AN IMPROVED MARSHALL'S REAGENT FOR ETCHING OF COLD ROLLED AND ANNEALED INTERSTITIAL FREE (IF) STEEL SHEET

摘要

preparing a chemical etchant in two parts, a first part comprising oxalic acid, sulphuric acid and distilled water at room temperature, and a second part comprising 30% solution of H2O2 at a temperature of 15-20° C for controlling the rate of etching; mixing freshly made solutions of said first and second part in equal proportion; etching samples of said steel sheets with said chemical etchant for 30- 40 seconds; and ultrasonic cleaning of the etched surface for about 15-20 minutes.