Microstructural Features of Cold-Rolled Carbon Steel Evaluated by X-ray Diffraction Line Profile Analysis and Their Correlation with Mechanical Properties

Abstract

Line profile analyses of cold-rolled carbon steels were conducted to evaluate microstructural features such as dislocation density, crystallite size, and M values. After the samples were subjected to 40% coldrolling, dislocation density increased from 7 × 10 13 m −2 to 2 × 10 15 m −2 and crystallite size decreased from 155 nm to 35 nm. The component ratio of screw and edge dislocations was approximately 1:1, as determined from the evaluation of the q values. The M value that indicated interaction of dislocations substantially decreased during the initial stage of cold-rolling, which means interaction of dislocations becomes strong. Proof stress, hardness, and tensile strength were increased by the cold-rolling process. Furthermore, the ratios between proof stress and hardness were initially 2 and increased to approximately 3. The correlation between the microstructures and the mechanical properties was demonstrated according to the Bailey-Hirsch relationship between flow shear stress and dislocation density. Variations in the proof stress and hardness as a function of the square root of dislocation density indicated that the work-hardening of the material is affected by not only the total amount of dislocations but also other factors, such as crystallite size and arrangement of dislocations.

Quantitative Analysis of the Recovery Process in Pure Iron Using X-ray Diffraction Line Profile Analysis

“…The values of ρe and ρs are the edge-and screw-dislocation densities, respectively. The value of q is 1.29 when all dislocations are edge dislocations, while the value of q is 2.64 when all dislocations are screw dislocations [16]. Thus, edge-and screw-dislocation densities can be estimated by Equations (8) and 9, respectively.…”

Assessment of Mechanical Properties and Microstructure Characterizing Techniques in Their Ability to Quantify Amount of Cold Work in 316L Alloy

“…Several studies show strong correlation between cold work percentage and peak width in Xray diffraction profiles for both steels and nickel based alloys [29,30,31]. In this study the (200) peak was examined because it shows detectable broadening for steel [18]. The (200) reflection is affected by the strain broadening similar to other reflections: (220) and ( 222) [32].…”

“…A variety of experimental techniques have been used in assessment of CW alongside SCC testing. These include: electron backscatter diffraction (EBSD) maps and calculated Kernel Average Misorientation (KAM) values, broadening of X-ray diffraction peaks, microhardness, yield strength, residual stress measurement, transmission electron microscopy (TEM) scans, and others [16,17,18,19]. Although investigations of SCC behavior in cold-worked materials often include more than one of these techniques [13,20,21,22], there has not yet been a rigorous comparison between these techniques.…”

A novel operando approach to analyze the structural evolution of metallic materials during friction with application of synchrotron radiation

“…They proposed methods for analyzing the dislocation structure influence on FWHM of diffraction peaks, which are typically referred to as the modified Williamson-Hall (MWH) method and the modified Warren-Averbach (MWA) method. These methods have been successfully tested for different materials, including ironbased alloys like cold-rolled iron [53], high-alloy cold-rolled steel [54], cold drawn pearlitic steel [55] and cold rolled medium carbon steel S45C [56]. The latter one is the Japanese analog of the steel used in this study.…”