Single crystals for welding research
Most welds last for many years, but a few fail after a relatively short time. Knowing the reasons why welds fail is important because cracks in welds can threaten the safety of people in buildings, airplanes, ships, automobiles, and power plants. Bad welds can lead to costly, extended shutdowns of industrial facilities such as petroleum refineries. Thus, research on this very important fabrication technology is critical to the multibillion-dollar welding industry. Research at ORNL and elsewhere strives to determine the structural features that make some welds strong and others weak. The goals are to find cost-effective ways to characterize the structure and strength of a new weld, correctly predict whether it will last a long time, and determine the welding conditions most likely to produce high-quality welds. There is more to welding than meets the eye. The cracks that make welds fail result from the complexities of microstructures formed during welding. Thus weld microstructure is linked to weld properties such as mechanical strength. As the hot weld material cools from a liquid into a solid, the crystalline grains grow at different speeds and in different directions, forming a new microstructure. By using single crystals rather than polycrystalline alloys to study different weld microstructures, scientists at ORNL have developed a way to predict more accurately the microstructures of various welds. The results could guide welders in providing the right conditions (correct welding speed, heat input, and weld thickness) for producing safer, higher-quality, and longer-lasting welds.
- OSTI ID:
- 6666314
- Journal Information:
- Oak Ridge National Laboratory Review; (United States), Vol. 24:2; ISSN 0048-1262
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ALLOYS
WELDING
WELDED JOINTS
MECHANICAL PROPERTIES
MICROSTRUCTURE
MONOCRYSTALS
CRYSTALS
FABRICATION
JOINING
JOINTS
360101* - Metals & Alloys- Preparation & Fabrication
360102 - Metals & Alloys- Structure & Phase Studies
360103 - Metals & Alloys- Mechanical Properties