Deposited metal of EDCoCr type cobalt-based alloy surfacing electrode has excellent comprehensive heat resistance, corrosion resistance and oxidation resistance, and can maintain high hardness at a high temperature above 600 degrees. The commonly used cobalt-based alloy surfacing is EDCoCr -A, EDCoCr-B, EDCoCr-C, three types, cobalt-based alloy electrode deposited metal contains 25-33% chromium, it has oxidation resistance, when it contains 3-14% tungsten, it has high temperature strength, and cobalt It has corrosion resistance and is a solid solution matrix. Carbon is an element that can improve the strength of the deposited metal. When carbon and chromium are combined into a hard carbide, the hardness of the deposited metal can be increased, and with As the carbon content increases, the hardness of the deposited metal increases, and the toughness decreases to meet the needs of different applications.The deposited metal with lower carbon content has good toughness and can withstand the impact of cold and hot conditions, as well as corrosion and erosion. It is suitable for surfacing welding of high temperature and high pressure valve sealing surfaces, pump shafts, hot forging dies, hot shear blades, etc.The high-carbon and high-tungsten surfacing materials have high hardness, good wear resistance, but weak impact resistance, and It is not easy to process, and is often used for surfacing welding of roller cone bits, bearings, rotating impellers, blades of crushers, feeders in Chinese, etc.
At a high temperature of 540-650 degrees, the cobalt-based alloy deposited metal has good creep resistance and high temperature hardness, which is the main reason why they are widely used in many occasions
Because there is more than 25% chromium in the deposited metal, it can form a thin and tightly adhered, protective oxide scale under oxidation conditions. In addition, the cobalt-based alloy deposited metal has good performance in general corrosive media. Corrosion resistance, so it is often used under conditions that require wear resistance and corrosion performance
Although the cobalt-based alloy surfacing electrode has a wide range of applications in terms of wear resistance, if high temperature and corrosion are not important factors, then the iron-based surfacing electrode can also obtain the corresponding wear resistance.
Cobalt-based alloy electrode surfacing adopts DC reverse polarity. In order to prevent cracking, it should be preheated and slowly cooled during surfacing. After cobalt-based alloy surfacing, it can be put into operation under normal circumstances, but it is recommended to carry out large-area surfacing. Used after stress relief heat treatment, while using nickel-chromium austenitic stainless steel as the surfacing transition layer