Application of electrolytic coloring of stainless steel：Application,electrolytic,color
Stainless steel not only has excellent corrosion resistance and wear resistance in environmental media in general, but also by the electrolytic oxidation surface can be a variety of colors, which add bright gorgeous appearance, become a high-grade decorative materials and daily necessities. The coloring film coloring film obtained by surface coloring treatment of stainless steel is different from the surface of aluminum alloy, it is not form colored surface covering film, the transparent film but on the generation of optical interference color. The thickness and surface roughness surface display color and chemical composition, surface membrane structure, membrane associated. In general, the thin film showed a blue or brown, moderately thick film gold yellow or red, thick oxide films are shown in green or dark. A unit of SUS304 stainless steel electrolytic with application of golden yellow, has certain reference function.
1 Stainless Steel Coloring Process
Stainless steel workpiece mechanical polishing a washing a chemical oil removing a water electrolytic polishing a washed acid activated an anodic oxidation coloring a water electrolytic hardening a closed a washing drying of a product.
2 oxidation pretreatment of coloring
(1) oil removing oil mainly in the removal of mechanical polishing residue in the ointment stainless steel surface, mainly to see the oil situation, can use chemical method, also can use other methods. Chemistry except for oil solution and process conditions are as follows:
Sodium hydroxide (NaOH) 30 to 509/L of sodium silicate (NazSi03) 15 to 509/L of sodium carbonate (Na2C03) 20 ～ 359/L solution temperature 40 ~ 50 "C sodium phosphate (Na3P04 · 12Hz0) 55 ~ 709/L degreasing time. In addition to clean up oil pollution
(2) the electrolytic polishing can use acid sulfate mixed solution electrolytic polishing, can
The surface smooth and bright. The following formula electrolytic polishing solution and process conditions: sulfuric acid (H2S04, P 15% ~ 20% 7K (HzO) 22% ～ l3%1.849/mL) solution temperature 45 ~ 55X2 phosphoric acid (HaP04, p= 63% ~ 67% anodic current density of 15 ~ 45A/dm21.709/mL) polishing time 5 ~ 10min
(3) stainless steel pickling pickling and activation must be living in the anodic oxidation coloring before
Treatment, pickling and activation solution formula and process conditions are as follows:
Sulfuric acid (H2S04) 25% ～ 35% processing time of 3 ~ 5min solution temperature 20 ～ 50 ´ C
3 oxidation anode Stainless Steel Coloring
(1) coloring liquid formula and process of anodic oxidation coloring with acid oxidation method, the solution formula and process conditions are as follows:,
Sulfuric acid (H2S04) 350 ～ 450mL/L chromic anhydride (Cr03) 15 ～ 259/L manganese sulfate (MnS04) 2 ～ 49/L additive YZ 30 ～ 409/L sodium acetate (NaAc) 10 ～ ll9/L solution temperature 45 ~ 55X2 current density of 0.3 ~ o.5A/din2 processing time surface color 3min Yellow Gold
(2) influence of coloring effect factors in the electrolytic coloring solution is stable, have great influence on color time process conditions such as temperature, coloring solution and current density on the surface of stainless steel coloring, as follows.
The relationship between temperature of colouring solution temperature and coloring effect of elevated, the coloring film thickening, film color deepened. At the same time the coloring film wear resistance and corrosion resistance were improved, but poor surface finishes, gloss is slightly poor. For gold, should be controlled at about 50 ℃ for optimal operation temperature.
