Reducing Mechanical Wear of Elbows and Pipes Due to Solid Particles Flow by Using Nano Coating Technique

Abstract

The problem of failure for elbows and pipes due to the effects of solid particles flow with a high velocity, facing a lot of industrial foundations now days. This work investigated factors that cause failure by mechanical wear inside elbows and pipes of cement transportation which manufacturing from low carbon steel (St-52-3) and find out a method for reducing this mechanical wear. Coating with layers of nanoparticles of tungsten carbides (WC) using a thermal spray process with a high-velocity oxy-fuel technique (HVOF) is one of those methods. The coating process was done for samples from the same material of elbow and pipe material. Some tests were done for these samples with different coating thicknesses (30, 40, and 50 µm) by placing them inside the elbow as well as standard wear tests (pin on disc). The results showed a decrease in the mechanical wear for the sample coated with 50 µm of WC layer by 71% compared with that without coating, while the results of the pin on disc test showed a decrease in wear about 97% for the sample coated with 50 µm. The photographs of the scanning electron microscope (SEM) were used to determine the thickness of the coating layer on samples. The numerical simulation was also implemented to simulate the erosion profile inside the elbow by using the commercial code STAR CCM + based on the CFD technique; the predicted results showed a good agreement with the experimental data with accuracy reaches 94%.