Not logged inAmerican Welding Society Forum
Forum AWS Website Help Search Login
Up Topic American Welding Society Services / Certifications / Impact Tests
- - By Bryan Bidewell (*) Date 03-31-2009 13:59
As part of a change in company policy we are looking to move towards base metals tested to -40ºc for primary steel compared to that of -20ºc, which we have been using. As a result of this do I need to requalify my PQR's as the base metals are still within the same base metal grouping, AWSD1.1 table 4.6 suggests that requalification is required only in the event of a change in group number to the base metals being used?
Parent - By jon20013 (*****) Date 03-31-2009 15:37
Not sure what your question is but the "loophole" you mentioned is no good in your case.
Parent - - By js55 (*****) Date 03-31-2009 17:35
If I understand the question properly you do not need to requal. However, you might give some consideration to why you are reducing the test temp of your base metal, and consider the properties of the weld metal as well.
Parent - - By Bryan Bidewell (*) Date 04-01-2009 13:30
My question is, as we are going to be using base metals that have charpy impact tests to -40ºc do I need to requalify my PRQ's as they were tested at -20ºc. Therefore the welds have been tested to -20ºc so do they now need to be requalified by testing them at -40ºc?
Parent - - By js55 (*****) Date 04-01-2009 14:27
Your impact testing requirements are not related to the material, its related to service requirements.
For example, SA-333 Gr 6 material is quite common in piping systems. This material is automatically, by specification, tested at -50degF for impact toughness. However, this does not kick in the requirement that a weld metal or WPS be requalified to -50.
However, the language in some of the codes ties it through the base material (for example, if the base material requires impact testing the weld metal requires impact testing, and sometimes the HAZ) but it is still ultimately related to the requirements of the service design. In other words, if the service design requires impacts on the base metal it may require impacts on the weld metal.
Parent - - By Bryan Bidewell (*) Date 04-02-2009 09:26
So if my weld metal is already tested to -40 or greater, am I right to think that no further testing is required or does the actual weld itself require impact testing to -40?
Parent - - By js55 (*****) Date 04-02-2009 11:57
"Your impact testing requirements are not related to the material, its related to service requirements."
Parent - - By Bryan Bidewell (*) Date 04-03-2009 08:58
I understand that about the base metal, so therefore what you are saying is, if I have a PQR tested to -20 but I am working on a project that has a service temperature of say -30 or -40 then I need to requalify the weld at that temperature, it that correct?
Parent - By js55 (*****) Date 04-03-2009 12:35
A service temperature as established by your customers design specification. Your customer, by code, is required to supply you with that design temperature.
Yes. You will have to requal to -30 or -40.
Parent - By spots (**) Date 04-03-2009 12:44
It looks like it would depend on how your WPS is written. Table 4.5 (PQR Essential Variables) #29 states if you change your base metals to something other than what is on the PQR or qualified by table 4.8 you need to re-qualify.

However, it is the Engineer's (the big E) responsibility to set impact toughness requirements per D1.1 1.4 (5).

So my question is, is this a company policy or a contract requirement? If it is company policy you would only have to re-qualify your procedures as required by contracts specifying the -40 impact toughness values.
Up Topic American Welding Society Services / Certifications / Impact Tests

Powered by mwForum 2.29.2 © 1999-2013 Markus Wichitill