Charpy V Notch Impact Test

[Mechotron]

Hi,

I have from API quoted a test requirement of 20J on the transverse direction on a 10mm x 10mm specimen for a V Notch impact test. The material supplier has done the test on the longitudinal direction and has obtained a value of 75J. Is there any means of converting this value to transverse direction. If so can you provide detail of conversion. I am not much into material testing either so possibly i am going to take this oppurtunity to know more about V Notch impact test. Does anyone know the source on the internet to find some material.

Mechotron

 

[metengr]

Mechotron;
There is no orientation conversion for CVN impact values. The specific orientation of sample removal and test reporting are essential variables for CVN testing, and this cannot be converted to a standardized value.

You can visit the web site below for decent background information on CVN testing;

http://www.key-to-steel.com/default.aspx?ID=Articles

 

[salmon2]

Mechotron,

You can not relate the longitudinal Charpy to transverse easily, usually you will see the transverse is a lot less than the longitudinal. You should feel happy if transverse is higher than .5% of longitudinal. The ratio will depends on the tramp element such as S and non-metallic inclusions. Simply saying the material is isotropic and people hope so though.

The v-notch Charpy standard ASTM E23 requires 10X10X55mm for full scale bar but this is not applicable for small OD tubing often times. So API exempted longitudinal or sub-scales for this case, which I personally do not think it is a good idea, but has prevail.