摘要:
以典型成分Nb-Ti-IF钢冷轧硬卷为研究材料,结合连续热镀锌线工艺特点,系统研究了退火工艺对试验钢组织和织构的影响。研究结果表明,退火加热温度在720℃以上时为完全再结晶组织,加热温度在720~840℃间变化时,铁素体晶粒度在10.0级左右,加热温度为880℃时,铁素体晶粒度为9.0级;随加热温度的升高,试验钢的硬度下降,当加热温度为920℃,因保温后快速冷却得到非等轴组织,虽然组织粗化,但硬度却有所提高;当加热温度为840℃时,保温时间在30~60 s间变化时,铁素体晶体尺寸变化较小,但当加热时间从30 s增加到45 s时,显微硬度明显降低,加热时间进一步增加到60 s时,显微硬度变化不大。试验钢退火后具有较强的{223}<110>和{114}<110>织构,且退火工艺条件对它们的影响较小,随着退火温度的升高,{554}<225>、{111}<112>和{111} <110>等组分的取向密度增加趋势较明显。
Abstract:
According to the processes of continuous hot-dip galvanizing lines,an industrially hot rolled and cold rolled Nb-Ti-IF steel was used to study the effect of annealing processes on the microstructures and recrystallization textures.The results showed that the steel was fully recrystallised above an annealing temperature of 720℃. When the annealing temperature is between 720℃and 840℃,the grain size is measured to be about ASTM grade 10.0 and it tended to grow to be ASTM grade 9.0 as the annealing temperature was increased to 880℃.When the annealing temperature was increased,the hardness of the experimental steel was decreased.However,although the grain was coarsened when the annealing temperature was 920℃,the hardness was increased when non polygonal microstructure was obtained due to water cooling after annealing.The change of holding time at 840℃from 30 s to 60 s had little effect on grain size.However,the hardness tended to reduce remarkably when the holding time was increased from 30 s to 45 s and remain almost constant when the holding time was further increased from 45 s to 60 s.Strong {223} <110>and {114} <110> texture components were fotmd after annealing,the intensity of them was little affected by the annealing processes while the intensity of {554} <225>,{111} <112> and {111} <110 > recrystallization texture tended to increase when the annealing temperature was increased.
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