Influence of higher and high temperature on anticorrosive properties of diamond-like carbon coating on S355 steel

Influence of higher and high temperature on anti-corrosive properties of a diamond-like carbon coating (DLC), produced by plasma enhanced chemical vapor deposition (PECVD) on 5355 steel substrate (S355/DLC), was investigated. Corrosion test of materials was carried out by electrochemical method. Corrosive environment was an acidified sodium chloride solution. It has been demonstrated that the DLC coating effectively protects the 5355 steel surface from contact with an aggressive corrosive environment The thermal treatment was carried out in an atmosphere of hot air at temperatures of 400 or 800 degrees C. It was found that after thermal treatment at 400 degrees C the DLC coating partially loses its anti-corrosive properties. Due to changes in the surface structure of the S355/DLC layer its microhardness (HV) increases. However, after heat treatment at 800 degrees C the carbon coating is destroyed and thus loses its protective effect.