【作者】 朱静； 程志英； 陈锡花； 周惠华； 孙新军； 刘清友；

【Author】 Zhu Jing Cheng Zhiying Chen Xihua Zhou HuihuaElectron Microscopy Laboratory, School of Materials Science and Engineering,Tsinghua University Beijing 100084Sun Xinjun Liu Qingyou Central Iron and Steel Research Institute Beijing 100081

【机构】 清华大学材料科学与工程研究院电子显微镜实验室； 钢铁研究总院；

【摘要】 经1180℃奥氏体化,冷至844℃变形后立即淬火工艺制备的超低碳微合金钢由混合尺度的铁素体晶粒、亚晶粒及沿晶界和亚晶界分布的薄的网状铁素体组成。网状铁素体为形变诱导铁素体,在原奥氏体晶界和形变奥氏体内的胞块的胞壁处形核并沿其长大,将奥氏体晶粒分割而导致奥氏体细化。随变形量增加,网状铁素体在细化的奥氏体晶粒内进一步形成而使奥氏体晶粒细化程度提高。在变形结束后立即淬火的过程中发生γ→α相变,等轴铁素体晶粒被限制在被网状铁素体所围的奥氏体内形成。因而奥氏体被分割的越细,等轴铁素体晶粒越小。更多还原

【Abstract】 There are ferrite grains and subgrains and a thin network of ferrite delineating ferrite grain boundaries in an ultra-low carbon steel by thermomechanical processing. The network of ferrite forms as a result of strain-induced γ→αtransformation happening on cell block boundaries within deformed austenite grains during hot deformation, leading to the subdivision of austenite grains. With increasing strain, the subdivision takes successively place on finer and finer scale and results in the further refinement of austenite. The refined austenite grains transform into ferrite grains owing toγ→α transformation during quenching.更多还原