High Silicon Cast Iron Double-ended Rodlike anode

High silicon iron Impressed Current Cathodic Protection anodes are widely used usually in conjunction with carbonaceous backfills in soils. HSI anode has also found limited use in marine and freshwater environments.
High Silicon Iron Anode 's maximum operating current density is determined by the type of alloy and the environment.

The high silicon content ensures that the alloy forms a protective film containing silicon dioxide, SiO₂.

Silicon dioxide is highly resistant to acids but it is readily dissolved in alkaline conditions. High silicon iron anodes are extremely hard and cannot be machined easily. They are generally cast and then stress relieved by annealing.