Correlation in the parameters obtained by direct-fitting method and modifed williamson-hall method for cold worked iron

In the dislocation characterization using radiation diffraction, the modifed Williamson-Hall method gives the parameter a, f and S, in which the information about crystallite size, dislocation density and screw component of dislocation are contained respectively. On the other hand, the direct-ftting method gives the parameter a, micro-strain e and the correction parameter ωh00. In this study, the correlation in these parameters was investigated in cold rolled ferritic steel (Fe-0.0056%C). Results obtained are as follows: Almost same values were obtained for the parameter a in both methods. The value of parameter e increases as the S-value becomes small even under the same dislocation density. At the constant S-value, however, linear relationship was found between e and f. Between the parameter S and ωh00, there is an identical relationship expressed by the equation; S=1.16+1.46ωh00-3.71ωh002 regardless of dislocation density. In addition, it was confrmed that there is no large effect of texture on the dislocation characterization by the direct-ftting method and the modifed Williamson-Hall method.