A Comparative study of the crystallite size and the dislocation density of bent steel plates using Bragg-edge transmission imaging, TOF neutron diffraction and EBSD

ブラッグエッジ透過イメージング法、TOF中性子回折法、及び電子線後方散乱回折法を用いた曲げ鉄鋼の結晶子サイズ及び転位密度の比較検討

及川 健一   ; Su, Y. H.  ; 友田 陽*; 川崎 卓郎   ; 篠原 武尚   ; 甲斐 哲也   ; 廣井 孝介  ; Zhang, S.*; Parker, J. D.*; 佐藤 博隆*; 鬼柳 善明*

Oikawa, Kenichi; Su, Y. H.; Tomota, Yo*; Kawasaki, Takuro; Shinohara, Takenao; Kai, Tetsuya; Hiroi, Kosuke; Zhang, S.*; Parker, J. D.*; Sato, Hirotaka*; Kiyanagi, Yoshiaki*

TOFブラッグエッジ透過イメージング法を用い、塑性変形させた曲げ鉄鋼試料の微細構造を解析し、得られた結果を中性子回折法及びEBSD法により比較検証を行った。その結果、テキスチャ等は非常に良い一致を示したが、結晶子サイズを中性子回折法による消衰効果から見積もることはうまく行かなかった。そこで、回折プロファイルのブロードニング幅解析から結晶子サイズを求めることを試み、またEBSD法から結晶歪みの解析結果も合わせて再検討を行った。

Time of flight Bragg edge transmission (BET) imaging was adopted to the plastically bent plates of a ferritic steel and a duplex stainless steel, and the obtained results were validated using neutron diffraction method and electron backscatter diffraction (EBSD) observations. The BET imaging results of texture distribution and phase volume fractions showed good agreements with those obtained by neutron diffraction and EBSD. The crystallite size evaluation using extinction correction was succeeded by the RITS code where Sabine's primary extinction function was applied, however, the crystallite size was not obtained by the Rietveld refinement where the same function was used for the evaluation. In this study, we comparatively reinvestigate the crystallite size and the dislocation density of the plastically bent steel plates by the use of Pawley analysis on the diffraction data and grain analysis on EBSD data.