Abstract <p>This paper presents an experimental and statistical investigation into the influence of low-frequency vibration parameters—frequency, amplitude, and vibrational acceleration—on residual deformations in butt-welded joints of low-alloy steel 09G2S. A full factorial experimental design (2³) with three replicates per condition was employed to evaluate the effects of these parameters on the deflection (bowing) of welded plates. The results indicate that vibration treatment significantly reduces residual deformation, with the amplitude of vibration being the most influential factor. Increasing the amplitude from 0.6 to 1.0 mm leads to a pronounced reduction in deflection, decreasing it by nearly 16%. In contrast, vibrational acceleration alone has no statistically significant effect. However, a significant interaction between frequency and acceleration is observed: the beneficial effect of higher frequency (100 Hz vs. 50 Hz) is only fully realized under conditions of elevated acceleration (20 mm/s²), where it contributes to a substantial drop in deflection. Microstructural observations support these findings, showing grain refinement and reduced microporosity under vibratory conditions. A regression model in coded variables was developed and validated using Fisher’s F-test, confirming its adequacy. The model was transformed into natural variables for practical application. The study demonstrates that residual deformation in welded joints can be effectively controlled through optimized dynamic loading, offering a rapid, non-thermal method for enhancing the geometric stability and mechanical reliability of welded structures.</p>