诱导晶内铁素体形核的夹杂物控制

结合晶内铁素体的形核机制与异质形核理论,系统介绍了可以诱发晶内铁索体形核的夹杂物的类型和尺寸范围.分析认为,诱导IGF的有效形核核心一般为复合夹杂物,夹杂物上须有与IGF共格品面错配度较小的析出相.内部氧化物与边缘析出相形成的凹形边缘为IGF的形核提供了有利条件.诱导IGF形核的夹杂物类型不同,几何尺寸也有所差异,但均...

The Inclusion Control Inducing Nucleation of Intra-Granular Ferrite

The type and size of inclusions inducing nucleation of intra-granular ferrite （IGF） are systematically introduced according to the mechanisms of IGF nucleation and the theory of heterogeneous nucleation. Analysis shows that the effective nucleus inducing nucleation oflGF are generally complex inclusions, and the precipitates adhering to the inclusions which possess small lattice mismatch with IGF on the coherent interface are intergrant. As a result, the concave structure shaped by the internal oxides and external precipitates creates bene- ficial conditions for the nucleation of IGF. The inclusion sizes, have an average value of 1μm, are different depending on the type of in- clusions. Many precipitates adhere to the bigger inclusions and this increase the nucleation ratio of IGF. In order to make inclusions dis- tributed dispersively and reached the effective size to nucleation, it is reasonable to control T. O content less than 50×10^-6with addition of Ti, incubation time about 300 s and cooling rate higher than 50 K/min.