基于X70高级管线钢多道焊缝和单道焊缝组织EBSD研究
安 栋,徐学东,张 海基于X70高级管线钢多道焊缝和单道焊缝组织EBSD研究
安 栋,徐学东﹡,张 海
(北京工业大学固体微结构与性能研究所,北京100124)
摘 要:本文选用X70管线钢两种不同形式焊接接头为研究对象,使用EBSD技术对径向焊缝的横截面的Fe3C相分布、取向差角分布、晶粒有效尺寸、大角度晶界和小角度晶界的比率以及Taylor因子进行表征。结果发现,多道焊缝析出相分布很均匀、随机;各种颜色的晶粒取向均有分布且少量呈柱状存在;晶粒有效尺寸起伏较大,大小不一,但总是交替进行;大角度晶界比率较大,韧性较好;Taylor因子灰度图分布略有起伏,平均数值较大,抵抗塑形变形能力较差。单道焊缝则反之。
关键词:EBSD;X70管线钢;多道焊缝;单道焊缝;韧性
中图分类号:TG142;TG115.23;TG115.21+5.3 文献标识码:A
EBSD analyses of multiple-passandsingle-pass weldingmicrostructure based on X70 pipeline steel
AN Dong,XU Xue-dong﹡,ZHANG Hai
(Institute of Microstructure and Property of Advanced Materials, Beijing University of Technology, Beijing 100124)
Abstract :The X70 pipeline steelweldmentoftwo different forms was analyzed byelectron backscatter diffraction (EBSD) technique to characterize the Fe3C phasedistribution, misorientationangledistribution, effectivegrainsize, the ratio of high-angle grain boundariesandsmall-angle grain boundariesandtheTaylorfactor.The results indicate thatthe distribution of precipitation and misorientationis homogeneous and random in multi-pass welded joint. A variety of colors and a small amount of columnar microstructure are presented in grain orientation. Theeffectivegrainsizeis not uniform and changes greatly,but always presents alternately. The fraction of high-angle grain boundaries issignificant, and thus the toughness is good. Thegrayscale of Taylorfactordistribution varies slightly. The large average valueendores poorresistance toplastic deformationcapacity. The situation for single-pass welding is the opposite.
Keywords:EBSD;X70 pipeline steel;multiple-pass welding;single-pass welding;toughness