Relaxation Behavior of Shot Peening Induced Residual Stresses in AISI 4140 due to Quasistatic Uniaxial Loading at Elevated Te

Author:  Holzapfel, Schulze, Vohringer, Macherauch
Source:  Conf Proc: ICSP-6, (p.385-396)
Doc ID:  1996084
Year of Publication:  1996
Abstract:  
The relaxation behavior of shot peening residual due to quasistatic loading was investigated for the steel AISI 4140 in a normalized and a quenched and tempered condition. For tensile or compressive loadings at room temperature, 250 deg C and 400 deg C the deformation behavior of the shot peened specimens and the remaining residual stresses after unloading from several loading stress levels were determined. The critical stress for the onset of stress relaxation and the stress relaxation rate are influenced in a characteristic manner by tensile or compressive loadings and by the material state. Differences due to the temperature dependence of residual stress relaxation at the two heat treatment conditions are discussed with respect to the effort of dynamic strain ageing. Additionally, results obtained from a finite element modelling show that the thermal residual stress relaxation is only effective during heating and waiting for temperature compensation before quasistatic loading and can be completely neglected during quasistatic loading.