Abstract: Observation of microstructure of X80 pipeline steel (/% : 0.043C, 0.25Si, 1.86Mn, 0.085Nb, 0.00lTi, 0.028Al, 0.0027N) has been carried out by using environmental scanning electron microscope, and characteristics of structure and grain-texture orientation of the pipeline steel are analyzed by X-ray diffraction ( XRD) and electron backscatter diffraction ( EBSD) technique. Results show that with increasing {112}〈110〉、{110}〈110〉 orientation and small-angle boundary ratio, the pipeline steel's drop weight tear test ( DWTT) shearing area ratio enlarges and the toughness of steel increases； with decreasing finishing rolling temperature and increasing cooling rate after rolling, it is a- vailable to get more acicular ferrite and favlurable to DWTT performance.

Key words: X80 Pipeline Steel, Rolling Process, Structure, Texture, Properties

摘要： 利用环境扫描电子显微镜对X80管线钢(/%:0.043C、0.25Si、1.86Mn、0.085Nb、0.001 Ti、0.028Al、0.002 7N)的显微组织进行了观察,并借助于X射线衍射仪和电子背散射衍射技术,分析了管线钢组织与晶粒织构取向的特点。结果表明,{112}〈110〉、{110}〈110〉取向增加、小角度晶界比率提高,使管线钢的落锤撕裂面积增大,韧性提高;降低终轧温度、提高冷却速度,能够得到较多的针状铁素体,对落锤撕裂性能是有利的。

关键词: X80管线钢, 轧制工艺, 组织, 织构, 性能