2D matte surface 439 ferritic stainless steel cold annealing pickling production process

Abstract

This invention discloses a 2D matte surface 439 ferritic stainless steel and its cold annealing and pickling production process. The production process includes: Step 1: Cold-rolled base material annealing: The cold-rolled base material after hot wire annealing and pickling is cold-rolled to obtain a rolled hard state material of the target thickness, and then enters a cold annealing and pickling line for annealing treatment; Step 2: Neutral salt electrolysis: A Na2SO4 solution with a concentration of 180-220 g / L is used as the electrolyte, the current is 3000-5000 A, and electrolysis is performed at 55-65℃ for 0.72-1.67 min; Step 3: Mixed acid pickling: A mixture of nitric acid and hydrofluoric acid is used for pickling, wherein the concentration of nitric acid is 90-120 g / L, the concentration of hydrofluoric acid is 9-14 g / L, the pickling temperature is 41-45℃, and the pickling time is 0.68-1.67 min. The production process of this invention overcomes the defect of alternating light and dark color difference that is easily generated in the existing 2B bright 439 ferritic stainless steel production process, reduces the subsequent grinding process, and meets the application requirements of decorative panels and exhaust systems with high corrosion resistance and high surface quality.

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