Method for measuring contents of residual austenite in steel and iron materials with carbide

Abstract

The invention relates to a method for measuring the contents of residual austenite in steel and iron materials, in particular to a method for measuring the contents of residual austenite in steel and iron materials with carbide. The method includes measuring the volume fractions of the residual austenite in the carbide in metallographic specimens by the aid of image analyzers; measuring the volume fractions of the residual austenite in the metallographic specimens by the aid of X-ray diffraction instruments combined with the image analyzers. The method has the advantages that influence of the carbide in the metallographic specimens on the contents of the residual austenite can be eliminated, the method is easy to implement, and accurate measurement results can be obtained by the aid of the method.

Description

technical field [0001] The invention relates to a method for measuring the content of retained austenite in steel materials, in particular to a method for measuring the content of retained austenite in steel materials containing carbides. Background technique [0002] After quenching, steel materials often have a certain amount of retained austenite, and the amount of austenite has an important impact on the mechanical properties and service life of the material. In order to improve the mechanical properties and service life of iron and steel materials, a reasonable heat treatment system must be adopted to control the austenite content in the material. Therefore, how to accurately measure the austenite content in the material is an important topic for testers. [0003] To measure the content of retained austenite in iron and steel materials with little or no carbide content, the People's Republic of China Ferrous Metallurgy Industry Standard "YB / T5338-2006 X-ray Diffraction ...

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Problems solved by technology

This measurement method cannot exclude the influence of carbides on the retained austenite content in steel materials

However, for iron and steel materials with a lot of carbides, using this measurement method will lead to a large error in the measurement results obtained, and even the obtained measurement results cannot be used

[0004] When using traditional metallographic techniques (image analyzers) to measure, because the metallographic colors of carbides and retained austenite in steel materials are very similar, it is impossible to distinguish the metallographic structure of carbides and retained austenite, and can only measure The total amount of carbides and retained austenite in steel materials, the content of carbides or retained austenite cannot be measured separately

[0005] There are many carbides in many steel materials in actual production, but for steel materials with a lot of carbides, using the above measurement method will lead to large errors in the measurement results obtained and even the obtained measurement results cannot be used

[0006] The existing method for measuring carbides in metallographic samples of iron and steel materials is to weigh the total weight of the metallographic samples first, then dissolve the iron in the metallographic samples to obtain solid carbides, weigh the solid carbides, and finally weigh the solid carbides. The weight of the solid carbide is compared with the total weight of the metallographic sample to obtain the content of the carbide in the metallographic sample of the iron and steel material, and then combined with the above method to eliminate the influence of the carbide on the retained austenite, and then obtain the content of the carbide in the metallographic sample. The content of retained austenite, this method needs to destroy the metallographic sample, the metallographic sample cannot be restored and reused, and the cost of the experiment is relatively high

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