Method for measuring thickness of coating of steel wire

Abstract

The invention discloses a method for measuring the thickness of the coating of a steel wire. According to the method, the diameter of the steel wire containing a coating is measured according to a method of averaging multiple measurement; the inlaying of the steel wire is performed according to an arbitrary angle, so that a sectional metallographic sample is prepared; the prepared metallographic sample is arranged in a scanning electron microscope, and observation is performed; backscattering photographs are taken; the center of the elliptical steel wire section is determined; the thickness ofthe coating at any point on the section is measured; and the actual thickness of the corresponding coating can be calculate according to a proportional formula. The analysis method is simple and easyto implement, is not affected by the size of the steel wire. With the method adopted, special sample preparation methods are not required; special testing equipment is not required; more accurate test results can be provided; and the measurement requirements of the thickness of the coating of the steel wire can be satisfied.

Description

technical field [0001] The invention belongs to the field of material microstructure inspection methods, and in particular relates to a method for measuring the thickness of a steel wire coating by using a scanning electron microscope. Background technique [0002] Traditional coating testing methods include non-destructive testing methods and destructive testing methods. Commonly used non-destructive testing methods include magnetic thickness gauges, eddy current thickness gauges, ultrasonic thickness gauges, micrometer thickness gauges, and X-ray spectroscopy. The property detection methods include metallographic method and coulometric method. The non-destructive testing method has certain special requirements on the materials of the substrate and the coating, and the test results have a large error compared with the destructive testing; the metallographic method needs to ensure that the prepared cross-sectional sample is perpendicular to the coating to be tested. It is r...

AI Technical Summary

Problems solved by technology

The non-destructive testing method has certain special requirements on the materials of the substrate and the coating, and the test results have a large error compared with the destructive testing; the metallographic method needs to ensure that the prepared cross-sectional sample is perpendicular to the coating to be tested. It is relatively easy to implement for block samples, but it is basically impossible for steel wires with a diameter of less than 1mm, especially 0.06mm; the Coulomb method is only suitable for flat samples, and it is impossible to measure the thickness of steel wire coatings

At present, there is also a scanning electron microscope to measure the coating thickness of the steel wire section, but for very thin steel wire, it cannot be guaranteed that the prepared cross-sectional sample is a vertical plane in the direction of the steel wire length, and a slight inclination will cause a large measurement error, so it is measured. Confidence is too low for coating thickness values

The existing coating thickness testing methods can solve the measurement of the thickness of large samples, but for such thin steel wires, there are shortcomings such as inability to measure or samples cannot be prepared, resulting in unsatisfactory test results.

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