一种高Nb-IF冷轧薄板钢的组织性能及织构

 采用拉伸试验、金相、ODF织构分析及电子背散射衍射(EBSD)技术研究了一种冷轧高Nb-IF钢和传统Nb+Ti-IF钢在不同退火温度下的组织性能、织构及晶界特征。结果表明：与传统Nb+Ti-IF钢相比，该新型高Nb-IF钢由于添加了质量分数为60×10-6的碳和010%的铌，其再结晶温度和再结晶完成温度均大幅度提高；新型高Nb-IF钢具有晶粒细小、组织均匀性良好的组织和γ取向织构发展充分且强点密度高的织构，能够获得强度高、伸长率高和r值高的优异的综合性能。EBSD分析结果表明，该新型高Nb-IF钢中小角度晶界和低指数重位点阵(ΣCSL)晶界含量较多，这也是试验钢获得优良成形性能的原因之一。

Microstructure, Mechanical Properties and Texture of a Cold Rolled High Nb-IF Steel Sheet

Microstructure,mechanical properties,texture and grain boundaries characterization of novel high Nb-IF steel sheet and convention Nb+Ti-IF steel sheet annealed at different temperatures were investigated using tension test,metallography,X-ray diffraction ODF analysis and electron backscatter diffraction(EBSD) technique.The results show that the relatively higher carbon content near 60×106 with a suitable carbide forming element niobium(0.10%) significantly increases the recrystallization temperature and the fully recrystallization temperature of the novel high Nb-IF steel sheet compared with those of conventional Nb+Ti-IF steel sheet after subjected to the same hot and cold rolling.While this steel has excellent comprehensive properties such as higher strength,higher elongation and higher r-value due to the formation of the fine grain structure with more homogeneous microstructure and the γ fiber texture sufficiently develops.EBSD analysis show that more small angle and low coincidence site lattice(ΣCSL) boundaries in the high Nb-IF steel sheet is one of the reasons obtain well formability.