Surface Hardness Measurment and Microstructural Characterisation of Steel by X-Ray Diffraction Profile Analysis

An X-ray diffraction line will broaden considerably when steels change into martensitic structure on quenching. The results presented in this paper show that X-ray diffraction technique can be employed for a rapid and nondestructive measurement of hardness of hardened steel. Measurement on various quenched and tempered steels showed that the breadth of its diffraction peak increased with increasing hardness. Some empirical equations are derived to correlate the width of the diffraction line with the hardness. The diffraction profile analysis can offer good indication about the material's characteristics and the microstructural evolution caused by heat treatment or by mechanical loading.