Retained Austenite Amount Determination Comparison in JIS SKD11 Steel Using Quantitative Metallography and X-Ray Diffraction Methods

Abstract

This research compares the difference in determining the austenite amount in SKD 11 tool steel using the micrographic method as opposed to the X-ray diffraction method. Calculating the amount of retained austenite in tool steel using X-ray diffraction analysis requires first taking off the primary carbide content. By etching the SKD11 specimen using Beraha’s CdS reagent, the retained austenite, martensite and carbide are shown as white, red and blue regions in the microstructure, respectively. With quantitative metallography, the retained austenite can be distinguished as separate micro-constituents and properly counted. However, the calculated values are lower than those acquired from the X-ray diffraction. It is more accurate to evaluate the amount of retained austenite with carbide by X-ray diffraction analysis.