Normal temperature leather diaphragm passivating agent before periodically spraying and coating cast iron and steel workpiece and preparation method thereof

Abstract

The invention relates to a normal temperature leather diaphragm passivating agent before periodically spraying and coating a cast iron and steel workpiece, comprising the raw materials by mass percent: 3-9% of phytic acid, 0.1-0.6% of tartaric acid, 0.5-1.5% of citric acid, 0.1-0.4% of bromic acid, 4-8% of sodium benzoate, 0.1-0.3% of benzotriazole, 5-9% of triethanolamine, 0.1-0.2% of industrialalcohol and the rest of tap water. A preparation method comprises: adding the tap water into a reaction kettle and stirring; then, sequentially adding the tartaric acid, the citric acid, the bromic acid, the sodium benzoate, the triethanolamine, the phytic acid, the industrial alcohol and the dissolved solution of the benzotriazole; and finally, stirring the mixed solution until the solution is even light purple transparent water-soluble liquid. The passivating agent can be used under the condition of normal temperature, leads the continuous, complete and conpact leather diaphragm passivationreaction to be carried out on the surface of the cast iron and steel workpiece, and generates a diaphragm with strong adsorbability, adhesiveness, rust-proof property and bonding property; the passivating agent needs no heating treatment, simplifies the equipment, has low cost, and is non-toxic and harmless; furthermore, the preparation method is simple in technique, easy to control and convenientfor operation.

Description

technical field [0001] The invention relates to a passivating agent and a preparation method thereof, in particular to a normal temperature skin film passivating agent and a preparation method thereof before periodic spraying of cast iron and cast steel workpieces. Background technique [0002] Cast iron and cast steel workpieces should undergo phosphating treatment before spraying and coating, so that a layer of phosphating film with a certain roughness and porous adsorption can be formed on the surface. The main functions of this layer of phosphating film are: first, to enhance the adhesion between the basic surface of the cast iron cast steel workpiece and the sprayed coating; second, to improve the comprehensive resistance of the joint layer to the erosion of corrosive media in the atmosphere. However, some processed workpieces are not allowed to be pre-treated by phosphating process due to dimensional accuracy requirements and technical conditions, but require passivati...

AI Technical Summary

Problems solved by technology

There are also workpieces that do not allow phosphating treatment

It is difficult to adopt film passivation treatment technology for the surface of ordinary carbon steel