Cavitation and high-velocity slurry erosion resistance of welded Stellite 6 alloy

The cavitation and slurry erosion resistances of Stellite 6 coatings and 13-4 stainless steel were compared in laboratory. The Cavitation Resistance (CR) was measured according to ASTM G32 standard and the Slurry Erosion Resistance (SER) was tested in a high-velocity erosion tester under several impact angles. The results showed that the coatings improved the CR 15 times when compared to bare stainless steel. The SER of the coatings was also higher for all the impingement angles tested, the highest erosion rate being observed at 45°. The main wear mechanisms were micro-cracking (cavitation tests), and micro-cutting and micro-ploughing (slurry erosion tests).

► In cavitation erosion tests of Stellite 6 alloy, the maximum stable erosion rate was 0.015 mm3 h−1 for the Stellite 6 and 0.122 mm3 h−1 for the 13-4 steel.
► In slurry erosion, the results showed that the highest resistance in Stellite 6 was observed at an impingement angle of 15° while the mass losses were greater at 45°.
► During the development of the welding procedure some craters and transverse cracks were observed.
► Those discontinuities were related to weldability problems.