混合稀土La-Ce对一种抗冲击防护钢组织与冲击性能的影响

为了研究不同混合稀土含量下一种抗冲击防护钢的冲击性能,对钢在室温和-40℃低温冲击性能进行测试,并对其冲击断口形貌及显微组织进行观察分析。结果表明,试验钢中加入混合稀土La-Ce后,改善了回火马氏体组织、细化了奥氏体晶粒,同时,变质了钢中的夹杂物,长条状的MnS夹杂物变质为球状复合稀土夹杂物,夹杂物尺寸由6μm减小到2μm;与不含稀土的试验钢相比,含混合稀土试验钢的室温冲击性能和-40℃低温冲击性能均有所提高,混合稀土La-Ce含量为102×10^-6时,防护钢的室温冲击功增加了24.5%,-40℃低温冲击功增加了17.4%。

Effect of Mixed Rare Earth La-Ce on Microstructure and Impact Property of an Anti-impact Protection Steel

In order to study the impact properties of an anti-impact protection steel with different mixed rare earth contents, impact energy of the steel at room temperature and-40 ℃ low temperature environment was tested, and the impact fracture morphology, microstructure of tested steel were observed. The results show that the tempered martensite structure and austenite grain are refined after mixed rare earth La-Ce added to the steel. Meanwhile, the inclusions in the steel are deteriorated from long strip MnS inclusions to spherical complex rare earth inclusions, and the size of inclusions are reduced from 6 μm to 2 μm. Compared with the tested steel without rare earth, the impact energy of samples containing mixed rare earth at room temperature and-40 ℃ is improved. When the steel contains mixed rare rare earth La-Ce is 102×10^-6, the impact energy at room temperature of tested steel is increased by 24.5% and the impact energy at-40 ℃ is increased by 17.4%.