Diffusible hydrogen content

By SWN1158 (***)

Date 11-08-2018 20:20

We have a D1.8 project, which requires that the electrodes meet diffusible hydrogen requirements for H16, per Appendix W in the AISC Seismic Specification. I'm aware of three different designators... H4, H8, and H16. Im thinking that H4 or H8 will meet H16, but can someone please verify this?

By jwright650 (*****)

Date 11-08-2018 22:09

yes....
https://www.lincolnelectric.com/en-us/support/welding-how-to/Pages/low-hydrogen-metal-detail.aspx

By SWN1158 (***)

Date 11-09-2018 12:41

Thank you John! We're now looking at solid mig wire, which is an exception to the H16 requirement in Appendix W of the AISC Seismic Provisions.

By jwright650 (*****)

Date 11-09-2018 14:05

FCAW is also Low Hy but there is a limit on atmospheric exposure before you need ovens for the rolls. Solid wire can't absorb moisture out of the air, so if you aren't using the welding wire rolls up quickly, it may be your better option.

By SWN1158 (***)

Date 11-09-2018 17:09

Thank you!

By 803056

Date 11-10-2018 13:25

The electrode meets low hydrogen requirements if it is demonstrated that it produces no more than 16 ml [H] per 100 g of weld deposit.

XXX8-H8 means the electrode produces no more than 8 ml [H] per 100 g of weld deposit and then there is XXX8-H4 that produces no more than 4 ml [H] per 100 g of weld deposit.

All of this is based on the electrodes being stored in accordance with the applicable standard.

Al

By SWN1158 (***)

Date 11-10-2018 18:07

Thank you Al !

By 803056

Date 11-10-2018 19:51

I should add that not all flux cored electrodes are created equal. Some introduce as much hydrogen as a rutile electrode, while others can meet H4 requirements. Likewise, not all FCAW electrodes are required to meet CVN requirements. The bottom line; choose carefully.

Al

By SWN1158 (***)

Date 11-11-2018 02:55

Ok. We're proceeding with much caution. Thank you Al !