Fe－C－Si合金上贝氏体碳化物析出源的研究

The Investigation on the Source of Bainitic Carbide Precipitation in Fe-C-Si Alloy

用透射电镜研究了Ｆｅ－Ｃ－Ｓｉ合金在４８０℃等温形成的上贝氏体。电子衍射和晶体学分析证实：合金中碳化物的析出源是初始碳含量低于平均碳含量的过饱和贝氏体铁素体（ＢＦ）．提出钢中贝氏体转变是奥氏体中碳扩散控制相变位错运动的切变过程。

The upper bainite formed isothermally at 480℃ in Fe-0.38C-1. 73Si aLloy hadbeen studied by using transimissaion electron mieroscope. The electron diffraction and the crystallo-graphic analysis showed that the source of bainitic carbide precipitation was the supersaturatedbainitic ferrite(BF) in which the initial supersaturation did not come up to the average carbon con-tent of the alloy, It is suggested that the bainitic transformation in steel should be the shear process ofthe transformation dislocation movement controlled by the carbon diffusion in the austenite.