GH4169高温合金复合热压缩界面愈合与界面氧化物研究

Research on interfacial healing and interfacial oxides for superalloy GH4169 composite hot compression

由于成分偏析和冶炼能力的限制,大型GH4169高温合金锻件难以实现国产化制造。利用小坯料生产大尺寸锻件的构筑成形技术可实现大型高温合金锻件的匀质化制造。通过GH4169高温合金的复合热压缩试验,研究了变形工艺参数对GH4169高温合金构筑成形界面愈合情况和界面氧化物的影响规律,得到了GH4169高温合金构筑成形的最佳工艺参数。结果表明:在始锻温度、采用较小的应变速率、压缩量大于50%,并在压缩后保温保压一定时间的综合条件下,界面愈合的效果最好,应避免在高应变速率+大变形量的条件下进行构筑成形;在高温下经过较长时间的热处理后,界面内部的氧化铝未明显扩散,从表面沿着界面向内发生严重的氮化反应,且界面边缘出现缝隙。

Due to the limitation of composition segregation and smelting capacity,it is difficult to realize nationalized manufacturing of large superalloy GH4169 forgings,and the additive forming technology of producing large-size forgings from small blanks can realize the homogenized manufacturing for large superalloy forgings.Therefore,through the composite hot compression experiment of superalloy GH4169,the influence laws of deformation process parameters on the interfacial healing and interfacial oxides of superalloy GH4169 additive forming were studied,and the optimal process parameters of superalloy GH4169 additive forming were obtained.The results show that under the comprehensive conditions of initial forging temperature,smaller strain rate,compression amount more than 50%and heat preservation and pressure holding for a certain period of time after compression,the interfacial healing effect is the best,and the additive forming should be avoided under the condition of high strain rate and large deformation amount.After a long time of heat treatment at high temperature,the alumina inside the interface do not diffuse significantly,the severe nitriding reaction occurs from the surface along the interface inward,and gaps appear at the edges of interface.