Extending the Lifetime of Oil and Gas Equipment with Corrosion and Erosion-Resistant Ni-B-Nanodiamond Metal-Matrix-Nanocomposite Coatings

摘要

The increasing pressure to eliminate hard chromium in oil and gas applications because of environmental concerns related to hexavalent chromium has fueled the need for substitutes with comparable economics and performance. Nickel (Ni) presents a viable alternative coating material, which is widely used in industrial applications over the past five decades because of its unique characteristics in improving resistance to corrosion, abrasion and wear. Performance of Ni-based coatings can be further improved with the development of metal-matrix-nanocomposite coatings (MMnC). This paper presents the development of a new class of MMnCs prepared by electrolytic deposition. The nanocomposite coatings are formed by the simultaneous impingement of the nanoparticles onto the growth surface and the envelopment of said particles by the depositing Ni ions. In this new process, the metal matrix comprises Ni-B compositions produced with a nontraditional Boron (B) source, which enables higher B-contents in the matrix, resulting in superior hardness and resistance to corrosion. Incorporation of diamond nanoparticles into the matrix improves resistance to wear without negatively affecting the corrosion resistance. Dispersed nanodiamond decreases the grain size of Ni-B matrix and improves the mechanical properties of the coatings. Ultimately, size, nature and content of particles dispersed in the matrix determine the properties of the coatings. This paper describes the impact that Boron and nanodiamond incorporated in the matrix have on the growth, microstructure, corrosion and mechanical properties of the new class of metal-matrix nanocomposite coatings. Experimental results also show that this material outperforms current commercially available electroless Ni-B coatings. The novel coatings presented extend the lifetime of equipment used in corrosive and erosive environments in the exploration and production of oil and gas.