Thermal Spraying of FeMnCrSi Alloys: An Overview

The FeMnCrSi alloys have been developed and studied regarding the application of cavitation resistance coatings on hydraulic runners, mainly the CA6NM stainless steel made. In this way, the increasing of cavitation resistance was chased, by changings on alloy´s chemical composition and the B addition, by the use of different thermal spraying processes and their optimization of parameters, spraying by ASP (Arc Spraying Process), HVOF (High-Velocity Oxy-Fuel) with propylene and kerosene fuels, and HVAF (High-Velocity Air-Fuel). The post-treatments on the coatings were tested also, like shot-peening and remelting by PTA (Plasma Transferred Arc). This work has the objective of present a compilation of previous articles published in the theme of the FeMnCrSi cavitation resistance coatings. Comparing the different results, a general understanding is the increasing of particle velocity and decreasing of oxidation of the coating promoted best results, highlighting the HVOF-kerosene, with cavitation test mass loss of 1.69 mg.h^-1. However, for the repairs of large runners in field, the ASP process had presented appreciable results, with mass loss of 6.98 mg.h^-1, considering that CA6NM substrate material has the 6.70 mg.h^-1 reference value.