This work aims at studying the corrosion behavior of electroless Ni-P coating on mild steel substrate heat-treated by microwave and conventional furnace (muffle) annealing. The corrosion behavior of the deposits has been evaluated by potentiodynamic polarization studies in 3.5 wt% sodium chloride solution. The heat treatment temperatures of both the microwave and the conventional furnace annealing were kept at regular intervals to study the corrosion performance of the coatings. Microwave heat treatment significantly improved the corrosion performance of the coatings. Further, corrosion mechanisms of as-coated, various microwave- and conventional heat-treated coatings were discussed for the consideration of phase constituents, grain sizes and microstrain.

Electroless nickel coating treatment improves the corrosion resistance of mild steel. This work aims at studying the corrosion behavior of electroless Ni-P/ TiO 2 composite and multilayer coatings applied to the mild steel substrate as their as-plated state and furnace annealed at various temperatures and compared both the coatings ' corrosion performance. The corrosion behavior of the deposits was evaluated by potentiodynamic polarization studies in 3.5 wt% sodium chloride solution. The results showed that the corrosion resistance of the multilayer coating was two times higher compared to the composite coatings. Further, the corrosion mechanism was discussed in terms of microstructure, phase transformation, grain size, and microstrain.

No abstract

This research work compares annealed and as-coated electroless Ni-P's resistance to corrosion and electroless Ni-B coating prepared on the mild steel substrate. The coatings' resistance to corrosion was estimated by Tafel electro chemical polarization method utilizing electrochemical analyser in 3.5wt % solution of Sodium Chloride. Both the coatings' annealing temperatures were maintained at normal intervals to consider their corrosion resistance performance. Further, the corrosion behaviour of both the coatings with their as-coated and various annealed temperature were discussed for the deliberation of deposits phases, crystallite sizes and micro strain.

The Co-deposition of TiO2 particles (anatase type) of 200–300 nm with Ni-P electroless coatings on low carbon steel. The coated specimen was annealed by microwave and common electric furnace. The effects of microwave and furnace annealing temperatures on these coatings were characterized via. XRD, SEM, EDAX, and the corrosion performance was characterized through electrochemical polarization technique. The corrosion medium used for this work was sodium chloride (NaCl) solution and which contains 3.5 wt-% in distilled water. The result showed that, the microwave annealing method was enhanced the corrosion performance of the coating by diffused TiO2 particle into the matrix and reduced the micro voids presented in the matrix. Further, the corrosion mechanisms of the non-treated and the annealed coated materials have been explained in the consideration of crystallization, transformation of phases, grain size, and micro strain.