Nace CP 1 - Page 526

TM0101-2001
NACE International 15
Spike
"On" Potential
"Instant-Off" Potential (Polarized Potential)
Depolarizing Line
Voltage Drop (IR Drop)
Polarization Decay
Figure 2a
Polarization Decay
Normal Operation
"On" Potential
Current Interruption
"Instant-Off"
Potential
Polarization
Cathodic Protection Applied
Corrosion Potential
Polarizing Line
Figure 2b
Polarization Formation
FIGURE 2
Cathodic Polarization Curves
Time Period
(May be seconds, minutes, hours, or days
Pipe-to-Electrolyte Potential (-mV)Pipe-to-Electrolyte Potential (-mV)
Time Period
(May be seconds, minutes, hours, or days
1,100
1,000
900
800
700
600
500
400
1,200
1,100
1,000
900
800
700
600
500