An important property of high silicon (12 - 18%) cast iron is the high

High silicon iron-based alloys are excellent corrosion resistant materials with advantages of superior corrosion resistant properties, low cost and saving on noble metals such as nickel and chromium.
When containing 14.5% or more silicon, the corrosion resistance of these iron-based alloys is better than that of some cast irons containing a significant amount of chromium, nickel and/or molybdenum, and even than that of certain nickel based alloys in some severe corrosion conditions.