Özet:

This paper presents the results of the study of nickel-based coatings fabricated by cold gas spraying. In this study, compositions based on Ni, Ni–Cu, Ni–Zn, and Ni–Al 2O 3/TiC coatings applied to low-alloyed steel bases were investigated. The composition, type of powder (mechanical mix or mechanically alloying), and thickness varied to choose the optimal characteristics for recovery, repair procedures, and specific applications in the oil and gas industry media. The second phase was added to Ni-based coatings to increase corrosion and wear resistance. Pure nickel coatings were also studied as a benchmark. Corrosion resistance was studied by means of electrochemical testing and autoclave testing in simulated oilfield conditions. Hydroabrasive resistance was studied using a unique testing bench. Scanning electron microscopy mappings, microhardness testing, and adhesion testing were used to correlate the results of the tests with the structure, continuity, and porosity of the studied coatings. It was shown that applying mechanical alloying of the powder did not lead to an effective increase of corrosion and hydroabrasive resistance. All the studied coating specimens have a sufficiently high adhesion. Ni–Zn coating has the lowest corrosion resistance and high hydroabrasive resistance. Ni–Cu coatings have high corrosion and the lowest hydroabrasive resistance. Al 2O 3/TiC additives give ambiguous results in the studied properties. A thickness of 40–60 microns provides sufficient performance of the studied coatings. Thus, varying chemical composition and thickness of coatings allows for obtaining the optimal qualities of Ni-based coatings made by cold gas spraying for use in the oil and gas industry.

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