Deposition of DLC film on the inner surface of N80 pipeline by hollow cathode PECVD

Abstract

The corrosion and wear of N80 pipeline in oil and gas field environment has always been an urgent problem to be solved in the field of oil and gas exploitation. DLC film is considered to be an effective material for prolonging the service life of pipeline due to its excellent properties. However, it is very difficult to deposit a uniform DLC film on the inner surface of long pipeline. In this paper, DLC film was deposited on the inner surface of a 1 m-long N80 pipeline with an inner diameter of 75 mm by hollow cathode plasma enhanced chemical vapor deposition (HC-PECVD) using the pipeline itself as the deposition chamber and cathode. The uniformity of microstructure, mechanical properties, corrosion resistance and tribological properties of DLC film were discussed. The results show that the DLC film deposited on the inner surface of N80 long pipeline by HC-PECVD equipment possesses excellent axial uniformity. The deposition of DLC film increases the corrosion potential and reduces the corrosion current density, which greatly improves the corrosion resistance of N80 pipeline. In addition, the deposition of DLC film also reduces the friction coefficient and wear rate, which greatly improves the wear resistance of N80 pipeline. Therefore, the deposition of DLC film is an effective protection method for the inner surface of N80 pipeline, which prolongs the service life of the pipeline. HC-PECVD equipment with pipeline as cavity uniformly deposits DLC film on the inner surface of long pipeline, which is a potential deposition method to prolong the service life of long pipeline in oil and gas exploitation.