DETERMINATION OF THE PLATING PARAMETERS AND CORROSION CHARACTERISTICS OF COPPER PLATED STEEL IN CORROSIVE MEDIA

Abstract

Locally produced steels (NST60Mn and ST50-2) were electroplated with copper to determine the optimum electroplating parameters in an acid-sulphate bath. The corrosion characteristics of copper-electroplated steels in six media O.1M NaOH, 3.5M NaCl, O.1M H2S04, tap water, well water and rainwater were used to study the integrity of the coating. The results obtained from the copper- plating and corrosion tests were used to develop a computer program in V-Basic language to simulate the coating thickness required to protect any given size of steel work piece. The results show that steel could be best plated in acid-sulphate bath at 2V applied voltage, 200g/1 CuS04.5H20 electrolyte concentration, 120mm anode-cathode minimum separation, on 600llm surface finishing grades using O.5g/1 saccharin as brightening agent. The results of corrosion [or 30days revealed that copper coated steels have lower corrosion rates than as-received steels in the six media. From the computer programming results, a copper film of not less than 3.lllm thickness will be required to protect a 40mm x 15mm x 5.5mm steel for 1year in the least corrosive medium (well water) when a perfect adhesion of Cu film to steel surface at constant room temperature is maintained.