原始晶粒尺寸对低碳钢中铁素体动态再结晶的影响  

EFFECT OF INITIAL GRAIN SIZE ON DYNAMIC RECRYSTALLIZATION OF FERRITE IN A LOW CARBON STEEL

作　　者：李龙飞[1] 杨王玥[1] 孙祖庆[2] 

机构地区：[1]北京科技大学材料科学与工程学院,北京100083 [2]北京科技大学新金属材料国家实验室,北京100083

出　　处：《金属学报》2004年第2期141-147,共7页Acta Metallurgica Sinica

基　　金：国家自然科学基金50171004;国家重点基础研究发展规划G1998061506资助项目

摘　　要：采用Gleeble1500型热模拟试验机进行单轴热压缩实验,研究了4种不同原始晶粒尺寸的低碳钢在变形温度为700和600℃,应变速率为10~1—10^(-3)s^(-1)条件下的变形特性及组织演变规律,探讨了原始晶粒尺寸和热加工参数Z值对铁素体动态再结晶过程的影响。结果表明:在本实验变形条件范围内,4种不同原始晶粒尺寸的低碳钢均可发生铁索体动态再结晶,原始晶粒尺寸的减小,不但在恒定Z值条件下有利于动态再结晶过程的进行,而且使铁素体可以发生动态再结晶的临界Z值和发生不连续动态再结晶的临界Z值均增大,形变强化相变生成的细小铁素体晶粒在热变形时易于发生动态再结晶,只要控制好热加工参数,可以利用动态再结晶过程,进一步细化形变强化相变生成的铁素体晶粒。The hot deformation behavior and the microstructure evolution of a low carbon steel with different initial grain sizes are investigated by uniaxial hot compression at deformation temperatures of 700 degreesC and 600 degreesC and strain rates of 10 s(-1) to 10(-3) s(-1). The effect of initial grain size and hot deformation parameter Z on dynamic recrystallization of ferrite is approached. The results indicate that under the present deformation conditions, the dynamic recrystallization of ferrite takes place in the low carbon steel. The decrease of initial grain size is not only of benefit to the dynamic recrystallization of ferrite at a certain Z value, but also leads to the increase of the critical values of Z for both the dynamic recrystallization of ferrite and the discontinuous dynamic recrystallization of ferrite. It is suggested that the fine ferrite formed by deformation enhanced transformation is beneficial to the occurrence of dynamic recrystallization of ferrite during hot deformation. Further refinement of the fine ferrite can be realized by the dynamic recrystallization of ferrite under a suitable Z value.

关 键 词：铁素体 动态再结晶 低碳钢 原始晶粒尺寸 热加工参数 变形温度 应变速率 

分 类 号：TG142.31[一般工业技术—材料科学与工程] TG111.7[金属学及工艺—金属材料]