Microstructure and its effect on high temperature tensile properties of T92/HR3C dissimilar weld joints. (October 2022)

• Record Type: Journal Article
• Authors: Wang, Qibing; Xin, Ruishan; Wang, Zhichun; Han, Zhewen; Jiao, Xiangdong; Kang, Ju
• Is Part Of: Journal of manufacturing processes. Volume 82(2022)
• Page Start: 792
• Page End: 799
• Publication Date: 2022-10
• Subjects: Dissimilar weld joints -- T92 steel -- Strength mismatch -- Serrated flow behavior -- Microstructural evolution; Production management -- Data processing -- Periodicals; Manufacturing processes -- Periodicals; Procestechnologie; Productietechniek; Production -- Gestion -- Informatique -- Périodiques; Fabrication -- Périodiques; Manufacturing processes; Production management -- Data processing; Periodicals; 670.5
• DOI: 10.1016/j.jmapro.2022.08.046
• Languages: English
• ISSNs: 1526-6125

Abstract

Abstract: A T92/HR3C dissimilar metal weld joint, which is widely used in the boiler components of ultra-supercritical power plants, was fabricated by manual tungsten inert gas welding with Inconel 82 as the filler metal. This study reports the high-temperature tensile properties, deformation behavior, and fracture mechanism of dissimilar weld joints. The results of tensile tests at 640 °C show a severe strength mismatch between the weld metal and the heat-affected zone of the T92 steel (T92-HAZ). The serrated flow behavior of the T92/HR3C weld joint at different tensile rates was observed during plastic deformation. Based on the results of transmission electron microscopy, dynamic recrystallization and re-precipitation of Cr23 C6 carbides both likely triggered the serrated flow behavior and enhanced the tensile strength of the weld metal. Additionally, the inter-critical T92-HAZ was the weakest zone in the weld joint because of the dissolution of a large amount of carbides and the transformation of martensite laths into equiaxed subgrains.