materials-finishes

Stainless Steel SUS316 Marine Grade Cylinders: Pitting Resistance in Salt Fog

Engineering Overview: Metallurgical evaluation of austenitic SUS316 stainless steel lock cylinders for coastal, offshore oil platform, and maritime port hardware.

Technical & Engineering Specifications

Alloy Grade Austenitic Stainless Steel SUS316 (1.4401)
Application Marine Ports, Coastal Resorts, Offshore Platforms
Molybdenum Content 2.0% - 3.0% Mo
PREN Pitting Index PREN >= 24
Salt Spray Benchmark ASTM B117 > 1500 Hours Continuous

Maritime Coastal Metallurgy

In coastal architectural installations and offshore platforms, high airborne chloride ion concentrations cause rapid dezincification and green verdigris on standard brass locks. Marine Grade Stainless Steel (SUS316 / AISI 316) provides ultimate pitting corrosion resistance.

Molybdenum Chemical Shielding

  • 2.0%–3.0% Molybdenum (Mo): Drastically increases the Pitting Resistance Equivalent Number (PREN >= 24).
  • ASTM B117 Endurance: Withstands > 1500 hours continuous neutral salt spray with zero microscopic pitting.

Frequently Asked Engineering & Selection Questions

Q1: Why is SUS316 stainless steel specified for marine lock cylinders?

Its 2-3% molybdenum content prevents chloride pitting corrosion in coastal salt fog where standard brass or SUS304 hardware would degrade.