stellite 20 is a capability of all types of wear and corrosion and high temperature oxidation of carbide.
The general lack of cobalt-based superalloy coherent strengthening phase, stellite 20 although the intensity of the low temperature (only 50-75% of nickel-based alloys), but higher than 980 °C, have high strength, good thermal fatigue, thermal erosion and abrasion performance, and has good weldability. Suitable for production of aviation jet engines, industrial gas turbines, marine gas turbine nozzle guide vanes and nozzle guide vanes and other engine. Cobalt carbide strengthening phase in high temperature alloy carbides is the main MC, M23C6 and M6C in the cast Stellite alloy, M23C6 is slow cooling, the grain boundaries and interdendritic precipitation. In some alloys, the small γ M23C6 formed with the eutectic matrix. MC carbide particles is too large, the dislocation can not have a significant direct effect, and thus little effect on alloy strengthening, while the dispersed carbide is a good strengthening effect. Located in the grain boundary carbides (mainly M23C6) can prevent grain boundary sliding, thereby improving the endurance strength, cobalt-based superalloy HA-31 (X-40) of the microstructure of dispersed strengthening phases (CoCrW) 6 C-type carbide. In some stellite alloy topology appears in the close-packed Laves phases such as sigma phase and is harmful, will become brittle alloy. Stellite alloy less intensive use of intermetallic compounds, as Co3 (Ti, Al) Co3Ta not stable at high temperatures, etc., but in recent years, intermetallic compounds with enhanced stellite alloy also developed. Stellite alloy carbides good thermal stability. Temperature increases, the carbides grow faster than the concentration of nickel-based alloys grew up in the γ phase is slower, re-dissolved in the matrix back to a higher temperature (up to 1100 °C), so the temperature rises, the Division is too Li alloy strength decreases generally slow.
stellite 20
