Corrosion control methods

摘要

There are provided methods of suppressing corrosion of a corrodible metal surface that contacts a water stream in a water system, the method comprising: (a) introducing into the water stream a shot dose of a treatment composition comprising a corrosion inhibitor, the shot dose being introduced into the water stream over a first time period and the water stream having a first concentration of corrosion inhibitor during the first time period; (b) then reducing the amount of treatment composition that is introduced into the water stream; and (c) after the first time period, maintaining a second concentration of corrosion inhibitor in the water stream over a second time period, the second concentration being less than 25% of the concentration of corrosion inhibitor during the first time period. There is also provided, after the second time period, introducing into the water stream a second shot dose of the corrosion inhibitor, the second shot dose being introduced into the water stream over a third time period, the third concentration being greater than the second concentration.

主权项

1. A method of suppressing corrosion of a corrodible metal surface that contacts a water stream in a water system, the method comprising:
(a) introducing into the water stream a shot dose of a treatment composition comprising a corrosion inhibitor in amounts sufficient to provide a stable film of Tin(IV) on the metal surface, the shot dose being introduced into the water stream over a first time period and the water stream having a first concentration of corrosion inhibitor during the first time period; (b) then reducing the amount of treatment composition that is introduced into the water stream; (c) after the first time period, maintaining a second concentration of corrosion inhibitor in the water stream over a second time period, the second concentration being less than 25% of the concentration of corrosion inhibitor during the first time period; and (d) then increasing the amount of treatment composition that is introduced into the water stream during a third time period at a third concentration that is higher than the second concentration and is in the range of 20 to 100% of the first concentration, the third concentration being sufficient to maintain or re-stabilize portions of the stable film of Tin(IV) on the metal surface.