Structural, Adhesion and Electrochemical Characterization of Electroless Plated Ni-P-Carbon Black Composite Films on API 5L X80 Steel

• Published in: Journal of materials engineering and performance Vol. 28; no. 8; pp. 4751 - 4761
• Main Authors: de Oliveira, Mara Cristina Lopes, Correa, Olandir Vercino, da Silva, Rejane Maria Pereira, de Lima, Nelson Batista, de Oliveira, Jefferson Thadeu Dias, de Oliveira, Leandro Antônio, Antunes, Renato Altobelli
• Format: Journal Article
• Language: English
• Published: New York Springer US 15-08-2019
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Corrosion and Coatings; Engineering Design; Materials Science; Quality Control; Reliability; Safety and Risk; Tribology; scanning electrochemical microscopy; corrosion; Ni-P-carbon black composite films
• ISSN: 1059-9495; 1544-1024
• DOI: 10.1007/s11665-019-04245-2

In this work, composite Ni-P-carbon black coatings were obtained by electroless deposition on API 5L X80 substrates. The effect of carbon black on structural, adhesion and electrochemical properties of the plated samples was evaluated. Scanning electron microscopy analyses were carried out to examine the top surface and cross section of the films. Scratch tests were employed to evaluate coating adhesion properties. Potentiodynamic polarization tests were carried out to investigate the global electrochemical behavior of the deposited layers. Scanning electrochemical microscopy (SECM) was employed to measure local electrochemical activity over the coated surfaces. The carbon black concentration markedly affects the morphology, adhesion and electrochemical properties of the Ni-P-carbon black layers. The results point to an optimum carbon black content to achieve the best performance against corrosion. The coatings obtained at a carbon black concentration of 0.25 g L
−1
provided the best protection ability. The results are discussed with respect to coating morphology, adhesion and electrochemical activity.