Nb对中铬耐磨铸钢组织及力学性能的影响

Effect of Nb on Microstructure and Mechanical Properties of Medium Cr Wear-Resistant Cast Steel

采用扫描电镜,室温拉伸试验机和XRD分析仪等实验设备研究了Nb对中铬耐磨铸钢基体组织、碳化物含量和类型以及力学性能的影响。研究结果表明,随着Nb的添加,钢中碳化物含量增加,主要碳化物由(Cr,Fe)7C3向Nb C转变;Nb含量的增加使抗拉强度升高,但对硬度的影响不大。Nb含量为0.2%左右时,碳化物呈细小不连续状分布,细晶强化和固溶强化共同作用而表现出良好的力学性能。

Scanning electron microscopy, room temperature tensile testing machine and XRD analyzer were used to investigate the effects of Nb on the microstructure, content and type of carbide and mechanical properties of medium chromium wear-resistant cast steel. The results show that with the increase of Nb content, the carbide content in the steel increases, and the main kind of carbide transforms from （Cr, Fe）7C3 to NbC. The tensile strength increases with the addition of Nb, but the hardness is not affected very much. When the content of Nb in the sample is about 0.2%, the carbides are small and discontinuous, and the steel shows relatively good mechanical properties due to mechanisms of fine-grained strengthening and solution strengthening.