GH169合金细晶锻造工艺研究

A STUDY OF THE TECHNIQUE FOR FINE GRAIN STRUCTURE FORGINGS OF ALLOY GH169

为了提高涡轮盘的强度和低周疲劳性能,要求锻件具有ASTM10级以上的细晶组织国外在大型压力机上采用低温大变形锻造和直接时效热处理以获得性能良好的细晶锻件,而我国则试图采用锻锤生产GH169合金涡轮盘锻件,因此,需要探索适合国情的GH169合金细晶锻造工艺。根据以往的研究,δ相对GH169合金的显微组织有明显影响。

The technique for fine grain structure forgings of alloy Gh169 is explored based on the study of the phase precipitation pattern from solid solution and its rule of controlling microstructure during forging process. It is found that when alloy GH169 is forged at a certain higher temperature and deformation with the use of hammer the fine and uniform recrystallized structure with the grain size of ASTM 10 or finer than ASTM 10 can be obtained. If an adequate intermediate heat treatment is adopted before finish forge, Widmanstatten structure of phase can be formed to guarantee the acquirement of the structure with the grain size of ASTM 10-12. At the same time, finish forging temperature may be raised 20-40℃, thus the deforming load can be decreased to a certain extent. Moreover, the results of the electron microscopic study indicate that it is appropriate to take the direct aging as the finish heat treatmewnt when the intermediate heat treatment is used.