Investigations of Local Corrosion Behavior of Plasma-Sprayed FeCr Nanocomposite Coating by SECM
- PDF / 1,878,002 Bytes
- 10 Pages / 593.972 x 792 pts Page_size
- 34 Downloads / 220 Views
Technical Note
Investigations of Local Corrosion Behavior of Plasma-Sprayed FeCr Nanocomposite Coating by SECM Xi Shi, Mingyong Shu, Qingdong Zhong, Junliang Zhang, Qiongyu Zhou, and Quoc Binh Bui (Submitted June 19, 2015; in revised form December 20, 2015) FeCr alloy coating can be sprayed on low-carbon steel to improve the corrosion resistance because of FeCr alloyÕs high anti-corrosion capacity. In this paper, Fe microparticles/Cr nanoparticles coating (NFC) and FeCr microparticles coating (MFC) were prepared by atmospheric plasma spraying and NFC was heat-treated under hydrogen atmosphere at 800 °C (HNFC). EDS mapping showed no penetration of Ni in MFC and NFC while penetration of Ni occurred in HNFC. X-ray diffraction results indicated the form of the NiCrFe (bcc) solid solution in HNFC. SECM testing in 3.5 (wt.%) NaCl revealed that the anticorrosion capacity of NFC improved compared with MFC, while HNFC improved further.
Keywords
corrosion protection, heat treatment, nanocomposite, plasma spray forming, protective coatings
1. Introduction Fe-Cr alloy coatings deposited by APS have been studied for their potential applications as coating materials (Ref 1). Ando studied containers deposited by a plasmasprayed FeCr alloy coating (Ref 2), finding that NaOH would penetrate through these pores, react with the substrate and generate H2 gas. The amount of H2 gas generated was proportional to the existence of permeable pores in the sprayed coating and the size of the pores. A sulfide corrosion-resistant plasma-sprayed FeCr alloy coating was studied in sulfide solution (Ref 3), and it was found that Cr2S3 and Cr3S4 formed in the sulfide layers on the high Cr-Fe alloy surface. Because of the features of the conventional thermal spraying process, the microstructures of the coatings are often characterized with various pores and cracks (Ref 4). By spraying nanoparticles instead of conventional microparticles, coatings that exhibit compact microstructures and enhanced properties can be obtained (Ref 5, 6). In this study, Fe microparticles/Cr nanoparticles coating (NFC) and FeCr microparticles coating (MFC) with the nominal composition Cr: 13.4 (wt.%) and Fe: 86.6 (wt.%) were deposited by atmospheric plasma spraying (APS) on Q235 low-carbon steel and NFC was heat-treated under Xi Shi, Mingyong Shu, Qingdong Zhong, and Junliang Zhang, State Key Laboratory of Advanced Special Steels, Shanghai University, Shanghai, China; Qiongyu Zhou, School of Materials Science and Engineering, Jiangxi University of Science and Technology, 86 Hong Qi Road, Ganzhou, China; and Quoc Binh Bui, Vietnam Maritime University, Haiphong, Vietnam. Contact e-mail: [email protected].
Journal of Thermal Spray Technology
hydrogen atmosphere (HNFC). Commercial Ni microparticles were used as the undercoating material (Ref 7). The bond strength between the coating and the substrate will be increased (Ref 8). Scanning electrochemical microscopy (SECM) is a relatively new and powerful technique in corrosion science (Ref 9, 10), and it has been employed to
Data Loading...
