OS04W0258 Residual stress measurement of the quenching material by the neutron diffraction

Abstract

Neutron diffraction method has attracted much attention in recent years to measure residual stresses inside of the material by using high penetration power of neutron ray as one of non-destructive detection technique. It is necessary to know the non-distortion angle to measure stresses distribution inside of bulk material. However, during heat treatment such as quenching, since phase transformation near surface modifies the microstructure of the material, determination of the residual stresses is very difficult considering the gradient distribution of martensite. In this paper, residual stress in the quenching material with phase transformation is measured using the neutron diffraction method. Moreover, from metallo-thermo-mechanical theory, simulation using the coupled analysis by finite element method is carried out, and the residual stresses in materials are predicted. Then, experiment results and calculation value are compared and examined.