Microstructure of a safe-end dissimilar metal weld joint (SA508-52-316L) prepared by narrow-gap GTAW

Journal Article · Sun Jan 15 04:00:00 EST 2017 · Materials Characterization

DOI:https://doi.org/10.1016/J.MATCHAR.2016.11.029· OSTI ID:22689694

Ming, Hongliang ^[1]; Zhang, Zhiming ^[1]; Wang, Jianqiu ^[1]; Han, En-Hou ^[1]; Wang, Peipei; Sun, Zhiyuan ^[2]

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1. Key Laboratory of Nuclear Materials and Safety Assessment, Liaoning Key Laboratory for Safety and Assessment Technique of Nuclear Materials, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China)
2. Shanghai Research Center for Weld and Detection Engineering Technique of Nuclear Equipment, Shanghai 201306 (China)

The microstructure, residual strain and interfacial chemical composition distribution of a safe-end dissimilar metal weld joint (DMWJ, SA508-52-316L) prepared by narrow-gap gas-tungsten arc welding (NG-GTAW) were studied by optical microscope (OM) and scanning electron microscope equipped with an energy dispersive X-ray microanalysis (SEM/EDX) and an electron back scattering diffraction (EBSD) system. Complex microstructure and chemical composition distribution are found, especially at the SA508-52 interface and the 52-316L interface. In brief, a complicated microstructure transition exists within the SA508 heat affected zone (HAZ); the residual strain, the fraction of high angle random grain boundaries and low angle boundaries decrease with increasing the distance from the fusion boundary in 316L HAZ; neither typical type II boundary nor obvious carbon-depleted zone is found near the SA508-52 interface; dramatic and complicated changes of the contents of the main elements, Fe, Cr and Ni, are observed at the distinct interfaces, especially at the SA508-52 interface. No carbon concentration is found at the SA508-52 interface. - Highlights: •Residual strain and GBCD change as a function of the distance from FB in 316L HAZ. •Neither type II boundary nor obvious carbon-depleted zone is found in SA508 HAZ. •No carbon concentration is found at the SA508-52 interface. •The middle part of the DMWJ has the highest residual strain.

• OSTI ID: 22689694
• Journal Information: Materials Characterization, Journal Name: Materials Characterization Vol. 123; ISSN 1044-5803; ISSN MACHEX
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BACKSCATTERING
CARBON
CHEMICAL COMPOSITION
CONCENTRATION RATIO
ELECTRON DIFFRACTION
GAS TUNGSTEN-ARC WELDING
GRAIN BOUNDARIES
HEAT AFFECTED ZONE
INTERFACES
MICROANALYSIS
OPTICAL MICROSCOPES
SCANNING ELECTRON MICROSCOPY
STRAINS
TUNGSTEN
WELDED JOINTS
X RADIATION