Method for forming corrosion inhibiting film on steel and iron surface

Abstract

The invention relates to a method for forming a corrosion inhibiting film on a steel and iron surface, which comprises the following steps that: firstly, a steel and iron sheet is gradually ground and polished by No. 1# to 6# metallographic abrasive paper grade by grade, is cleanly washed by deionized water, is degreased by acetone and is cleanly washed by the deionized water, an oxidation film is removed through dilute sulphuric acid, and the steel and iron sheet is cleanly washed by the deionized water for use; self assembly solution is formed by diazonium salt solution with the concentration being 0.005mol/L to 0.02mol/L and dilute sulphuric acid solution with the concentration being 0.01 to 0.1mol/L; the steel and iron sheet is soaked into the mixed self assembly solution, the soakingtemperature is the room temperature, and the assembly time is 1 to 3h; cathodic polarization is carried out on electrode in the mixed solution (at the potential range being -0.5 to -1.5V), and the time is 200 to 400s. The method has the beneficial effects that the method for forming the corrosion inhibiting film on the surface of the iron and steel electrode is simple, the operation is simple andconvenient, and the corrosion inhibiting effect is excellent. Electrochemical data shows that the corrosion inhibiting efficiency of the corrosion inhibiting film in corrosion media of 0.1mol/l HCl, 0.05mol/L H2SO4 and 5 percent NaCl is respectively higher than 90 percent.

Description

technical field [0001] The invention relates to a corrosion inhibiting film on the surface of steel and a preparation method thereof, belonging to the technical field of steel corrosion and protection. Background technique [0002] Self-assembled membranes (SAMs) are thermodynamically stable and regularly arranged molecular membranes formed spontaneously by membrane molecules through chemical interactions between molecules and the substrate. Forming a dense and ordered self-assembled film of organic molecules on the metal surface can prevent the corrosion of the metal substrate by the corrosive medium. Steel has very important applications in various fields of the national economy, and is one of the most important materials, and the annual loss due to corrosion reaches about 20% of the output, so the research on steel corrosion and protection is very necessary. So far, the self-assembled corrosion inhibitors on the surface of steel materials are mainly prepared by immersion...

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Problems solved by technology

The method of using diazonium salt to form a corrosion inhibition film through self-assembly and electrochemical polarization has not been reported at home and abroad as a surface treatment method to prevent steel corrosion.

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