Evaluation of Corrosion Resistance of as-Sprayed WC–Co–Cr on DH-36 Steel with Addition of 3% GNPs

• Published in: Transactions of the Indian Institute of Metals Vol. 77; no. 5; pp. 1413 - 1421
• Main Authors: Shrivastava, Shreyansh, Verma, Rajeev, Kumar, Vijay, Soni, Rahul, Saini, Gaurav
• Format: Journal Article
• Language: English
• Published: New Delhi Springer India 01-05-2024; Springer Nature B.V
• Subjects: Chemistry and Materials Science; Coating; Corrosion and Coatings; Corrosion products; Corrosion resistance; Corrosion resistant steels; Corrosion tests; Materials Science; Metallic Materials; Original Article; Structural steels; Substrates; Tribology; Tungsten carbide; DH 36; Tungsten carbide; Corrosion; HVOF; Graphene nano-particles
• ISSN: 0972-2815; 0975-1645
• DOI: 10.1007/s12666-023-03045-6

DH 36 is a naval grade steel that is widely used in shipbuilding components and offshore due to its high strength, durability, and usability. However, it suffers from corrosion and slit erosion in acidic and service environments such as sea applications. To address the above concern, a tungsten carbide coating with and without the addition of 3% grapheme nano-platelets is applied to DH 36 steel using the high-velocity oxy-fuel deposition technique. After a coating has been applied, its corrosion resistance was tested by exposing it to a 3.5% Nacl environment for 56 h at environmental temperature of 35 °C and salt mist temperature of 47 °C, as per ASTM B-117, to ensure its integrity. Scanning electron microscopy is used to investigate coating morphologies. After 8 h of corrosion study, it was determined that the coated substrates had no corrosion sign while the DH-36 steel substrate had noticeable pits. The corrosion products were analyzed using the XRD pattern and it was observed that various oxides like WO
4
, WO
3,
CoO, W
18
O
49
, and FE
3
O
4
were formed after corrosion. This reported coating promises to outperform the pristine substrate in terms of corrosion resistance.