Surface phosphating treatment

What is the surface phosphating treatment? 1, improve the corrosion resistance. Phosphating film is thin, but since it is a layer of non-metallic non-conductive isolation layer, can make excellent conductors on the surface of the metal artifacts into a poor conductor, inhibit the formation of metal surface micro battery, thus effectively prevent corrosion of the coating. 2, improve the substrate and the coating or other organic finishing adhesion between the layers. On the one hand, phosphating film and the overall structure of the metal workpiece is a combined closely, on the other hand, phosphating film with porous, can make the paint penetrated into the pore, coating and phosphating film together, improve adhesion. 3, provide clean surface. Phosphating film only in no pollution and no rust layer of the metal surface to grow, as a result, after phosphating metal artifacts, can provide clean, uniform surface, no oil and no rust. 4, improve the performance of cold work on the material. 5, improve skin friction performance, in order to promote its slide. Conventional parameters: the temperature: room temperature than heavy: 1. 38 - 1. 50 yan color: green with groove parameters: phosphorus liquid: 2. 4% - 4. 8% cu into agent: 0. 06% of the total acid degree: 14 - 30 points to swim away from acid: 0. 6 - 1. 4 promote into agent: 0. 8 - 4 P H value: 2. 5 - 3. - 5 phosphating time: 8 Detection: 20 minutes total acidity: take work within 10 ml to 250 ml conical flask liquid, add distilled water to 50 ml, drip into the 3 - 5 drops of phenolphthalein reagent, with 0. 1 n sodium hydroxide titration, drop until pink, reads zero. 1 n the amounts of sodium hydroxide used the number of total acidity. Free acid: take work within 10 ml to 250 ml conical flask liquid, add distilled water to 50 ml, drip into the 3 - 5 drops bromophenol blue reagent, with 0. 1 n sodium hydroxide titration, drop until pale blue, reads zero. 1 n the amounts of sodium hydroxide used the free acidity. Accelerator: use a tube filled with liquid fermentation, the fermentation within 3 - 4 grams of amino sulfonic acid, until not reaction, accurate read parameters. PH: the precision test is used to test is recommended. With slot: In a 1000 l) To inject a quarter of the water in the phosphating slot first, then add to calculate good promoter 0. 6 kg, continue to inject water, when the water add to 3/4, 48 kg to join calculate good phosphating liquid inside, the filling water to 1000 l. Detection of total acidity and free acidity, with sodium hydroxide or sodium carbonate adjust total acidity and free acid to standard parameters. Note: when sodium hydroxide or sodium carbonate, is used to adjust, to calculate good water and sodium hydroxide or sodium carbonate dissolved completely, after mixing, while slowly add sodium hydroxide or sodium carbonate solution to phosphating slot.