shown in Fig.1.The samples of quenching in water showed primary a aud martensite a';and quenched plus 550C aging showed long B precipitates inside and along boundaries of martensites,but no interfacial phase was observed.For samples of F,A and D,the morphology of interfacia!phase is.saown in Fig.2. Most of the interfacial phase werc dcuble layer structure.The layer adjacent to B was monolithic layer with smooth boundaries and that adjacent to a was striated layer with saw-tooth boundarics.Thickness of the inlerfacial phase could reach 100 nm.Single layer interfacial phase was als,observed as shown in Fig.3 and Fig.4. 0,38m Fig.2 Typical interfacial phase with double structure Fig.3 Dark field of monolithic Fig.4 Dark fleld of striated layea layer(30000×) (60000×) 1.3 Structure and Orientation Fig.5 shows SAD pattern and the corresponding indexed results.It was identified that monolithic layer was fcc with lattice parameter a=0.423 nm and A 570个 。 扭宜 呈 。 盖改。 丫 。 刀 ， “ 。 ， · ， ， ， 。 ， · · 生 刀 七 一 王 比 一 丁 · ，声 卜 一 。 一 月