哈氏合金C-22焊接接头性能研究及微观组织分析OA北大核心CSTPCD

Welding tests were carried out on Hastelloy C-22 alloy using tungsten argon arc welding(GTAW)and electrode arc welding(SMAW),respectively,and the various regions of the welded joints were studied and analyzed in terms of mechanical properties,corrosion resistance and microstructure.The results show that the surface of the weld applied by these two welding methods is well formed and free of cracks,blowholes,inclusions and other defects.Due to the differences in the solidification rate of the molten pool and the temperature gradient,the grain sizes are not uniform in all regions of the welded joint,and there are differences in the grain morphology,so the microhardness tends to decrease from the weld to the base metal.There are no cracks and other defects in the welded joints welded by both welding methods under the bending load,and the test results are qualified.Tungsten argon arc welded joints grain is slightly smaller than that of the electrode arc welded joints,which also makes the mechanical properties and corrosion resistance of the GTAW butt joints are better than the latter.The average tensile strength of GTAW welded joints can reach 799 MPa,which is slightly higher than that of the base metal,and the average corrosion rate is only 0.299 mm/a,which is 18.31%lower than that of the base metal.This study provides a reference for manufacturing of the pressure vessels for strong corrosive media.