热等静压冷速对SLM成形K536合金力学性能的影响

Effect of Hot Isostatic Pressing Processing Cooling Rate on Mechanical Properties of SLM Formed K536 Superalloy

采用激光选区熔化工艺制备K536航空发动机零件,研究了不同冷速的热等静压HIP工艺对制件组织及力学性能的影响。结果表明,激光选区熔化K536高温合金制件经HIP处理后,制件内部产生完全再结晶,金相组织为奥氏体基体及晶内和晶界碳化物,合金强度降低、塑性上升,数据分散性下降;随HIP冷速的增大,组织中晶界碳化物减少,晶内出现少量颗粒状碳化物,有效提升了合金在815℃的高温屈服强度。

The effect of hot isostatic pressure(HIP) process with different cooling rates on the microstructure and mechanical properties of K536 aero-engine parts was studied. The results show that after HIP treatment, the laser selective melting of K536 superalloy produces complete recrystallization, and the microstructure is austenitic matrix, intracrystalline and grain boundary carbide, the strength of the alloy decreases, the plasticity increases, and the data dispersion decreases.With the increase of HIP cooling rate, grain boundary carbides in the microstructure decreased, and a small amount of granular carbides appeared in the crystal, which effectively increased the yield strength of the alloy at high temperature of 815 ℃.