Three Dimensional Microstructure–Microtexture Characterization of Pipeline Steel

Abstract

The microstructural anisotropy together with the crystallographic texture of an industrial grade of X70 pipeline steel is studied by means of the 3D-EBSD technique known also as EBS3 which was recently developed by FEI. Samples of size 8x10x3mm³ were cut from the middle thickness of an industrial rolled plate and after special sample preparation have been studied in a Nova 600 dual beam scanning electron microscope equipped with a field emission gun and HKL Channel 6 EBSD data collection software for crystallographic orientation, which allows multiple sectioning of the sample in automatic mode and, afterwards reconstruction of both the 3D microstructure and texture of the examined volume. Three scanned zones of different volumes that varied between 15x10x27 4m³ and 16x14x6 4m³ have been examined and the results for the crystallographic orientation, grain shape and grain shape orientation are discussed together with the data for the anisotropy of the Charpy impact toughness of the material.