Electrochemical Corrosion Behavior of High Velocity Oxy-Fuel (HVOF) Superalloy Coatings On Ductile Irons

Abstract

In this study, alloyed and unalloyed ductile irons (DI) were coated with two different Ni-based superalloy materials by HVOF method. Microstructure and phase analyzes of the coatings were performed by using SEM, EDX, XRD methods.  The electrochemical corrosion behavior of alloyed and unalloyed DI is investigated in 3.5% (w / v) NaCl solution. As a result of the characterization studies, it was observed that a dense non-porous coating layer of about 80 μm thickness was obtained on the cast iron samples and continuous adhesion was provided between the coating and the substrate. It has been determined that the cast iron coated with AMDRY 9624 contains γ and β intermetallic phases and the coating produced with AMDRY 9951 commercial powder contains only γ phase. As a result of coating process, the corrosion rate of the alloyed and unalloyed spherical graphite cast irons is reduced. Also, the corrosion rate of the coating produced with AMDRY 9951 is higher than the coating produced with AMDRY 9624. The presence of intermetallic phases in the coating produced with AMDRY 9624 increased the corrosion resistance of the coatings.

Keywords

• HVOF,Ductile Iron,Electrochemical Methods

References

1. [1] R., Singh, “Cast Iron Metallurgy. Materials Performance”, 48 (9), pp. 58-61, 2009.
2. [2] R., O'Rourke, “Cast Iron: The engineered metal”, Advanced Materials Processes, 159 (1), pp. 65-68, 2001.
3. [3] J.L., Liu, G.Q., Shi, P.D., Ding, H.O., Ye, Z.X., Ou, “Features of laser alloying of grey cast iron”, Lasers in Engineering, 6(2), pp. 81-101, 1997.
4. [4] X., Cheng, S.B., Hu, W.L., Song, X. S., Xiong, “Improvement in corrosion resistance of a nodular cast iron surface modified by plasma beam treatment”, Applied Surface Science, 286, pp. 334-343, 2013.
5. [5] Z., Lestan, M., Milfelner, J., Balic, M., Brezocnik, I., Karabegovic, “Laser deposition of Metco 15E, Colmony 88 and VIM CRU 20 powders on cast iron and low carbon steel”, International Journal of Advanced Manufacturing Technology, 66(9-12), pp. 2023-2028, 2013.
6. [6] A.L. Maco and F.J. Belzunce, “Laser surface hardening of gray cast irons”, Revista De Metalurgia, 34(2), pp. 126-130, 1998.
7. [7] V., Ozcelik, U., Oliveira, M., Boer, J.T.M., Hosson, “Thick Co-based coating on cast iron by side laser cladding: Analysis of processing conditions and coating properties”, Surface & Coatings Technology, 201(12), pp. 5875-5883, 2007.
8. [8] F., Fernandes, A., Cavaleiro and A., Loureiro, “Oxidation behavior of Ni-based coatings deposited by PTA on gray cast iron”, Surface & Coatings Technology, 207, pp. 196-203, 2012.

9. [9] P., Fauchais and A., Vardelle, “Thermal sprayed coatings used against corrosion and corrosive wear, in Advanced plasma spray applications”, InTech., 2012.[10] J., Yoganandh, S., Natarajan and S.P.K., Babu, “Erosion Behaviour of WC-Co-Cr Thermal Spray Coated Grey Cast Iron under Mining Environment”, Transactions of the Indian Institute of Metals, 66(4), pp. 437-443, 2013.
10. [11] J., Vetter, G., Barbezat, J., Crummenauer, J. Avissar, “Surface treatment selections for automotive applications”, Surface and Coatings Technology, 200(5), pp. 1962-1968, 2005.
11. [12] I.G., Wright and B.A., Pint, “Bond coating issues in thermal barrier coatings for industrial gas turbines”, Proceedings of the Institution of Mechanical Engineers Part a-Journal of Power and Energy, 219(A2), pp. 101-107, 2005.
12. [13] Y., Itoh, M. Saitoh M. Tamura, “Characteristics of MCrAIY coatings sprayed by high velocity oxygen-fuel spraying system”, Journal of Engineering for Gas Turbines and Power-Transactions of the Asme, 122(1), pp. 43-49, 2000.
13. [14] Z.W., Huang, Z.G., Wang, S.J., Zhu, F.H., Yuan, F. G., Wang, “Effect of HVOF sprayed MCrAIY coating on thermomechanical and isothermal fatigue life of superalloy M963”, Surface Engineering, 23, pp. 373-374, 2008.
14. [15] M., Seiersten and P. Kofstad, “Sodium Vanadate-Induced Corrosion of Nickel and Mcraiy Coatings on Inconel-600”, Materials Science and Technology, 3(7), pp. 576-583, 1987.
15. [16] S.V., Joshi and R. Sivakumar, “Particle Behavior during High-Velocity Oxy Fuel Spraying”, Surface & Coatings Technology, 50(1), pp. 67-74, 1991.[17] J.R., Davis, “Handbook of thermal spray technology”, ASM international, 2004.
16. [18] M. Shibat, S., Kuroda, M., Watanabe, Y., Sakamoto, “Oxidation property of CoNiCrAlY coatings prepared by various thermal spraying techniques”, High-Temperature Oxidation and Corrosion, 522-523, pp. 339-344, 2006.
17. [19] P.S. Grewal, V., Chawla and J.S., Grewal, “High Velocity Oxy-fuel Sprayed Coatings- a Review”, Journal of the Australian Ceramic Society, 47(2), pp. 30-36, 2011.
18. [20] J., Koutsky, “High Velocity Oxy-Fuel spraying”, Journal of Materials Processing Technology, 157, pp. 557-560, 2004.
19. [21] S., Saeidi, K.T., Voisey and D.G., McCartney, “Mechanical Properties and Microstructure of VPS and HVOF CoNiCrAly Coating”, Journal of Thermal Spray Technology, 20(6), pp. 1231-1243, 2011.
20. [22] S., Saeidi, K.T., Voisey and D.G., McCartney, “The Effect of Heat Treatment on The Oxidation Behavior of HVOF and VPS CoNiCrAly Coating”, Journal of Thermal Spray Technology, 18(2), pp. 209-216, 2009.
21. [23] K., Fritscher and Y.T., Lee, Investigation of an as-sprayed NiCoCrAlY overlay coating microstructure and evolution of the coating. Materials and Corrosion-Werkstoffe und Korrosion, 56(1), pp. 5-14, 2005.
22. [24] C.T., Kwok, P.K., Wong, F.T., Cheng, H.C., Man, “Characterization and corrosion behavior of hydroxyapatite coatings on Ti6Al4V fabricated by electrophoretic deposition”, Applied Surface Science, 255, pp. 6736–6744, 2009.
23. [25] A.L.A., Escada, D., Rodrigues, J.P.B., Machado, A.P.R., Alves Claro, “Surface characterization of Ti–7.5Mo alloy modified by biomimetic method”, Surface & Coatings Technology, 205, pp. 383–387, 2010.
24. [26] G.K., Kariofillis, G.E., Kiourtsidis, D.N. Tsipas, “Corrosion behavior of borided AISI H13 hot work steel”, Surface & Coatings Technology 201, pp. 19–24, 2006.
25. [27] H.H., Uhlig (Ed.), “Corrosion Handbook”, second ed., John Wiley & Sons, New York, 2000.
26. [28] M.M., Verdian, K., Raeissi, M., “Salehi, Characterization and electrochemical properties of Ni(Si)/Ni5Si2 multiphase coatings prepared by HVOF spraying”, Applied Surface Science, 261, pp. 493–498, 2012.
27. [29] A., Balamurugan, G., Balossier, S., Kannan, J., Michel, J., Faure, S., Rajeswari, “Electrochemical and structural characterization of zirconia reinforced hydroxyapatite bioceramic sol-gel coatings on surgical grade 316L SS for biomedical applications”, Ceramics International, 33, pp. 605-614, 2007.
28. [30] S., Kannan, A., Balamurugan, S., Rajeswari, “H2SO4 as a passivating medium on the localised corrosion resistance of surgical 316L SS metallic implant and its effect on hydroxyapatite coatings”, Electrochimica Acta, 49, pp. 2395-2403, 2004.
29. [31] H.N., Cheng, R.A., Gross, “Polymer Biocatalysis and Biomaterials”, ACS Symposium, 900, pp. 560, 2005.