Impact energy acceptance criteria

[georgacus]

ASTM A370 specifies a range of impact energies that can be used as an acceptance criteria for a Charpy impact test. How do you decide what impact value to use for a particular specimen size? Some material specs state the impact energy acceptance criteria and temperature that the test has to be performed at, but others don't.

I'm generally looking at stainless steels such as A479 316 and carbon steels such as A352 LCB.

 

[EdStainless]

The table that you posted is simply to offer correlation between various sample sizes.
It has nothing to do with acceptance levels.
If you have a steel that requires testing at -40, and a 20lb-ft min, but you can't get a full size sample then you use this table to tell you what that translates to for a 1/2 size sample.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

 

[georgacus]

Ed, thanks for the clarification. I think I meant to ask is that some material specs give you an impact energy value to test against (20lb-ft for example). Other specs don't specify a value. In this case, how is the impact energy acceptance criteria decided?

 

[weldstan]

Impact acceptance criteria is stated either by the Material Specification or the Design Code. It may also be determined by the Purchaser/End User.

 

[metengr]

weldstan has it correct.