On the weld bead, the residual stress is approximately equal to zero. Tensile stresses from 200 MPa to 300 MPa are observed in the heat-treated area in the base metal. In the sandblasted area, the mapping chart shows that the tensile stress has changed to the compressive stress of about -1000 MPa by the sandblast treatment. By using the CCD camera with a zoom function, the images of the sandblasted and non-sandblasted areas are recorded as shown in the pictures.
