Failure Analysis of a Kaplan Turbine Blade in Iraq’s Haditha Hydropower Plant

Kaplan turbines are widely used in low-water-head and large-capacity hydropower plants. The design of such systems is based on long-term performance. Nevertheless, many failures are reported in the industry, which lead to economic losses for the purpose of major repairs or replacement of a part of the system. Therefore, it is very important to know the failures, their causes, and finally provide useful solutions for their prevention or early treatment. In the present article, the authors focused on the failure detection of a Kaplan turbine blade in an Iraqi hydropower plant, and then, determined the direction of their future research. Quantometric test, tensile test, compression test, microhardness test, metallographic examination and study of the damaged surface were conducted from damaged runner blade. It was revealed that the raw material for manufacturing runner blade of Kaplan turbine was 304 stainless steel by employing cold drawing or rolling process. In addition, annealing treatment has also been done. In addition, it was found that the predominant damage in the studied part was severe cavitation.