热处理工艺对激光熔化沉积制造JBK-75合金组织及性能的影响  

Effect of heat treatment routes on microstructure and mechanical properties of JBK-75 alloy fabricated by laser melting deposition

作　　者：李佶纳 苏杰[1] 刘赓 王敖 伊勇 Li Jina;Su Jie;Liu Geng;Wang Ao;Yi Yong(Institute of Special Steels,Central Iron and Steel Research Institute Co.,Ltd.,Beijing 100081,China)

机构地区：[1]钢铁研究总院有限公司特殊钢研究院,北京100081

出　　处：《金属热处理》2023年第4期111-117,共7页Heat Treatment of Metals

摘　　要：采用激光熔化沉积技术制备JBK-75合金,选取750℃直接时效和1180℃高温固溶+750℃时效两种不同热处理工艺路线,分析了其沉积态的显微结构,对比两种不同热处理态的组织和力学性能。结果表明,沉积态JBK-75合金组织表现为各向异性,存在柱状晶、胞状组织和Ti元素偏聚。直接时效处理JBK-75合金打印组织未发生溶解,打印组织对强化相(γ′相)的析出行为几乎没有影响,但是Ti元素的偏聚促进了晶界有害相(η相)的生成。高温固溶+时效处理JBK-75合金打印组织消失,获得细小均匀的γ晶粒且在晶界未发现η相。高温固溶+时效处理激光熔化沉积JBK-75合金表现出最佳的强塑性配比,抗拉强度为1055 MPa、屈服强度为679 MPa、断后伸长率为29%,达到锻件JBK-75合金热处理态力学性能水平。Fe-Ni based JBK-75 alloy was fabricated by laser melting deposition,then direct aging at 750°C and 1180℃high-temperature solution treatment+aging at 750℃were selected to be the heat treatment routes.The microstructure of the as-deposited JBK-75 alloy was analyzed,and the microstructure and mechanical properties of the two different heat trcatment states were compared.The results show that the microstructure of the as-deposited JBK-75 alloy is anisotropic,with columnar crystal,cellular structure and Ti segregation.The two different heat treatment routes show little effect on the precipitation behavior of the strengthening phase(γ′phase),while in the direct aged specimen the segregation of Ti element promotes the formation of harmful phase(ηphase)at grain boundaries.After the high-temperature solution and aging treatment,the laser melting deposited JBK-75 alloy obtains fine and uniformγgrains and avoids the grain boundaryηphase,and exhibits the best mechanical properties,with the tensile strength of 1055 MPa,yield strength of 679 MPa and elongation of 29%,which reaches the level of mechanical properties of the forged JBK-75 alloy after heat treatment.

关 键 词：激光熔化沉积 JBK-75合金 元素偏聚 析出 固溶+时效处理 

分 类 号：TG142.25[一般工业技术—材料科学与工程]