Evaluation of microstructures and mechanical properties of steel with tensile loading process using x-ray line profile analysis

Abstract

Synopsis: X-ray line profile analysis, modified Williamson-Hall method/modified Warren-Averbach method, was carried out to measure microscopic parameters such as dislocation density and crystallite size of S45C steel with tensile loading after released. As the result, X-ray line profiles were broadened after yield process due to convolution of increase of dislocation density and refinement of crystallite size. Correlations between microscopic parameters and macroscopic parameters such as flow stress, plastic strain, and Vickers hardness were also discussed. Then followings were clarified, relationship between flow stress and dislocation density that measured by X-ray diffraction agrees with conventional relationship, τ = τ0 + κμbρ1/2, which had been obtained by TEM observation and etch-pit technique; plastic strain after plateau region has relationship to dislocation density, ρ = ρ0 + Dεpm, which means it is able to measure plastic strain by X-ray diffraction; Vickers hardness relates to square root of dislocation density as linear function.