18Cr-4Ni Duplex Stainless (var. 2)

metal

This is a lean duplex stainless steel with 18% chromium and ~4% nickel, alloyed with molybdenum for enhanced corrosion resistance and modest cobalt addition. It occupies a middle ground between austenitic 300-series and fully ferritic duplex grades, offering a dual-phase microstructure that balances strength with corrosion performance—making it suitable for moderately aggressive environments where cost must be controlled relative to super-duplex alternatives. The material is employed in offshore oil & gas piping, desalination plants, chemical processing equipment, and seawater cooling systems where chloride-induced pitting and stress corrosion cracking are concerns but where the expense of 6Mo super-duplex is not justified.

offshore piping and subsea componentsseawater heat exchangerschemical processing vesselsdesalination plant equipmentchloride-environment fastenerspulp and paper bleach plants

Compliance & Regulations

?Conflict Free?RoHS?REACH?TSCA?Prop 65
Units:
siimperial
PropertyValueUnitConditionsSource
Elongation at Break(εf)
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-——
Ultimate Tensile Strength(σUTS)
—
ksi——
Yield Strength (0.2% offset)(σy)
—
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.