Table 5: Tafel slopes and corrosion rate.

Solution and time of measurementPipe 𝛽 𝑎 (mV/decade) 𝛽 𝑐 (mV/decade)CR (mm/year)

Static tap water after one year1123.51310.074
2116.9118.850.12
31821970.12

Aerated tap water after one year1207.6215.50.286
2223.72330.239
3179.9187.30.303

Aerated solution of 3.5% NaCl after six months182.484.50.69
23131.60.53
329.129.70.6