Adequacy of FCAW process 14

[fakhfakh]

Hello every body,

For butt welding of material A283GrD thickness 22mm, we use FCAW process with E71T1-MJ filler metal with gas 20%CO2+80%Argon. UT is used for weld inspection and defects found are up to 3%.
Based on what we heard about this process, I have a doubt about its adequacy even if the UT results are satisfactory. Can somebody help me to know about the risk of this process against quality and if any failure can occure for pressurased items in service.
For exemple, can some types of lack of fusion produced by this process not be identified by UT?

Thank you

 

[weldtek]

Unclesyd
Please don't interpret my comments on defect rates to indicate my personal acceptance of such. The point I'm making is that stick welding can be more prone to defects than Fluxcore. I'm not saying that fluxcore is the panacea of the welding world, I am saying it has it's place and in many situations is a superior process. I say superior because in addition to the advantage of requiring fewer starts and stops it offers greater control over the arc and resultant puddle.
Sure we can all point to problems with any process, and we could critique the welds on bicycle frames in Walmart and say that GMAW is junk, or look at a weld made with sub arc where the operator missed the seam and left a line running through the film, but the truth is that all of the commonly used weld processes have their place, and fluxcore is no exception. At least that's my opinion.

 

[swall]

Unclesyd--you made my day with the "graphitic analysis" comment. Haven't heard that one in a long time.

 

[robsalv]

I generally practice caution when I see FCAW being proposed for thin vessels and fillet welds. I'm of the opinion that FCAW is too easy to mess up with and could more likely lead to LOF and other defects. A one run joint is not one I'm willing to accept when FCAW is involved - especially if the QA/QC has any doubt at all.


Having said that, in the hands of a good operator, with good procedures and QA/QC, I've had no problems using it in lowish temperature vessels (> -45C), with production run off tabs that are tested for adequacy.

Cheers,

Rob