JPS62127619A - Method for measuring plating thickness - Google Patents

Abstract

PURPOSE:To quickly and non-destructively analyze a plating thickness by providing a liquid analyzer for determining the components of zinc and iron in a plating bath and feeding the information thereon forward to a thickness gage. CONSTITUTION:A plating liquid 1 is continuously fed to the liquid analyzer 2 and the fluorescent X-ray intensities of the zinc and iron excited by the irradiation of X-rays to the liquid are measured. the concns. of the zinc and iron in the liquid 1 are determined and the component ratio of the zinc and iron is determined. The component ratio is outputted as the feed forward information to the thickness gage 3 for measuring the total thickness. The fluorescent X-ray intensity of the zinc excited by the irradiation of X-rays to a plated steel sheet 6 is measured in the plating thickness gage 3 for measuring the total plating thickness. The measured intensity is subjected to the correction by the metallic component ratio and is fitted to a calibration curve by an interface 4 and a microcomputer 5, by which the total zinc-iron alloy plating thickness is determined.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is incorporated into a zinc-iron plating line and measures the metal component ratio (Zn/Zn+Fe) of the plating solution in its liquid state using fluorescent X-rays. However, the plating film thickness is determined by measuring the fluorescent X-rays of zinc and correcting it based on the metal component ratio to obtain the total zinc-iron plating thickness.

[Summary of the invention]

In the present invention, when measuring the plating thickness of iron-zinc full plating on a steel plate using fluorescent X-rays, the fluorescent X-rays of iron, which have a problem with overlapping, are not measured, but the total plating thickness of zinc is measured. death,
Analyze the component ratio of the plating with a plating solution analyzer, calculate the results and the total zinc plating thickness data mentioned above,
Measure the thickness.

[Conventional technology]

Other methods for determining the adhesion amount and component amount of zinc-iron alloy plating include: 1. Dissolving the plating layer by electrolysis and quantifying this solution by chemical analysis or instrumental analysis.

■There is a surface analysis method that measures and quantifies secondary ions and light emitted by sputtering the surface with ions and glow discharge.

[Problem that the invention seeks to solve]

All of the above methods are destructive tests in which a measurement sample is taken from a product, and are also poor in speed.

For example, in the fluorescent X-ray analysis method, which determines the thickness and metal content of zinc-iron alloy plating on a steel sheet by measuring α X-rays during the production process, This measurement is difficult due to the large overlap.

[Means for solving problems]

In the present invention, the total plating thickness is determined by measuring only the fluorescent X-rays of the other component, zinc, without measuring the fluorescent X-rays of iron, which has a problem with overlapping. However, if the metal component ratio changes, the measured zinc fluorescence X will change as shown in Figure 1.
Since the line strength also changes, it will affect the thickness determination.

To solve this problem, a liquid indenter is installed to determine the zinc and iron components in the plating bath, and correction is performed by feeding this information forward to the thickness gauge.

〔Example〕

An embodiment of the invention is shown in FIG. First, the plating solution 1 in the plating bath is continuously fed to the liquid dispensing needle 2 through a sampling device (not shown), and the powder of zinc and iron is excited by irradiating it with X-rays. By measuring the optical X-ray intensity and calculating the concentration of zinc and iron in plating solution 1 using a calibration curve obtained in advance using a standard solution with a known concentration, the zinc and iron component ratio (Zn/Z
n+Fe ) is determined. This component ratio is output as feed forward information to a thickness gauge that calculates the total thickness. The plating liquid measured by the liquid indenter is a fluid and is returned to the plating bath 7 as it is. Therefore, the response to changes in liquid composition is quick, and the reliability as composition correction information for the thickness gauge is high.

Next, using the plating thickness gauge 3 to measure the total plating thickness, the plating thickness gauge 3 measures the fluorescent X-ray intensity of zinc excited by irradiating the plated steel plate 6 with X-rays. By applying correction based on the metal component ratio and applying it to a calibration curve as shown in FIG. 1 using the interface 4 and microcomputer 5, the total zinc-iron alloy plating thickness can be determined without any problem with compositional changes. In order to maintain the accuracy of the present invention, it is necessary that hydrogen ion concentration, bath temperature, plating current, etc. in the production line be efficiently controlled.

〔Effect of the invention〕

As described above, the method of the present invention has the effect that the plating composition can be controlled using a liquid dispensing needle in a zinc-iron alloy electroplating line, and furthermore, the plating thickness can be analyzed quickly and non-destructively by applying this information. .

This makes it possible to control the amount of plating within a predetermined range while ensuring a predetermined plating quality.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of a calibration curve for zinc-iron alloy plating, and FIG. 2 is a block diagram of an embodiment of the present invention. 1... Plating solution 2... Liquid indenter 3... Plating thickness meter 4... Interface 5... Microcomputer 6... Plating steel plate 7... Plating bath or higher

Claims (1)

[Claims] A liquid analyzer that measures the metal component ratio of zinc-iron plating solution,
A continuous, rapid, and non-destructive method consisting of a fluorescent X-ray plating thickness meter that measures the plating thickness by correcting the metal component ratio by inputting the metal component ratio immediately after the plating is applied. A method for measuring plating thickness that is directly connected to the plating production process.