8/8/2023 0 Comments Lightning ground rodThis study is considered to be one of the most complete corrosion studies ever held. Comparison with galvanized rodsįrom 1910 to 1955 the National Institute of Standards and Technology of the United States (NIST) held an extensive study of underground corrosion, during which 36 500 samples representing 333 different coatings of ferrous and nonferrous metals and protective materials were tested in 128 locations across the United States *. On a separate page " Copper-bonded steel" you will see a detailed description of the main characteristics, processes during the manufacture and the held coating tests. The key factor in the manufacture of a high-quality ground rod is formation of a firm homogeneous copper coating of the required thickness with minimal impurity elements on a steel blank. In the future, at the operation of the ground electrode with such violations there appear seats of galvanic corrosion ("copper-iron"), leading to its complete destruction during 2-3 years. This thin coating is easily damaged during the installation by strokes and friction in the coupler. This is due to the electrolysis peculiarity: thickening of the coating in the dimples / depressions, due to which the main material (steel) on the thread can only be covered with a thin (0.03 - 0.05 mm) copper layer. * Peculiarities of creation of thread "Correct" thread is applied AFTER coppering coating - by rolling, because this is the only way that allows to achieve high overall quality of the rod.Īn alternative "technology" of copper coating: with the already formed thread (before coating) is cheaper, but it shows the worst (and dangerous during the operation) result. These features guarantee a high corrosion resistance of the ground rod and ensure long service life (up to 100 years). This is especially important on the thread where a thinner layer of copper would be completely destroyed by loads and friction with the coupler when the rod is plunged into the soil (installation) *. This ensures its (cover) resistance to bending, peeling and scratching during the installation. Thickness of the copper bonding is at least 0.250 mm throughout the entire length of the rod (including the thread). The rods have a high tensile strength (600 N / mm²) and can be plunged to a great depth (up to 40 meters) into the soil using a jackhammer. In addition to its role as a conductor, high-quality steel in such a ground electrode system performs a mechanical role necessary to plunge the electrode into the soil. On the edges of each rod there is thread applied by the rolling method, for the interconnection with the help of a compression coupler. It is a drawn steel rod with a diameter of 14 mm and a length of 1.5 meters, covered by electrolytic deposition (electrolysis) of copper with the purity of 99.9%, forming a coating of molecular and indissoluble bond to the steel.
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