Investigation Of Fatigue Property Of Wind Power Generator Ductile Iron Casting Hub With MW Grade

Wind power generator ductile iron hub of MW grade is important force unit joint of connecting its three blades and main axis. Because it often works in hostile environment, and need endure the high impulse and low temperature, meanwhile it works at over hundred meters upper air, so it is difficult to replace, and its cost much expensive.so it has practical meaning to study its fatigue properties. In this paper, low temperature impact test, low cycle strain fatigue test and fracture analysis are applied to research its fatigue properties, so as to find the way that can improve fatigue properties.The research premise the low properties of Wind power generator ductile iron hub. Low temperature impact test is applied to QT350-22L and QT400-18L from -20℃to-80℃. And low temperature impact test of 1.9%-2.45% Si content for ductile iron at-20℃. At the same time in contrast to the impact test result of 0.1%-1.0% Ni content into QT350-22L at-20℃, find the major factor of affecting its low temperature properties.Besides, this paper analyses fatigue fracture of wind power generator ductile iron hub of MW grade which strain amplitude is from 0.25% to 0.6% for QT350-22L, meanwhile compared with the fracture of the impact test and tensile test at normal and low temperature, analyzing and concluding the reason that fatigue phenomenon appear. In order to find the factor affecting fatigue properties and the way improving it.