Ni在球墨铸铁中的行为及作用  

THE BEHAVIOR AND FUNCTION OF Ni IN DUCTILE IRON

作　　者：郭新立[1] 刘治国[1] 刘俊明[1] 孟祥康[1] 苏华钦[1] 董鄂[1] 

机构地区：[1]南京大学固体微结构物理国家重点实验室,东南大学,南京理工大学

出　　处：《材料研究学报》1995年第4期289-293,共5页Chinese Journal of Materials Research

摘　　要：采用电子探针、图象处理仪和差热分析仪等测定观察了Ｎｉ在球铁中的偏析分布特性，研究分析了Ｎｉ对铸态球铁组成相比例、Ｆｅ－Ｃ－Ｓｉ平衡相图、Ｍｓ点和贝氏体转变动力学的影响及其机制结果表明：Ｎｉ在球铁中呈连续负偏析，其加入可以改变铸态球铁中各组成相的比例，使得Ｍｓ点降低，奥氏作稳定性增加，等温转变过程中。By use of the electron probe, image analyzer and differential thermal analysing device, the segregation of Ni in ductile iron was characterized. The influence of Ni on phase constitution, Fe-C-Si equilib rium diagram, Ms point and the kinetics of bainitic transformation were studied.The results show that Ni distributs in as-cast ductile iron in the form of negetive segregation. With the increase of Ni content the percent of pearlite and graphite phase constitution were increased, whereas the ferrite was decreased. The Ms point and the isothermal transformation rate of bainite were decreased, whereas the thermal stability of austenite was increased. When the Ni content was increased from 0 to 3%, the start and end temperatures of three-phase field and the Ms point in Fe-C-Si alloys were decreased 24℃, 20℃ and 62℃ respectively,whereas the carbon content in austenite and the inoculation time of bainitic transformation were increased 0. 11% and 21s, respectively. The reason was mainly attributed to the enhancement of Ni to the thermal stability of austenite.

关 键 词：球墨铸铁 铁素体 奥氏体 球光体 镍 

分 类 号：TG143.5[一般工业技术—材料科学与工程]