Just to share a bit of experience.

On my 2001MY XJR the rear muffler (silencer) broke clean off the exhaust pipe many months ago. It hung down a bit, but did not affect performance at all, and did make the car sound a bit more meaty...the thing I least like about the XJR is the lack of gut rumbling noise when pressing on. The car can be a beast, but does not sound like one.

Anyway, today I lined it back up and re-welded the carbon steel pipe to the stainless steel muffler (original Jaguar muffler). Access was a little tight one side, and partly overhead welding so not the prettiest weave in the world...but it is strong, lines up well, and now slightly quieter (never mind).

I believe the muffler to be 410 stainless (11-13 chrome) as it is ferritic (and so magnetic). I was a bit worried about its weldability, but it was fine using 0.6 mild steel wire on a MIG with Argoshield Light gas. Good weld pool, flowed well, very little spatter. I'd bought some 300 series austenitic stainless wire and already have a small spool of Inconel wire (v expensive)...but I did not need these, and need not have worried about it.

Long term, that mild steel weld consumable may suffer some preferential weld corrosion, but I'd expect it will last 5 years or so.

PS I did disconnect both terminals from the battery before welding...I was nervous that would create some electrical gremlins when I hooked it back up but nothing to note so far.

One more job off the list then. Happy Motoring.

 

Good info. I'm about to try the same repair.