TH17484B - Soaking process for cleaning steel pieces And especially the bars of stainless steel - Google Patents

Abstract

DC60 (02/05/40) The process consists in the use of a cleaning solution containing hydrochloric acid and ferric and ferrous ions in the solvent and for the purpose of treatment. Power of cleaning Hydrochloric acid solution With a pH less than 1, which maintains a concentration of Ferric ion At values between 1 g / l to 300 g / l by oxidation oxidation method Ferrous Ion That occurred during Soak clean Redox potential is maintained at a value between 0 and 800 millivolts. Potential is measured between the platinum electrode and the silver / silver chloride reference electrode. Which was placed in solution The process consists in the use of a cleaning solution containing hydrochloric acid and ferric and ferrous ions in the dissolving agent and for therapeutic purposes. Power of cleaning Hydrochloric acid solution With a pH less than 1, which maintains a concentration of Ferric ion At values between 1 g / l to 300 g / l by oxidation oxidation method Ferrous Ion That occurred during Soak clean Redox potential is maintained at a value between 0 and 800 millivolands. Potential is measured between platinum and silver / silver chloride reference electrodes, which are placed in solution.

Claims (15)

1. The process for immersion cleaning of steel pieces, and specifically stainless steel strips, involves the use of an aqueous immersion solution containing hydrochloric and ferric acids and ferrous ions. For the purpose of maintaining the hydrochloric acid aqueous solution with a pH below 1 after immersion, the ferric ion concentration is maintained between 1 g/L and 300 g/L by reoxidation using the oxygenation of ferrous ions produced during the immersion cleaning. The redox potential is maintained between 400 and 600 millivolts. This potential is measured between a platinum electrode and a silver/silver chloride reference electrode placed in the solution. 2. The process under claim 1, whereby the reoxidation of the ferrous ions by oxygenation is achieved by aeration of the immersion solution. 3. The process under claim 1, whereby the aeration of the immersion solution is achieved by a chosen route from a group of methods including pumping and releasing the solution into the open air, foaming, stirring, injecting oxygen-containing gas, and atomizing the immersion solution in a closed, air-filled system. 4. The process under claim 1, whereby such reoxidation is completed by the addition of a compound selected from a group comprising peroxides, persalts, hydrogen peroxide H2O2, potassium permanganate KMnO4. 5. The process under claim 1, where the solution contains a hydrochloric acid concentration between 35 g/L and 250 g/L. 6. The process under claim 1, which includes the use of the aforementioned immersion solution within a temperature range of 10°C and 95°C. 7. The process under claim 1, which includes the use of the aforementioned immersion solution within a temperature range of 65°C and 85°C. 8. The process under claim 1, which includes heating the material to be immersed before applying the solution. 9. The procedure under claim 1, which involves applying the said solution to the said strip for a period of less than 2 minutes. 10. The process for utilizing the immersion cleaning effect of steel pieces, and specifically stainless steel strips, which is rapidly processed in a continuous production line, involves the use of an immersion aqueous solution containing hydrochloric acid and ferric ions. For the purpose of maintaining the cleaning power of the hydrochloric acid aqueous solution with a pH below 1, the concentration of ferric ions is maintained between 1 g/L and 300 g/L by reoxidation using the oxygenation of ferrous ions produced during the cleaning process. The redox potential is maintained between 400 and 600 millivolts. This potential is measured between a platinum electrode and a silver/silver chloride reference electrode placed in the solution. 11. Continuous production processes for the manufacture of steel coils and, in particular, stainless steel coils, which are comprised of: pathways for the continuous processing of such strips with: mechanical treatment, preliminary immersion cleaning, deformation action, annealing action, final immersion cleaning; and at least one of the final immersion cleaning actions is achieved by pathways for the use of an aqueous immersion solution containing hydrochloric acid and ferric and ferrous ions for immersion, and, for the purpose of maintaining the immersion power of such aqueous solution of hydrochloric acid with a pH below 1, pathways for maintaining the concentration of ferric ions at values between 1 g/L and 300 g/L by reoxidation using the oxygenation of ferrous ions produced during such immersion cleaning, pathways for maintaining the redox potential at values between 400 and 600 millivolts, and pathways which are comprised of: Platinum and a silver/silver chloride reference electrode are placed in the solution for measuring the redox potential between these electrodes. 12. A continuous production line pursuant to claim 11, whereby the mechanical treatment is leveling of the plate under tensile stress. 13. Continuous production line pursuant to claim 11, where the mechanical treatment is abrasive blasting. 14. A continuous production line pursuant to claim No. 11, whereby such mechanical treatment includes the tensile leveling of the plates and the surface polishing of the plates. 15. A continuous production line pursuant to claim 11, whereby the said deformation action includes the rolling action.