Nb对EA4T钢表面激光熔覆Fe基涂层组织与性能的影响  

Effect of Nb on Microstructure and Properties of Laser Cladding Fe-based Coating on EA4T Steel Surface

作　　者：吴谊彬 罗照洋 陈文静[1] 吴显文 WU Yibin;LUO Zhaoyang;CHEN Wenjing;WU Xianwen(School of Materials Science and Engineering,Xihua University,Chengdu 610039,China)

机构地区：[1]西华大学材料科学与工程学院,四川成都610039

出　　处：《电焊机》2025年第1期1-8,共8页Electric Welding Machine

基　　金：四川省科技支撑项目(2020Yfh0134);西华大学重点项目(Z202123);国家自然科学基金(52375387)。

摘　　要：通过在EA4T钢表面激光熔覆Fe-Cr-Ni-Nb粉末,研究不同Nb含量对熔覆层的微观组织和力学性能的影响规律。利用光学显微镜(OM)和扫描电子显微镜(SEM)分析熔覆层的组织形貌,采用显微硬度计和冲击试验测试熔覆层的硬度及冲击韧性。结果表明:在不同Nb含量的熔覆层中,主要由奥氏体、FeNi固溶体和(Cr、Fe)7C3组成;随Nb含量的增加,熔覆层的晶粒尺寸呈现细化现象。但与不含Nb的熔覆层相比,当添加Nb元素后,熔覆层的拉伸强度和屈服强度均得到显著提高,0.3%Nb、0.6%Nb和0.9%Nb熔覆层试样的平均拉伸强度分别提高了42.5%、37.7%、13.1%,平均屈服强度分别提高了26.5%、18.9%、14.1%,均明显高于基体。此外,熔覆层的冲击韧性也随着Nb含量的增加而得到提高,与未添加Nb的熔覆试样相比,平均冲击功分别增加8.3%、9.4%、26.4%。综合来看,Nb含量为0.9%的熔覆层综合力学性能最好。In this paper,the effects of different Nb contents on the microstructure and mechanical properties of the cladding layer were studied by laser cladding Fe-Cr-Ni-Nb powder on the surface of EA4T axle steel.The microstructure of the cladding layer was analyzed by optical microscope(OM)and scanning electron microscope(SEM).The hardness and impact toughness of the cladding layer were tested by microhardness tester and impact test.The results show that the cladding layer with different Nb content is mainly composed of austenite,FeNi solid solution and(Cr,Fe)7C3.With the increase of Nb content,the grain size of the cladding layer is refined.However,compared with the cladding layer without Nb,when the Nb element is added,the tensile strength and yield strength of the cladding layer are significantly improved.The average tensile strength increases by 42.5%,37.7% and 13.1%,respectively,and the average yield strength increases by 26.5%,18.9% and 14.1%,respectively.In addition,the impact toughness of the cladding layer is also improved with the increase of Nb content.Compared with the cladding sample without Nb,the average impact energy is increased by 8.3%,9.4% and 26.4%,respectively.On the whole,the cladding layer with Nb content of 0.9% has the best comprehensive mechanical properties.

关 键 词：激光熔覆 Nb元素含量 显微组织 力学性能 

分 类 号：TG457.1[金属学及工艺—焊接]