SA-573 Gr.70 and SA-516 Gr.70 are they the same?

[takiyasamsama]

Guys,

From ASME Section II Part D I could not found SA-573 but when I see its UNS number which is K02701 also not available, however I SA-516 Gr.70 UNS number is K02700 and when I refer to both mechanical and chemical composition, they're practically similar.

My question is are these material equivalent? If yes what distinguish between these two materials i.e. cost, manufacturing availability, or others?

Thank you

 

[JStephen]

I know they're not the same. If I remember right, A573 is a structural steel, A516 is a pressure-vessel steel for starters. At one time, A573 was readily available and used in the tank industry; not so much now. Allowable stresses were different in the tank codes.

 

[IFRs]

They are similar but different. For API 650 they are both Group IV with different yield and tensile strengths and allowable product and hydrotest strengths.

 

[takiyasamsama]

Say that I need to perform analysis and 573 is not available, is it permitted to use 516 instead?

 

[IFRs]

if the tank was designed using the allowable stressed for A573 then no, you can't substitute A516. If you are starting out designing the tank, you can use either.

 

[tankSnvessels]

A516 is far superior material than A573. A573 cannot be used in pressure vessels. A516 can be used for tanks and vessels both.