PRODUCTION AND EVALUATION OF AISI 420 STEEL COATINGS OBTAINED BY THERMAL-SPRAY PROCESSES

摘要

Thermal-spray processes, provide a great variety of deposited materials, layer types and thickness, produce layers with high hardnesses either for protection or restoration of the substrate on which they are applied using thermal spray processes, it is possible to coat metallic substrates with polymers, metals or ceramics. Of these thermal-spray processes, the HVOF (High Velocity Oxygen Fuel), Arc-spray and Flame-spray are among the most used in industry. The purpose of this work is to compare wear resistance of AISI 420 stainless steel coatings applied by all three processes on an AISI 1045 steel substrate. The deposited layers were characterized by measuring layer thickness, porosity, hardness and micro- abrasive wear tests. The wear tests were performed at ambient temperature using an abrasive suspension of 5um alumina. The layers were deposited by HVOF, Arc-spray and Flame-spray processes and the following values were obtained respectively: hardness (HV): 648.7, 544.2 and 413.6; porosity (%): 6.4, 13.0, and 16.9; thickness (μm): 374, 247 and 256. Of the three processes, HVOF yielded the best performance, with respect to hardness, porosity and better wear resistance. The flame spray provided the worse performance.