API RP 581 - 3rd Ed.2016 - Add.2-2020 - Risk-Based Inspection Methodology

2.B-8 API RECOMMENDED PRACTICE 581
Table 2.B.2.5—HCl Corrosion—Estimated Corrosion Rates for Alloys 825, 20, 625, C-276 (mpy)
Alloy
Cl −
Concentration
(wt%)
Temperature (°F)
100 125 175 200
Alloy 825 and
Alloy 20
0.50 1 3 40 200
0.75 2 5 80 400
1.0 10 70 300 999
Alloy 625 0.50 1 2 15 75
0.75 1 5 25 125
1.0 2 70 200 400
Alloy C-276 0.50 1 2 8 30
0.75 1 2 15 75
1.0 2 10 60 300
Table 2.B.2.5M—HCl Corrosion—Estimated Corrosion Rates for Alloys 825, 20, 625, C-276 (mm/y)
Alloy
Cl −
Concentration
(wt%)
Temperature (°C)
38 52 79 93
Alloy 825 and
Alloy 20
0.50 0.03 0.08 1.02 5.08
0.75 0.05 0.13 2.03 10.16
1.0 0.25 1.78 7.62 25.37
Alloy 625 0.50 0.03 0.05 0.38 1.91
0.75 0.03 0.13 0.64 3.18
1.0 0.05 1.78 5.08 10.16
Alloy C-276 0.50 0.03 0.05 0.20 0.76
0.75 0.03 0.05 0.38 1.91
1.0 0.05 0.25 1.52 7.62