Which alloy is the 940 exhaust manifold made of?

[Metallo]

My exhaust manifold cracked after 3 years (Turbo 940). Of course, I am talking about a genuine Volvo one.

Today, I visited a shop that specializes in engine rebuilding for both automotive and marine applications. I was really impressed by the quality of their work.

I brought in my exhaust manifold to see if it could be welded. I told them it’s a genuine Volvo [P/N 3514440] made of cast iron. The first thing they noticed was its weak magnetism. They showed me how much stronger a magnet sticks to real cast iron.
This probably explains why the original manifold lasted 25 years while the replacement lasted only three.

Unfortunately, they’ve been seeing this kind of alloy change more and more often—especially since COVID—and not just with Volvo parts.

As a side note, this manifold was made in Eastern Europe. I mention that just for reference, although I suspect most of them are manufactured there now.

So their question to me—which I’m now passing on to the experts—is: Does anyone know what alloy this manifold is made from?

They’re asking because they want to select the correct welding material based on the alloy’s composition.

And if no one knows the exact alloy, for those of you who have had one of these manifolds welded: Do you know what welding material was used?

Thank you!
Alex