Fracture Analysis of Blades of Adjustable-blade Axial-flow Forced Draft Fan

The blades of a forced draft fans in one power plant fractured after short time service, which seriously impacted the safe and economic operation of power plant. Through a set of tests of chemical compositions analysis, metallographic examination, mechanical properties test, fracture analysis and energy spectrum analysis, fracture reasons of the blades were analyzed. The results show that the main cause of failure was that the quality of blades was defective and there were serious crack-like original defects on the blades. And the unqualified chemical compositions, many casting porosity defects and poor plasticity and toughness of material of the blades were also factors that resulted in the fracture of blades.