The coating consists of three protective layers (A, B, and C):  

- C Layer: Made of an amorphous structure containing tungsten and phosphorus. It has high hardness, providing excellent wear and erosion resistance, effectively shielding the inner layers (A and B).  

- B Layer: Has a layered crystalline structure that acts as a sacrificial barrier.  

- A Layer: Has a columnar crystalline structure, offering deeper protection.   Because the B and A layers have different crystalline structures, their pores do not align, reducing the chance of corrosion penetrating through.

  Additionally, B has a higher electrode potential than A, meaning that if a small amount of corrosive material passes through the C layer and reaches B, B will corrode first, protecting A. Only after B is fully corroded will A start to degrade, significantly extending the overall lifespan of the coating.  

 This multi-layer protection system greatly enhances corrosion resistance, making it highly effective for oilfield applications.