Method of measuring martensite content in dual-phase steel by using electron backscatter diffraction (EBSD) technique

Abstract

The invention relates to a method of measuring a martensite content in a dual-phase steel by using an electron backscatter diffraction (EBSD) technique. The method comprises the following steps: 1) ato-be-measured sample is inlaid and is ground and polished to be made to a common metallographic sample; 2) the well-polished common metallographic sample is subjected to vibration polishing in a vibration polishing machine; 3) the metallographic sample after vibration polishing is corroded, wherein a corrosion solution is a 1% to 4% nital solution, and the corrosion time is 10 to 15 s; 4) the well-made metallographic sample is placed in a field emission scanning electron microscope sample chamber; and 5) through reasonable parameter setting, EBSD data are acquired, software is used to analyzethe data, a kikuchi slope map is acquired, a new subset is formed, the M phase in the subset is extracted, and thus, the percentage content of a martensite structure in the to-be-measured sample is thus acquired. The scheme can accurately and efficiently extract the martensite phase in the dual-phase steel structure and solves the problems that the martensite structure and a ferrite structure aredifficult to distinguish and the accurate percentage content cannot be obtained.

Description

technical field [0001] The invention relates to a method for measuring martensite content in dual-phase steel by using an electron backscattering diffraction technique, belonging to the technical field of material analysis. Background technique [0002] Hot-rolled dual-phase steel is based on phase transformation strengthening. Its microstructure is ferrite in soft phase and martensite in hard phase. It has very low yield ratio, high strength and high formability, and is widely used in automobile reinforcement. Panels, chassis, bumpers and other car body components. As the hard phase in dual-phase steel, martensite has a direct impact on the tensile strength, elongation, yield ratio and other mechanical properties of dual-phase steel. Therefore, accurate and quantitative analysis of hot-rolled dual-phase steel The percentage of martensite in the steel is of great significance for the optimization of the production process of the steel and the evaluation of its mechanical pr...

AI Technical Summary

Problems solved by technology

[0007] The present invention is aimed at the technical problems existing in the prior art, and provides a method for measuring the content of martensite in dual-phase steel by electron backscatter diffraction technology, which can accurately and efficiently extract the martensite in the structure of dual-phase steel Bulk phase, which solves the problem that the martensitic structure and ferrite structure are difficult to distinguish and the precise percentage cannot be obtained

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