Residual Stresses in Austenitic Stainless Steel due to High Strain Rate

Austenitic stainless steel (SUS316L) was used as specimen material, and the plate specimens were deformed plastically with a wide range of strain rates (6.67x10(-5)similar to 6.70x10(2)/s). The residual micro-stress for each lattice plane was measured with hard synchrotron X-rays. The residual macro-stress due to tensile deformation depended on strain rate. The residual micro-stresses varied from tension to compression, depending on the diffraction elastic constant. The soft lattice plane had tensile residual stress, and the hard lattice plane had compressive residual stress. The higher the strain rate, the smaller the difference in residual micro-stresses. The residual micro-stresses of the surfaces peened with the laser-peening or water-jet-peening were examined. Both surfaces had exhibited large compressive residual stress. The residual micro-stress on the peened surfaces showed a tendency opposite to residual micro-stress due to tensile deformation.