“…A Widmanstätten structure has been found with a typical acicular ferrite, which shows a fabrication on fast cooling state. In order to obtain the quantitative mapping, six reference steel samples were used to build a calibration curve for macro-and micro-analysis in previous works [19,20]. They all have the equilibrium homogeneous phases with the carbon concentrations of 0.006%, 0.08%, 0.44%, 0.45%, 0.59% and 0.75%.…”