21/4Cr-1Mo weld build-up: multiwire GMAW feasible?

[bagnamento]

Hi everybody,
we're considering the possibility to weld internal build-up on 21/4Cr-1Mo plates using multiwire GMAW technique.

AWS website (

http://www.aws.org/wj/2003/06/040/)

concentrates on improvements due to high productivity and low heat input.
Other references just concentrate on productivity.
This seems to indicate that this process is suitable for weld build-up fabrication.

However, some colleagues have experienced cracks on weld build-up made of this kind of material with GMAW single wire process.

Would these problems remain with multiwire GMAW process?
Is it applicable to weld-build up fabrication?

 

[metengr]

I have seen few problems with an automatic multi-wire MIG process. The problems with the single wire process has always been LOF type defects.

To answer your question, yes, it can be used for weld build-up on ferritic materials. However, if deposition rate is what you need my recommendation would be to go with a hot wire GTAW process.