纯铁块状转变机制探索  

Study on massive transformation mechanism of pure iron

作　　者：李峰[1] 

机构地区：[1]内蒙古工业大学材料科学与工程学院,内蒙古呼和浩特010051

出　　处：《材料热处理学报》2007年第3期44-46,共3页Transactions of Materials and Heat Treatment

摘　　要：根据纯铁相变和扩散理论建立原子的扩散模型,并根据经典的扩散理论模型对扩散相变机制进行验证.通过理论计算表明在温度为800℃,冷却速度在2000℃/s左右时,扩散所需要的时间比相变的时间长两个数量级,证明此温度时是由扩散所控制的.当温度在740℃时,冷却速度在5000～30000℃/s之间时,扩散所需要的时间小于相变的时间而且计算结果在同一个数量级,所以为界面控制的相变.而大于30000℃/s时,扩散所需要的时间大于相变所需的时间,因此发生马氏体相变.Based on the phase transformation of pure iron and diffusion theory, the atom diffusion model is put forward, and according to the classical diffusion theory the diffusion phase transformation mechanism is examined. Making use of the theory calculation, it is shown that the diffusion time is longer the two orders of magnitude than the transformation time while the temperature is at 800°C and the cooling speed is at -2000°C/s, it indicates that the phase transformation is controlled by diffusion at this temperature. But the diffusion time is less than the phase transformation time and the calculation result is in the same order of magnitude while the temperature at 740°C and the cooling speed between 5000 and 30000°C/s, so the phase transformation is controlled by the interface. But the diffusion time is more than the phase transformation time while the cooling speed at 30000°C/s, therefore it indicates the Martensite transformation occurs.

关 键 词：块状相变 扩散 相变机制 

分 类 号：TG111.5[金属学及工艺—物理冶金] TG111.3[金属学及工艺—金属学]