It is sometimes noted that stainless steel castings are magnetic as opposed to their counterpart wrought products.  This is a good thing that is not fully understood by many not possessing a degree in Metallurgical Engineering.

The stainless steel foundry has the opportunity to balance the exact chemistry of austenitic stainless steels  ( ie. CF-8M, etc. ) to give approximately 10% of a phase called Ferrite in and otherwise Austenitic matrix phase.  Elements such as Chromium, Molybdenum and Silicon are Ferrite stabilizers while Nickel, Manganese, Carbon and Nitrogen are Austenite stabilizers.  With the use of Schaeffler diagrams the amount of stable Ferrite phase can be predicted and controlled.  Wrought producers avoid steels with Ferrite phase because it complicates the forging process.  The Ferrite phase does strengthen the steel and give better corrosion resistance in many media’s and can improve machinability via better chip breakage.  Nuclear applications require minimum levels of Ferrite even in wrought products as an example.  Caution though, like many things, too high of a Ferrite level, over 20% can start to reduce the ductility of the steel.