F44 is a highly alloyed austenitic stainless steel containing approximately 20% chromium, 18% nickel and 6% molybdenum, together with nitrogen and copper. This alloying system provides substantially higher localized corrosion resistance than conventional 300-series stainless steels.

The high molybdenum and nitrogen contents provide excellent resistance to pitting and crevice corrosion, particularly in seawater and other chloride-rich environments. Its high nickel content helps maintain a stable austenitic structure while contributing to toughness and resistance to stress-corrosion cracking.

Copper further improves corrosion performance in certain acidic environments. The combination of chromium, molybdenum and nitrogen gives F44 a high PREN, making it suitable for severe applications where conventional grades such as 316L may provide insufficient localized corrosion resistance.

Typical applications include seawater systems, desalination equipment, heat exchangers, chemical-processing plants, pulp and paper equipment, flue-gas desulfurization systems and offshore process equipment.