X-ray diffraction measurements and investigation of the stress relaxation in autofrettaged AISI 4140 steel thick walled cylinders

Hydraulic autofrettage is a manufacturing process that induces favorable compressive residual stresses and is especially suitable for the treatment of internally pressurized components. If autofrettage is not the final treatment applied, the application of post-machining or other cold working processes can lead to a relaxation and redistribution of the stresses induced by the autofrettage process. In this paper, comprehensive X-ray diffraction residual stress measurements were performed and the influence of the applied autofrettage pressure and post-machining on the resultant residual stress vs. depth profiles was investigated. (author)