Normalized Material Vs. PWHT 2

[keens]

Hello,

I have a Pressure Vessel that I am working on for another Customer, that has specified SA516-70N & it also needs to be PWHT. I would like to know if anybody knows wheather I can get rid of the Normalized requirement, if I PWHT to the Temperature required to Normalize the Material. The thing that is driving this question is cost. Normalized Material is about 0.30$ more than Non-Normalized Material. Thanks...

 

[unclesyd]

The advice on distortion is real, I've seen it several times when this or similar approaches were taken in the PWHT heat treatment of fabricated components.

I think that if you look at the overall cost, the added heating, the additional support, you will probably find that the $0.30 adder is cheap.

 

[pve5]

I agree with unclesyd( Materials ), the cost of performing PWHT of whole vessel to saitsfy requirements of SA 516N and client will be much more then 0.3/lb. Client or third party inspector will never accept such option.

For low temperature service and also to avoid any problem during forming and fabrication, our engineering standards always calls for procurement of all SA 516 Gr. 70 plate material for pressure components procured in normalized condition.

 

[keens]

Does anyone know the difference in the Temperatures between a PWHT and Normalization?

 

[metengr]

For carbon steel, PWHT minimum at 1100 deg F to 1275 deg F.

For normalization heat treatment 1600-1650 deg F, rapid cool, temper at 1100 to 1300 deg F.

The time for PWHT and normalize and temper is one hour per inch of material thickness.

 

[unclesyd]

A little off target, but since we are talking heat treating take a look at this site and the Navimat data base. There are two other pieces off software that are also interesting.

http://www.werkstofftechnik.com/english/software/navimat.php?&id=soft&subId=stw