Structure related corrosion behavior of DLC films in high Cl- environment

The diamond-like carbon (DLC) films were successfully fabricated on the surface of 13Cr super martensitic stainless steel by plasma enhanced chemical vapour deposition, and the microstructure changed with the variation of pulse voltages of the high pulse power supply. The microstructure of the DLC films was characterized by atomic force microscope, and the corrosion behavior of the films in a high Cl- environment was analyzed by open circuit potential, polarization curve and electrochemical impedance spectroscopy. It is found that the substrate corrosion occurred first for the DLC films with open pores, followed by a substrate surface passivation before the final corrosion failure. The DLC film with closed pores can effectively prevent Cl- from attacking the substrate before the corrosion pits formed at the local defects.

Automated summary

The research indicates that DLC films with open pores lead to substrate corrosion first, while DLC films with closed pores effectively prevent Cl- from attacking the substrate.