flux cored weld wire

By hogan

Date 03-20-2006 22:11

i think that aws d1.5 has requirements for fcaw exposure. but it only applies to fracture critical

By billz

Date 03-20-2006 22:16

How do you define fracture critical?

By hogan

Date 03-20-2006 22:36

job specs or dwg will state when f.c. requirements are imposed
sorry i didn't read your question correctly-
a fracture critical member is a tension member of a bending member. the failure of this member would cause the failure of a bridge

By Zeke

Date 03-21-2006 14:23

It is good that you are concerned as this can be a very critical mistake some make. As for how long wire can be exposed, that is truly dependant upon the seam of the wire and to what environment the wire has been exposed to. Some manufacturers use a butt or apple type seam which is very prone to picking up Hydrogen. Some use an overlap type seam which generally protects the core very well. Then there are some who do a seamless type. It is a little more expensive, but obviously has advantages for your situation. As far as baking the spool, the main concern is getting it to an effective temperature without ruining the spool itself. I would not recommend this procedure anyway. In a critical application, if in doubt, throw it out!

By 803056

Date 03-21-2006 14:29

Check the FEMA literature. I don't have it with me, but I recall some requirements listed in their seismic requirements. You can also check with the manufacture.

Al

By jwright650 (*****)

Date 03-21-2006 14:51

Al,
You are correct FEMA does infact regulate the exposure time of FCAW welding wire.
FEMA 353 Part I Chapter 3
3.3.3 Electrode Storage and Exposure limits
FCAW electrodes shall be received and stored in original undamaged manufacturer packaging, until ready for use. Electrodes in packages that have had the internal plastic wrapping damaged shall not be used for welds in Seismic Weld Demand Category A or B. Modifcations or lubrication of an electrode after manufacture is not permitted, except that drying is permitted as recommended by the manufacturer.
The exposure time limit for all FCAW electrodes shall be based upon the results of tests as described in Appendix D. These tests may be conducted by the manufacturer or supplier, by the Contractor, or by an independant laboratory with suitable equipment.
In lieu of testing, when welding is suspended for more than 8 hours, electrodes shall be removed from the machines and stored in an electrode wire oven maintained at a temperature between 250F and 550F, or as recommended by the manufacturer. Electrodes not consumed within 24 hours of accumulated exposure outside closed or heated storage shall not be used for welds in Seismic Weld Demand Category A or B. Electrode spools shall be identified to facilitate monitoring of total atmospheric exposure time. FCAW electrodes that have been exposed for periods exceeding an accumulated 24 hours may be redried if manufacturer's testing and recommendations show that drying is effective at removing moisture and restoring electrodes to their designated diffusible hydrogen level.

John Wright

By billz

Date 03-21-2006 17:56

That was very good information.
I did check the FEMA site out, it is all there as described. It seems the 24 hr limitation is very strict and I wonder how many people employ this in practice when not welding in seismic critical applications. Thank you for all the good inputs.