大规格镍基高温合金轮盘长时时效对组织影响  

Effect of Long-term Aging on Microstructureof Large-sized Nickel-based Superalloy Disc

作　　者：江雷[1] 颜家振[2] 张晓林 高振桓[1] 杨吉辉[1] JIANG Lei;YAN Jiazhen;ZHANG Xiaolin;GAO Zhenhuan;YANG Jihui

机构地区：[1]东方汽轮机有限公司清洁高效透平动力装备全国重点实验室,四川德阳618000 [2]四川大学机械工程学院,四川成都610040

出　　处：《大型铸锻件》2024年第6期55-59,共5页Heavy Casting and Forging

摘　　要：镍基高温合金轮盘是燃气轮机关键部件,长时时效组织演化对轮盘服役寿命有较大影响。大规格轮盘镍基高温合金4725FC1标准热处理后取样分别在620℃650℃温度下选用不同时间进行长时时效,最长10000 h。研究表明:镍基高温合金4725FC1碳化物主要形式为MC型,碳化物尺寸小于10μm,在620℃和650℃温度下10000 h时效合金晶粒无明显变化,随时效时间增加,晶界上的δ相明显增多且呈现出连续化的趋势,同时晶内的针状δ相数量也增加;650℃下时效10000 h后晶内会出现白色的富Nb、Cr、Mo元素相,会降低基体的固溶度进而影响合金的力学性能。长时时效一定程度上能增加合金的硬度,但是增加的幅度不大。Nickel-based superalloy disk is a key component of gas turbine.The long-term aging microstructure evolution has a great influence on the service life of disk.After standard heat treatment,samples of large-sized nickel-based superalloy 4725FC1(with a composition similar to IN718)were taken and subjected to long-term aging at temperatures of 620℃/650℃ for different durations,with a maximum of 10000 hours.Research has shown that the main form of carbides in nickel-based superalloy 4725FC1 is MC type,and the size of carbide is less than 10μm.The grain size of the alloy aged at 620℃ and 650℃ for 10000 h has no obvious change.With the increase of aging time,the δ phase on the grain boundary increases significantly and shows a continuous trend,and the number of needle-like δ phases in the crystal also increases.After aging at 650℃ for 10000 h,white Nb-rich,Cr-rich and Mo-rich phase will appear in the crystal,which will reduce the solid solubility of the matrix and affect the mechanical properties of the alloy.Long-term aging can increase the hardness of the alloy to a certain extent,but the increase is not large.

关 键 词：IN718 燃机轮盘 长时时效 Δ相 

分 类 号：TG132.3[一般工业技术—材料科学与工程]