Characterization of Cobalt-Based Stellite 6 Alloy Coating Fabricated by Laser-Engineered Net Shaping (LENS)

Abstract

The results of microstructure and mechanical properties evaluation of a Stellite 6 (Co-6) alloy deposited on X22CrMoV12-1 substrate by the laser-engineered net shaping (LENSTM) technology are presented in this paper. The Stellite 6 alloy is widely used in industry due to its excellent wear resistance at elevated temperatures and corrosive environments. Specific properties of this alloy are useful in many applications, e.g., as protective coatings in steam turbine components. In this area, the main problems are related to the fabrication of coatings on complex-shaped parts, the low metallurgical quality of obtained coatings, and its insufficient adhesion to a substrate. The results of recently performed investigations proved that the LENS technology is one of the most effective manufacturing techniques of the Co-6 alloy coatings (especially deposited on complex-shaped turbine parts). The microstructural and phase analyses of obtained Stellite 6 coatings were carried out by light microscopy techniques and X-ray diffraction analysis. A chemical homogeneity of Co-6 based layers and a fluctuation of chemical composition in coating–substrate zone after the laser deposition were analyzed using an energy dispersive X-ray spectrometer coupled with scanning electron microscopy. The room temperature strength and ductility of the LENS processed layers were determined in static bending tests.

Effect of Mo on wear resistance of Stellite31 cladding layer

“…[1][2][3] Surface-modified materials created with Stellite alloys have a wide range of application contexts in the field of surface engineering. Due to the discrete distribution of hard phases, Stellite alloys can maintain high wear resistance in environments at high temperatures [4][5][6] and have good service performance in combustion turbines, 7 hightemperature valves 8 and petrochemical components. 9 At room temperatures, Stellite alloys have advantages in some applications, too.…”

Fatigue Life and Residual Stress of Flat Stainless Steel Specimens Laser-Cladded with a Cobalt-Based Alloy and Postprocessed with Laser Shock Peening

“…Stellite 6 is a cobalt-based alloy (with 28% chromium as an alloying component) widely used in applications that require high resistance to oxidation, corrosion, and abrasion. The use of this type of cobalt-based alloy is found in the coating of mechanical parts such as pump seals, bearings, blades in aircraft engines, or nozzles in internal combustion engines [8].…”