Research On Corrosion Behavior Of Superalloy Treated By High Current Pulsed Electron Beam

Hastelloy X is a kind of nickel-based superalloy used for aeroengine combustion chambers and other high temperature components.The combustion chamber would be damaged to high temperature oxidation,corrosion and other damage during the service process,which accelerates its failure.In order to prolong the service life of combustor,surface modification technology is used to treat the combustion chamber material to improve its surface properties.High Current Pulsed Electron Beam(HCPEB)was used to modify the surface of Hastelloy X.Morphology observation,high temperature oxidation performance test,hot corrosion performance test and electrochemical corrosion performance test were carried out to investigate the change of surface structure and chemical properties of Hastelloy X after HCPEB modification.During the surface modification of HCPEB,the metal surface would melt,the distribution of surface elements became uniform,the typical pit morphology appeared on the metal surface,and the surface grains were refined.After HCPEB,the surface of samples rapidly cooled and solidified,showing corrugated wrinkle morphology.The material formed a remelting layer and heat-affected zone from outside to inside;and the surface was deformed with plastic deformation,such as slip band and other deformation structures.With the increase of HCPEB treatment times,the density of melting pits on the alloy surface decreases,the size increases,and the range of remelting layer and heat affected zone increases.The results of high temperature oxidation experiment showed that the high temperature oxidation resistance of the samples treated by HCPEB was significantly improved,and the sample bombarded 5 times had the highest temperature performance.The results of hot corrosion test showed that the hot corrosion resistance of Hastelloy X increased with the increase of HCPEB bombardment times.The results of electrochemical experiments showed that HCPEB treatment improved the electrochemical corrosion resistance of Hastelloy X,and the sample after one bombardment had the best corrosion resistance.In this paper,the reason why HCPEB treatment improves the chemical properties of Hastelloy X surface is explained by microstructure analysis: the effect of grain refinement promotes the high temperature oxidation resistance of the samples;the increase of element solubility improves the thermal corrosion resistance of the samples;and the homogenization of surface structure promotes the electrochemical corrosion resistance of the samples.