Normal temperature electrolytic phosphating technology and phosphating solution

Abstract

The invention discloses a normal temperature electrolytic phosphating technology. A phosphating solution comprises 10-63 g / L of zinc ions, 10-100 g / L of calcium ions, 50-120 g / L of phosphate radical,40-200 g / L of nitrate radical, 10-50 g / L of organic acid and 1-45 g / L of an additive, wherein the phosphate radical is P2O5, the phosphating temperature is the normal temperature, and current with thedensity being 3-100 A / dm<2> is applied through direct-current power supplies; the phosphating time is 3-120 s; and the weight of phosphated film is 8-20 g / m<2>, the drawing speed is 4-10 m / s, the phosphating temperature is the normal temperature, no phosphated residue is produced, electrodes do not need to be cleaned periodically, the phosphating solution contains no heavy metal, and environmentprotection standards are met.

Description

【Technical field】 [0001] The invention relates to the field of metal wire surface treatment, in particular to phosphating treatment before steel wire drawing. 【Background technique】 [0002] Phosphating treatment refers to the process of treating metal in a solution containing phosphate to form a phosphate chemical conversion film on the surface of the metal. For more than 100 years, phosphating film can be applied to steel, aluminum, magnesium and other metals or alloys, which can not only improve the corrosion resistance, improve the adhesion between the substrate and the coating, but also significantly improve the surface friction properties of the workpiece. Improve the cold workability of the material. The zinc phosphate conversion coating layer has good ductility, and can react with sodium stearate under certain conditions to form a zinc stearate film, and the zinc stearate has excellent lubricating properties. Therefore, the zinc phosphating process is widely used i...

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Problems solved by technology

However, due to the selection of zinc or iron as the anode, zinc or iron dissolves into the treatment bath during the electrolysis process, and zinc sludge and phosphating slag are easily produced, which not only produces solid waste residue, but also affects the stability of the solution.

[0005] At present, the electrolytic phosphating solution for mechanical peeling in the market needs to be heated to 50-60°C, and the concentration of the phosphating solution is high, with a total acid of up to 300 points, and a large amount of phosphating slag is generated, and the electrode needs to be cleaned almost once a month.

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