COMPARATIVE STUDY OF SLURRY EROSION RESISTANCE OF COATED 16/5 MARTENSITIC STAINLESS STEEL

Abstract

Study was being carried out to enhance the slurry erosion resistance of 16/5 martensitic stainless steel by coating technique. 1-ugh velocity thermal detonation spray process was used to develop a carbide based and oxide based coating of Cr3C2-NiCr and A1203.TiO2, on 16/5 martensitic stainless steel as substrate, for comparative study. Adhesion to the substrate and porosity across transverse section was observed using scanning electron microscope (SEM). Erosion resistance of prepared samples was estimated by slurry erosion test done for 24 hours at two different sand particle size (200 microns and 300 microns) and two different slurry concentration (10 kg/rn3 and 15 kg/rn3 with velocity of 3.6 m/s and impingement angle of 900. SEM image and Microindentation study of surface was done to identify influence of factors affecting wear mechanism and mechanical properties. Slurry test results showed both coatings were successful in reducing wear rate. However. Cr3C2-NiCr coating showed slightly better results. As seen from SEM images the main mechanism responsible for erosion was fracture and detachment of coating at boundaries.