Effect of ozone on corrosion of carbon steel and copper in the presence of HEDP and TTA in cooling water
- Wuhan Univ. (China)
- Clarkson Univ., Potsdam, NY (United States). Dept. of Chemical Engineering
- Diversey Water Technologies, Inc., Chagrin Falls, OH (United States)
Ozone is used to treat cooling water in large air-conditioning and refrigeration systems. The stability of two corrosion inhibitors, I-hydroxyethylidene diphosphonate (HEDP) and tolyltriazole (TTA), in the presence of 0.1 ppm of dissolved ozone in water was examined with coupon exposure tests of AISI 1010 steel and CDA 122 copper in a laboratory water-recirculating system over a range of water velocity of 0.5 to 9.5 ft/s (0.15 to 2.9 m/s) at 90 F (32 C). A linear polarization probe was used to measure the instantaneous corrosion rate of carbon steel and copper. Water analysis was performed to determine the concentration change of the inhibitors during the corrosion tests. It was found that ozone reacted with HEDP and TTA in both soft and hard water, and the corrosion-inhibition efficiency of HEDP and TTA was reduced by ozone. Pitting occurred on carbon steel in the presence of corrosion inhibitors; ozone increased pit density at the same test conditions.
- OSTI ID:
- 392473
- Report Number(s):
- CONF-960254--
- Country of Publication:
- United States
- Language:
- English
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