duplex Stainless Steel
Duplex was given to this grade of stainless steel as it consists two-phases, grains of ferritic and austenitic steel. When the duplex grade gets melted, it solidifies from its liquid phase to a complete ferritic structure. Half of the ferritic grains is transformed to austenitic grains when the metal is brought down to room temperature.
The advantages of using this metal is that it's corrosion resistant making it perfect for all weather conditions. Another contributing factor is that it is twice as strong as ferritic and austenitic stainless steels, although it does not have the same toughness and ductility as that of austenitic grades.
Due to the duplex grade having a lower count of nickel and molybdenum than that of their counterparts of which has a similar corrosion resistance, the cost is of the duplex stainless steel is lower.