Preparation and Characterization of Ceramic Film on Drilling Pipe Joint

A metallic ceramic film consisting of nitrides, carbides and oxides of Ti, Cr and Al was prepared on the surface of a drilling pipe joint by low pressure chemical vapor deposition (LPCVD). The film was characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The adhesive ability and the corrosion resistance performance were evaluated by scratch test and corrosion test, respectively. The results show that the film is dense and homogeneous with 15 μm in thickness including a 5 μm transition layer. The film presents a good adherence to the substrate with no cracks and no pores. It could decrease electrochemical corrosion and chemical corrosion through separating the harmful atoms or ions from the substrate. Particularly, it could also effectively prevent H2S and CO2 from contacting the steel, avoiding hydrogen blistering (HB) and hydrogen to induce cracking (HIC). Consequently, the service life of drilling pipe can be greatly improved.