基于电子背散射衍射技术的低碳钢原奥氏体晶界的显示技术探讨

常规对原奥氏体晶界的显示均采用晶界腐蚀法,但是该方法成功率不高,具有一定的局限性,且所使用的苦味酸溶液属于危险品,因此,为了更好地显示出原奥氏体晶界,实验借助电子背散射衍射技术(EBSD)对低碳钢原奥氏体晶界的显示方法进行了详细研究。结果表明,与常规的晶界腐蚀法相比,借助EBSD技术可以显示原奥氏体晶界,其最佳晶界取向差在20°~50 °之间,且该低碳钢原奥氏体平均晶粒尺寸为40.02μm,与晶界腐蚀法统计的结果基本一致,但是对于经过大变形的原奥氏体晶界,实验方法并不适用,这可能与变形后马氏体变体之间的取向差随之变化有关。

Discussion of display technology for the prior austenite grain boundary in low-carbon steel based on electron backscatter diffraction

The display of the prior austenite grain boundary usually adopts grain boundary corrosion method. However, the success rate of this method is not high with certain limitation. Moreover, the picric acid solution used belongs to dangerous goods. In order to better display the prior austenite grain boundary, the display technology for the prior austenite grain boundary in low-carbon steel was systemically investigated based on electron backscatter diffraction (EBSD). The experimental results showed that the prior austenite grain boundary could be displayed by EBSD technology compared to the conventional boundary corrosion method. The optimal grain boundary disorientation was in range of 20°-50°. Moreover, the average grain size of prior austenite in this low-carbon steel was 40.02μm, which was basically consistent with the statistical results by boundary corrosion method. However, the experimental method was not applicable for the prior austenite grain boundary after large deformation, which was possibly due to the change of disorientations among the deformed martensite variant after deformation.