Normal-temperature phosphating process

Abstract

The invention discloses a normal-temperature phosphating process which comprises the steps of: 1, settling, cleaning and filtering a phosphating solution, regulating the phosphating solution to ensure that the proportion of free acidity to total acidity is 1:(20-30), wherein the phosphating solution comprises the following raw materials of 60-90g / l of manganese dihydrogen phosphate, 70-120g / l of zinc nitrate, 2-4g / l of sodium nitrite and 0.2-0.5ml / l of hydrogen peroxide, wherein the solvent is water; 2, phosphating a workpiece in the phosphating solution; 3, washing the phosphating solution remained on the surface of the workpiece in a washing mode; and 4, neutralizing the workpiece in an alkaline solution. According to the normal-temperature phosphating process, by steps of adopting the special phosphating solution and regulating the proportion of the free acidity to the total acidity of the phosphating solution, under the conditions of no need of heating, simple components of the solution and convenience in operation, a film is rapidly formed, and a gray black or deep gray black phosphating film with the characteristics of corrosion resistance, greatly improved wear resistance, uniformity in crystallization, firmness and compactness and complete shape is obtained rapidly.

Description

technical field [0001] The technical field of the phosphating treatment method of the present invention, more specifically, relates to a normal temperature phosphating process. Background technique [0002] Phosphorization is a process in which chemical and electrochemical reactions form a phosphate chemical conversion film, and the formed phosphate conversion film is called a phosphating film. The purpose of phosphating is mainly to provide protection for the base metal and prevent the metal from being corroded to a certain extent; it is used as a primer before painting to improve the adhesion and anti-corrosion ability of the paint film layer; it can reduce friction in the metal cold processing process Use lubricated. The phosphating treatment process has been applied in industry for more than 90 years, which can be roughly divided into three periods: the period of laying the foundation of phosphating technology, the period of rapid development of phosphating technology a...

AI Technical Summary

Problems solved by technology

At present, the traditional domestic phosphating process at room temperature has the advantages of no need for heating, saving phosphate and stable solution; however, its phosphating film has low corrosion resistance, weak phosphating film bonding, long processing time, and low production efficiency. Severely restricts the mass production of products and has certain production limitations

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