12CrNi3钢粒状贝氏体的组织与性能

Microstructure and Properties of Granular Bainite in 12CrNi3 Steel

通过光学显微镜、电子显微镜研究了12CrNi3钢在不同的热处理条件下获得不同数量的粒状贝氏体,并测定其力学性能,得到粒状贝氏体含量与力学性能关系曲线,同时观察了其断口形貌特征。结果表明:在12CrNi3钢中,当粒状贝氏体含量占混合组织(马氏体+粒状贝氏体)含量30%以下时,合金的力学性能与单一板条马氏体的力学性能相比差别不大;合金中粒状贝氏体数量越多,其强度降低、塑性增加、冲击韧度增加;由断口分析知,不论是马氏体组织还是粒状贝氏体,或者是二者的混合组织,其断裂都表现为韧性断裂。

The mechanical properties of different amount granular bainite in 12CrNi3 steel under different conditions of heat treatment were studied using optical microscope and electron microscope. The mechanical properties were tested and the curves between different content granular bainite and mechanical properties were gained. At the same time, the fracture surface feature was observed. The results show that the mechanical properties have little difference compared with the single sheet martensite when granular bainite content of mixture microstructure is below 30%.The more the granular bainite content in the steel, the lower the strength, the higher the plasticity and the impact ductility. Both martensite granular bainite and mixing microstructure of fracture are toughness fracture.