what is the diffrence between material SA-516-GRADE 60 AND GRADE 70 1

[Momo1988]

what is the diffrence between material SA-516-GRADE 60 AND GRADE 70
can i use material 516 gr 70 instead of GR 60?

 

[SectionIX]

You mean beyond the chemical and physical (SMTS 60 ksi vs 70 ksi) properties?

The choice to substitute 516/70 for 516/60 depends on the application, WPS to be used, etc.

More information needed.

 

[marty007]

SA-516-70 is commonly used for CS fabrication. It has a higher allowable stress in ASME VIII-1, allowing fabricators to design thinner pressure boundaries.

SA-516-60 is a nominally weaker material, but it comes with the benefit of typically being 'softer', which lends itself to certain applications. For sour service for example, hardness is an important variable in the design. By specifying SA-516-60, you are typically lowering the material hardness, making it less susceptible to sour service attack.

If your customer has specified SA-516-60, you need to understand why. If the vessel is in sour service, you may have a hard time convincing them to accept a substitution.

 

[JStephen]

Note that the material properties and chemistry overlap, so it is possible to find A516-70 plate that also qualifies as A516-60.
Refer to the A516 or the SA 516 specifications for exact requirements.

 

[weldstan]

This material is often triple specified as Grade 60, 65 and 70. If you need the softer material, you will need to specify additional chemistry limits on carbon and manganese to assure.

 

[Shmulik]

SA-516 Gr. 60 has better Charpy impact toughness properties at low temperature.

 

[weldstan]

Shmulik,
Not really. Almost all of the SA-516 is triple certified and it doesn't really matter. The HAZ of lower carbon equivalent Gr 60 (if it actually has a lower carbon equivalent) will generally have superior toughness and will be better able to meet hardness limitations in SCC service w/o PWHT.

 

[Shmulik]

thanks weldstan