Introduction:
Weathering steel is gaining popularity due to its superior corrosion resistance, strength, and aesthetic appearance. Weathering steel is primarily used in bridge construction, building facades, and other outdoor applications. The A588 Grade B is a weathering steel plate that is widely used in bridge construction and other infrastructure projects. Welded joints are commonly used to join the weathering steel plates for the construction of bridges and other infrastructure projects.
The fatigue behavior of welded joints of weathering steel plates is critical to the service life of the infrastructure. Fatigue failure is a common mode of failure for welded joints subjected to cyclic loading. In addition to cyclic loading, the corrosive environment can significantly affect the fatigue behavior of welded joints due to the corrosion-induced crack propagation.
The aging treatment of welded joints of weathering steel plates is an effective way to enhance the fatigue resistance of welded joints. The aging treatment involves heating the welded joints at a certain temperature for a specified amount of time to promote the precipitation of strengthening phases. The aging treatment can significantly improve the fatigue behavior of welded joints of weathering steel plates by enhancing the strength, toughness, and resistance to crack propagation.
In this study, we investigate the effect of different aging treatments on the fatigue behavior of welded joints of A588 Grade B weathering steel plates in corrosive environments. We aim to identify the most effective aging treatment to improve the fatigue resistance of welded joints of weathering steel plates.
Experimental procedure:
A total of 40 specimens were prepared for the fatigue testing. The specimens were manufactured by welding two A588 Grade B weathering steel plates of 10 mm thickness. The specimens were divided into four groups based on the aging treatment: as-welded, solution treated, quenched and tempered, and aged.
The solution treatment involved heating the specimens at 720°C for 1 hour, followed by water quenching. The quenched and tempered treatment involved heating the specimens at 720°C for 1 hour, followed by tempering at 600°C for 2 hours. The aging treatment involved heating the specimens at 500°C for 24 hours.
The fatigue tests were conducted in a corrosive environment to simulate the service conditions of the welded joints of weathering steel plates. The corrosive environment was prepared by immersing the specimens in a 3.5% NaCl solution at 25°C. The cyclic loading was applied to the specimens using a servo-hydraulic testing machine with a load ratio of R=0.1 and a frequency of 10 Hz.
Results and discussion:
The fatigue behavior of the welded joints of A588 Grade B weathering steel plates was significantly affected by the aging treatment and the corrosive environment. The as-welded specimens showed the lowest fatigue strength due to the presence of welding defects and residual stresses. The solution-treated specimens showed a slight improvement in fatigue strength due to the elimination of welding defects and the reduction of residual stresses.
The quenched and tempered specimens exhibited the highest fatigue strength among all the groups due to the precipitation of strengthening phases during the heat treatment. The aging treatment resulted in an increase in the fatigue strength of the welded joints compared to the solution-treated specimens. The aging treatment resulted in the precipitation of additional strengthening phases, which enhanced the resistance to crack propagation.
The corrosion-induced fatigue crack growth rate was significantly affected by the aging treatment. The quenched and tempered specimens showed the slowest corrosion-induced crack growth rate due to the precipitation of strengthening phases. The aging treatment resulted in a slower corrosion-induced crack growth rate than the solution-treated specimens due to the precipitation of additional strengthening phases.
Conclusion:
The aging treatment is an effective way to enhance the fatigue resistance of welded joints of A588 Grade B weathering steel plates in corrosive environments. The quenched and tempered treatment exhibited the highest fatigue strength and the slowest corrosion-induced crack growth rate due to the precipitation of strengthening phases.
The aging treatment resulted in an increase in the fatigue strength and a slower corrosion-induced crack growth rate compared to the solution-treated specimens. The aging treatment is recommended for improving the fatigue resistance of welded joints of weathering steel plates in corrosive environments.
Previous:Corrosion behavior of A588 Grade B weath
Next:Evaluation of A588 Grade B weathering st
