Ti(C,N)对Ni基高温合金组织结构、力学性能和抗氧化性的影响

Effect of Ti(C,N) on Microstructure, Mechanical Properties and Oxidation Resistance of Ni-based Superalloys

摘要:

采用粉末冶金法制备Ni-20Cr-4Mo-0.15C和Ni-20Cr-4Mo-0.15C-12.85TiC-3TiN(质量分数, %)两种合金，研究Ti(C,N)质点引入对Ni基高温合金组织结构、力学性能和800 ℃抗氧化性的影响。结果表明，经1280 ℃真空烧结1 h后，因12.85%TiC和3%TiN引入形成的Ti(C,N)质点，弥散分布于奥氏体基体的晶内和晶界处，使奥氏体基体晶粒明显细化，合金的密度从8.38 g/cm3降至7.59 g/cm3，维氏硬度从1850 MPa升至3430 MPa，抗拉强度从752 MPa升至1192 MPa。此外，合金在800 ℃空气中仍具有较好的抗氧化性，形成的氧化膜主要由α-Cr2O3和TiO2组成

Abstract:

Ni-20Cr-4Mo-0.15C and Ni-20Cr-4Mo-0.15C-12.85TiC-3TiN (wt%) alloys were prepared by powder metallurgy method, in order to investigate the effect of Ti(C,N) on microstructure, mechanical properties and oxidation resistance at 800 °C of Ni-based superalloys. Results show that due to the addition of 12.85wt% TiC and 3wt% TiN, the formed Ti(C,N) particles dispersed within grains and at grain boundaries of austenite matrix, therefore austenite grains became fine. The density of supralloys decreased from 8.38 to 7.5 g/cm3, the hardness increased from 1850 to 3430 MPa, and the tensile strength increased from 752 to 1192 MPa. In addition, the superalloys still exhibited good oxidation resistance in air at 800 °C, and the oxide scale formed mainly consisted of α-Cr2O3 and TiO2