Industrial Applications of 1.4470 Cast Stainless Steel

1.4470 is a castable duplex stainless-steel family member widely chosen where a combination of high mechanical strength and enhanced resistance to localized corrosion (pitting, crevice corrosion, stress-corrosion cracking) is required in chloride-containing or otherwise aggressive aqueous environments.

In practice this grade is used across oil & gas, petrochemical, desalination, marine, power and chemical process industries for cast components that must resist corrosion while carrying significant mechanical load.

1. Why 1.4470 Cast Stainless Steel is specified

• High resistance to localized corrosion: good pitting and crevice resistance in chloride-bearing media compared with conventional austenitic stainless steels.
• High yield and tensile strength: duplex microstructure (ferrite + austenite) gives higher strength than 300-series stainless, allowing lighter, smaller components for the same loads.
• Good resistance to stress-corrosion cracking (SCC): duplex grades are less prone to chloride SCC than many austenitics.
• Good weldability and toughness: with correct procedures, welded castings retain good toughness and corrosion performance.
• Cost-effective performance: provides many corrosion/strength benefits at lower cost than high-nickel alloys for many service conditions.

2. Principal industrial sectors & representative uses

Oil & Gas — upstream, midstream and subsea

• Well-head components, valves, valve bodies and bonnets, chokes, tool housings, subsea connectors and flanges.
• Rationale: exposure to chloride-bearing produced waters, CO₂/H₂S-containing fluids, and cyclic mechanical loads where SCC resistance and higher strength are required.

Petrochemical & Chemical Processing

• Pump housings, compressor casings, reactors internals, heat-exchanger cast headers, pipe fittings and large valve bodies.
• Rationale: process streams with chlorides, acids in moderate concentration, and elevated pressures/temperatures — demand both corrosion resistance and structural integrity.

Marine & Offshore

• Seawater pump casings, seawater-cooled heat exchanger parts, propeller shafts housings, seawater valves, intake/outlet fittings.
• Rationale: long-term exposure to seawater and splash environments where pitting and crevice resistance are critical.

Desalination and Water Treatment

• High-pressure pump bodies, brine valves, manifolds and fittings used in reverse-osmosis plants and thermal desalination units.
• Rationale: continuous exposure to high-salinity brines and the need for long life with minimal maintenance.

Power Generation and Thermal Plants

• Cooling-water components, condensate pump casings, piping fittings in coastal power plants and district heating systems.
• Rationale: seawater or brackish water cooling circuits and the combination of mechanical loading and corrosive environments.

Pulp & Paper, Mining and Process Industry

• Pumps, slurry-handling housings, wear-resistant cast parts in mildly corrosive slurries.
• Rationale: abrasion with corrosion — duplex grades provide superior strength and acceptable corrosion resistance vs many standard stainlesses.

Food, Beverage and Pharmaceutical (select applications)

• Large hygienic housings, valves and pipe fittings where mechanical strength and corrosion hygiene are needed, though austenitics still dominate many hygienic applications.

3. Limitations and when not to use 1.4470 Cast Stainless Steel

• Very high temperature service (sustained) — duplex grades are typically not intended for prolonged elevated temperatures.
• Extremely oxidizing acids or highly concentrated reducing media — some specialty alloys outperform duplex alloys in such chemistries.
• Ultra-low magnetic / non-magnetic requirements — duplex steels are magnetic; if non-magnetic is essential, select austenitic grades.
• Environments with high sulfide stress-cracking risk — evaluate carefully; some duplex grades resist SCC better than austenitics but not in all cases.

4. Conclusion

1.4470 cast stainless steel is widely used where a robust compromise between corrosion resistance and strength is needed in chloride-containing or otherwise aggressive environments.

It is an excellent choice for pump and valve bodies, subsea and offshore components, heat-exchanger parts, and a broad set of industrial hardware where improved pitting resistance, SCC resistance and higher strength reduce part size, weight and life-cycle cost compared with conventional austenitics.

Successful use hinges on correct casting practice, heat treatment, welding discipline and material qualification.