Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1575061 | Materials Science and Engineering: A | 2014 | 8 Pages |
Abstract
Submerged arc weld metal of a high strength low alloy steel was subjected to friction stir welding (FSW) at a higher rotation rate of 400Â rpm (FSW-a) and a lower rotation rate of 125Â rpm (FSW-b), respectively. The microstructures and mechanical properties of three typical phase structures, coarse bainite phase in the weld metal, refined bainite phase and ferrite phase in the nugget zones (NZs) of FSW joints were investigated. Compared to the weld metal, enhanced mechanical properties were achieved in the NZs of both FSW joints. Large cracks apparently propagated along the bainite lath in the coarse grains of the weld metal, which would cause the brittle quasi-cleavage fracture. However, large crack propagation was inhibited in the refined bainite phase structure in the NZ of FSW-a joint, and enhanced strength and toughness with dimple fracture were achieved. Meanwhile, enhanced mechanical properties, including strength and ductility, as well as toughness, were obtained in the NZ of FSW-b joint, because of the refinement of the ductile ferrite structure.
Related Topics
Physical Sciences and Engineering
Materials Science
Materials Science (General)
Authors
P. Xue, Y. Komizo, R. Ueji, H. Fujii,