1. Material Properties Overview
Mg (1.0%) + Si (0.6%) primary alloying elements
Cu (0.25%) + Cr (0.2%) trace elements
T6: Yield strength 276 MPa (most common marine grade)
T651: Stress-relieved for better machining stability
T4: Solution heat treated (for subsequent forming)
2. Corrosion Resistance Performance
2.1 Saltwater Exposure Data
EnvironmentCorrosion Rate (mpy)Test DurationTropical seawater0.8-1.25-year studyTemperate coastal0.5-0.93-year studySplash zone1.5-2.0Accelerated testing
Note: mpy=mils per year (1 mil=0.001 inch)
2.2 Prodection Methods
Anodizing: Type II (25μm) reduces corrosion by 85%
Epoxy systems (300-500μm dry film thickness)
Minimum 100mm separation from copper alloys
3. Mechanical Performance in Marine Service
10^7 cycles @ 90MPa (in air)
10^7 cycles @ 70MPa (in seawater)
75% of yield strength for T6 temper
85% of yield strength for T73 temper
4. Comparative Analysis with Other Marine Alloys
Property6061-T65083-H1165052-H32Yield Strength (MPa)276215193Corrosion ResistanceGoodExcellentVery GoodWeldabilityGrade BGrade AGrade ACost Factor1.01.40.8
5. Best Practice Applications
<8m) with proper coating
High-load bearing components in splash zones
6. Maintenance Requirements
Inspection interval: 6 months for critical components
Industry Standard References: ASTM B928, DNVGL-RU-0179, ISO 9223
