FCAW for sour service

[CoCoE]

Is there any reason behind the restriction of FCAW for sour service vessel fabrication? I could see some companies are not preferring FCAW or they are not allowing FCAW in sour service. If anyone knows the technical background, Kindly share.

Cococa

 

[weldstan]

Todays FCAW carbon steel filler metals will have no problem meeting hardness and toughness criteria and soundness criteria to meet sour service requirements. During the 1970s and 1980s, filler metals had higher hardness and lower toughness, especially in the PWHT condition. Because constant current power supplies were extensively used then and because the process is highly voltage sensitive, soundness was also somewhat of a problem, especially in field welding applications.
John Stanley P.E.