Refinery Corrosion and Metals

Neutralizing chemicals (incl. half of desalting cost). 

The corrosiveness of sulfur-bearing oils is not directly proportional to the sulfur content. Crude oils that contain 2 per cent sulfur and that 

Number o times better performance (than for carbon sted) 

Chromium steel is the standard material, for withstiuiding sulfide corro sion. Resistance becomes noticeable at about 1 per cent chromium, but in most instances the use of more than 13 per cent is not justified. The high-chromium (13 per cent up) steels tend to lose ductility, particularly if used at high temperatures, and hence nickel is employed with the chromium to assist in avoiding loss of ductility. 

Neutralizing chemicals, particularly lime, are widely used to combat sulfide corrosion. The effect of ammonia is not entirely known, but caustic soda causes troublesome scaling or clogging of tubes and evaporator surfaces. 

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