Sediment wear of turbine guide vane before and after tungsten carbide treatment

Abstract

This paper describes three-dimensional unsteady simulations of sand–water flow within a turbine passage. Sand abrasion of a movable guide vane made from ZG06Cr13Ni4Mo is tested before and after tungsten carbide spray-coating. ZG06Cr13Ni4Mo forms medium- and high-strength stainless steel castings for engineering structures. Different sand particle sizes produce different wear forms on the guide vane. For 0.4-mm sediment particles, the guide vane head is more seriously worn by impact; for 0.058-mm sediment particles, the guide vane tail is more seriously worn by sediment scouring. Spray-coating the guide vane with tungsten carbide produces significant anti-sand-wear performance. Before tungsten carbide spraying, the total guide vane wear at the maximum position reached 45 μm after 90 h of testing, but after spray-coating, the guide vane wear at the maximum position was only 2.6 μm after 136 h of testing. Sand abrasion test results before and after tungsten carbide treatment are used to derive a calculation formula that provides a basis for anti-silt-abrasion hydraulic turbine design and operation. The movable guide vane’s life expectancy in a power plant was estimated. Before spraying, the guide vane had to be replaced after 22.7 months of operation at P = 11.4 MW, but it operated for 44.2 months after spray-coating.