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用ＴＥＭ研究了新型钎钢４０ＭｎＭｏＶ的正火组织，发现它与Ｓｉ—Ｍｎ—Ｍｏ系的另一种钎钢５５ＳｉＭｎＭｏ相似，由无碳化物上、下贝氏体Ｂｕ、Ｂｌ、以孪晶马氏体为主的“块状组织”Ｌ和约１５％残余奥氏体Ａｒ组成，但４０ＭｎＭｏＶ的Ｂｕ、Ｂｌ较多，Ａｒ和Ｌ则较少；Ｂｕ板条较粗大，其间分布着不连续的Ａ小片条；Ｂｌ片中有渗碳体与奥氏体Ａ共存：Ｌ的尺寸较小，硬度较低。讨论了该钢正火时贝氏体（Ｂ）相变的原因及影响贝氏体形态和数量的因素。
The normalized microstructure of the new 40MnMoV brazing steel was investigated by TEM and found to be similar to 55SiMnMo, another brazing steel for the Si-Mn-Mo family. The microstructure of the 40MnMoV brazing steel was composed of carbide-free upper and lower bainite Bu, Bl, Bulk “bulk” L and about 15% retained austenite Ar, but 40MnMoV Bu, Bl more, Ar and L is less; Bu slab thick, during the distribution of discontinuous A small piece Article; Bl film with cementite and austenite A coexistence: L smaller size, lower hardness. The reasons for the phase transformation of bainite (B) during normalizing and the factors affecting the morphology and quantity of bainite are discussed.