High-efficiency electrolytic phosphating solution

Abstract

The invention relates to a high-efficiency electrolytic phosphating solution which is composed of 100-150 g / L phosphoric acid, 71-75 g / L zinc oxide, 60-80 g / L nitric acid, 180-220 g / L calcium carbonate, 8-40 g / L additive and the balance of deionized water. The additive is citric acid or tartaric acid or sodium nitrate or nickel nitrate or copper sulfate or fluosilicic acid, or a mixture of any combination. The preparation method comprises the following steps: injecting the deionized water into a container, adding the phosphoric acid and nitric acid, heating while stirring, slowly adding the zinc oxide while stirring when the temperature reaches 80 DEG C, and stopping heating when the zinc oxide is completely dissolved; continuing stirring for half an hour, adding the calcium carbonate, and continuing stirring for half an hour; and cooling the obtained solution to room temperature, adding the additive, continuing stirring until the additive is completely dissolved, and adding the deionized water to the specified volume, thereby obtaining the electrolytic phosphating solution. The phosphating solution has the characteristic of no toxicity, can be used at normal temperature, and avoids physical damage to the operators and the waste of resources.

Description

technical field

[0001] The invention relates to a pretreatment agent for metal cold working, in particular to an electrolytic phosphating solution which forms a protective film on the surface of a metal material with improved corrosion resistance and workability. Background technique

[0002] In the metal cold plastic deformation treatment, in order to avoid the damage of the mold caused by the direct contact between the processing mold and the processed material, the surface treatment is often carried out on the processed material. At present, the traditional medium and high temperature phosphating process is a relatively mature technology in the cold plastic processing of steel materials. In order to meet the requirements of resource conservation and environmental protection, phosphating technology is developing towards low-temperature phosphating. Phosphating treatment requires a long reaction time, and both need to add accelerators such as nitrite or chlorate and organic...

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