Microstructure Characterization of the Fusion Zone of an Alloy 600-82 Weld Joint

• Published in: Journal of materials science & technology 2015-10, Vol.31 (10), p.1011-1017
• Main Authors: Ma, Cheng, Mei, Jinna, Peng, Qunjia, Deng, Ping, Han, En-Hou, Ke, Wei
• Format: Article
• Language: English
• Subjects: Alloy 600; Cold working; Deformation; Dislocations; Fusion zone; Heat affected zone; Microstructure; Strain; Strain concentration; Strain distribution; Weld joint; Welded joints; 合金; 应力分布规律; 微观结构表征; 残余应变; 焊接接头; 焊接热影响区; 焊缝; 熔合区
• ISSN: 1005-0302; 1941-1162
• DOI: 10.1016/j.jmst.2015.08.013

Characterization of the microstructure of the fusion zone of an Alloy 600-82 weld joint was conducted, with focus on the weld residual strain distribution and the comparison of the microstructure of heat affected zone （HAZ） with that of cold worked alloy. Peak of the residual strain was observed to approach to the fusion boundary in HAZ while the strain increased from the top of the weld to the root. Strain distribution in the HAZ was found to be concentrated adjacent to grain boundaries （GBs）, with a peak of approximately three times of that in grain. Further, triple junctions of the GB appear to cause a higher strain concentration than single GBs. The microstructure of HAZ consists of partially tangled dislocations, which is different from slip bands of high density dislocations in cold worked alloy. This may cause a relatively higher intergranular cracking resistance of HAZ due to the difficulty in transferring tangled dislocations to GB in HAZ under deformation.