Defusible hydrogen content testing

Date 07-11-2008 15:09

Hello and Good morning!!

I have been asked to look into who does this kind of testing in or around the DFW area. I know nothing about it other than it is some sort of testing pertaining to underwater welding, which I have NO experiance with. From what I have been told it requires the use of a eudiometer and/or a gas chromatagraph.

What brought this on was an inspector that I know is stuck in the field with no internet access and has asked me to put ot some feelers on who if anybody around Dallas/Fort Worth does this sort of testing. He is calling but it is a long process and I am just trying to lend him a hand while learning something along the way.

Thanks in advance,
jrw159

By HgTX

Date 07-11-2008 15:50

Diffusible hydrogen testing is routine for electrodes used in bridge welding (it's what gives those H4, H8 designations). Typically it's done by the electrode manufacturers themselves.

Try Hurst Metallurgical in Euless or Trinity Metals Lab in Dallas, but their websites don't list that particular test. I'm not aware of any electrode manufacturing facilities in the DFW area.

Can you find out why he needs this test done, and on what?

Hg

By jrw159

Date 07-11-2008 16:14

Yeah, I will see if I can get more info. I should see him about one oclock today.

Thanks a bunch. :-)

jrw159

By jwright650 (*****)

Date 07-11-2008 16:25

Take a quick look at the pics in this thread...they depict hydrogen diffusion.
(Al posted a pic) and (my pics are way down towards the bottom).

http://www.aws.org/cgi-bin/mwf/topic_show.pl?pid=61032

By jrw159

Date 07-11-2008 16:56

Thanks John! :-)

jrw159

By jrw159

Date 07-11-2008 19:15

OK. It is for a welding procedure for an underwater welding company. Due to salt water corrosion hydrogen content needs to be a known factor for the writing and approval of this procedure.

Referance AWS A4.3-93

Also Hurst does not do this. We will check with Trinity.

The use of the gas chromatograph and/or eudiometer is required for the testing of the procedure.

Thanks alot,
jrw159

By HgTX

Date 07-11-2008 19:28

If they order an electrode with H4 or H8 designation, that gives them an upper limit on the electrode diffusible hydrogen. But they want the WELD tested, after welding in accordance with the proposed procedure? A4.3 and the applicable A5 spec dictate the base metal & welding procedure to be used for the test specimen, which may not be compatible with what the desired WPS has to say.

Can he fax you the spec that has this requirement? I'm wondering if simply ordering H-designated electrodes will do it for them.

Also try Houston Metallurgical. If they don't do it either, I don't know who in Texas will. And I don't see it on their list of services.

Hg

By jrw159

Date 07-11-2008 20:08

I will see if he can. He said that this is a requirement of AWS A4.3-93 and I do not have access to this.

BTW He is a CWI as well and he will most likely be registering here shortly. He was like me and had no idea this forum was here and how valuable it is.

I was in the dark about this forum and am so glad that I now have access to it and all the wonderful people here and thier knowledge and willingness to share, help, and guide.

jrw159

By HgTX

Date 07-11-2008 20:16

A4.3 is the spec that the electrode manufacturers follow when they test their electrode for diffusible hydrogen. What I'm wondering about is where he is reading the requirement for testing in accordance with A4.3. I'm not the world's most experienced person, but I'm not familiar with having to do diffusible hydrogen testing as part of welding procedure qualification.

Hg