Why Use Nickel Pig Iron
Austenitic Stainless Steels:
When nickel is added to stainless steel in sufficient amounts the crystal structure changes to "austenite". The basic composition of austeniltic stainless steels is 18% chromium and 8% nickel. Austenitic grades are the most commonly used stainless steels accounting for more than 70% of production (type 304 is the most commonly specified grade by far).
So, why use nickel pig iron.
As with most things the main reason is price advantage.
Adamite Heavy Castings: Manufacturers of heavy castings, particularly roll manufacturers are able to use nickel pig iron as a direct source of nickel, chrome, silicon and carbon mixed with HS1/2 scrap to give a much reduced cost of raw materials.