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

2.B-26 API RECOMMENDED PRACTICE 581
Table 2.B.3.8—High Temperature Sulfidic and Naphthenic Acid Corrosion—Estimated Corrosion
Rates for Austenitic SS Without Mo (mpy)
Sulfur
(wt%)
TAN
(mg/g)
Temperature (°F)
≤450 500 550 600 650 700 750 >750
1.0 1 1 1 1 1 1 1 1
0.2
1.5 1 1 1 1 1 1 1 1
3.0 1 1 1 1 2 3 4 4
4.0 1 1 1 2 3 4 5 6
1.0 1 1 1 1 1 1 1 1
0.4
1.5 1 1 1 1 1 1 1 1
3.0 1 1 1 1 2 3 4 4
4.0 1 1 1 2 3 4 5 6
1.0 1 1 1 1 1 1 1 1
0.8
1.5 1 1 1 1 1 1 1 1
3.0 1 1 1 2 3 4 5 6
4.0 1 2 2 4 6 8 10 12
1.0 1 1 1 1 1 1 1 1
1.5
1.5 1 1 1 1 1 1 1 1
3.0 1 1 1 2 3 4 5 6
4.0 1 2 2 4 6 8 10 12
1.0 1 1 1 1 1 1 1 1
2.5
1.5 1 1 1 1 1 1 1 1
3.0 1 2 2 4 6 8 10 12
4.0 1 2 4 7 10 14 17 20
1.0 1 1 1 1 1 1 1 2
3.0
1.5 1 1 1 1 1 2 2 2
3.0 1 2 2 4 6 8 10 12
4.0 1 2 4 7 10 14 17 20
NOTE
Austenitic stainless steels without Mo include 304, 304L, 321, 347, etc.