Improvement of the high-temperature oxidation resistance of 254SMo using ultrasonic strengthening grinding

Abstract

This paper used ultrasonic strengthening grinding (USGP) to process 254SMo welded joints. The mechanical properties of processed and unmachined samples of welded joints, including grain size, dislocation, microhardness, residual stress, and high-temperature oxidation resistance at 900 °C, were investigated. The results indicate that the grains of the processed samples exhibit significant refinement and a high dislocation density and that the maximum microhardness and residual compressive stress are 392.5 HV0.3 and −633.44 MPa, respectively. In addition, the processed sample exhibits excellent oxidation at high temperatures. At 900 °C, the mass gain of the USGP-processed sample is reduced by 47.5 % compared to its mass gain prior to processing. These results highlight the potential of this method in improving the high-temperature resistance of various mechanical components, particularly those made from special materials.

Keywords

• Ultrasonic strengthening grinding
• 254SMo
• Laser welding
• High temperature oxidation
• Surface modification