Pretreatment process method for improving electroplating quality of strip steel

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 invention relates to a pretreatment process for preparing steel plates, which belongs to the technical field of steelmaking, and in particular to a pretreatment process for improving the electroplating quality of strip steel. Background technique [0002] The surface state and cleanliness of the strip before electroplating are prerequisites for obtaining a good galvanized layer. On the surface of the steel strip with oil stains, iron powder and metal oxides, it is impossible to obtain a coating with good adhesion and excellent corrosion resistance. At present, the electroplating units in steel plants will have pre-plating treatment, that is, the traditional cleaning section: degreasing - rinsing - pickling - rinsing. The degreasing treatment is divided into two parts: chemical spray degreasing and electrolytic degreasing. Chemical degreasing uses lye to impact the surface of the strip steel at high speed, and can clean about 90% of the rust-proof ...

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.

Images