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利用透射电镜研究了Ｆｅ－１．８３Ｃ（％）马氏体在室温时效后衍时斑点的漫散射及显微组织变化。利用双倾试样技术得出了漫散时斑强度在倒易空间的分布。结果表明：马氏体斑点呈漫散的角状，其立体形态由对顶的两个四棱锥构成对漫散射的Ｆｏｕｒｉｅｒ分析及ＴＥＭ显微组织分析表明：马氏体在时效时发生了调幅分解，其调幅结构由波长为≈１ｎｍ的主波和波长大于１ｎｍ的次波叠加而成；同时发现Ｆｅ－Ｃ马氏体调幅分解的一个显著特点是，调幅结构时效数月后也未长大。对马氏体正方度的研究表明：在调幅分解过程中碳原子的再分布仅限于Ｏ＿ｚ八面体间隙亚点阵中。
Transmission electron microscopy (TEM) was used to study the diffuse scattering and microstructure changes of the Fe-1.83C (%) martensite at room temperature. Using double dip sample technique, we get the distribution of diffuse scattering intensity in reciprocal space. The results show that the martensite speckles are diffusely angular, and its stereo morphology is composed of the two quadrangular pyramids on the top. Fourier analysis and TEM microstructure analysis show that the martensite undergoes amplitude modulation decomposition The amplitude modulation structure is composed of the main wave of wavelength ≈1nm and the sub-wave of wavelength greater than 1nm. It is also found that the amplitude modulation of Fe-C martensite does not grow after several months of aging. The study on the squareness of martensite shows that the redistribution of carbon atoms during the AM decomposition is limited to the O_z octahedral sub-lattice.