The Effect of Reverse Pulse Plating and Lanthanum Addition in Plating Bath on Corrosion Resistance of Austenitic Steel in Chlorine Solution

The 316L nickel-chrome molybdenum austenitic stainless steel is commonly employed in various industries. This type of steel is particularly of interest in chemical industries, especially in harsh and corrosive environmental conditions. Although 316L stainless steel has good mechanical and corrosive characteristics, it fails to perform well in chlorine-containing aqueous environments. To overcome this issue, a Ni-La-Cr-Fe layer is applied to the 316L steel using the electroplating method. In addition, the reverse pulse plating method is used to control the ion deposition kinetics. The plating current application duration (on-time), the current disruption duration (off-time), and (TRev) are the control parameters of the duration and polarity of the pulse. Finally, the coated layer acquires an average thickness of 6.83 after applying on-time and off-time repeatedly and performing SEM and polarization tests in 1.5% solution at 50 Celcius degrees. Furthermore, the desired surface morphology is achieved, and corrosion resistance is 160 times higher than 316 bare steel. Applying the reverse pulse plating method, adding beneficial compounds of saccharin and SDS, and using lanthanum chloride in the plating bath are the essential reasons to successfully add a coating layer on the 316 bare steel.