Why is 904L stainless steel suitable for highly corrosive environments?

Nickel (Ni): High nickel content (around 25%) provides excellent resistance to stress corrosion cracking and helps maintain corrosion resistance in active (corroding) states.

 

Molybdenum (Mo): High molybdenum levels (around 4-5%) are crucial for resisting pitting and crevice corrosion, especially in chloride-rich environments and sulfuric acid.

 

Copper (Cu): The addition of copper significantly improves its performance against strong reducing acids, such as sulfuric and formic acid.

 

Low Carbon (C): A very low carbon limit (max 0.020%) prevents carbide formation during welding, eliminating the risk of intergranular corrosion.