ELECTROPOLISHING OF COPPER AND STAINLESS STELL IN LOW TEMPERATURE MOLTEN SALT ELECTROLYTE

摘要

The present invention provides a new improved method for electro polishing of copper and stainless steel from low temperature molten salt electrolyte pertaining imidazolium type of ions. Experiments were carried out separately for copper electro polishing as well as stainless steel at normal atmospheric pressure without hazardous chemicals used in normal electro polishing. Before electro polishing copper and stainless steel specimens were pretreated. For electro polishing of copper with imidazole ethylene glycol was added to lower the crystallisation temperature whereas for electro polishing of stainless steel methyl iodide and suphamic acid was added with ethylene glycol and the polishing was carried out in 5-10 minutes. The molar concentrations of used chemicals , temperature, current density were optimised depending upon the quality of electro polishing. The quality of electro polishing has been obtained as in normal electro polishing i.e; normal aqueous electrolytes. Temperature, current density and the molar ranges of chemicals used for electro polishing in molten salt electrolyte were optimised after conducting the experiments in trial and runs. We could achieve bright electro polishing in novel simple route at normal atmospheric pressure(90mm Hg) without any sophisticated facilities as already claimed prior in so many patents and literature.