Abstract: In situ observation of the growth process of bainitic plate in βbrass by means of high-temper- ature TEM is conducted.The lengthening and thickening kinetics of bainitic plate is analysed with Trivedi's model and Zener-Hillert's model,respectively.It is found that the stacking fault substructure exists just in the growth tip of fresh bainitie plate and so does the shear stress in the matrix around the tip.The measured lengthening rate of bainitic plate is not con- sistent with Trivedi's model.The thiekening process is only macroscopieally controlled by vol- ume diffusion but its nature is a shear process.

Key words: β-brass, bainite, growth kinetics, shear, volume diffusion