GH4169合金小余量小尺寸静子叶片锻造工艺及显微组织控制

针对GH4169合金叶片锻件粗晶、混晶等晶粒组织不合格问题,以某压气机小余量小尺寸静子叶片锻件为研究对象,首先分析锻件结构,确定锻造工艺路线,然后通过选取2种规格坯料、5个变形量、4个锻造温度来组成12组试验,探究变形量、锻造温度对组织的影响以及演化规律,同时对选取的保温时间、锻造火次的稳定性进行分析,得到合理锻造工艺参数。研究表明,变形量在35%~45%内可获得均匀的组织,但对晶粒度大小无明显影响;温度是影响晶粒度的主要因素,大于1000℃时叶身晶粒粗化现象明显,在990~1000℃之间叶身可获得细腻、均匀的组织;预锻时组织已成形稳定,终锻无明显变化,在选取的保温时间内组织稳定;在变形量40%及锻造温度990℃下获得的叶片锻件具有优良的综合力学性能及细晶组织,均高于标准要求。

Forging process and microstructure control for alloy GH4169 stator blade with little allowance and small size

For the unqualified problem of grain structure for alloy GH4169 blade forgings,such as mixed grains and coarse grains,based on stator blade of a compressor with little allowance and small size,the forging process route was determined by analysis of forging structure,and the influences and evolution laws of deformation and forging temperature on microstructures were analyzed by twelve sets of experiments consisting of two kinds of billets,five different deformation amounts and four different forging temperatures. Meanwhile,the stability of selected holding time and forging times was analyzed,and the reasonable forging process parameters were obtained. The results show that the deformation amount of 35%-45% obtains uniform structure,but has less effect on grain size. The temperature is the major factor affecting on grain size. However,the grain growth of blade body is obvious when the temperature is over 1000 ℃,and the fine grain of blade body is obtained when the temperature is 990-1000 ℃. Furthermore,the structure is stable during pre-forging,and there is no obvious change in final forging,which means the grain structure is stable in the selected holding time. Thus,the superior comprehensive mechanical properties and fine grain structure of blade forgings are obtained with the deformation amount of 40% and the forging temperature of 990 ℃,which are higher than standard requirements.