退火均热时间对IF钢织构及深冲性能的影响

Effects of Annealing Duration on Texture and Deep Drawability of IF Steel

分别在退火温度850℃,均热时间为30、60、90 s条件下对72%冷轧压下率的IF钢进行连续退火试验,利用电子背散射衍射(EBSD)技术及拉伸试验对样品全厚度方向的织构类型及其含量、深冲性能进行了测试,比较了不同均热时间下织构的变化情况及深冲性能,探讨了不同均热时间下织构与深冲性能的关系。结果显示:IF钢中再结晶织构的形成机制为定向形核。随着均热时间的增加,r值逐渐增大,但均热时间为60 s时,r值增加并不明显,只有当均热时间达到90 s时,r值才明显提升;随着均热时间增加,r值逐渐减小,但变化幅度很小。在均热时间分别为30、60 s时,Δr值分别为0.51和0.45;当均热时间达到90 s时,Δr值增加到0.93。随着均热时间的增加,{111}/{100}的值逐渐增加,变化趋势与r值的变化趋势一致。

The continuous annealing test of IF steel with 72%cold rolling reduction rate was carried out under the condition of annealing at 850℃for 30,60 and 90 s.The texture types and their contents in the full thickness direction and the deep drawing properties of the samples were measured by electron backscatter diffraction(EBSD)and tensile test.The texture variation and deep drawing performance under different soaking time were compared and the relationship between texture and deep drawing property at different soaking time was discussed.The results show that,the formation mechanism of recrystallization texture in IF steel is directional nucleation.With the increase of soaking time,the r value increases gradually However,when the heating time is 60 s,the increase of r value is not obvious.When the holding time reaches 90 s the r value increases significantly.With the increase of soaking time,the r value decreases gradually,but the variation is very small.When the heating time is 30 s and 60 s,theΔr values are 0.51 and 0.45,respectively.When the heating time reaches 90 s,theΔr value increases to 0.93.The value of{111}/{100}increases with the increase of the heating time,and the trend of change is consistent with that of r value.