摘要
In the present study,the microstructure,fracture toughness,and fracture behavior of Inconel 617 B narrow gap tungsten inert gas(NG-TIG)welded joint were investigated systematically at the designed service temperature of 700℃.Fracture toughness(J0.2)of base metal(BM)and heat affected zone(HAZ)was higher than that of weld metal(WM).In HAZ and BM,strain mainly loc alised at grain boundaries with large misorientation and there were lots of coincidence site lattice(CSL)∑3 boundaries related to twins inside grains,which led to the much higher fracture toughness of BM and HAZ than WM.The high numbers of twins as well as the less serious strain localization at grain boundaries resulted in the most outstanding fracture toughness of BM.
In the present study, the microstructure, fracture toughness, and fracture behavior of Inconel 617 B narrow gap tungsten inert gas（NG-TIG） welded joint were investigated systematically at the designed service temperature of 700℃. Fracture toughness(J0.2) of base metal（BM） and heat affected zone（HAZ） was higher than that of weld metal（WM）. In HAZ and BM, strain mainly loc alised at grain boundaries with large misorientation and there were lots of coincidence site lattice（CSL）∑3 boundaries related to twins inside grains, which led to the much higher fracture toughness of BM and HAZ than WM. The high numbers of twins as well as the less serious strain localization at grain boundaries resulted in the most outstanding fracture toughness of BM.
基金
financially supported by the National Natural Science Foundation of China(Project No.51775300)
Shanghai Turbine Company,Shanghai,China
the State Key Laboratory of Tribology,Beijing,China.
