TRIBOLOGICAL STUDY OF HVOF SPRAYED TUNGSTEN CARBIDE COATED STAINLESS STEEL

Abstract

Corrosion and Wear, or combination of both, are the main causes of degradation of metals used in various industrial sector. Degradation of the metals can be slowed down by adding a layer of resistant coating on metal surface. This coating separates the base metal from a corrosive environment, reduces wear and improves the appearance of the metal. The workpiece after coating becomes a composite that have properties far better than the substrate alone. There are various coating techniques, HVOF is one of the most important and widely used process to protect the metals from wear, corrosion by providing hard and dense coatings. WC coating done by the high velocity oxy fuel (HVOF) spray method is the widely used method for providing a layer of corrosive resistance to a wide range of materials which are used in many different industries. In this study, Tungsten carbide (WC-12CO) Coating, HVOF Spray method was studied in great detail. Tungsten Carbide coating was done on a SUS400 Stainless steel substrate using HVOF Spray Process. And, Experiment was done to analyse the various effect of different parameters namely, oxygen rate, propane (fuel) rate, powder rate, spray distance on hardness and surface roughness of a SUS 400 Stainless Steel substrate. Process optimization was done by using Taguchi and ANOVA methods. It was found that, achieving maximum hardness was greatly depended on propane (fuel) rate followed by powder rate, spray distance and oxygen rate. Hardness decreases with increasing fuel rate. And, achieving minimum surface roughness was greatly depended on spray distance followed by oxygen rate, propane (fuel) rate, powder rate. Surface Roughness increases with increasing spray distance.