Charpy V Notch Test 1

[deaconp]

Hi,
I have just been reviewing a material Cert, a requirement was asked for Charpy V Notch @ -32 degreec C.
The critera asked for a min 24 Joules and Average of 34 Joules.

The three figures I received for the three test where like 108,112,97?
Is there a method for deriving you're min and average values for impact testing or is it as simple as adding the values together and dividing by 3 for the average? in which case my material is way out the requienments.

Any help would be great thanks

 

[metengr]

Your material more than meets the "minimum" requirements for CVN impact energy, so you are fine. Remember, your intent is to assure that the material meets the minimum CVN impact energy requirements, anything above and beyond is icing on the cake. The minimum CVN impact energy value is as stated and the average value is obtained by averaging between the three test results.

 

[deaconp]

Thanks Metengr, that is cool i was not losing my head then thinking thee was some weird science between the average value

again may thanks
Deaks

 

[HgTX]

Just to pile on here long after the fact:

(1) Some specs call for 5 specimens. The top and bottom values are tossed out to allow for weird outliers that sometimes happen with CVN testing, and then the remaining three are averaged.

(2) It's not uncommon to see values over 100 when the minimum requirement is more like 25, depending on your material.
Hg

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