Computational and Experimental Studies of High Temperature Crack Growth in the Presence of Residual Stress

Residual stresses have been introduced into a notched compact tension specimen of a 347 weld material by mechanical compression. The required level of compressive load has previously been determined from finite element studies. The residual stresses in the vicinity of the notch root have been measured using neutron diffraction and the results compared with those obtained from finite element analysis. The effect of stress redistribution due to creep has been examined and it is found that significant reduction in stress is measured after 1000 hours at 650 °C. The implications of these results with regard to the development of damage in the specimen due to creep relaxation are examined.