管线钢中晶界取向差特征分布分析

Analysis on misorientation angle distribution of pipeline steels

利用电子背散射衍射（EBSD）技术对X70，X80和X1003种管线钢进行了取向成像分析。结果表明，尽管3种管线钢的强度级别不同，微观结构存在较大的差异，但都具有相似的取向差择尤分布，其取向差主要分布在2°～15°和47°～60°区间，呈“双峰”分布特征。进一步的分析表明，奥氏体主要以K—S关系向中温铁素体转变，Dahmen的二维不变线模型验证了这一结果。K-S关系变体间特定的取向差关系是造成这3种管线钢取向差择尤分布的原因。

Three grades pipeline steels of X70, X80 and X100 were analyzed by means of orientation imaging microscopy based on electron baekscattered diffraction （EBSD） technique. The results show that the three pipeline steels have the similar ＇bimodal＇ misorientation distributions, the misorientation angle mainly is in the ranges of 2° - 15 ° and 47° _ 60° though their mierostrueture is variant. Further analysis indicates that the Kurdjumov-Saehs （K-S） relation dominates the orientation relationships during intermediate transformation, and the invariant line model of Dahmen verifies it. It is concluded that the misorientation between the variants of K-S relation caused the mesotexture of the three pipeline steels of X70, X80 and X100