通过光学显微镜和透射电镜对不同锰元素含量的9Ni钢的显微组织进行观察和分析,研究了锰对热轧态、调质态钢板显微组织和力学性能的影响。结果表明,锰含量对试验钢显微组织的类型没有明显影响,但会影响生成的M/A岛的数量;锰含量的增加,可使钢的固溶强化作用增强,提高强度,但会使锰的偏析情况更加严重;降低9Ni钢中锰元素含量可使低温钢的低温冲击性能明显提高;经调质热处理后,钢板的组织更加细化、均匀,钢板的冲击性能得到明显改善。 The microstructure of 9Ni steel with different contents of manganese was observed and analyzed by optical microscope and transmission electron microscope. The effects of manganese on the microstructure and mechanical properties of hot-rolled and tempered steel were studied. The results show that the content of manganese has no significant effect on the microstructure of the test steel, but it will affect the number of M / A islands produced. The increase of manganese content can enhance the solid solution strengthening effect and increase the strength of the steel, The segregation of manganese is more serious; reducing the content of manganese in 9Ni steel can significantly improve the low temperature impact resistance of low temperature steel; after quenched and tempered heat treatment, the structure of the steel plate is more refined and uniform, and the impact performance of the steel plate is obviously improved.