Characterization of cobalt based stainless coating deposited GMAW process for use of cavitated surfaces

Abstract

Cavitation wear represents one of the main problems encountered in turbines, being one of the areas of protection of hydraulic solutions recovered with a cavitation resistant protection by the GMAW process. This work aimed to characterize samples obtained after deposition of a cobalt-based austenitic stainless coating on ASTM A-743 CA6NM substrate, performed through the mechanized MIG process, evaluating the microstructures obtained with the aid of optical microscopy, MEV/EDS, EBSD, DRX and Microhardness techniques. It can be identified the presence of austenitic microstructure on the surface, with an average grain size of 11.27 μm and traces of ferrite from the next surface line with mostly martensitic substrate. Above the ZF, the morphology of the microstructure was in a dendritic form with a direction towards heat. The size provided did not adjust the thermal components, maintaining their characteristics and durability, without having superior protection of the thermal coating, without adequate protection of the supervised components, its use can maintain an excellent alternative for its use and durability. microstructure that favors the absorption of energy from the cavitation process.

Keywords:
Austenitic stainless steels; Coatings; Cavitation; Microstructural characterization