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

RISK-BASED INSPECTION METHODOLOGY, PART 2, ANNEX 2.B—DETERMINATION OF CORROSION RATES 2.B-69
2.B.9.4 Tables
Table 2.B.9.1—High Temperature Oxidation—Basic Data Required for Analysis
Basic Data
Material of construction
Maximum metal temperature (°C :°F)
Comments
Determine the material of construction of this equipment/piping.
Determine the maximum metal temperature. The tube metal temperature for
furnace tubes is the controlling factor.
Table 2.B.9.2—High Temperature Oxidation—Estimated Corrosion Rate (mpy)
Material
Maximum Metal Temperature (°F)
925 975 1025 1075 1125 1175 1225 1275 1325 1375 1425 1475
CS 2 4 6 9 14 22 33 48 — — — —
1 1 /4 Cr 2 3 4 7 12 18 30 46 — — — —
2 1 /4 Cr 1 1 2 4 9 14 24 41 — — — —
5 Cr 1 1 1 2 4 6 15 35 65 — — —
7 Cr 1 1 1 1 1 2 3 6 17 37 60 —
9 Cr 1 1 1 1 1 1 1 2 5 11 23 40
12 Cr 1 1 1 1 1 1 1 1 3 8 15 30
304 SS 1 1 1 1 1 1 1 1 1 2 3 4
309 SS 1 1 1 1 1 1 1 1 1 1 2 3
310 SS/HK 1 1 1 1 1 1 1 1 1 1 1 2
800 H/HP 1 1 1 1 1 1 1 1 1 1 1 2
Table 2.B.9.2M—High Temperature Oxidation—Estimated Corrosion Rate (mm/y)
Material
Maximum Metal Temperature (°C)
496 524 552 579 607 635 663 691 718 746 774 802
CS 0.05 0.1 0.15 0.23 0.36 0.56 0.84 1.22 — — — —
1 1 /4 Cr 0.05 0.08 0.1 0.18 0.3 0.46 0.76 1.17 — — — —
2 1 /4 Cr 0.03 0.03 0.05 0.1 0.23 0.36 0.61 1.04 — — — —
5 Cr 0.03 0.03 0.03 0.05 0.1 0.15 0.38 0.89 1.65 — — —
7 Cr 0.03 0.03 0.03 0.03 0.03 0.05 0.08 0.15 0.43 0.94 1.52 —
9 Cr 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.05 0.13 0.28 0.58 1.02
12 Cr 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.08 0.2 0.38 0.76
304 SS 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.05 0.08 0.1
309 SS 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.05 0.08
310 SS/HK 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.05
800 H/HP 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.05