Environment-friendly rust removing and resisting agent applied to acid pickling

Abstract

The invention relates to an environment-friendly rust removing and resisting agent applied to acid pickling. The rust removing and resisting agent is prepared from the following raw materials in percentage by mass: 17-35% of phosphorous acid, 1-8% of zinc dihydrogen phosphate, 1-8% of an oxidant, 1-10% of a complexing agent, 0.05-5% of a passivator, 0.01-2% of a surfactant, 0.01-2% of a corrosioninhibitor and the balance of water, wherein the oxidant is selected from one or two of cerous nitrate or zinc nitrate; the passivator is sodium molybdate; the corrosion inhibitor is selected from oneor two of rodine and benzotriazole; the surfactant is selected from JFC (fatty alcohol-polyoxyethylene ether) and OP-10 (alkylphenol polyethylene ether). Through the rust removing and resisting agent,the rust removing and resisting effect can be achieved by carrying out acid pickling under the normal temperature; a good galvanization effect can also be achieved after steel products are placed inthe air for a period of time after removing rust; meanwhile, the rust removing and resisting agent has the advantages of low production cost, simple operation process, no harm to operators and environment friendliness.

Description

technical field [0001] The invention relates to a pickling, rust-removing and rust-preventing agent for the surface of iron and steel products, in particular to an environment-friendly pickling, rust-removing and rust-preventing agent applied to the surface pretreatment of steel products before galvanizing. Background technique [0002] Before iron and steel products are subjected to processes such as cold rolling, electroplating, hot galvanizing, chemical plating, and metal surface coating, the oxide layer or rust layer on the surface must be removed. After being placed in the middle for a period of time, it will be re-oxidized. After galvanizing, there will be a large area of ​​missing plating, which will affect the quality of the product. [0003] In industrial production, metal surfaces are usually pre-treated with strong acid pickling, mainly hydrochloric acid and sulfuric acid pickling. The pickling speed of hydrochloric acid is fast, the hydrogen embrittlement is sma...

AI Technical Summary

Problems solved by technology

The pickling speed of hydrochloric acid is fast, the hydrogen embrittlement is small, and it can be operated at room temperature, but hydrochloric acid is a controlled raw material, and there are the following fatal disadvantages in the process of use: (1) produce pungent odor and form fog; (3) The quality and source of raw materials are unreliable, and there are residues on the surface after severe pickling, which may easily cause post-processing difficulties; (4) The surface is rapidly oxidized after pickling; (5) A large amount of waste acid is produced liquid and flushing acid wastewater, increasing the cost of wastewater treatment

The treatment liquid takes a long time to remove rust, and the cleanliness of the metal surface after treatment is not high and the surface is black, which fails to achieve a good purpose of rust removal and rust prevention. The metal surface after galvanizing has missing plating

The Chinese invention patent with the application number 201610076612.8 relates to a metal derusting and rust-removing liquid and a rust-removing and rust-preventing method. Although the rust-removing liquid can achieve the effect of rust-removing and rust-preventing, the chromic anhydride in the formula is highly toxic and has a strong Acidic and corrosive, not advocated by industrial production and environmental protection

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