The effect of specimen dimension on residual stress relaxation of carburized and quenched steels

In this study X-ray diffraction was used to measure the redistribution of residual stress in carburized and heat treated AISI 8620 steel specimens of different sizes during successive sectioning. Finite-element modeling was used to simulate the stress relaxation. Comparing the results of modeling to experimental results of ring-shaped specimens shows that the residual stress relaxation associated with the size reduction was almost negligible. However, significant stress relaxation occurs while reducing the thickness of the specimens. The results seen in ring-shaped test specimens were verified by sectioning actual gear samples.