Corrosion products copper

In addition to bonding with the metal surface, triazoles bond with copper ions in solution. Thus dissolved copper represents a "demand" for triazole, which must be satisfied before surface filming can occur. Although the surface demand for triazole filming is generally negligible, copper corrosion products can consume a considerable amount of treatment chemical. Excessive chlorination will deactivate the triazoles and significantly increase copper corrosion rates. Due to all of these factors, treatment with triazoles is a complex process. 

Internal surfaces of all tubes were severely attacked (Fig. 4.29). A brown deposit layer consisting of magnetite, iron oxide hydroxide, and silica covered all surfaces. Deposition was thicker and more tenacious along the bottom of tubes. These deposits had a distinct greenish-blue cast caused by copper corrosion products beneath the deposit. Underlying corrosion products were ruby-red cuprous oxide crystals (Fig. 4.29). Areas not covered with deposits suffered only superficial attack, but below deposits wastage was severe. 

Figure 13.64 Red, dezincified gasketed surface of a cast valve throat. Note the partial spalling of the copper corrosion product.

Figure 13.9 Stratified copper corrosion product in plug-type dezincification. Denickelification...

Figure 13.116 Porous copper corrosion products filling an internal surface depression. The edge of one crater seen in Fig. 13.11A is to the right.

Several books contain general summaries of the corrosion behaviour of copper and its alloy and the formation of copper corrosion products and methods for their identification have been described in a number of papers... 

NOTE Where iron and copper corrosion products develop in CR systems, typically the copper is approximately 10% of iron level. 

At above the critical pressure of 3,203.6 psi, virtually no solids can be tolerated in boiler FW because all of the water is converted to steam, which passes through the turbine. Copper corrosion products tend to be the most troublesome contaminant in supercritical boilers, consequently all efforts must be made to prevent copper and other metallic oxides from entering the boiler. FW quality guidelines include ... 

Thomas, R.G. (1990). Mineralogy of Copper Corrosion Products. Unpublished PhD Thesis, Department of Chemistry, University of Wales, Cardiff. 

The pre-boiler equipment, consisting of feedwater heaters, feed pumps and feed lines, is constructed of a variety of materials, including copper, copper alloys, carbon steel, and phosphor bronzes. To reduce corrosion, the makeup and condensate must be at the proper pH level and free of gases such as carbon dioxide and oxygen. The optimum pH level is that which introduces the least amount of iron and copper corrosion products into the boiler cycle. This optimum pH level should be established for each installation. It generally ranges between 8.0 and 9.5... 

Iron particles are believed to have been introduced to the paper from the water used for the papermaking process or come from the machinery used. The latter explanation has some validity as there are some papers with brass (Cu/Zn alloy) particles in them these have often corroded to black or green copper corrosion products that may include chlorine from residues of bleaching agents. 

Collectors use commercial acne treatments to remove green ear from dolls PVC skin. Green ear comprises copper corrosion products formed on earrings, pins or metal fasteners, which are transported hy plasticizer. 

Experience has shown that wherever possible, only one type of alloy or family of nonmetaUics should be exposed in a given test apparatus. If several alloys or nonmetaUics are exposed in the same apparatus the corrosion products from one material may affect the corrosion rate on another material. For example, copper corrosion products can inhibit corrosion of stainless steel but accelerate corrosion of aluminum. 

Connectors are a critical part of an electronic S5rstem. Corrosion mechanisms at connector interfaces include pore corrosion, corrosion product creep, fretting, and SCC and general attack. Pore corrosion in connectors is associated with surfaces plated with gold or other precious metals. Corrosion product creep in connectors usually involves copper corrosion products originating from exposed base... 

Presence of small amounts of some sulfur compounds in certain refined products (gas and liquid) can have a corrosion effect on copper alloy components of users equipment that adversely affects their function. For example, copper corrosion products could cause plugging of metering and pilot valves. Consequently, product specifications may call for the product to pass a copper corrosion test such as ASTM D 1838, Test Method for Copper Strip Corrosion by Liquefied Petroleum (LP) Gases, or ASTM D 130, Test Method for Detection of Copper Corrosion from Petroleum Products by the Copper Strip Tarnish Test, or ASTM D 4048, Test Method for Detection of Copper Corrosion from Lubricating Grease. 

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