Location of test specimen

Date 08-24-2009 16:43

Nandesh,
Both API 1104 and ASME IX show exactly the position of the specimens that are to be cut to be submitted to tests when qualifying either WPS and welders.
Giovanni S. Crisi
Sao Paulo - Brazil

By HgTX

Date 08-24-2009 19:03

Are you talking about why it is that the CVN comes from the middle of the test specimen length whereas the side bends come from closer to the ends? No idea. Good question. I was recently wondering about that myself.

For macroetch, it makes sense to take from the middle and both ends to get an idea of what's happening along the full cross section.

Hg

By 803056

Date 08-25-2009 00:26

It’s called standardization. Simply put, so that everyone is testing in the same manner.

Al

By HgTX

Date 08-25-2009 14:39

But was there any thought put into the location of the specimens? Ferinstance, there are good explanations for where within the cross section a CVN specimen is taken, and at what location, and the locations of the macroetches also make sense. Or was it just a case that the first person to develop the PQR plate decided more or less at random where to take the various slices for tensile, bend, etc., and ever since then it's been carved in stone (forged in steel)?

Hg

By js55

Date 08-25-2009 14:55

I'm guessing that other than the exceptions you noted there was probably some logic used to establish the orderlyness but this would not necessarily exclude other logic. In other words, I cannot think of a single metallurgical or mechanical reason for the locations other than this was the logic they chose.
And it would not be the first or last time that an arbitrariness in code decisions became carved in stone as if it were some mystery from on high.
Not saying this is necessarily the case here, but it happens.

By jwright650 (*****)

Date 08-25-2009 15:19

I was thinking that it was just an example. Showing that the sample had enough material to get all of the testing samples cut from it, if you cut it like this or that.

By hvymax

Date 08-28-2009 14:42

Standardization aside(but incredibly important in these things) it can ensure that various aspects are tested . A verticle up may test very differently from an underside of a weld than on the top where gravity may be more of a friend so we need samples that represent the different variables such as position John B.