Using backscattered electron diffraction to understand weldability
The weldability of many alloys is strongly dependent on the type of phases that form in the fusion zone and heat-affected zone (HAZ) during welding. For example, austenitic stainless steels that solidify by a primary ferrite solidification mode are well known to exhibit good resistance to solidification cracking, while alloys that solidify as primary austenite are more prone to this welding defect. Similarly, the type and amount of phases that form in the grain boundaries and interdendritic regions during the terminal stages of solidification control, in large part, the weldability of nickel-based alloys. Phases that solidify at lower temperatures widen the solidification temperature range and increase the tendency for cracking. The formation of solidification cracks caused by the presence of low-temperature phases can often be directly observed by metallographic examination. BEKD analysis provides a fast, accurate method of identifying submicrometer phases that typically form in weld fusion zones and heat-affected zones. Identification of such phases is invaluable for establishing relations between alloy composition, weld microstructure and weldability behavior. This will provide welding engineers and researchers with a new technique for improved weld microstructure characterization for both research and engineering applications.
- Research Organization:
- Lehigh Univ., Bethlehem, PA (US)
- Sponsoring Organization:
- US Department of Energy
- DOE Contract Number:
- AC04-94AL85000
- OSTI ID:
- 20020747
- Journal Information:
- Welding Journal (Miami), Journal Name: Welding Journal (Miami) Journal Issue: 3 Vol. 79; ISSN 0043-2296; ISSN WEJUA3
- Country of Publication:
- United States
- Language:
- English
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