welding process change (SMAW To GMAW)

[jha1982]

Hello Expert,
I am seeking your technical advice in terms of Welding process.

For welding of crane girder we are using SMAW welding with root and hot pass DPT.
Now people want to change the welding process from SMAW to GMAW. (but root with SMAW)
Plate thickness ranging from 25 mm to 50 mm.

Please give your advice,
Your prompt action will be highly appreciated

Regards
Aakash

 

[metengr]

I would consider flux core in lieu of GMAW for this project. The reason is that GMAW may present problems with lack of fusion defects especially with welders inexperienced using GMAW. You will need to qualify a new WPS for this project especially with the change in welding process.

 

[racookpe1978]

On a crane girder?

Who is your certifying authority and your insurance company?

 

[Stdsp]

If the Crane is made to CMAA and or to ANSI then welding process employed shall be compliant with AWS D 1.5,

If the Crane is pedestal type then the welding shall be as per AWS D 1.1

As per AWS D 1.1 (the mother of AWS D 1.5) and AWS D 1.5 there is no reason for someone to object (Unless of course end user of the crane has imposed some restriction) the use of GMAW so long as the weld produced is sound and weld is performed by qualified welder using WPS (that is supported and backed by PQR, if the PQR is tested (Instead of being Pre-Qualified) then it is all the more better).

As a personal preference, i would also go for FCAW instead of GMAW, but this is just preference and not mandate.