tracción Change of residual stresses during plastic deformation under uniaxial tension test

Abstract

Change of longitudinal and transverse residual stresses was studied by X Ray diffraction method as the applied plastic deformation, measured as A %, was increased in a standard tension test. The starting material, hot rolling Armco iron, has values close to 0 MPa in longitudinal direction, but it reaches 600 MPa with only A = 1,5 %, this value remains constant until necking is produced. In transverse direction the starting values are -300 MPa, changes are small and residual stresses remain compressive until the end of tension test. In addition, studies of the changes of residual stresses with time and with misalignment between incident X Ray and drawing direction are presented.