Corrosion Resistance of Duplex and 4-6 percent Mo-Containing Stainless Steels in FGD Scrubber Absorber Slurry Environments (14055)
By B. S. Phull, W. L. Mathay, R. W. Ross, reprinted from Corrosion 2000 Field tests using spectrum racks were performed in six operating flue gas desulphurization (FGD) scrubber absorbers to determine the corrosion resistance of a 22CR-5Ni duplex alloy, a 4% Mo-containing (Type 317LMN) stainless steel, and a 6%-Mo-containing stainless steel. Type 316 stainless steel and alloy C-276 specimens served as highly-susceptible and highly-resistant controls, respectively. The chlorine levels in the six absorber slurry environments ranged from ~9,000 to 70,000 ppm. The pH was typically ~5.5 with the slurry temperature in the 120-154?F (~49-68?C) range. Duplicate specimens were tested with "loose" and "tight" crevices for two exposure periods.