Non-destructive Measuring Internal Residual Stress along Radial Direction in Cold Hole Expansion Strengthening A100 Steel Using Short-wavelength Characteristic X-ray Diffraction

The residual compressive stress field near the surface of the workpiece directly affects its fatigue performance. In order to study the residual stress state in the specimen with cold hole extrusion strengthening, using an independent researched and developed short-wavelength X-ray diffractometer, the radial distribution of residual stress field in the center layer of 2.4 mm thick cold hole expansion A100 steel plate was determined non-destructively. The results show that cold hole expansion strengthening would introduce residual compressive stress. The maximum compressive stress was located at the 4.6 mm point of the distance from the hole surface, and the value was -302 MPa. The depth of the residual compressive stress field was about 30 mm.