Use and nature of corrosion coupon!
To conduct a comprehensive metal corrosion test, preparation of the metal test piece is essential. The test piece is initially weighed and then subjected to a specific duration within the test system, typically ranging from 30 to 90 days. Following this exposure period, the test piece is removed for corrosion observation, cleaning, and re-weighing. By comparing the initial and final weights, users can determine the extent of weight loss due to corrosion, often expressed in mils/year or mm/year (where 1 mpy equals 0.0254 mm/year). This process not only helps quantify corrosion rates but also enables identification of corrosion type and pitting depth.
Various standard corrosion test pieces are available for water treatment applications, such as corrosion coupons and cooling water treatment standard corrosion coupons. These test pieces are fabricated from materials like A3 carbon steel, 20# carbon steel, stainless steel, brass, red copper, aluminum, and cast iron. The data obtained from the metal coupon test is influenced not only by the corrosive environment but also by factors like surface treatment, placement location, exposure duration, and metallurgical composition of the coupon.
