不同应变速率下硼对低碳冷轧钢再结晶过程组织转变影响的研究

Investigation on the effect of boron on phase transformation of low carbon cold-rolled steel during the crystallization process at different strain rates

利用Gleeble-1500热模拟试验机和光学显微镜研究了低碳冷轧钢在不同应变速率下,硼的加入对其应力-应变曲线和初始奥氏体晶粒的影响.结果表明:在应变速率为0.05,10s-1时,硼的加入导致了εc/εp增加,且含硼钢初始奥氏体晶粒尺寸较大、形状不均匀,硼的加入推迟了动态再结晶;在应变速率为4s-1时,硼的加入导致了εc/εp降低,且含硼钢初始奥氏体晶粒尺寸较小,其形状近似于球状,形核较均匀,硼的加入加速了动态再结晶.

In this study, the effects of adding B on the stress-strain curve of low-carbon cold-rolled steel and the initial austenite grain size were investigated at different strain rates by using Gleeble-1500 thermal simulation testing machine and optical microscopy. The results showed that when the strain rate was 0.05 s^-1 and 10 s^-1 , the εc/εp of low-carbon cold-rolled steel increased due to adding B element and meanwhile, the B-containing steel had large initial austenite grain size and uneven shape, and thereby adding boron delayed dynamic recrystallization; when the strain rate was 4 s-1 , the εc/εp of low-carbon cold-rolled steel decreased due to adding B element and the B-containing steel had smaller initial austenite grain size and shape similar to spherical as well as more uniform nucleation, and thereby adding boron accelerated the dynamic recrystallization.