普碳钢中板表层组织超细化的变形机理  

Deformation Mechanism of Ultra-fine Grained Microstructure in the Surface Layers of Plain Low Carbon Steel Plate

作　　者：范建文[1] 张维旭[1] 代晓莉[1] 谢瑞萍[1] 

机构地区：[1]首钢技术研究院,北京100041

出　　处：《材料热处理学报》2005年第6期69-74,共6页Transactions of Materials and Heat Treatment

基　　金：北京市科技新星计划资助项目(H013610320111)

摘　　要：采用单向压缩热模拟试验进行了普碳钢中厚板表层组织超细晶化研究.材料奥氏体化后快速冷却到550～800℃范围内变形,结果表明,随着变形温度的升高,材料分别发生形变后铁素体静态再结晶、形变过程中的铁素体动态再结晶,形变诱导奥氏体-铁素体相变并获得超细晶粒铁素体.随着保温时间增加,形变诱导相变获得的铁素体逆相变为奥氏体.实验室轧制9mm钢板的铁素体晶粒度,轧后空冷达到11级(约7μm),与热模拟试验的结果相一致,轧后快冷铁素体晶粒进一步细化到12级(约5μm).实验室条件下,钢板的屈服强度,轧后空冷接近350MPa,轧后快速冷却,能再提高90MPa左右,但断后伸长率明显下降.The hot rolling and cooling process of plain low carbon steel was simulated by the compression of cylindrical specimen to study the formation of ultra-fine grained ferrite in the surface layers of the plates. The austenized specimens were rapidly cooled to specific temperature and deformed in the temperature range of 550°C-800°C. The results indicate that with the increase of deformation temperature the static recrystallization and dynamic recrystallization of the ferrite and the strain induced ferrite transformation occur, respectively. Ultra-fine grained ferrite can be obtained by strain induced phase transformation. With the increase of holding time at high temperature, the strain induced transformation ferrite can reversely transformed to austenite. The experiments carried out in laboratory confirm that the ferrite grains of the plates air cooled were refined to about 7 μm (ASTM E112 No.11), which is similar to the size of hot-simulation specimens. Furthermore, the ferrite grains can be refined to about 5 μm (ASTM E112 No.12) under rapidly cooling. Yield strength of the former is up to 350 MPa and that of the latter rises by more than 90 MPa with the relatively low elongation.

关 键 词：普碳钢中板 超细晶粒铁素体 形变机理 

分 类 号：TG113[金属学及工艺—物理冶金] TG335[金属学及工艺—金属学]