Repair welding High alloy cast steel ASTM A297 Gr HK - MIG not used" by experienced producers&q 1

[Tmoose]

We have some 147 lb castings resembling a funnel 13" DIA by 24 inches long. Wall thickness 1" in the cylindrical part and 0.5" on the cone.

The foundry has had difficulties providing castings that come close to meeting ASTM A802 level III quality.
A recent litter is going to need weld repairs to pass.

The foundry sent info for the weld material and process they propose. It based on Lincoln Blue Max MIG 330 MIG wire.

The Steel Founders' Society of America publishes Steel Castings 2004 Handbook - Supplement 7 "Welding of High Alloy Castings".
It says MIG welding is NOT used for repair welding of the HK material, based on a survey of experienced producers.
Please see attached image file.
TIG or SMAW is used for repairs.

I am imagining that if MIG is "not used" there are reasons why, probably based on problems producing good welds or parts.

1 - Can anyone confirm if this is still true today, 14 years later?
2 - Can anyone offer insite why MIG is "not used?"

thanks,

Dan T

 

[catserveng]

At one time I did quite a bit of field welding repair, this issue came up quite a bit with some of the materials we had to repair. Best overall explanation one of our really good technical welders had was that with MIG process he had learned there were two issues, penetration control and cleaniness. We typically used SMAW process with alloys defined manufacturer or our Eutectic rep. I haven't done this type of work for quite some time, but I found the Eutectic folks were very helpful in determining process and alloys for repairs.

There is also a forum at the AWS website my son (he is a heavy equipment mechanic) uses to help figure out stuff like this,

https://app.aws.org/forum/forum_show.pl

Hope that helps, MikeL

 

[Tmoose]

Hi MikeL,

Thanks for the information. I'll be joining the AWS forum, if they let me.

This is not so much a field repair. It will be done in the foundry or machine shop, the same as a fabrication using castings of that material might be done, and MIG for fabrication IS ok according to that Steel Founders' Society of America publishes Steel Castings 2004 Handbook - Supplement 7.

thanks again,

Dan T

 

[metengr]

Not recommending GMAW (MIG) for repairing of defects in high alloy castings has to do more with cleanliness concerns and obtaining subsequent defect free repair welds.