铁素体区轧制低碳钢的显微组织和力学性能

Microstructure and Mechanical Properties of Low-Carbon Steel Rolled in Ferrite Region

利用光学显微镜、扫描电子显微镜和拉伸试验研究了铁素体区终轧温度和卷取温度对低碳钢组织和力学性能的影响,并与奥氏体区和两相区轧制的钢进行了对比。结果表明:随着终轧温度的降低,热轧板晶粒尺寸先增大后减小,铁素体区轧制的热轧板组织均匀,{001}、{112}织构增强;随着卷取温度的升高,形变铁素体晶粒进一步回复、长大;当终轧温度为750℃、卷取温度为650℃时,铁素体区热轧、冷轧和退火的低碳钢板的显微组织均匀,屈服强度、抗拉强度和断后伸长率均达到要求,塑性应变比略微降低。

Effect of finish rolling temperature and coiling temperature in the ferrite region on microstructure and mechanical properties of the lowcarbon steel was investigated via optical microscope,scanning electron microscope and tensile test,and compared with the steel rolled in austenite region and two phase region.The results showed that(a)as the finish rolling temperature decreased,the grain size of the hotrolled plate increased at first and then decreased,the microstructure of the plates hotrolled in the ferrite region was uniform,and the{001}and{112}textures were enhanced;(b)as the coiling temperature increased,the deformed grains further recovered and grew;(c)when the finish rolling temperature was 750℃and the coiling temperature was 650℃,the microstructure of the lowcarbon steel plate hotrolled,coldrolled and annealed in the ferrite region was uniform,and its yield strength,tensile strength,and elongation all met the requirements,while the plastic strain ratio slightly decreased.