use for allowable stresses in the creep range when an annealed and Q&T heat treatment is allowable. The creep coefficients specified by the MPC omega method clearly show different creep coefficients.

This is not an everyday problem, as I mentioned, but can get tricky for fitness for service problems This would not be specific to Section I.

 

[mfgenggear]

Well I suggest to ask ASME directly.
It's interesting that in the specification
It's not specified.
Make sure you have the latest revision first.
Do any of time and temperatures co-inside?
I would use both. To obtain the creep feed desired.
I know in my field AMS specification were not caught up to individual aerospace
Companies. But there getting better.
I don't want to guess. So get in writing from ASME.

 

I find Section II-A to be frustratingly fuzzy when it comes to 'heat treatment'.
What kind of heat treatment is frequently not defined. It comes down to industry practice, which requires some product knowledge.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."