Microstructure and high temperature fracture toughness of NG-TIG welded Inconel 617B superalloy. (15th February 2020)

• Record Type: Journal Article
• Authors: Li, Xiaogang; Li, Kejian; Li, Shanlin; Wu, Yao; Cai, Zhipeng; Pan, Jiluan
• Is Part Of: Journal of materials science & technology. Volume 39(2020)
• Page Start: 173
• Page End: 182
• Publication Date: 2020-02-15
• Subjects: Nickel alloys -- Welding -- Fracture behavior -- Microstructure -- Misorientation; Metals -- Periodicals; Materials science -- Periodicals; Materials science; Metals; Periodicals; 620.1105
• DOI: 10.1016/j.jmst.2019.07.021
• Languages: English
• ISSNs: 1005-0302

Abstract

Abstract: In the present study, the microstructure, fracture toughness, and fracture behavior of Inconel 617B narrow gap tungsten inert gas (NG-TIG) welded joint were investigated systematically at the designed service temperature of 700 °C. Fracture toughness ( J 0.2 ) of base metal (BM) and heat affected zone (HAZ) was higher than that of weld metal (WM). In HAZ and BM, strain mainly localised 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.