Experimental Study on the Low-Temperature Charpy Impact Property of Typical Rudder Materials

A series of temperature impact tests were conducted on submersible rudder materials in a polar low-temperature environment. By using an impact testing machine and a scanning electron microscope, the impact performance of samples at different temperatures was tested, and the fracture morphologies were observed. A systematic study was conducted on the low-temperature impact mechanical behavior of two base materials and their welded joints. The results indicate that within the temperature range of −60 to 20 °C, the rudder base material 925A exhibits excellent low-temperature impact toughness; as the test temperature decreases, the fluctuation range of its impact absorption energy remains relatively small. At −60 °C, the shear lip region of the sample fracture forms a uniform and dense fine dimple structure, endowing the material with the highest crack propagation energy. As the temperature increases, the crack propagation energy tends to decrease. The impact test temperature has a significant zoning effect on the fracture morphology. At room temperature (20 °C), the fiber zone of the fracture presents a fine and deep dimple morphology, corresponding to a higher crack initiation energy. The experimental data obtained from this study provides theoretical and data support for the engineering application of submersible rudder materials under polar low-temperature conditions.