Final Report - Strategic Environmental Research and Development ...

Corrosion Area (mm 2 )
corrosion rate (mm/yr)
Corrosion Volume (mm 3 )
T3 were stronger than that between Ti-6Al-4V and AA2024-T3 due to the corrosion area, but not
corrosion rate.
30
25
20
15
10
5
0
Ti-6Al-4V
316 CRES
0.0 0.2 0.4 0.6 0.8 1.0
n/(N+1)
Figure 6.44. Corrosion volume listed by fastener type in ASTM G85 for 360 h.
3
2
Ti-6Al-4V
316 CRES
1
0
0.0 0.2 0.4 0.6 0.8 1.0
n/(N+1)
Figure 6.45. Corrosion rate listed by fastener type- ASTM G85 for 360 h
1200
1000
800
600
400
200
0
Ti-6Al-4V
316 CRES
0.0 0.2 0.4 0.6 0.8 1.0
n/(N+1)
Figure 6.46. Corrosion area listed by fastener type in ASTM G85 for 360 h.
b. Efficacy of Surface Treatment. In Figure 6.47, Surtec 650 and Alodine 1200S, two types of
surface treatments involving with chromium, provided better protection than the other
chromium-free surface treatment in ASTM B117, as the samples with those two surface
treatments had smaller volume of material lost. However, the results of corrosion rate were
opposite to what the corrosion volume expressed (Figure 6.48). It was mainly due to the
corrosion area. Samples with Alodine 1200S or Surtec 650 were corroded in the area close to
322