18Cr-4Ni Duplex Stainless (var. 3)

metal

18Cr-4Ni duplex stainless steel is a two-phase ferritic-austenitic alloy that combines the corrosion resistance of austenitic stainless steels with the strength and stress-corrosion cracking resistance of ferritic grades, positioned as a cost-effective alternative to higher-nickel duplex variants. This material is widely employed in chemical processing, desalination plants, offshore platforms, and pulp-and-paper manufacturing where resistance to chloride corrosion and pitting is critical, particularly in moderately aggressive environments where standard austenitic grades (like 304/316) would require thicker sections or more frequent maintenance. Engineers select this composition for applications demanding both corrosion performance and mechanical strength without the premium cost or nickel supply constraints of super-duplex grades, making it especially attractive for large structural components and pressure equipment in marine and industrial settings.

chemical processing equipmentoffshore pipelines and structuresseawater heat exchangersdesalination plant componentspulp and paper mill vesselschloride-rich industrial environments

Compliance & Regulations

?Conflict Free?RoHS?REACH?TSCA?Prop 65
Units:
siimperial
PropertyValueUnitConditionsSource
Elongation at Break(εf)
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-——
Ultimate Tensile Strength(σUTS)
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ksi——
Yield Strength (0.2% offset)(σy)
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ksi——
Verified Unverified Low confidence (<80%) Link to source

Regulatory Screening

Environmental

Quality & Standards

Industry-Specific

RoHS, REACH, and Prop 65 statuses are validated against official substance lists (ECHA SVHC Candidate List, OEHHA Prop 65, RoHS Annex II). Other regulations are estimated from composition and material classification. All screening is a starting point for due diligence — always verify with your supplier before making compliance decisions.