Page 318 - Challenges in Corrosion Costs Causes Consequences and Control(2015)

296 CORROSION CONTROL AND PREVENTION

TABLE 4.46 Corrosion Failure Mode with Average Frequency of Occurrence
Failure Mode Average Frequency (%)
Cracking 36
General corrosion 26
Localized corrosion 20
Temperature effects 7
Velocity effects 5
Voltage effects 3
Hydrogen effects 2
Biological 0
Total 99

TABLE 4.47 Stress Corrosion Cracking Failures of Different Alloys
Material Average Frequency (%)
Stainless steels 61.4
Steel 30.4
Copper alloys 4.3
Nickel alloys 2.8
Titanium 0.7
Tantalum 0.3
Total 99.9

Figure 4.11 SCC colony found on a high-pressure gas pipeline (6).

4.28.1 Corrosion-Resistant Alloys
These alloys are widely used in the chemical process industry. It is always better
to use a more corrosion-resistant alloy in spite of its cost as it solves the corrosion
problems and saves money in the long run. The relative costs of some alloys used in
corrosion control relative to type 316L stainless steel as the reference with a ratio 1.0
are given in Table 4.48.