Bill this is very interesting.....keep us informed of your findings

I had trouble back in the early '90s.  I got no satisfaction from the manufacturers.  My requirement was for a New York State Bridge, which uses the New York State Steel Construction Manual.  The annual "Typical" Certifications that the manufacturer performs per AWS A5 could not be duplicated when I received the product.  It was necessary to get a more expensive "Premium" electrode.  I cannot name the guilty parties.  My product was an E71T-1.  In my recollection, we had to pay $650$ extra to have the DH content and Impacts performed on the actual material.  I believe that they had already performed this testing per A5.20, but I had to pay if I wanted to get it, and then they would do it on the actual product they were shipping to you.

With FCAW wire, I often found that my supplier had sent me product he acquired from an auction.  This material had age issues, and supposedly picked up moisture. This resulted in rampant porosity from many of the spools we received from that lot.  With SAW Flux, or FCAW electrode, I do not see how anyone could rely on the results from the annual A5 Testing.  If you have to know, or you should know for certain, you had better test that lot.

I had trouble duplicating the MFGRS. Impact results on some SAW products, and found out from a consultant that the manufacturer had the best testing lab in the world, and they metallographically polished the notch in the CVN specimen, which resulted in better properties.  (This is legal!  I was also told this by a LLoyds of London Rep., so I believe it could possiblly be true. )

Bill,

I agree with John and Joseph, this sounds very interesting.

I remember very well a lecture of Prof. Bill Lucas (TWI - The Welding Institute - Great Britain) presented on the Intermediate Meeting of IIW-Commission XII (Arc welding processes and production systems) in 2005. The paper dealt with an investigation directly comparable with what you have described in your post. The presentation was entitled: "The Cause Of Variations In Charpy Energy Levels - Electrode Approvals at Five Test Houses". Mentioned by the way, it is available by the International Institute of Welding (IIW Doc. XII-1851-05).

It explaines the normal practice of consumable manufacturers, to determine and ensure data for metal composition and mechanical properties of their filler materials. And further, that users are going to carry out independent batch controls to find out if they meet the requirements and to compare with the data been provided by the consumable manufacturer.

The initial for the investigations was such a "normal" batch control been ordered from the british Ministry of Defence (MoD) and been carried out by five different test houses in GB. Well what they could find out was, although all the test houses received the same batch of electrodes they had significant discrepancies in Charpy impact energy values! Therefore the MoD instigated an investigation into the cause of the variations in the impact test levels. Before they started the investigation they collected the following potential reasons for causing the discrepancies:

- Differences in the test house procedures and practices
- The effect of using different welders to produce the batch control test plates.
- Differences in the Charpy notch profile, and
- The effect of the quality of broaching.

I ask for your understanding for not treating the entire details of mechanical procedures and tests herein but what I would like to tell you is, the results they could determine for being the reasons of variations were tremendous. They have shown extraordinary differences between the different test houses who carried out the tests under using the same batch of electrodes and same welding procedures. Similar this is comparable for me with Joseph's posted predication, "...had the best testing lab in the world,... which resulted in better properties..." which is showing in the same direction the TWI could find out.

For me one of the most important predications made by Prof. Luacs and his brilliant team, I would like to cite here:

"The lack of agreement between the test houses as to the Charpy energy level for the same test weld, in particular, calls into question the suitability of this test in its present form for assessing the toughness of the weld metal."

I guess this says more than a thousand words. I can only recommend to get and read the mentioned IIW-paper since it contains a lot of fantastic information for you, certainly replying a great share of your inquiry in an appropriate way.

Regards from Germany
Stephan

I do know that AWS A4.3 for testing diffusible hydrogen was recently revised.  Two of the significant changes (I don't have the document, but have been told by a manufacturer), are that now the amperage used for the test has to be within 25% of the manufacturers maximum recommended amperage, and there is tighter control on the stickout as well.  This results in higher hydrogen levels than previous test practices.  It is a lot harder to buy an H4 FCAW wire than it used to be.  As for CVN properties, some of the manufacturers practice exact bead placement and size so that the CVN sample comes from mostly grain refined HAZ in the weld metal.  This can improve the results they get.  That is why the new MIL standard for testing the MIL-10718 electrode prohibits using 2 passes per layer for more than a certain percentage of the layers.  There are other factors, some of which have been mentioned, such as machining practices, etc., but these are tow more to consider when comparing results. 

I know offshore oil specifications require that the CVN results on the manufacturers MTR from the lot of electrode used on the PQR be repeated by the manufacturer on each subsequent lot of filler metal.  This is independant of the CVN results from the PQR.  That is one way industry has found to address the issue.