温轧FeCrAl钢退火组织演变对力学性能的影响

摘要：研究采用电子背散射衍射技术（EBSD）对温轧及退火态Fe-13Cr-4.5Al-2.2Mo-1.1Nb（质量分数，%）钢的织构、晶界类型和Laves相进行了表征，并讨论了对力学性能的影响。结果表明，300℃温轧变形，70% 的样品出现显著的变形不均匀组织，利用Taylor因子解释了不均匀变形特征，晶粒取向以变形织构α、γ和<100>//ND为主，比例分别为43.3%、39.0%和17.1%，屈服强度和抗拉强度为1298.1MPa和1371.6MPa，伸长率4%。750～800℃退火30～60min后，再结晶晶粒尺寸小于10μm，γ织构比例减少至11.9%～15.5%，此时屈服强度为790～860MPa，抗拉强度为840～890MPa，伸长率为20%左右。1000℃退火5min后再结晶晶粒明显长大，γ织构增加至39.1%，此时屈服强度、抗拉强度和伸长率分别为567.7MPa、800.7MPa和25.6%。1000℃时随退火时间增加，γ织构增加至50%以上，Laves相的钉扎是γ织构增加的原因。600℃温轧的微观组织和300℃温轧的类似，但屈服强度和抗拉强度略有下降，伸长率增加。

Effect of microstructure evolution during annealing on mechanical properties of warm rolled FeCrAl steel

Texture, grain boundary and Laves phase of warm rolled and annealed Fe-13Cr-4.5Al-2.2Mo-1.1Nb were characterized by electron backscatter diffraction (EBSD), and their effects on the mechanical properties were discussed in details. The results show that, the 300℃ warm rolled sample with 70% reduction shows obvious in-homogenous deformed microstructure, which was explained by Taylor factor. The grain orientation of warm rolled sample is dominated by three texture of α, γ and <100>//ND, and the fraction are 43.3%, 39.0% and 17.1% respectively. The yield and tensile strength of warm rolled sample are 1298.1MPa and 1371.6MPa, and the elongation is 4%. After annealing at 750-800℃ for 30-60min, the recrystallized grain size of the samples is less than 10μm, and the proportion of γ fiber decreased to 11.9%-15.5%, and the yield strength is 790-860MPa, the tensile strength is 840-890MPa, elongation is 20%. After annealing at 1000℃ for 5min, the recrystallized grain grow significantly, the proportion of γ fiber increased to 39.1%. The yield strength, tensile strength and elongation are 567.7MPa, 800.7MPa and 25.6%, respectively. With the increase of annealing time at 1000℃, the proportion of γ fiber increases to more than 50%. The pinning effect of the Laves phase is the reason why the proportion of γ fiber increased. The microstructure features of 600℃ warm rolled sample are similar to that of 300℃ warm rolled one, the strength decreases and the elongation increases.