The selection of finger spring material
Date：2020-07-10 Author： click：
Contact spring welding _ spring contact production process _ There are three kinds of contact spring materials used in GIS at present, which are chromium-zirconium copper (implementing standard ASTM -- C18150).
Beryllium cobalt copper (ASTM -- C17500) and beryllium copper (ASTM -- C17200), the main properties of three materials.
The conductivity is arranged from large to small with high chromium-zirconium copper and low beryllium copper. The order of strength from high to low is chrome-zirconium copper lower and beryllium copper higher. The higher the conductivity of the material, the lower the strength.
Can a finger spring with high conductivity, low strength and low contact pressure, exceed the flow capacity of a beryllium-cobalt-copper finger spring? The allowable current density of beryllium cobalt copper is twice that of beryllium copper. The contact springs of beryllium cobalt copper and chromium-zirconium copper of the same size were installed in the same position for comparison through a number of GIS temperature rise tests. The test current is 2000~4400A. It is found that under the same current, the temperature rise of the contact surface of chromium-zirconium copper is 4~10℃ lower than that of beryllium-cobalt copper, and the greater the test current is, the more obvious the difference is. It is proved that although the chromium-zirconium copper contact spring with high conductivity material has low strength and low contact pressure, its conductivity is still better than that of beryllium-cobalt-copper with low conductivity material.
