Treatment method of corrosion coupon

Video Link:

https://www.youtube.com/watch?v=VB484uLyTYI&list=PLDJGpwaJfv-m2F2BokEPLVNYCmgWzsH4J

1. Nature of corrosion coupon

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Corrosion coupon is hung in the test vessel or on the pipeline. Standard metal coupon is usually used to detect or evaluate the internal corrosion of the pipeline. Generally, the pre processed and weighed metal test pieces are put into the pipeline for corrosion rate test, and taken out after a period of time (30-90 days) to observe the corrosion. It determines the corrosion weight loss degree and corrosion type of metal by reweighing after cleaning. In addition to the influence of corrosive media, the data of metal coupon are also related to the surface treatment, placement position, exposure time and other factors.

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2. Storage and use methods

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The standard corrosion coupon is usually processed by the manufacturer, and the common materials are carbon steel, copper, aluminum, alloy and other materials.

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（1） Degrease and scrub the corrosion coupon for test in distilled water, and then rinse it with distilled water for 15 seconds

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（2） Degrease and scrub the corrosion coupon for test twice in chemical pure absolute ethanol

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（3） Place the corrosion coupon for test on the dry filter paper and dry it with cold air

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（4） Wrap the corrosion coupon for test with filter paper and place it in a dry environment, wait for 24 hours, then weigh it and use it

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4. Treatment of coupon after use

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（1） Carefully take out the used coupon, observe and record the surface condition

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（2） If the corrosion deposition is not obvious, wipe it with an eraser to expose the true color of the metal, and then put it into absolute ethanol and scrub it twice with absorbent cotton. Then, soak it in clean absolute ethanol for a while and take it out. Put the hanging piece on clean filter paper and dry it with cold air, then wrap it with filter paper and put it in a dry environment. After 24 hours, weigh and calculate the corrosion rate

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（3） For the coupon with large amount of corrosion deposits, chemical cleaning shall be used to remove the corrosion products. Then repeat the above steps.