Corrosion of Heat Treated Electroless-Ni Plated Mild Carbon Steels in Dilute H 2 SO 4

Abstract

The corrosion of heat-treated Electroless-Nickel (EN) plated mild carbon steel (MCS) in dilute H 2 SO 4 is investigated and reported in the study. The MCS samples were electroless-Ni plated in alkaline Nimudeen 850. EN plated samples were soaked at different selected temperatures between 150-370 o C at constant time. The weight loss of the specimens by full immersion method was employed to assess the corrosion damage and corrosion rates of the as-received, EN plated MCS and four heat treated EN plated samples in the 0.5 M H 2 SO 4 solution. The test specimens were regularly examined at every 12 hrs interval for 30 days (720 hrs). The materials corrodes in 0.5 M H 2 SO 4 in the order of MCS10 > MCS14 > MCS15 > MCS11 > MCS13 > MCS12. Based on the results obtained, it will be justified to choose EN-plated samples (MCS 11) and the heat treated EN film (MCS12 and MCS13) for the purposed of solving the problem of corrosion in the medium. This is because; the application of EN deposition reduced the corrosion of MCS at much lower rate than the heat-treated EN film (MCS14 and MCS15) in 0.5 M H 2 SO 4 environment. Atomic Absorption Spectrometer (AAS) Thermo series 2000 model and Scanning Electron Microscopy (SEM) with the Energy Dispersive X-Ray (EDX) facilities (Jeol JSM-7600F model) were used to ascertain the chemical compositions and the microstructures of samples.