Pretreatment process method for improving strip steel plating quality

Abstract

The invention discloses a pretreatment process method for improving the electroplating quality of strip steel, and belongs to the technical field of cold rolling. The pretreatment process method comprises the processes of stretching and straightening, chemical degreasing, first rinsing, electrolytic degreasing, second rinsing, acid pickling and third rinsing before electroplating treatment of thestrip steel. By strictly controlling parameters of each process stage and reasonably solving abnormal conditions, the defect of electroplating spots caused by incomplete cleaning is effectively controlled, the surface quality of electroplated strip steel is ensured to be in good condition, and the designed process method is suitable for pretreatment of any electrogalvanized steel grade.

Description

Technical field [0001] The present invention relates to a pre-treatment process for preparing a steel sheet, which is a pre-treatment process for improving the quality of steel plating quality. Background technique [0002] The surface state and clean level of the steel in electroplating are prerequisites for obtaining excellent galvanized layers. On the surface of the strip, iron powder and metal oxide, the plating layer having excellent binding force and excellent corrosion resistance can not be obtained. At present, the plating unit of steel mills will have pre-plated treatment, that is, traditional cleaning segments: degreasing - rinsing - pickling - rinsing. The degreasing treatment of chemical spray degreasing and electrolytic degreasing, chemical degreasing through the high-speed impact steel surface of the alkali solution, can be cleaned by about 90% rust-proof oil and impurities in the surface of the steel surface, and the electrolytic degreasing is to infiltrate the ste...

AI Technical Summary

Problems solved by technology

The above methods do improve the spot defects on the surface of the strip to a certain extent, but cannot completely eliminate the occurrence of such defects

[0006] 1. Unable to solve spot defects after electroplating, such as: white spot, mottle and other spot defects

Leading to a large number of revisions, currently high-end home appliances and automotive panels do not accept such defects

Once a quality defect occurs, the production can only be slowed down, but at low speed, the electroplating solution will accelerate the corrosion of the strip steel, and the low current density will cause new surface quality

[0007] 2. The labor intensity of the workers is high

[0008] 3. The influence of human factors is greater

Titration analysis requires a high level of human experience and sense of responsibility. For the same sample, different people will have different titration results;

[0009] 4. Process fluctuation

Since the original addition of lye and acid is intermittently added based on the results of artificial testing, the components of lye and acid fluctuate within a limited range at this time, and the conductivity still has a negative impact on the stability of product quality.

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