摘要 |
<p>A method of stainless-steel surface finishing by which even a 13Cr steel with a high carbon content, a free-cutting stainless steel with a high sulfur content, and the like are beautifully finished so as to have an opaque-white surface with excellent gloss. The method comprises, after scale removal, (1) immersing the steel for 5 to 180 seconds in a first treating liquid containing 5 to 40 g/L nitric acid, 2 to 10 g/L hydrofluoric acid, and 15 to 50 g/L iron(III) ions and washing it with water and (2) subsequently immersing the steel for 30 to 300 seconds in a second treating liquid containing 120 to 250 g/L nitric acid and 15 to 40 g/L iron(III) ions and then washing it with water.</p> |