Both the chain (look at the welds) and the shackle (look at the cast lettering) in that picture are of Chinese origin and manufactured to a price point. That stuff should have never been used in any application, other than decorative.

High quality duplex stainless makes excellent anchor chain. Mud slides right off of it and it doesn't pile up at all. Pretty much lasts forever. This stuff will not suffer stress cracks and crevice corrosion. BUT, you will pay $30-40/ft for 8-10mm chain. Anything less and you are not getting appropriate chain. The cost makes it pretty much a non-starter for almost everyone. And no Chinese or South African (the most common sources) - only the Italians, Germans and French make the good stuff. I would be extra careful about buying US SS.

Mark