Investigation of Erosion Wear of Ductile Materials With and Without Coating

Abstract

Wear is one of the most common problems encountered in industries like thermal power plants, hydropower plants, mining industries, food-processing industries etc. in which solid liquid mixture is transported through pumps and pipes. Wear is the loss of material from a component due to a mechanical interaction with another object. Many types of solids, liquids, and even highvelocity gases can remove material and change the physical dimensions and functionality of a part. Corrosion and erosion are the main causes of wear. Corrosion is caused by chemical reaction of material with its environment. Erosion wear is due to exposure to moving liquids and gases, which may or may not contain hard particulate.Effect of erosion wear in slurry pumps and pipes is predominantly more as compared to corrosion. The service life of equipment of slurry transport system is reduced by erosion caused by solid-liquid mixture following through the slurry transport system. Present work is to study the erosion behaviour of ductile materials. 13Cr4Ni steel taken for the study of erosion wear of pump and piping system with fly ash slurry. To improve the wear resistance of 13Cr4Ni steel , aluminium oxide and chromium oxide powder coatings were done by HVOF thermal spray coating method. The erosion wear evaluated with varying the parameters impact angle, flow rate and time and using jet tester as test apparatus. It is observe that both coatings shows better performance than uncoated steel in all conditions in which erosion wear test was performed. Chromium oxide coating shows the minimum wear among the other aluminium oxide coating and uncoated 13Cr4Ni steel. The maximum erosion wear reported at 30° impact angle and minimum at 90° in both coated and uncoated steel. Cr2 O3 coated steel shows approximately 3 times better performance than uncoated 13Cr4Ni steel. Erosion of uncoated steel under normal impact is due to platelet mechanism but for coatings under similar condition is due to crack formation. Erosion wear of both coated and uncoated steel increases with increase in flow rate and test time duration.