X-ray stress measurement of high manganese austenitic steels

By using psi0 oscillation method with CrKβ γ(311) diffraction, the X-ray stress measurement was made on five specimens, which were obtained by water toughening and various plastic working treatments (tensile pre-strain, hammered and explosive hardening) from Hadfield's high manganese austenitic steel, and their mechanical elastic constants, X-ray elastic constants and the accuracy of measurement were examined. The results obtained are as follows: (1) The mechanical elastic constant for 13% Mn austenitic steel after water toughening was 18900 kg/mm2. This value gradually decreased with increasing tensile pre-strain. But it changed little when the specimen was treated by hammered or explosive hardening. (2) The K-value (K sub(X) = -37.26 kg/mm2/deg) of austenitic steel adopted in the standard method of X-ray stress measurement is considered suitable for the X-ray stress measurement of 13% Mn austenitic steel which has not been subjected to severe plastic deformation. (3) The error in stress measurement Δσ in the X-ray stress measurement of high manganese austenitic steel becomes larger, depending more on the statistical fluctuation parameter, than that of ferritic steel. (author)