为研究25Mn钢不同状态的冲击性能的差异，采用示波冲击试验、硬度测定、显微组织观察和冲击断口的SEM形貌分析等方法，分别对轧制态、正火和淬火+回火的试样进行了测定。结果表明，用示波冲击试验能得到不同变形和断裂阶段载荷、变形及能量消耗的变化。如淬火+回火态的变形抗力和变形能力都较高，但其总冲击功仅比正火态平均高6J，可却使其材料的裂纹扩展功平均提高16.78J。分析冲击试样的裂纹形成功和裂纹扩展功，以及断口形貌可以判断材料的韧脆性。

The Charpy impact test、hardness test、microstructure and morphology analysis of impact fracture by SEM were introduced to research the difference of impact toughness on 25Mn, which were in the state of hot-rolled, normalized and quenched & tempered. The results showed that the changes of load, deformation and energy exhaust in different stage of deformation and fracture could be gained by Charpy impact test. 25Mn in quenched & tempered has more deformation resistance and deformation property than which in other staties. The total impact works was 6J higher than which in normalized in average, however, the crack propagation works was 16.78J higher in average. Ductile-brittle property of the material can be estimated by the analysis of crack formation works, crack propagation works and fracture morphology on samples.