Method for evaluating adhesion performance of coating of cold rolled automobile sheet

Abstract

The invention discloses a method for evaluating the adhesion performance of a coating of a cold rolled automobile sheet phosphated by a zinc-system, which has the advantages of no harm to operators and simple and accurate evaluation. The method comprises steps of sample preparation, measurement and evaluation; the adhesion performance of the coating is predetermined by measuring the proportion of the Zn element in all phosphating film components in a phosphating film on the surface of the cold rolled automobile sheet; the proportion of the Zn element in all phosphating film components is determined by an energy dispersive spectrometer; when the proportion of the Zn element is less than or equal to 8 percent, the adhesion performance of the coating is excellent; when the proportion of the Zn element is more than 8 percent and less than or equal to 10 percent, the adhesion performance of the coating is good; when the proportion of the Zn element is more than 10 percent and less than or equal to 12 percent, the adhesion performance of the coating is general; and when the proportion of the Zn element is more than 12 percent, the adhesion performance of the coating is poor.

Description

technical field [0001] The invention relates to a method for evaluating the coating adhesion performance of a cold-rolled automobile sheet, in particular to a method for evaluating the adhesion performance of a cold-rolled automobile sheet coating treated with zinc-based phosphating. Background technique [0002] For cold-rolled automotive sheets, whether it is from the protective performance or the decorative performance, the adhesion performance of the coating must be evaluated. [0003] At present, there are 3 effective national standards for the determination of paint film adhesion, and there are 2 items commonly used in the test of coating adhesion performance of cold-rolled automobile sheets: 1. GB / T 1720-79 (89) "Determination of Paint Film Adhesion In this method, the model is fixed on a platform that can be moved back and forth. While the platform is moving, the stylus used as a circular motion cuts through the paint film and can draw lines of overlapping circular r...

AI Technical Summary

Problems solved by technology

However, this method needs to be completed by means of an X-ray diffractometer. X-rays have strong radiation hazards to the human body and have high requirements for operators, so most units cannot carry out this test; When the value is greater than 90%, due to the serious overlap of the two measured diffraction peaks, it is very difficult to test the "P ratio" value of the phosphating film, and the test results are prone to errors

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