Not really. Siedfleisch is a cut of meat that's commonly just boiled, but it's similar to brisket, so it can be used to make good corned beef, preferably the "durchgezogen" or fattier variation.
To make corned beef, you need to soak the beef in a brine of pickling spices and pickling salt (nitrites are essential for the distinctive taste and color for real corned beef) for 5 days, then boiled for a few hours until tender. I make this all the time for Rueben Sandwiches, and corned beef hash.
Mind you, this is the American version of corned beef, I have no idea how it compares to the Irish version, though I imagine they're very similar.
This reminds me that next time I go to Italy (in a week), I should buy a big chunk and corn it at the cousins' rather than here, as that we we can bring up to 7kg back.