Oh god, spare me please, I hope someone can lock this down before we have to endure another science project.
For starters you can tell your welder that your Mag. Frame isn’t Mag.
Where is it cracked or broken? I may give different advice depending how critical the problem is.
I’m fairly certain the Husky frames are a good quality Cro Mo.
For most areas I would recommend TIG welding with ER70 or plain MIG wire.
That’s what I would be doing anyway.
Unless it’s cracked through one of the major cradle tubes then I may get more serious or if it just a number plate tag then I would get less serious.
I’m actually repairing a frame at the moment and have been taking some pictures as I go, (except my studio pictures suck) so I may post a thread on the subject in the next week or so.