Determination of residual stress in GH4169 alloy disc by neutron diffraction method and contour method
YU Hongyao 1,2，QIN Hailong 1,2，SHI Songyi 1,2
1. High Temperature Materials Research Institute, Central Iron & Steel Research Institute, Beijing 100081, China;
2. Beijing GAONA Materials & Technology Co., Ltd., Beijing 100081, China
Abstract： The distribution characteristics of residual stress of the GH4169 alloy disc parts on service were characterized by neutron diffraction method and contour method, respectively. The mechanism of two testing technologies was totally different. The measurements results were compared and verified to determine the value of residual stress with higher reliability. First, the stress in axial direction, radial direction, and hoop direction of GH4169 alloy disc after full heat treatment was accurately characterized by timeofflight neutron diffraction technique. The residual stress level was about -300 to 300 MPa. The stress was mainly in the hoop direction and radial direction, showing the distribution characteristics of "External pressure and internal tension". Then, the two-dimensional(2D) distribution map of residual stress in hoop direction along the cross section of dimeter was measured by contour method. The hoop residual stress in cutting section obviously showed the distribution characteristics of "external tension and internal pressure". The order of magnitude of residual stress was about -300 to 250 MPa. In the section of thickness center of alloy disc, the measuring results of neutron diffraction technique and contour method were basically consistent in both trend and absolute value. The reliability of measurement results was high.
2022, Vol. 40 
