Chemical Polishing of Q235 Steel

The chemical polishing baths of nitric acid-based solution and hydrogen peroxide-based solution were optimized.The polishing affecting factors and their reaction mechanisms are discussed.And the advantages and disadvantages of the two chemical polishing systems are summarized.For nitric acid system,the best polishing effect could be gained under conditions of 100～140 ℃,4 min,HNO3 16%,H3PO4 50%,H2SO4 34% and CrO3 10g/L.For hydrogen peroxide system,the best polishing effect could be gained under conditions of room temperature,3~6 min,H2O2 130 ml/L,oxalic acid 75 g/L,carbamide 20 g/L,H2SO4 3 ml/L and glycerin 2 ml/L.