Normalizing 516 gr 70 for use at high temperatures

[McT178]

Is there any advantage to using normalized 516 gr 70 at temperatures around 800F?

 

[metengr]

McT178;
There is no significant advantage for using this pressure vessel steel in elevated temperature service. The reason is slightly lower creep strength in comparison to coarse-grained steels, which are tailored for use at elevated temperature service. The normalized steels are good for moderate to low temperature service.

 

[McT178]

Thanks metengr. I always thought normalizing was only helpful at lower temperatures, and its benefits were lost at higher temperatures - but the customer is asking for it.

 

[stanweld]

The fine grained, normalized SA-516 gr 70 steels have lower higher temperature creep properties and a greater tendency to graphitize than A-515 gr 70, especially at 800 F.

 

[Guest102023]

Agree with Stanweld, something like A515 is a better choice.
BTW A515 is NOT a good choice for low temperature service.

 

[McT178]

Just for my curiosity if you don't mind - how does the grain structure effect the creep strength at different temperatures?

 

[metengr]

McT178;
Coarse grained material means fewer grain boundaries, which means fewer sites for creep void nucleation, which ultimately means higher creep strength.