Residual Stress and Deformation After Finishing of a Shell Structure Fabricated by Direct Metal Lamination Using Arc Discharge

Arc welding technology has been used to melt metal, and a fabrication system for three-dimensional metallic parts has been developed around it: direct metal lamination using arc discharge. Here, the relationship between residual stress in the shell structure and temperature distribution in the shell structure after lamination are explored. Deformation caused by residual stress release is also measured. The results clarify that the local maximum value of the residual stress is small when the temperature in the shell structure is high. It is also found that the temperature distribution can be controlled through heat-input conditions and a cooling method using water. The residual stress distribution is formed by a non-uniform compressive plastic strain distribution. Plastic deformation is caused by the temperature distribution. No significant deformation due to residual stress release is observed when the lateral surface is finished.