Codes and standards
300 series alloys are in every stainless steel application standard, for pressure vessels, tanks, food and pharmaceutical equipment, structural use, etc.
Ductility
The 300 series alloys have outstanding ductility, which means outstanding formability. That is important in deep drawing and for producing complex shapes. As ductility decreases with increasing strength, the duplex grades have decreased formability, although still suitable for most forming operations.
Higher temperature properties
The strength of the austenitic structure shines compared to other families, especially in the creep strength temperature range. A major consideration though is how the properties will transform with time. Many stainless steel alloys become brittle in certain temperature ranges, but the higher nickel austenitic alloys are most often the best choice.
Corrosion resistance
There are many different 300 series alloys available for general and specific applications, ranging from the 18/8 versions to alloys that compete with some of the nickel alloys.
Recyclability
While all stainless steels are recyclable, the 300 series are more likely to be recycled because they have a higher inherent value at end-of-life.