2007 Volume 48 Issue 9 Pages 2319-2323
Gas tungsten arc welding (GTAW) was performed on AISI 304 stainless steel; steady-state vibration was produced by a mass-eccentric motor. The vibration weld shows a very small δ-ferrite structure, uniform composition distribution, less residual stress and less δ-ferrite content relative to the weld without vibration. The results illustrate that the vibration reduces the micro supercooling and improves the nucleation of δ-ferrite to form a grain refined structure. Vibration-induced stacking faults are identified as the major cause of the line broadening of X-ray diffraction profile. Correlating the literature and the result in the study, the mechanism of vibratory stress relief can be represented as the breakdown of dislocation into a pair of partial dislocations. This mechanism can comprehensively explain all the phenomena that take place during vibratory stress relief.