A method for rapidly detecting the content of lead and cadmium in the coating of galvanized steel sheet

Abstract

The invention provides a method for rapidly detecting the lead content and the cadmium content in a zinc plating steel plate plating layer. The method comprises: establishing calibration working curves of various elements including Pb and Cd according to a standard sample; analyzing a detected zinc plating sample through the calibration working curves, measuring to obtain the relation curve of the element components such as Fe, Zn, Pb and Cd in each layer along with the plating layer thickness change, and defining the plating layer depth and the mass integration depth of the detected elements such as Pb and Cd to obtain the integration masses of the Pb and Cd plating layer depth; carrying out integration treatment on the element mass fraction at the plating layer depth by using the time or the plating layer thickness, converting the time function into the depth function, summing the plating layer masses of all elements, and dividing the total plating layer mass by the plating layer masses of each element such as Pb and Cd to obtain the average mass fractions of the elements such as Pb and Cd in the plating layer. According to the present invention, with the method, the Pb content and the Cd content in the plating can be rapidly detected without chemical stripping or chemical dissolving of the zinc plating steel plate plating layer.

Description

technical field [0001] The invention relates to the technical field of inspection and testing, in particular to a method for quickly detecting the content of harmful elements such as lead and cadmium in a galvanized steel sheet coating by using a glow atomic emission spectrometer (GD-OES). Background technique [0002] Metallurgical coated steel sheets have excellent corrosion resistance and weather resistance, and are widely used in various fields. Various galvanized sheets and color-coated steel sheets are being widely used in construction, automobiles, electrical appliances, transportation, energy and other industries. With the EU RoHS directive restricting the use of harmful and toxic substances (lead, cadmium, mercury, Cr(Ⅵ), PBB, PBDE) in "homogeneous materials" from July 1, 2006, developed countries such as the European Union have successively formulated "Waste Electrical and Electronic Equipment Directive" (WEEE-2002 / 96 / EC), "Directive on Prohibiting the Use of Certa...

AI Technical Summary

Problems solved by technology

[0003] There are many reports on the ICP method for detecting Pb and Cd content in materials according to the "ROHS" instruction, but there are few reports on the determination of Pb and Cd content in the coating. Most of the methods used are inductively coupled plasma spectrometry (ICP) and mass spectrometry ( MS) and atomic absorption spectrometry, etc., for the determination of harmful elements in the coating, the chemical principle is usually used to dissolve and leach the coating with inorganic acid to make the solution to be tested in the coating, and then use the above-mentioned analytical instruments to measure, here There are the following problems: 1) Dissolving the coating by chemical principles requires researching and preparing a leaching solution for dissolving the coating. While the leaching solution dissolves the coating, an alloy layer is formed between the coating and the substrate, which will cause the substrate to be partially dissolved, resulting in The quality error of the substrate will eventually lead to analysis errors; 2) The coating dissolution and leaching process is complicated, and the analysis cycle is lengthy; 3) The analysis methods in the field of wet chemistry such as ICP and AAS have significant matrix effects, which usually need to be eliminated by means of matrix matching. Interference, complex operation, large consumption of chemical reagents

Images