Study on Fundamental Parameters for X-ray Stress Measurement of Centrifugally Cast Duplex Stainless Steel
Yun WANG
Abstract:With great corrosion resistance and mechanical property, ferrite-austenitic duplex stainless steels have been applied to many components in corrosive environments such as sea water pumps. Due to different coefficients of thermal expansion and elastic moduli between the two phases, phase stress and plastic deformation will occur during heat treatment history in material processing such as casting, forging or annealing, which may affect material properties such as fatigue strength, welding stability and so on. Therefore residual stress measurement is important for the application of this material. In this study, strain-free diffraction angle 2Į0 was measured from strain-free reference samples, which were carefully prepared as electropolished thin plates with thickness of lower than 90 micrometer, nearly equal to the grain size of austenitic phase. X-ray stress constants were measured and discussed. With those fundamental parameters, multiaxial phase stress analysis became available by X-ray diffraction method. Key Words:Duplex stainless steel, Residual stress, X-ray diffraction, X-ray stress constant, Strain-free diffraction angle